Agent for reducing the metal content of a food product and related method
阅读说明：本技术 用于降低食物产品中金属含量的试剂及其相关方法 (Agent for reducing the metal content of a food product and related method ) 是由 罗伯特·E·卡德瓦拉德 于 2019-02-14 设计创作，主要内容包括：一些实施方案涉及用于从蔬菜和植物来源制备具有降低的重金属含量的食物产品(包括营养补充剂)的金属结合剂和螯合剂。在一些实施方案中,植物来源包括大米。在一些实施方案中,当结合或络合至待去除的金属时,金属结合剂和螯合剂可以在加工期间从食物材料中分离(如,过滤等)。在一些实施方案中,金属结合剂和螯合剂是可有机认证的。(Some embodiments relate to metal binding agents and chelating agents for use in preparing food products (including nutritional supplements) with reduced heavy metal content from vegetable and plant sources. In some embodiments, the plant source comprises rice. In some embodiments, the metal binding agent and chelating agent can be separated from the food material during processing (e.g., filtration, etc.) when bound or complexed to the metal to be removed. In some embodiments, the metal binding agent and the chelating agent are organically certifiable.)
1. A process for preparing a food product having a reduced heavy metal content, the process comprising:
adding a food-grade or food-grade authenticatable binding agent to a food product containing heavy metals;
binding the binding agent to the heavy metal; and
separating the binding agent from the food product by filtering the binding agent out of the food product, thereby preparing an organic food product having a reduced heavy metal content;
wherein the food product is not a whole grain product;
wherein the binder comprises carbon or activated carbon.
2. A process for preparing an organic food product having a reduced heavy metal content, the process comprising:
adding an organically certified or certifiable binding agent to an organic food product containing heavy metals;
binding the binding agent to the heavy metal; and
separating the binding agent from the food product by filtering the binding agent out of the food product, thereby preparing an organic food product having a reduced heavy metal content;
wherein the food product is not a whole grain product;
wherein the binder comprises carbon or activated carbon.
3. The method of claim 1, further comprising adding a chelating agent to the organic food product.
4. The method of claim 2, wherein the organically certified or organically certified chelating agent is a peptide chelating agent, citric acid, or a salt thereof.
5. The method of any one of claims 1 to 3 wherein the food product is a macronutrient isolate.
6. The method of claim 4 wherein the macronutrient isolate is a carbohydrate isolate, a fat isolate or a protein isolate.
7. The method of any one of claims 4-5 wherein the macronutrient is of plant origin.
8. The method of any one of claims 1-3, wherein the food product is a flour.
9. The method of any one of claims 1 to 7, wherein the food product is derived from a plant material, such as white rice, brown rice, rice bran, linseed, coconut, pumpkin, hemp, pea, chia, lentil, fava bean, potato, sunflower, quinoa, amaranth, oat, wheat, or combinations thereof.
10. The method of any one of claims 1-4, wherein the food product is a vegetable protein.
11. The method of any one of claims 1 to 9, wherein the heavy metal is arsenic, cadmium, lead, mercury, or a combination thereof.
12. The method of any one of claims 1 to 10, wherein the separating step is performed by filtration through a filter.
13. The method of claim 11, wherein the binding agent is retained by/on the filter and the food product passes through the filter.
14. The method of claim 11, wherein the food product is retained by/on the filter and the food product passes through the filter.
15. The method of any one of claims 1 to 13, wherein the binding agent comprises one or more of charcoal, activated carbon, zeolite, alginate and/or clay.
16. The method of any one of claims 2-14, wherein the chelating agent is a peptide chelating agent, wherein the peptide chelating agent is prepared by hydrolyzing organic proteins for organic food products, and/or by hydrolyzing non-organic proteins for non-organic food products.
17. The method of claim 15, wherein the peptide chelator is prepared by enzymatic or chemical hydrolysis of the organic protein, and/or hydrolysis of a non-organic protein for use in a non-organic food product.
18. The method of claim 15 or 16, wherein the organic protein is derived from the same plant or animal as the food product, and/or wherein the protein is derived from a non-organic food product of the same plant or animal as used for the non-organic food product.
19. A composition comprising a plant protein isolate or concentrate comprising a heavy metal bound to one or more of an organically certified or organically certified binding agent and/or an organically certified or organically certified chelating agent; wherein the binder comprises carbon.
20. The composition of claim 18, wherein the organically certified or certifiable chelator is a peptide chelator or citric acid.
21. The composition of claim 18 or 19, wherein the binder comprises one or more of carbon, activated carbon, zeolite, alginate and/or clay.
22. An intermediate in the production of a nutritional supplement, the intermediate comprising a plant protein isolate or concentrate comprising a heavy metal bound to one or more of an organically certified or organically certified binding agent and/or an organically certified or organically certified chelating agent; wherein the binder comprises carbon.
23. An intermediate in the production of a nutritional supplement, the intermediate comprising a plant protein isolate or concentrate comprising a heavy metal bound to one or more of a non-organic food-grade or food-grade authenticatable binding agent and/or a non-organic food-grade or food-grade authenticatable chelating agent.
24. A composition comprising a plant protein isolate or concentrate comprising a heavy metal bound to one or more of a binding agent and/or a chelating agent; wherein the binder comprises carbon.
25. The composition of claim 24, wherein the chelating agent is a peptide chelating agent or citric acid.
Description of the related Art
When concentrating and separating vegetable and plant products, large amounts of material are typically separated and concentrated to give the final product. During this separation, heavy metals present in only small sources can become more concentrated and can reach unacceptably high concentrations.
Disclosure of Invention
Some embodiments relate to methods for preparing organic and non-organic food products with reduced heavy metals. Any of the methods described above or elsewhere herein can include one or more of the following features.
In some embodiments, the method comprises adding a binding agent or absorbent to water to prepare a binding agent mixture. In some embodiments, the method comprises adding a food product with heavy metals to water to prepare a food product mixture. In some embodiments, the binder mixture and the food product mixture are combined to prepare a food product metal reducing mixture. In some embodiments, the method comprises adding an organically certified or organically certified binding agent and an organic food product or a non-organic food certified binding agent and a non-organic food product containing a heavy metal to water simultaneously or sequentially to prepare a food product metal reducing mixture. In some embodiments, the food product metal reducing mixture is agitated for a period of time. In some embodiments, the pH of any one of the mixtures is adjusted during or prior to agitation. In some embodiments, the temperature of the food product metal reducing mixture is maintained at a particular temperature or is varied during agitation.
In some embodiments, the method comprises isolating the binding agent from the food product. In some embodiments, the method comprises separating the binding agent from the food product by filtering the binding agent out of the food product, thereby preparing an organic food product or a non-organic food product having a reduced heavy metal content. In some embodiments, the binder remains on/by the filter as a filter cake or solution/suspension. In some embodiments, the food product is retained on the filter as a filter cake, or retained by the filter as a retained solution/suspension. In some embodiments, the filter cake or retained filtration solution is washed to recover additional treated food product or to remove binding agent.
In some embodiments, the food product to be treated is not a whole grain product. In some embodiments, the food product to be processed is a macronutrient isolate. In some embodiments, the food product is a carbohydrate isolate, a fat isolate, or a protein isolate. In some embodiments, the food product to be treated is derived from a plant. In some embodiments, the food product to be treated is a flour. In some embodiments, the food product to be treated is derived from a plant source, such as white rice, brown rice, rice bran, linseed, coconut, pumpkin, hemp, pea, chia, lentil, broad bean, potato, sunflower, quinoa, amaranth, oat, wheat, or combinations thereof. In some embodiments, the food product to be treated is a vegetable protein.
In some embodiments, the heavy metal is arsenic, cadmium, lead, mercury, or a combination thereof.
In some embodiments, the method further comprises combining the chelating agent with the organic food product as a solid, liquid, or solution, or with the non-organic food product as a solid, liquid, or solution, before, during, or after mixing with the binder mixture. In some embodiments, the organically certified or certifiable chelator is a peptide chelator, citric acid or salt thereof, or the food grade chelator is a peptide chelator, citric acid or salt thereof.
In some embodiments, the binding agent and/or chelating agent is isolated by filtration through a filter. In some embodiments, the binding agent is retained on the filter and the food product is passed through the filter. In some embodiments, the food product is retained on the filter and the food product passes through the filter.
In some embodiments, the binder is one or more of charcoal, activated carbon, zeolite, alginate, and/or clay.
In some embodiments, the chelating agent is a peptide chelator, wherein the peptide chelator is prepared by hydrolysis of an organic protein. In some embodiments, the peptide chelator is prepared by enzymatic or chemical hydrolysis of an organic protein. In some embodiments, the non-organic protein is derived from the same plant or animal as the food product. In some embodiments, the chelating agent is a peptide chelator, wherein the peptide chelator is prepared by hydrolysis of a non-organic protein. In some embodiments, the peptide chelator is prepared by enzymatic or chemical hydrolysis of a non-organic protein. In some embodiments, the non-organic protein is derived from the same plant or animal as the food product.
Some embodiments relate to compositions comprising rice protein isolate comprising heavy metals bound to one or more of an organically certified or certifiable binding agent and/or an organically certified or certifiable chelating agent. In some embodiments, the organically certified or certifiable chelator is a peptide chelator or citric acid. Some embodiments relate to compositions comprising rice protein isolate comprising heavy metals bound to one or more of a non-organic food-grade binding agent and/or a non-organic food-grade chelating agent. In some embodiments, the non-organic food grade chelating agent is a peptide chelating agent, citric acid and salts thereof or ethylenediaminetetraacetic acid (EDTA) and salts thereof. In some embodiments, the binder is one or more of charcoal, activated carbon, zeolite, alginate, and/or clay.
Some embodiments relate to an intermediate for the production of nutritional supplements comprising rice and other plant protein isolates comprising heavy metals bound to one or more of an organic certified or organic certified binding agent and/or an organic certified or organic certified chelating agent or a non-organic food grade or non-organic food grade binding agent and/or a non-organic food grade chelating agent.
In some embodiments, the method comprises adding an organically certified or organically certified chelating agent to the organic food product containing the heavy metal, or adding a non-organic food-grade chelating agent to the food product containing the heavy metal. In some embodiments, the method comprises allowing the chelating agent to bind to the heavy metal to form a complex. In some embodiments, the method comprises isolating the complex from the food product to produce an organic food product or a non-organic food-grade product having a reduced heavy metal content.
In some embodiments, the organically certified or certified chelating agent is a peptide chelator, or the non-organically certified food-grade chelating agent is a peptide chelator, citric acid, EDTA (for non-organic food products) or a salt thereof. In some embodiments, the food product is a macronutrient isolate. In some embodiments, the macronutrient isolate is a carbohydrate isolate, a fat isolate, or a protein isolate. In some embodiments, the macronutrient is derived from a plant. In some embodiments, the food product is derived from a plant source, such as white rice, brown rice, rice bran, linseed, coconut, pumpkin, hemp, pea, chia, lentil, broad bean, potato, sunflower, quinoa, amaranth, oat, wheat, or combinations thereof. In some embodiments, the food product is a vegetable protein.
In some embodiments, the heavy metal is arsenic, cadmium, lead, mercury, or a combination thereof.
In some embodiments, the separating step is performed by filtration through a filter. In some embodiments, the complex is substantially soluble and passes through a filter. In some embodiments, the separating step is performed by decantation and/or centrifugation.
In some embodiments, the chelating agent is a peptide chelator, wherein the peptide chelator is prepared by hydrolysis of an organic protein or a non-organic food-grade protein. In some embodiments, the peptide chelator is prepared by enzymatic or chemical hydrolysis of an organic or non-organic food-grade protein. In some embodiments, the organic protein or non-organic food-grade protein is derived from the same plant or animal as the food product.
Some embodiments relate to compositions comprising plant-derived protein isolates. In some embodiments, the plant (e.g., rice) -derived protein isolate comprises a heavy metal bound to an organically certified or organically certified chelating agent or a non-organic food grade chelating agent. In some embodiments, the organically certified or organically certified chelating agent or non-organic food grade chelating agent is a peptide chelating agent, citric acid, or EDTA (for non-organic food grade products) and salts thereof. In some embodiments, the peptide chelator is a plant-derived protein hydrolysate. In some embodiments, the protein isolate is an intermediate in the production of a nutritional supplement. In some embodiments, the intermediate comprises a plant-derived protein isolate comprising a heavy metal bound to an organically certified or organically certified chelating agent or a non-organic food grade chelating agent.
Some embodiments relate to methods for preparing peptide chelators. In some embodiments, the method comprises enzymatically or chemically hydrolyzing an organic protein to form an organic peptide chelator. In some embodiments, the method comprises collecting the peptide chelator. In some embodiments, enzymes are used to enzymatically hydrolyze organic or non-organic food grade proteins.
In some embodiments, the enzyme comprises one or more of: acidic endopeptidase, alkaline endopeptidase, pepsin, papain, carboxypeptidase, trypsin, chymotrypsin or thermolysin.
In some embodiments, the method comprises fractionating the peptide chelator from the hydrolysate.
Some embodiments relate to peptide chelators. In some embodiments, the peptide chelator comprises a major (e.g., higher than average intensity and/or deeper than average) band (and/or peak from light intensity scan of those bands) from a PAGE gel of molecular weight ranging from about 21kD to about 19kD, from about 16kD to about 14kD, from about 13.5kD to about 12.5kD, from about 11.5kD to about 10.5kD, and/or from about 4kD to about 2 kD. In some embodiments, the major PAGE band (and/or peaks obtained from gel scans) of the peptide chelator is at one or more of about 20.5kD, about 15kD, and/or about 12.7 kD. In some embodiments, the major band and/or peak of the peptide chelator is at one or more of about 20.5kD, about 15kD, about 12.7kD, and/or about 11 kD.
Some embodiments relate to methods of making peptide chelators. In some embodiments, the method comprises the step of exposing a protein from a plant source to hydrolytic conditions for a period of time to produce a protein chelator. In some embodiments, the method comprises the step of removing the protein chelator from the hydrolysis conditions. In some embodiments, the method comprises the step of collecting the protein chelator.
In some embodiments, the period of time is less than or equal to about 1 hour, about 2 hours, about 4 hours, about 6 hours, or a range that includes and/or spans the aforementioned values.
In some embodiments, the protein is exposed to the enzyme during exposure to the hydrolyzing conditions.
In some embodiments, during collection of the peptide chelator, the peptide chelator is filtered to isolate the peptide chelator based on size and/or molecular weight.
In some embodiments, the peptide chelators prepared by the methods disclosed herein have major bands (e.g., peaks) from PAGE gels with molecular weights ranging from about 21kD to about 19kD, about 16kD to about 14kD, about 13.5kD to about 12.5kD, about 11.5kD to about 10.5kD, and/or about 4kD to about 2 kD. In some embodiments, the peptide chelator prepared by the methods disclosed herein has a major PAGE band and/or peak at one or more of about 20.5kD, about 15kD, and/or about 12.7 kD. In some embodiments, the peptide chelator prepared by the methods disclosed herein has a major PAGE band (e.g., peak) at one or more of about 20.5kD, about 15kD, about 12.7kD, and/or about 11 kD.
Some embodiments relate to peptide chelators comprising a protein hydrolysate comprising one or more peptides having a molecular weight in the range of about 2kD to about 25 kD. In some embodiments, the one or more peptides have a molecular weight range selected from the group consisting of: about 21kD to about 19kD, about 16kD to about 14kD, about 13.5kD to about 12.5kD, about 11.5kD to about 10.5kD, and/or about 4kD to about 2 kD. In some embodiments, the one or more peptides have a molecular weight selected from about 20.5kD, about 15kD, and about 12.7 kD. In some embodiments, the one or more peptides have a molecular weight selected from the group consisting of about 20.5kD, about 15kD, about 12.7kD, and about 11 kD.
Some embodiments relate to a peptide chelator prepared by a method comprising: a protein from a plant source is exposed to hydrolysis conditions for a period of time to produce a protein chelator. In some embodiments, the method comprises removing the protein chelator from the hydrolysis conditions. In some embodiments, the method comprises collecting the protein chelator. In some embodiments, the period of time in the hydrolysis conditions is less than or equal to about 1 hour, about 2 hours, about 4 hours, about 6 hours, or a range that includes and/or spans the above values. In some embodiments, exposure to hydrolysis conditions exposes the protein to an enzyme. In some embodiments, during the collection of the peptide chelator, the peptide chelator is filtered based on size and/or molecular weight to collect the peptide chelator. In some embodiments, the method results in a peptide chelator comprising one or more peptides having a molecular weight range selected from: about 21kD to about 19kD, about 16kD to about 14kD, about 13.5kD to about 12.5kD, about 11.5kD to about 10.5kD, and/or about 4kD to about 2 kD. In some embodiments, the methods result in a peptide chelator comprising one or more peptides comprising a molecular weight selected from about 20.5kD, about 15kD, and/or about 12.7 kD. In some embodiments, the methods result in a peptide chelator comprising one or more peptides comprising a molecular weight selected from about 20.5kD, about 15kD, about 12.7kD, and/or about 11 kD.
Brief Description of Drawings
Fig. 1 depicts data quantifying the metal content in various rice types and rice from various sources.
Figure 2A provides an overview of the total% heavy metal reduction from a protein mixture at different pH values using various chelators or water.
Figure 2B depicts the results of reducing heavy metals from a protein mixture at pH3 using various chelators or water.
Figure 2C depicts the results of reducing heavy metals from a protein mixture at pH6 using various chelators or water.
Figure 2D depicts the results of reducing heavy metals from a protein mixture at pH9 using various chelators or water.
Figure 2E depicts the results of arsenic reduction from protein mixtures using various chelating agents or water at different pH values.
Fig. 2F depicts the results of reducing cadmium from a protein mixture at different pH values using various chelating agents or water.
Figure 2G depicts the results of reducing lead from a protein mixture at different pH values using various chelating agents or water.
Figure 2H depicts the results of mercury reduction from protein mixtures using various chelators or water at different pH values.
Figure 2I depicts the results of arsenic reduction from protein mixtures using various chelating agents or water at different pH values.
Fig. 2J depicts the results of reducing cadmium from a protein mixture at different pH values using various chelating agents or water.
Figure 2K depicts the results of reducing lead from a protein mixture at different pH values using various chelating agents or water.
Figure 2L depicts the results of mercury reduction from protein mixtures using various chelators or water at different pH values.
Figures 3A-3B depict the results of water rinsing to remove arsenic from protein mixtures at different pH values.
Fig. 3C-3D depict the results of water washes to remove cadmium from protein mixtures at different pH values.
Figures 3E-3F depict the results of water rinsing to remove mercury from protein mixtures at different pH values.
Figures 3G-3H depict the results of water washes to remove lead from protein mixtures at different pH values.
FIG. 4A is an image of a polyacrylamide gel electrophoresis ("PAGE") peptide separation gel (Coomassie blue staining).
FIGS. 4B-4F are scans showing the molecular weight distribution from the trace of the PAGE gel of FIG. 4A.
Detailed description of the invention
Some embodiments disclosed herein relate to binding agents or absorbents and/or chelating agents, methods of making and using absorbents and/or chelating agents, and methods of using absorbents and/or chelating agents to reduce and/or remove metals from food products. In some embodiments, "binding agent" and "absorbent" are disclosed and used interchangeably herein. In some embodiments, the metal removed or reduced is a heavy metal. In some embodiments, the food product from which the metal is removed or reduced is a plant-derived material, such as a grain or vegetable. In some embodiments, the plant derived material, such as grain or vegetable, is subjected to a mechanical processing step prior to treatment with one or more absorbents and/or chelating agents. In some embodiments, the mechanical processing step comprises disrupting and/or grinding a plant-derived material, such as a grain or vegetable, to provide a plant-derived material, such as a grain pre-processed product or a vegetable pre-processed product. In some embodiments, after mechanical processing, the plant-derived material, such as a grain product or vegetable product, is a flour (e.g., a grain flour and/or a vegetable flour, respectively). In some embodiments, the food product to be treated comprises one or more of: a pre-processed product, flour, carbohydrate-based isolates isolated from various sources (including starch, cellulose, bran, fiber, carbohydrates, sugars, polysaccharides, oligosaccharides, maltodextrin, etc.), protein-based isolates (including amino acids, peptides, oligopeptides, proteins, etc.), fat-based isolates (e.g., oils, fats, etc.), minerals, and/or combinations thereof. In some embodiments, the food products are those isolated from any plant source. In some embodiments, the food product comprises plant matter or plant-derived material derived from: rice, rice bran, linseed, coconut, pumpkin, hemp, pea, chia, lentil, broad bean, potato, sunflower, quinoa, amaranth, oat, wheat, etc. In some embodiments, the food product is a cereal flour (e.g., a cereal that has been pulverized). In some embodiments, the food product is one or more of rice flour (brown or white rice), rice bran flour, linseed flour, coconut flour, pumpkin flour, hemp flour, pea flour, chia powder, pinto flour, broad bean flour, potato flour, sunflower flour, quinoa flour, amaranth flour, oat flour, wheat flour, and the like. In some embodiments, the rice is brown rice or white rice. In some embodiments, the food product is a seed containing any plant protein and/or a seed of the plant. In some embodiments, the food product is a cereal or vegetable protein isolate, including isolates from any of the protein sources mentioned elsewhere herein. In some embodiments, the food product comprises material isolated from a plant (e.g., plant material that is one or more of carbohydrate-based, protein-based, fat-based, and/or mineral-containing) and/or animal material (e.g., protein-based, fat-based, and/or mineral-containing animal material). In some embodiments, the food product is organic (e.g., organically certified or certifiable according to U.S., european or japanese organic certification standards). In some embodiments, the food product is a non-organic food grade product. In some embodiments, one or more absorbents and/or chelating agents are used to treat the food product at any step during the preparation of the food product. In some embodiments, an absorbent and/or chelating agent is used to remove or reduce heavy metals from food product meal as disclosed elsewhere herein. In some embodiments, one or more of an absorbent and/or a chelating agent is used during the separation of protein, carbohydrate, or fat from a protein source. In some embodiments, one or more of the absorbents and/or chelating agents are used after the isolate (e.g., protein, carbohydrate, fat, or combinations thereof) has been isolated. For example, the product may be subjected to metal reduction conditions for metal repair. In some embodiments, such as a flour, protein, fat, or carbohydrate, for example, is retreated with one or more of an absorbent and/or a chelating agent to remove metals. In some embodiments, one or more of the absorbents and/or chelating agents are also organic, organically certified, and/or organically certifiable (e.g., to produce organic food products), and in some embodiments, one or more of the absorbents and/or chelating agents are non-organic and food grade.
In some embodiments, the metal reduction processes disclosed herein can be accomplished using any one or more of the absorbents and/or chelating agents disclosed herein (alone or in combination) or with other absorbents and/or chelating agents that achieve the goal of preparing organic or organically certified foods or non-organic food grade foods having substantially removed or reduced heavy metal content. For example, in some embodiments, the absorbent and the chelating agent are used simultaneously (e.g., together) in one step in the process of reducing metals from a food product. In some embodiments, multiple absorbents and multiple chelating agents are used simultaneously in one step in the process of reducing metals from a food product. In some embodiments, various absorbents and chelating agents are used in separate metal reduction steps. In some embodiments, one or more absorbents are used to reduce the metal content of the food product, and no chelating agent is used. In other embodiments, one or more chelating agents are used to reduce the metal content of the food product and no absorbent is used. In some embodiments, any one step of the methods disclosed herein may be combined and/or omitted.
The demand for organic foods is growing due to the potential health risks and/or potential risks associated with eating chemically treated foods. In the united states, there are currently four different levels or classes of organic markers: 1) '100%' organic (all ingredients are produced organically); 2) 'organic' (at least 95% or more of the ingredients are organic); 3) ' made from (containing at least 70% organic components); and 4) 'less than 70% organic components' (where the three organic components must be listed in the component part of the label). Organically prepared foods must be free of artificial food additives and are generally processed with fewer artificial methods, materials and conditions, such as chemical maturation, food irradiation and genetically modified ingredients. Allowing the use of non-synthetic pesticides (as naturally occurring) or treatments, but generally not synthetic pesticides or treatments.
Although eating organically processed foods is considered healthier than eating non-organically processed foods, certain processed foods, even if organic, may contain harmful substances. For example, heavy metals may be present in organically processed foods (as in non-organically processed foods) despite their potential health benefits. These metals may be naturally present in the food product or may also enter the food product as a result of human activity, such as industrial and agricultural processes.
While some metals (e.g., calcium, magnesium, sodium, potassium, iron, etc.) are essential for biological functions, including cellular functions, some metals have no functional effect in the body and are harmful to the body. Metals of particular concern associated with having a detrimental effect on health are mercury (Hg), lead (Pb), cadmium (Cd), chromium (Cr), tin (Sn), and arsenic (Ar). The toxicity of these metals is due in part to the fact that: their accumulation in biological tissues is much faster than their excretion, a process known as bioaccumulation. As a result of exposure to food and metals in the environment, bioaccumulation occurs in all living organisms, including food animals such as fish and cattle and humans. In addition, these metals can become more concentrated in the foodstuff because the macronutrient products are isolated from most of the materials from which they are derived (e.g., carbohydrates, proteins, and/or fats).
As described above, concerns related to the toxicity of certain metals vary depending on the metal. Some metals have a potential impact on the brain and mental development of young children (e.g., mercury, lead, etc.). In addition to having an effect on the nervous system, prolonged exposure to certain metals (e.g., lead) can cause damage to the kidneys, reproductive, and immune systems. Some metals (e.g., cadmium) are toxic to the kidneys, while others (e.g., tin) can cause gastrointestinal irritation and discomfort. Some metals (e.g., arsenic) are of interest because of their cancer-causing nature. In view of the wide impact on health and the fact that these toxic metals accumulate in the body, it is very important to control the levels in foodstuffs in order to protect human health.
Some embodiments disclosed herein relate to absorbents and/or chelating agents (e.g., chelating sequestering agents) that reduce and/or remove metals from food products. In some embodiments, one or more absorbents and/or one or more chelating agents are added to a solution or mixture of food products. In some embodiments, the absorbent binds and/or captures one or more metal ions from the solution or mixture when mixed with the food product. In some embodiments, the chelating agent binds (forms a complex) with one or more metal ions in the solution or mixture. In some embodiments, the food product is rinsed from the metal-bound absorbent and/or complex (e.g., where the food product is soluble, substantially soluble, has greater solubility than the metal complex, and/or has a smaller particle size than the absorbent and/or complex). In some embodiments, the bound absorbents and/or complexes to be removed from the food product are rinsed from the food product (e.g., wherein the bound absorbents and/or complexes are soluble, substantially soluble, have greater solubility than the food product, and/or have a smaller particle size than the food product). In some embodiments, the complex comprises floe or floating material, which may be skimmed or decanted from soluble or insoluble solutions or mixtures of liquids and food products.
In some embodiments, an absorbent is used in addition to or in place of the chelating agent, as disclosed elsewhere herein. In some embodiments, the absorbent is a chelating agent. In some embodiments, the absorbent is a macromolecular structure and/or material. In some embodiments, the absorbent is a porous structure (e.g., a microporous structure). In some embodiments, the pores of the absorbent contain metal ions from the solution. In some embodiments, the absorber can trap the metal based in part on the size of the metal ion or metal atom. In some embodiments, the absorbent (e.g., absorber) also binds the metal (e.g., once the metal is in the pores of the absorbent and/or in contact with the absorbent). In some embodiments, the absorber can bind the heavy metal through electrostatic interaction.
In some embodiments, the bound metal particles (e.g., metal attached to or entrapped by the adsorbent) and/or metal complexes can be separated from the food product with an adsorbent of 400 μm to 850 μm size, in particulate form, and after binding or entrapping the metal, these adsorbents can be filtered, skimmed, or decanted from the food product. In some embodiments, the food product is processed (e.g., dry milled, wet milled, broken, etc.) to form a granulated food product, as disclosed elsewhere herein. In the case of rice, the rice may be subjected to wet milling or dry milling to prepare granules. In some embodiments, the granulated product (e.g., rice flour) is then placed in a liquid, such as water. In some embodiments, the food product powder is mixed with an absorbent. In some embodiments, because the particle size of the granulated product is smaller than the particle size of the absorbent, the absorbent can be filtered or sieved from the food product, leaving a heavy metal-reduced food product. In some embodiments, the absorbent has an average particle size of greater than or equal to about 50 μm, 100 μm, 150 μm, 250 μm, 500 μm, 1000 μm, 2000 μm, 5000 μm, or a range including and/or spanning the above values. In some embodiments, the food product has an average particle size and/or molecular size of less than or equal to about 1000 μ ι η, 500 μ ι η, 250 μ ι η, 100 μ ι η, 50 μ ι η, 25 μ ι η, 10 μ ι η,5 μ ι η,1 μ ι η, 0.1 μ ι η, 0.01 μ ι η, 0.0001 μ ι η, or a range including and/or spanning the aforementioned values.
In some embodiments, the food product and the binding agent are both solids. In some embodiments, these solids may be separated from each other, so long as they are of sufficiently different sizes to allow filtration of each other.
In some embodiments, when the bound metal particles and/or complexes are substantially or completely soluble and the food product is substantially insoluble or less soluble than the bound metal particles and/or complexes (e.g., as a solid suspension solution of the mixture), the mixture is decanted and the supernatant contains the bound metal particles and/or metal complexes, while the solids contain the food product with reduced metal content. In some embodiments, prior to decantation, the mixture is centrifuged to separate the solid and liquid phases. In some embodiments, decantation is performed by pouring, pumping (e.g., by vacuum), or otherwise removing supernatant from the solids. In some embodiments, the mixture is filtered and the filtrate containing the metal complex is removed from the filter cake containing the purified food product. In some embodiments, the filtrate may be removed from the solids using ultrafiltration, dialysis, or microfiltration methods.
In some embodiments, when soluble binding and/or chelating agents are used to capture and bind heavy metals and other metals, these agents carry the metals, for example, from materials of plant origin, such as grain and/or vegetable products (e.g., protein matrices), through the filtration device that retains the food product. In some embodiments, the filtration device allows the bound metal particles and/or complexes to leave the food product suspension, which can then be separated. The bound metal particles and/or chelating agent dissolve the metal and may be rinsed out of the matrix with water. In some embodiments, the use of peptides allows for heavy metal remediation after the food product has been prepared and/or during the process of metal binding to the peptides and removal via filtration or decantation during the preparation of the initially processed organic food product or non-organic food grade product.
In some embodiments, the binding agents and/or chelating agents disclosed herein are food grade, but not organic or organically certifiable. In some embodiments, the binding agents and/or chelating agents disclosed herein are organic, organically certified and/or organically certifiable, or non-organic food grade. In some embodiments, the organic, organically certified and/or organically certifiable binding agent and/or chelator is a metal chelator that occurs naturally or is produced using organically certified techniques. In some embodiments, the organic food product can be isolated from most organic food sources by using organic binders and/or chelating agents. In some embodiments, the organic, organically certified or organic certifiable binding agent and/or chelating agent is a metal chelating agent that can be isolated from a natural source or produced using organically certified techniques. In some embodiments, the binding agent and/or chelating agent is used to prepare a food product that is organic and/or organically certifiable and has a reduced heavy metal content. In some embodiments, the binding agent and/or chelating agent is used to prepare an organic protein isolate, a starch isolate, or a fat isolate. In some embodiments, the organic binding agent and/or chelating agent is used to prepare an organically certifiable organic protein isolate or organically certifiable other food product having reduced metals.
In some embodiments, the method can be accomplished using any of the following binding agents and/or chelating agents (together or separately), other binding agents and/or chelating agents that achieve the purpose of organically certified heavy metal removal, and combinations thereof. In some embodiments, any one of the steps or parameters disclosed below may be combined. In some embodiments, the steps may be omitted or combined in any manner to achieve sequestration of metals in food products to reduce the metal content in those foods.
In some embodiments, the chelating agent, binding agent, and/or absorbent is any material that absorbs and/or attracts positive ions (e.g., metal ions, heavy metal ions, cations, etc.). In some embodiments, the absorbent is a cation absorber. In some embodiments, the absorbent is a macromolecular structure and/or material in particulate form, as disclosed elsewhere herein. In some embodiments, the heavy metal reducing agent (e.g., binder) is one or more of carbon, activated carbon, zeolites (e.g., microporous aluminosilicate minerals), alginates (e.g., calcium alginate, sodium alginate, alginates, and the like), and/or clays (e.g., bentonite, kaolinite, and the like). In some embodiments, any other absorber that exhibits a negative charge to attract heavy metal cations is used. In some embodiments, the binding agent is selected that can be separated from the food product (e.g., meal mixture, protein solution, etc.) using filtration (e.g., using a filter, sieve, etc.).
In some embodiments, the binders may be selected based in part on their particle size. In some embodiments, selecting binders based on particle size allows for their separation from the food product based on the size difference between the food product and the binders (e.g., by filtration, sieving, microfiltration, ultrafiltration, and/or nanofiltration). In some embodiments, when a filter or sieve is used, the bound metal absorber is retained (while allowing the food product to pass through the sieve), and the binding agent is selected to have an average particle size equal to or at least about 5000 μm, 1000 μm, 840 μm, 500 μm, 420 μm, 300 μm, 100 μm, 50 μm, 10 μm, 1 μm, or a range including and/or spanning the above values. In some embodiments, the binding agent retained by a sieve having a sieve size equal to or greater than about 10, 20, 40, 50, 100, 200, 400, or a range including and/or spanning the above-described values, under U.S. standards (US screen).
In some embodiments, the particle size of the food product (e.g., ground rice or brown rice, rice or brown rice flour, etc.) is selected to allow it to pass through a filter, where the binding agent is retained. In some embodiments, when a filter or sieve is used to retain the bound metal absorber (while allowing the food product to pass through the screen), the food product is processed (e.g., by wet milling, etc.) to an average particle size equal to or less than about 5000 μm, 1000 μm, 840 μm, 500 μm, 420 μm, 300 μm, 100 μm, 50 μm, 10 μm, 1 μm, or a range including and/or spanning the above values. In some embodiments, the food product is ground (or otherwise processed) to have an average size sufficient to pass through a sieve having a US mesh number equal to or less than about 10, 20, 40, 50, 100, 200, 400, or a range including and/or spanning the above-mentioned values. In some embodiments, the food product is ground (or otherwise processed) to have an average size sufficient to pass through a sieve having a US mesh number equal to or less than about 10, 20, 40, 50, 100, 200, 400, or a range including and/or spanning the above-mentioned values. In some embodiments, the food product is ground (or otherwise processed) to have an average mesh size equal to or less than about 1, 5, 10, 20, 40, 50, 100, 200, 400, or a range including and/or spanning the aforementioned values. In some embodiments, multiple filtration steps may be performed. For example, filtration may be performed using a coarse filter and successively finer filters to remove large particles first, followed by small particles in turn. In other embodiments, a smaller filter may be used first to allow for the isolation of pure food product. Larger filters can then be used to recover food products having varying amounts of binding and/or chelating agents therein.
In some embodiments, the food product may be a meal or a fine powder as long as it is smaller than the absorbent particle size when it passes through the filter or sieve. For example, in some embodiments, using activated carbon with mesh sizes of 20-40, 12-20, 4-12, the food product can be ground to a smaller particle size (smaller mesh size as described above), allowing it to be collected by a filter. Alternatively, where the activated carbon is selected to allow it to pass through the filter, a smaller mesh of activated carbon and a larger food product particle size may be selected.
In some embodiments, a chelating agent is used in addition to or in place of one or more binding agent. In some embodiments, the chelating agent comprises citric acid or a salt thereof. In some embodiments, the chelating agent comprises a hydrolytically prepared peptide or oligopeptide ("peptide chelator"), mixtures thereof, and/or salts thereof. In some embodiments, the chelating agent may be ethylenediaminetetraacetic acid (EDTA) or a salt thereof. In some embodiments, one or more of citric acid, peptide chelating agents, and/or EDTA are used in combination. In some embodiments, the chelating agent can be attached to a solid support (e.g., beads, etc.) to facilitate its removal from the solution by filtration. For example, solid supports such as resin beads, glass beads, ceramic and polypropylene column packing units, or other similar types of supports may be used. In some embodiments, any of the following is used: magnetic beads are used and can be separated by electromagnetic fields; affinity chromatography/batch separation-antibodies/fragments against e.g. peptide chelators; and the like. In some embodiments, when a filter or sieve is used to retain the chelating agent (while allowing the food product to pass through the sieve), a solid support having an average particle size equal to or at least about 5000 μ ι η, 1000 μ ι η, 840 μ ι η, 500 μ ι η, 420 μ ι η, 300 μ ι η, 100 μ ι η, 50 μ ι η, or a range including and/or spanning the above values is selected. In some embodiments, the support retained by a screen having a sieve number equal to or greater than about 10, 20, 40, 50, 100, 200, or a range including and/or spanning the above values, under U.S. standards (US screens) is selected.
In some embodiments, the peptide chelator is derived from a plant (e.g., grain, vegetable, etc.) peptide produced by enzymatic and/or chemical hydrolysis of a protein. In some embodiments, enzymatic and chemical hydrolysis processes allow for the production of organic chelators for the reduction of heavy metals in plant materials such as grain and vegetable proteins. In some embodiments, one or more enzymes are used to prepare the peptide chelator. In some embodiments, the enzyme is an endopeptidase. In some embodiments, these enzymes selectively cleave proteins into peptide fragments between specific amino acid sequences. In some embodiments, one or more acidic endopeptidases and/or basic endopeptidases are used. In some embodiments, the acidic endopeptidase is used in an acidic environment. In some embodiments, the acidic endopeptidase is used in a solution having a pH equal to or less than about 2, 6.5, or a range including and/or spanning the above values. In some embodiments, the acidic protease is selected from one or more of pepsin, papain, carboxypeptidase, and the like. In some embodiments, the alkaline endopeptidase is used in an alkaline pH solution. In some embodiments, the alkaline endopeptidase is used at a pH of less than or equal to about 7.0, 12, or in a range that includes and/or spans the above values. In some embodiments, a basic endopeptidaseThe enzyme includes one or more of trypsin, chymotrypsin, thermolysin, etc. In some embodiments, the pH of the solution used to prepare the peptide chelator is less than or equal to about: 2.3, 4, 5, 6, 7, 8, 9, 10, 11, or a range that includes and/or spans the aforementioned values. In some embodiments, the enzyme comprises
In some embodiments, one or more endopeptidases are added to the cereal protein solution. In some embodiments, the pH is adjusted with a base such as sodium or potassium hydroxide or trisodium phosphate. In some embodiments, the pH is adjusted with an acid such as hydrochloric acid, citric acid, or phosphoric acid. In some embodiments, the pH is adjusted depending on the type of enzyme or the specific enzyme used. In some embodiments, a solution of protein and enzyme (and/or another hydrolyzing reagent) is agitated for a period of time to cleave peptides from the main cereal protein chains. In some embodiments, when an enzyme is used, the enzyme is denatured or otherwise inactivated once the desired peptide chelator properties are obtained. In some embodiments, for example, the enzyme environment is heated to above 85 ℃ for a period of time to inactivate the one or more enzymes.
In some embodiments, the peptide chelator is produced from the same food source (e.g., the same type of animal, plant, such as grain and/or vegetable source) as the food product being treated. In some embodiments, the peptide chelator is produced from a different food source than the food product being treated.
In some embodiments, the peptide chelator comprises a crude protein hydrolysate containing, for example, a mixture of peptides, oligopeptides, and/or amino acids. In some embodiments, certain fractions of the crude protein hydrolysate are fractionated and/or separated and/or concentrated via well-known separation techniques such as those based on molecular weight, charge, and/or binding affinity prior to use as a peptide chelator. In some embodiments, the metal-binding peptide component of the hydrolysate is enriched by affinity separation techniques (batch or chromatographic methods) in which the metal is immobilized on beads or separation media and the crude hydrolysate is exposed to the affinity media. Unbound fractions can be washed away, and then the metal-bound fractions can be displaced from the metal by higher affinity binders (counter ions, etc.), collected and/or concentrated before being used as a peptide chelator. In some embodiments, certain fractions of the crude protein hydrolysate are fractionated and/or separated and/or concentrated using one or more of filtration, density centrifugation, and the like. In some embodiments, the peptide chelator comprises a mixture of peptides, oligopeptides and/or amino acids that are used as an isolate following proteolysis from a plant source. In some embodiments, the peptide chelator comprises one or more polyfunctional acidic peptides (e.g., dicarboxylic acids, tricarboxylic acids, tetracarboxylic acids, or more) with or without amino acid spacers, or other spacers, between the acids. In some embodiments, these polyfunctional acids bind to the metal to form a metal complex. In some embodiments, the peptide chelator comprises one or more polyfunctional amine-peptides (e.g., dicarboxylic acids, tricarboxylic acids, tetracarboxylic acids, or more) with or without amino acid spacers between the amines. In some embodiments, these polyfunctional amines bind to the metal to form a metal complex. The acid and amine functional groups can be from any amino acid of the natural amino acids comprising an acid and an amine terminus (e.g., alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and/or valine). Bound acids or amines can also be generated from the side chains of amino acids, for example: glutamic acid and/or aspartic acid (acid); tryptophan, glutamine, lysine, histidine, asparagine, glutamine and/or arginine (amine and/or guanidine). In some embodiments, the peptide chelator comprises one or more metal-binding thio or hydroxy substituents (e.g., serine, threonine, cysteine, methionine, tyrosine).
In some embodiments, the peptide chelator is isolated based on hydrolyzing the molecular weight fraction of the treated protein. In some embodiments, the peptide chelator comprises a protein hydrolysate of peptides having one or more different molecular weights. In some embodiments, the protein hydrolysate is a plant protein hydrolysate produced by enzymatic digestion of a plant protein source. In some embodiments, the protein hydrolysate has one or more peptides with a molecular weight ranging from about 500kD to about 25,000 kD. In some embodiments, one or more peptides are further purified (e.g., by size exclusion and/or ion exchange chromatography) and used as peptide chelators. In some embodiments, the peptide chelator has a number average molecular weight (g/mol) and/or a weight average molecular weight (g/mol) equal to or less than about 500, 1000, 2000, 5000, 10,000, 15,000, 20,000, 25,000 or a range including and/or spanning the above values. In some embodiments, the molecular weight (g/mol) of the peptide chelator is equal to or less than about 500, 1000, 2000, 5000, 10,000, 15,000, 20,000, 25,000 or a range including and/or spanning the above values.
In some embodiments, a mixture of these amino acids with different functional groups are combined with a metal to form a complex. In some embodiments, amino acid configurations that produce 5-or 6-membered rings can provide a more favorable binding orientation (e.g., between thiol, amine, and metal in, for example, serine), but this is not required. Such configurations include those comprising GHK complexes (e.g., glycine amine with imidazole-bound metal of amide and histidine). Single amino acids and chains of amino acids (e.g., 2, 3,4, 5, 6, or longer in length) can be used as chelating agents.
In some embodiments, other chelating materials may be used in addition to or in place of those described above. In some embodiments, the chelating agent is derived from a plant material, such as algae, tea saponin, humic acid, potato peel, sawdust, black soybean hull, eggshell, coffee hull, sugar beet pectin gel, citrus peel, papaya wood, corn leaf, leaf powder, cogongrass, leaf powder, rubber leaf powder, peanut hull particles, sago waste, quinoa leaf, fern, neem bark, grape straw, chaff, spent grain (e.g., from breweries), bagasse, fly ash, wheat bran, corn cobs, weeds (Imperatayllindica leaf powder), fruit/vegetable waste, cassava waste, plant fiber, bark, red wine, alfalfa biomass, cottonseed hulls, soybean hulls, pea hulls, douglas fir hulls, walnut hulls, turkish coffee, nut shells, lignin, peat, bamboo pulp, orange peel (white inner skin), orange peel (orange peel), senna leaf, and combinations thereof.
In some embodiments, the removal or reduction of metals from the food product is performed in water (e.g., deionized water, RO, soft water, or tap water). In some embodiments, one or more binding and/or chelating agents and a food agent are each added to water. In some embodiments, the food product is added prior to the one or more binding and/or chelating agents. In some embodiments, the binding agent and/or chelating agent is added to the water prior to the food product. In some embodiments, the mixture is then agitated for a period of time equal to or at least about 15 minutes, 20 minutes, 60 minutes, 120 minutes, 180 minutes, or a range including and/or spanning the above values.
In some embodiments, different weight percent values (wt%) of the food product may be added to the water. In some embodiments, the wt% of the food product in water is equal to or at least about 5%, 10%, 25%, 50%, 60%, or a range including and/or spanning the aforementioned values.
In some embodiments, the amount of binding agent and/or chelating agent used to treat the food product is based on dry measurements. For example, in some embodiments, a 2% dry weight measurement of the food product represents 2 grams of chelant per 98 grams of food product (2 grams chelant per 100 grams total dry weight). In some embodiments, the dry weight measurement of the binding agent and/or chelating agent used to treat the food product is less than or equal to about 0.5%, 1%, 2%, 5%, 10%, or a range including and/or spanning the aforementioned values.
In some embodiments, the amount of binding agent and/or chelating agent (or combination thereof) used to treat the food product is based on the weight percentage measurement. For example, in some embodiments, the treated formulation includes a food product (e.g., a mixture and/or suspension of plant matter such as proteins, protein isolates, carbohydrates, etc.) in a liquid (e.g., water). In some embodiments, a 2 wt.% measurement of a formulation represents 2 grams of chelant (e.g., solute) for every 100 grams of formulation (e.g., food product (e.g., rice flour, etc.), chelant, and liquid solvent). In some embodiments, the wt% of binding agent and/or chelating agent used to treat the formulation is less than or equal to about 0.0125, 0.25%, 0.1%, 1%, 1.25%, 2%, 5%, 7.5%, 10%, or a range including and/or spanning the above values. In some embodiments, the weight percentage of dry food product in the formulation is equal to or greater than about 10%, 20%, 30%, 40%, 60%, 80%, 90%, 99%, or a range including and/or spanning the above values.
In some embodiments, no chelating agent is used, but instead a liquid that is free or substantially free of added chelating agent is used to remove metals from the food product. For example, in some embodiments, one or more combinations of liquids, such as water, ethanol, and the like, are used to remove the metal.
In some embodiments, the metal removal and/or reduction may be performed at different pH values. In some embodiments, altering the pH of the solution to which binding and/or chelation and/or filtration occurs increases the solubility of, for example, metal ions, metal complexes (if present), or metals, allowing their removal from, for example, a food product. In some embodiments, for example, when the binding agent and/or complex (if present) or metal is less soluble than the food product, the solubility of the food product can be increased by changing the pH of the solution in which it is placed. In some embodiments, the pH of the solution used for binding, complexing, and/or metal removal or reduction is less than or equal to about 2, 2.5, 3,4, 5, 6, 7, 8, 9, 10, 11, or a range that includes and/or spans the aforementioned values.
In some embodiments, the pH may be altered to enhance the solubility of the heavy metal entities. For example, lead is more soluble at higher pH ranges, while cadmium and arsenic are more soluble at lower pH ranges. In some embodiments, high protein yields can be achieved at the isoelectric point of the plant material being processed. However, in some embodiments, the isoelectric point of the food product may not be optimal for removal of heavy metals. In some embodiments, the pH of the solution can be changed (e.g., raised or lowered) at one or more different steps and/or times to achieve removal of different metals and/or increase the yield of the food product. For example, in some embodiments, a lower pH may be used to increase the binding of cadmium and arsenic. The pH may then be raised to facilitate lead removal. The use of a binder is particularly effective under these variable pH conditions because, for example, once within the pores of the binder, the metal does not substantially escape the binder even though the metal is no longer highly soluble in the external solution.
In some embodiments, organically certified and/or food grade acids and bases are used to alter the pH of the water mixture. In some embodiments, food grade acids and bases are used to alter the pH of the water mixture.
In some embodiments, the metal removal and/or reduction may be performed using methods at different solution temperatures. In some embodiments, the water is maintained at a temperature during the mixing of the food product with the one or more binding and/or chelating agents. In some embodiments, the water is at a temperature equal to or less than about 5 ℃, 15 ℃, 25 ℃, 45 ℃, 75 ℃, 85 ℃, 95 ℃, 99 ℃, or a range including and/or spanning the aforementioned values. In some embodiments, temperatures below about 23 ℃ are used to avoid blooming or swelling of certain plant materials, such as cereal starches (e.g., rice starch bloom). In some embodiments, higher temperatures are used to facilitate filtration. In some embodiments, altering the temperature of the solution undergoing chelation (if performed), metal dissolution, and or filtration increases the solubility of, for example, the metal complex (if present) or the metal, thereby allowing it to be removed from, for example, a suspended food product (e.g., where the metal complex is soluble and the food product is insoluble). In other embodiments, for example, when the complex (if present) or metal is less soluble than the food product, the solubility of the food product can be increased by changing the temperature. In some embodiments, the temperature of the solution used to perform the complexing and/or metal reduction is less than or equal to about 4 ℃, 10 ℃, 20 ℃, 40 ℃,60 ℃, 80 ℃, 99 ℃, or ranges including and/or spanning the above values.
In some embodiments, filtration (and/or sieving), microfiltration, ultrafiltration, and/or nanofiltration membrane techniques are used to retain bound metal absorbents and/or chelating agents and/or other impurities while allowing food products (e.g., grain and/or vegetable proteins) to pass through the membrane, resulting in a reduction of heavy metals in the food product. In some embodiments, filtration is performed with a sieve or filter having an opening size equal to or less than about 5000 μm, 1000 μm, 840 μm, 500 μm, 420 μm, 300 μm, 100 μm, 50 μm, 10 μm, 1 μm, 0.1 μm, 0.01 μm, or a range including and/or spanning the above values. In some embodiments, the sieving is performed with a sieve having a sieve number equal to or less than about 10, 20, 40, 50, 100, 200, 400, or a range including and/or spanning the above values, under U.S. standards. In some embodiments, filtration is performed using a microfiltration membrane having a molecular weight cut-off (in daltons) equal to or less than about 10,000, 100,000, 200,000, 500,000, 1,000,000, or a range including and/or spanning the above values. In some embodiments, filtration is performed with a microfiltration membrane having a pore size equal to or less than 0.1 μm, 0.5 μm, 0.8 μm, 1.0 μm, 1.2 μm, 1.4 μm, 2.0 μm, or a range including and/or spanning the above values. In some embodiments, microfiltration membranes having a molecular weight cut-off of about 100,000 daltons to 4 microns are used. In some embodiments, filtration is performed with an ultrafiltration membrane having a molecular weight cut-off (in daltons) equal to or less than about 700, 10,000, 50,000, 100,000, 500,000, 800,000, or a range including and/or spanning the above values. In some embodiments, filtration is performed with nanofiltration membranes having a molecular weight cut-off (in daltons) equal to or less than about 100, 300, 500, 1,000, or a range including and/or spanning the above values. In some embodiments, the microfiltration, ultrafiltration and/or nanofiltration membrane consists of a non-organic and/or organic matrix. In some embodiments, microfiltration, ultrafiltration and nanofiltration membrane modules may be comprised of spiral hollow fiber, plate and frame, tubular and/or extruded membrane constructions.
In some embodiments, the binding agent and/or chelating agent (e.g., filter cake) remaining on the filter or screen after filtration may be washed with one or more water washes (e.g., 1, 2, 3,4, or more) to recover additional food product. In some embodiments, the wash volume is smaller than the volume used during the initial metal removal step to avoid possible recontamination of metal into the food product. In some embodiments, the wash volume is about 50%, 80%, 90%, or a range including and/or spanning the above values, less than the treatment volume.
In some embodiments, the binding agent is removed by a filtration step, leaving a filtrate and the food product. In some embodiments, the food product is then filtered from the filtrate using a finer filter. In some embodiments, the binding agent may be washed with the filtrate again. In some embodiments, any of the above steps or any of the steps disclosed elsewhere herein can be performed continuously (continuous process) or as a batch process.
In some embodiments, a suspension and/or solution of the binding agent and/or chelating agent is prepared. In some embodiments, a suspension or solution of the food product is prepared. In some embodiments, these solutions and/or suspensions are mixed to provide a metal removal solution. In other embodiments, dry binders and/or chelating agents may be added to the solution and/or suspension of the food product. In other embodiments, the dry food product may be added to a solution and/or suspension of the binding agent and/or chelating agent.
In some embodiments, microfiltration, ultrafiltration, and/or nanofiltration membrane techniques are used to retain the target food product (e.g., grain and/or vegetable protein) while allowing the chelant and/or other impurities to pass through the membrane, thereby reducing heavy metals in the food product. In some embodiments, filtration is performed using an ultrafiltration membrane having a molecular weight cut-off (in daltons) equal to or less than about 1,000, 10,000, 100,000, 200,000, 500,000, 1,000,000, or a range including and/or spanning the above values. In some embodiments, filtration is performed with a microfiltration membrane having a pore size equal to or less than 0.1 μm, 0.5 μm, 0.8 μm, 1.0 μm, 1.2 μm, 1.4 μm, 2.0 μm, or a range including and/or spanning the above values. In some embodiments, microfiltration membranes having a molecular weight cut-off of about 100,000 daltons to 4 microns are used. In some embodiments, filtration is performed with an ultrafiltration membrane having a molecular weight cut-off (in daltons) equal to or less than about 700, 10,000, 50,000, 100,000, 500,000, 800,000, or a range including and/or spanning the above values. In some embodiments, filtration is performed with nanofiltration membranes having a molecular weight cut-off (in daltons) equal to or less than about 100, 300, 500, 1,000, or a range including and/or spanning the above values. In some embodiments, the microfiltration, ultrafiltration and/or nanofiltration membrane consists of a non-organic and/or organic matrix. In some embodiments, microfiltration, ultrafiltration and nanofiltration membrane modules may be comprised of spiral hollow fiber, plate and frame, tubular and/or extruded membrane constructions.
In some embodiments, the heavy metal removal and/or reduction process is performed in a vessel under agitation. In some embodiments, the heavy metal removal and/or reduction process is performed in a packed column containing an absorbent. In some embodiments, the slurry of food product, metal and water is flushed through the packed column. In some embodiments, the solution is passed under plug flow conditions (plug flow means low flow conditions which minimize turbulence, thereby minimizing back mixing, thereby providing a more accurate means of achieving a set solution residence time in the column or tube).
In some embodiments, the food product is soaked in hot water and wet milled prior to treatment with the binding and/or chelating agent, as disclosed elsewhere herein. In some embodiments, for example, whole grain brown rice or polished rice and/or polished rice grits can be processed by soaking in hot water followed by wet milling to a particle size smaller than the absorber particle size. In some embodiments, the wet milling solution can be treated at a temperature of milling (e.g., a temperature equal to or less than about 5 ℃, 15 ℃, 25 ℃, 45 ℃, 75 ℃, 85 ℃, 95 ℃, 99 ℃, or a range including and/or spanning the above values), or the solution can be heated or cooled at a temperature of milling, and the wet milling solution can be further enzymatically or chemically processed prior to addition to the absorber. In some embodiments, the pH may also be varied, as disclosed elsewhere herein. Some embodiments relate to the use of fabric and/or screen filter technology to retain target grain and/or vegetable products (e.g., proteins) while allowing one or more chelating agents and/or other impurities to pass through the membrane, resulting in a reduction of heavy metals. In some embodiments, the fabric may be any natural or man-made woven or extruded material. In some embodiments, the screen may be any metal or plastic material. In some embodiments, the screen can have a mesh size equal to or less than about 10 mesh, 100 mesh, 400 mesh, or a range including and/or spanning the above values. In some embodiments, the filter system uses a fabric and/or mesh, and/or a sintered stainless steel, ceramic, or glass filter. In some embodiments, the food product may be processed to a size small enough to pass through a fabric or filter while retaining the binding agent in the filter, as disclosed elsewhere herein.
In some embodiments, the filtration system is in the following configuration: a cartridge filter, a plate and frame filter, a bicontinuous band filter, a vacuum drum filter, a flat filter, an inclined filter, or an incremental band filter.
In some embodiments, the filtration process is performed using a solution at a temperature less than or equal to about 4 ℃, 10 ℃, 20 ℃, 40 ℃,60 ℃, 80 ℃, 99 ℃, or a range including and/or spanning the above values. In some embodiments, the membrane system operating pressure is conducted at a pressure equal to or at least about 1 bar, 10 bar, 20 bar, 40 bar, or a range including and/or spanning the values recited above. In some embodiments, membrane system operating pressures are required for the system and the membrane type and composition. In some embodiments, the fabric and/or mesh filtration system operating pressure may operate under vacuum (e.g., on the filtrate side of the filter).
In some embodiments, the filtration step and membrane system use water that is free or substantially free of heavy metals. In some embodiments, the filtration process can flush a variable volume of water through the membrane that removes the heavy metal chelate complex until a desired level of heavy metals remains in the food product (e.g., protein matrix). In some embodiments, water may be used at any pH desirable within the above ranges, and may also vary from the start of filtration to until filtration is complete. In some embodiments, the filtered water may be used at any temperature desirable within the above ranges, and may also vary from the beginning of filtration to the completion of filtration. In some embodiments, multiple filtration stages may be used in a continuous process stream, and different pH and/or chelating agents may be used in each stage. In some embodiments, a multi-stage continuous filtration process may be used, wherein the filtrate from the last stage is used as the flush of a preceding stage in a countercurrent fashion from the last stage to any preceding stage in a multi-stage filter system. In some embodiments, the operating pressure may be varied as desired at any time during the filtration process within the above ranges.
In some embodiments, a rinse solution having a different pH than the initial metal binding and/or chelating solution may be used to rinse bound binding agents and/or metal complexes from food products (e.g., flour, grain and vegetable proteins, etc.). These altered pH values as disclosed elsewhere herein may be used with any of the disclosed filtration techniques (e.g., using a screen or filter, using microfiltration, ultrafiltration, nanofiltration membrane techniques, or fabrics) to allow for the entrapment of the material to be removed while allowing for the passage of water of altered pH. In some embodiments, liquid rinses at different pH levels may be mixed or matched to remove various metals (or complexes) that may have a solubility that varies with pH.
In some embodiments, filtration is not used, and the soluble fraction (or smaller particle fraction) of the mixture is removed by decantation (e.g., using a centrifuge decanter). In some embodiments, a centrifuge may be used to separate the insoluble fraction (or smaller particle fraction) from the solution. In some embodiments, the insoluble fraction may be separated from the solution (supernatant) using a stacked disk centrifuge and/or a centrifugal basket centrifuge. In some embodiments, the supernatant is poured, pumped, or vacuumed away from the solid fraction. In some embodiments, the centrifuge decanter may be placed in a continuous staged operation. In some embodiments, in a staged operation, the supernatant from a centrifugal decanter may be counter-flowed as wash water to a previous centrifugal decanter.
In some embodiments, the metal removed by the methods disclosed herein comprises a metal having an atomic weight greater than or equal to about 63.5, 100, 200.6, 600, 700, or a range including and/or spanning the above values. In some embodiments, the metals removed and/or reduced include one or more of arsenic, zinc, copper, nickel, mercury, cadmium, lead, selenium, and chromium. In some embodiments, the chelating agent binds, removes, and/or reduces metals having a specific gravity greater than about 3.0, 5.0, 10.0, or a range including and/or spanning the above values.
In some embodiments, the chelating agents (or methods) disclosed herein allow for a reduction in the amount (e.g., weight or molar content) of one or more metals (e.g., Hg, Pb, Cd, Cr, Sn, Ar) of at least about 50%, 75%, 90%, 99%, 99.9%, or a range including and/or spanning the above values. In some embodiments, the chelators (or methods) disclosed herein reduce the amount of one or more metals in the food product to equal to or less than about 10ppm, 1ppm, 100ppb, 1ppb, or a range that includes and/or spans the aforementioned values. In some embodiments, the metal is reduced to an edible level acceptable by the FDA and/or european food Safety Authority (european food Safety Authority). In some embodiments, for example, Ar is reduced to equal to or less than about 125ppb, Cd is reduced to equal to or less than 250ppb, Pb is reduced to equal to or less than about 125ppb, and Hg is reduced to equal to or less than about 29 ppb.
The processes disclosed herein can be used to prepare food products mentioned elsewhere herein, including for example rice flour, maltodextrin and rice protein, from rice (e.g., white rice, brown rice, etc.) and rice grits (e.g., rice grains that are broken rather than intact and are typically damaged in the bran removal step (which is the mechanical abrasion of the rice grains) that have a reduced heavy metal content or are substantially and/or completely removed of heavy metals. In some embodiments, the metal chelator can be introduced during the production of a plant-derived food product to remove metals. In some embodiments, a method for removing metals is used, which is performed by using washing at a specific stage during the preparation of the rice product. In some embodiments, the products disclosed herein are hypoallergenic and can maintain their "organic food" state based on the techniques used to remove these metals.
Examples
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