阅读说明：本技术 低褐变无乳糖奶粉 (Lactose-free milk powder with low browning ) 是由 巴宁宁 杜玲玲 徐庆利 于 2021-07-15 设计创作，主要内容包括：本申请提供了一种低褐变无乳糖奶粉,其中无乳糖乳清蛋白粉采用超膜过滤方法制备,制备中使用的渗滤液使用部分乙醇溶剂并含有表面活性剂,以使得去除乳糖的同时保留多数非蛋白氮营养成分,并提供了良好的防褐变性能。(The application provides low-browning lactose-free milk powder, wherein lactose-free whey protein powder is prepared by adopting an ultrafiltration membrane filtration method, and a percolate used in the preparation process uses part of an ethanol solvent and contains a surfactant, so that most of non-protein nitrogen nutrient components are reserved while lactose is removed, and good browning prevention performance is provided.)

1. The lactose-free milk powder with low browning is characterized by comprising lactose-free whey protein powder prepared by an ultrafiltration method.

2. The low browning lactose-free milk powder of claim 1, having a formula of: 73% of vegetable fat powder A, 12% of vegetable fat powder D, 4.9% of potassium citrate, 2.5% of sodium citrate, 1.2% of calcium hydrophosphate, 1.05% of docosahexaenoic acid grease, 1% of white granulated sugar, 1% of potassium chloride, 0.9% of arachidonic acid grease, 0.9% of choline, 0.5% of minerals, 0.35% of inositol, 0.3% of vitamins, 0.3% of tricalcium phosphate, 0.03% of calcium carbonate, 0.02% of L-carnitine and 0.05% of nucleotides; wherein the vegetable fat powder A: 25.6% of maltodextrin, 16.4% of vegetable oil, 15.6% of lactose-free whey protein powder, 13.1% of solid starch sugar, 13.1% of anhydrous cream, 10% of glucose, 5.2% of sodium starch octenylsuccinate, 0.69% of mono-diglycerol fatty acid ester, 0.21% of L-sodium ascorbate, 0.04% of ascorbyl palmitate, 0.04% of mixed tocopherol concentrate and 0.02% of phospholipid; wherein the vegetable fat powder D: 41.7 percent of maltodextrin, 24 percent of vegetable oil, 15.8 percent of lactose-free whey protein powder, 17.4 percent of solid starch sugar, 0.69 percent of mono-diglycerol fatty acid ester, 0.34 percent of L-sodium ascorbate, 0.03 percent of ascorbyl palmitate, 0.03 percent of mixed tocopherol concentrate and 0.01 percent of phospholipid.

3. The lactose-free milk powder with low browning as claimed in claim 1 or 2, wherein the percolate solvent in the ultrafiltration membrane filtration method is 2:8 volume ratio of ethanol and water, and contains 5.1g/mL of NaCl, 4.0g/mL of NaOH, 9.8g/mL of KCl, and H₃PO₄35.5g/mL, citric acid monohydrate 40.3 g/mL.

4. The low browning lactose-free milk powder of claim 3 wherein the percolate also contains a surfactant.

5. The low browning lactose-free milk powder of claim 4, wherein the surfactant is propylene glycol fatty acid ester.

6. The low browning lactose-free milk powder of claim 5 wherein the surfactant is propylene glycol fatty acid ester 2.2 g/mL.

7. The method for preparing the lactose-free whey protein powder is characterized by using an ultrafiltration membrane filtration method.

8. The method of claim 7, wherein the percolate solvent in the ultrafiltration membrane filtration process is 2:8 volume ratio of ethanol and water containing 5.1g/mL NaCl, 4.0g/mL NaOH, 9.8g/mL KCl, H₃PO₄35.5g/mL of water40.3g/mL of synthetic citric acid and 2.2g/mL of propylene glycol fatty acid ester.

9. Use of the method according to claim 7 or 8 for preventing browning of lactose-free milk powder.

Technical Field

The application belongs to the field of dairy in food, and particularly provides lactose-free milk powder with low browning and a preparation method thereof.

Background

Lactose intolerance is caused by a lack of lactase or insufficient amount/activity of lactase, and occurs at a higher rate in east asian ethnic species. Lactose intolerant infants need to use special low-lactose or lactose-free milk powder products to avoid symptoms such as abdominal distension, abdominal pain, diarrhea and the like caused by lactose intolerance, and the products have wide requirements in China.

Except that the ingredient containing lactose is not added in the preparation of the low-lactose or lactose-free milk powder, the lactose in the milk needs to be removed as much as possible by using enzyme or an ultrafiltration membrane: although the lactase method has mild conditions and can provide glucose and galactose which are easy to absorb by human bodies, the enzymolysis process is difficult to control, the product quality stability is not high, the subsequent browning tendency is obvious, and in addition, the adding/inactivating process of the enzyme can bring potential risks to the product; in contrast, the physical treatment process of the ultrafiltration membrane without introducing any other components is obviously better in safety, and the product quality is more stable.

In the previous researches of the applicant, a large problem in ultrafiltration membrane treatment is that the loss degree of non-protein nitrogen is up to three-fourths, the non-protein nitrogen contains a large amount of small peptide components besides amino acid components, and a plurality of researches show that the small peptides have the effects of resisting oxidation, improving immunity, resisting bacteria and the like. Therefore, avoiding the loss of non-protein nitrogen is a feasible way for further improving the nutritional value of the milk powder product, and meanwhile, the beneficial effect can be brought to the preservation of the product.

Disclosure of Invention

The applicant finds that by adding a proper surfactant into percolate obtained by ultrafiltration, lactose can be normally removed, meanwhile, non-protein nitrogen loss can be effectively prevented through electrostatic acting force, the effect can be further enhanced through the use of a proper solvent, and better anti-browning performance can be provided

In one aspect, the application provides a low-browning lactose-free milk powder, which is characterized by comprising lactose-free whey protein powder prepared by an ultrafiltration method.

Further, the formula of the low-browning lactose-free milk powder is as follows: 73% of vegetable fat powder A, 12% of vegetable fat powder D, 4.9% of potassium citrate, 2.5% of sodium citrate, 1.2% of calcium hydrophosphate, 1.05% of docosahexaenoic acid grease, 1% of white granulated sugar, 1% of potassium chloride, 0.9% of arachidonic acid grease, 0.9% of choline, 0.5% of mineral, 0.35% of inositol, 0.3% of vitamin, 0.3% of tricalcium phosphate, 0.03% of calcium carbonate, 0.02% of L-carnitine and 0.05% of nucleotide; wherein the vegetable fat powder A: 25.6% of maltodextrin, 16.4% of vegetable oil, 15.6% of lactose-free whey protein powder, 13.1% of solid starch sugar, 13.1% of anhydrous cream, 10% of glucose, 5.2% of sodium starch octenylsuccinate, 0.69% of mono-diglycerol fatty acid ester, 0.21% of L-sodium ascorbate, 0.04% of ascorbyl palmitate, 0.04% of mixed tocopherol concentrate and 0.02% of phospholipid; wherein the vegetable fat powder D: 41.7% of maltodextrin, 24% of vegetable oil, 15.8% of lactose-free whey protein powder, 17.4% of solid starch sugar, 0.69% of mono-diglycerol fatty acid ester, 0.34% of L-sodium ascorbate, 0.03% of ascorbyl palmitate, 0.03% of mixed tocopherol concentrate and 0.01% of phospholipid;

further, ethanol and water with the volume ratio of 2:8 of leachate solvent in the ultrafiltration membrane filtration method contain 5.1g/mL of NaCl, 4.0g/mL of NaOH, 9.8g/mL of KCl and H₃PO₄35.5g/mL, citric acid monohydrate 40.3 g/mL.

Further, the leachate also contains a surfactant.

Further, the surfactant is propylene glycol fatty acid ester.

Further, the surfactant is 2.2g/mL of propylene glycol fatty acid ester.

In another aspect, the present application provides a method for preparing lactose-free whey protein powder, characterized in that an ultrafiltration method is used.

Further, the percolate in the ultrafiltration membrane filtration method is ethanol and water with the volume ratio of the solvent of 2:8, and contains 5.1g/mL of NaCl, 4.0g/mL of NaOH, 9.8g/mL of KCl and H₃PO₄35.5g/mL, citric acid monohydrate 40.3g/mL, propylene glycol fatty acid ester 2.2 g/mL.

In another aspect, the present application provides the use of the above method for preventing browning of lactose-free milk powder.

The term "lactose-free" as used in this application does not necessarily mean that the lactose content is zero, but is below a level or state/industry-related standard, such as 0.5g/100g, which may affect the health of the user.

The membrane used in the "ultrafiltration membrane" of the present application can be manufactured from various manufacturers, and the molecular weight standard is limited to the lactose-permeable but not the majority of the proteins, and can be routinely selected by those skilled in the art.

The browning in the application refers to the phenomenon that the color of the milk powder becomes dark and gradually turns brown during storage; browning can be assessed photometrically (with a variety of different calculations) or visually.

Drawings

Fig. 1 shows browning at 80 degrees celsius accelerated treatment.

Detailed Description

Main methods, reagents and apparatus

Whey protein powder:

in order to ensure stable quality, the same batch of whey protein powder (fresh milk microfiltration membrane filtration, high molecular weight ultrafiltration membrane preliminary separation and spray drying) self-made by the applicant is used in the research process, and the main relevant performances are as follows:

composition (I)	Content (wt.)
		Dried substance	919.2g/kg
Ash content	27.5g/kg
		Total nitrogen	775.2g/kg
Non-protein nitrogen	18.6g/kg
		Lactose	15.2g/kg

Ultrafiltration apparatus and diafiltration process:

Rhone-Poulenc carbosep (ceramic ultrafiltration membrane, cut-off 10 kD); percolation temperature 30-40 ℃, total time 12 hours, volume of percolate: the volume of the original material was 2.7: 1.

Non-protein nitrogen assay:

after precipitation of the protein using 15% trichloroacetic acid, the filtrate was digested and distilled, titrated with 0.01mol/L hydrochloric acid and the non-protein nitrogen content was calculated essentially according to the method of GB/T21704-2008.

And (3) measuring the browning degree:

a sample of milk powder was tested (light source: D65) using an UltraScan PRO colorimeter (hunter lab) to obtain a broad reflection spectrum of 10 ℃ and the browning index was calculated according to the following formula:

BI＝100(X-0.31)/0.17

X＝A+1.75L/A+5.645L-0.3012B

wherein L is the color brightness, + A is the chroma of red, -A is the chroma of green, + B is the chroma of yellow, -B is the chroma of blue.

Sucrose fatty acid ester: henan Andro Biotechnology Ltd;

soybean lecithin: henan Andro Biotechnology Ltd;

propylene glycol fatty acid ester: shandong Guo Shuo Biotech Co., Ltd;

other components are conventional domestic products meeting related food safety standards.

EXAMPLE 1 ultra Membrane permeation treatment

Dissolving whey protein powder with double distilled water to obtain 0.8% w/v solution, performing discontinuous ultrafiltration with the above device, collecting the filtrate, and adding percolate (NaCl, NaOH, KCl, H) with the same volume₃PO₄The citric acid and the basic dosage thereof are designed according to the change of the mineral content in the trapped phase, the dosages of sucrose fatty acid ester, soybean lecithin and propylene glycol fatty acid ester are optimized through preliminary experiments, and the dosages shown below are only representative formulas; the percolate solvent is water, and soybean lecithin and propylene glycol fatty acid ester which can not be completely dissolved are heated or ultrasonically assisted to prepare suspensionLiquid ready for use), the percolate formulation and the change after the percolation treatment are as follows:

table 1: representative leachate formulations

Table 2: treatment effect of different leachate

The results show that the addition of a suitable non-ionic surfactant to the leachate can effectively reduce the loss of non-protein nitrogen while substantially maintaining the lactose removal effect (the lactose content is slightly increased but still within the production-usable range, and other methods such as enzymatic hydrolysis can be used to further reduce the lactose content as required) by using the electrostatic force of charged amino acids on the membrane (preliminary experiments speculated). The retention of non-protein nitrogen is not only of great significance for the retention of nutrient components such as amino acid, but also the retention of certain polypeptide can be helpful for improving the effects of the product in the aspects of improving immunity, resisting oxidation and the like.

On this basis, the solvent improvement of the percolate was further investigated and it was found that the effect of the percolation of sucrose fatty acid ester, soya lecithin was reduced after the use of a portion of organic solvent, whereas the percolate 2.1 (ethanol was completely removed after subsequent spray drying) was formulated with a solvent consisting of ethanol and water in a 2:8 volume ratio, the lactose content after percolation being 3.4g/kg and the non-protein nitrogen being 10.7 g/kg.

EXAMPLE 2 formulation of lactose-free milk powder

The lactose-free milk powder is prepared according to the following formula:

73% of vegetable fat powder A, 12% of vegetable fat powder D, 4.9% of potassium citrate, 2.5% of sodium citrate, 1.2% of calcium hydrophosphate, 1.05% of docosahexaenoic acid grease, 1% of white granulated sugar, 1% of potassium chloride, 0.9% of arachidonic acid grease, 0.9% of choline, 0.5% of mineral, 0.35% of inositol, 0.3% of vitamin, 0.3% of tricalcium phosphate, 0.03% of calcium carbonate, 0.02% of L-carnitine and 0.05% of nucleotide;

vegetable fat powder A: 25.6% of maltodextrin, 16.4% of vegetable oil, 15.6% of whey protein powder, 13.1% of solid starch sugar, 13.1% of anhydrous cream, 10% of glucose, 5.2% of sodium starch octenylsuccinate, 0.69% of mono-diglycerol fatty acid ester, 0.21% of sodium L-ascorbate, 0.04% of ascorbyl palmitate, 0.04% of mixed tocopherol concentrate and 0.02% of phospholipid;

vegetable fat powder D: 41.7% of maltodextrin, 24% of vegetable oil, 15.8% of whey protein powder, 17.4% of solid starch sugar, 0.69% of mono-diglycerol fatty acid ester, 0.34% of L-sodium ascorbate, 0.03% of ascorbyl palmitate, 0.03% of mixed tocopherol concentrate and 0.01% of phospholipid;

the milk powder products prepared by the obtained whey protein powder treated by the percolate 2.1 and 4 are corresponding to the milk powder 2.1 and 4.

Example 3 accelerated browning of lactose-free milk powder

The browning conditions of the milk powders 2.1 and 4 under the condition of 80 ℃ accelerated treatment are shown in figure 1:

not only was milk powder 2.1 further evident in lactose content and non-protein nitrogen content, but it also achieved unexpected results in terms of browning inhibition, presumably primarily due to the fact that certain retained polypeptides or specific amino acids were detrimental to the maillard reaction.