阅读说明：本技术 一种环保节水的膜过滤分离制备橡子粉及精制鞣酸的方法 (Method for preparing acorn powder and refined tannic acid through environment-friendly and water-saving membrane filtration separation ) 是由 李玉川 胡海燕 李润华 于 2021-08-09 设计创作，主要内容包括：本发明属于食品加工技术领域,尤其涉及一种环保节水的膜分离制备橡子粉及精制鞣酸的方法；包括以下有效步骤：首先将橡子仁放入容器中加纯水逆流浸泡过滤；滤液Ⅰ经膜系统Ⅰ进行过滤分离；滤出的无机盐及大分子母液Ⅰ作为肥料或饲料,滤液Ⅱ做循环液或经膜系统Ⅱ进行过滤分离；母液Ⅱ富集后重结晶得高纯度鞣酸并循环,滤液Ⅲ做循环液；浸泡过的橡子仁粉碎再沉淀后得橡子淀粉,或经干燥后粉碎制备高纯度可食用橡子面粉。本发明利用纯物理方式,实现对橡子粉的分离提纯,能耗低,并实现了水的高效循环利用；另,采用多次循环过滤的方式,将无机盐和大分子滤出利用、鞣酸富集纯化利用,最终实现了加工过程的零污染物排放。(The invention belongs to the technical field of food processing, and particularly relates to an environment-friendly and water-saving method for preparing acorn powder and refined tannic acid by membrane separation; the method comprises the following effective steps: firstly, placing acorn kernels into a container, adding pure water, soaking and filtering in a counter-current manner; filtering and separating the filtrate I through a membrane system I; the filtered inorganic salt and the macromolecule mother liquor I are used as fertilizer or feed, and the filtrate II is used as circulating liquid or is filtered and separated by a membrane system II; after enriching the mother liquor II, recrystallizing to obtain high-purity tannic acid and circulating, and taking the filtrate III as circulating liquor; pulverizing soaked acorn seed, precipitating to obtain acorn starch, or drying and pulverizing to obtain high-purity edible acorn flour. The invention realizes the separation and purification of acorn powder by a pure physical mode, has low energy consumption and realizes the high-efficiency cyclic utilization of water; in addition, a multi-time circulating filtration mode is adopted, inorganic salt and macromolecules are filtered out and utilized, tannic acid is enriched, purified and utilized, and zero pollutant emission in the processing process is finally realized.)

1. An environment-friendly and water-saving method for preparing acorn powder and refined tannic acid by membrane filtration separation is characterized by comprising the following effective steps:

placing acorn kernels into a container, adding water, soaking in a counter-current manner, and filtering;

filtering and separating the filtrate I through a membrane filtration system I;

the filtered inorganic salt and macromolecular substance mother liquor I are circularly concentrated to be used as fertilizer or feed, and the filtrate II is used as circulating liquid or is filtered and separated by a membrane filtration system II;

circularly enriching the mother liquor II, cooling and recrystallizing to obtain a high-purity tannic acid product, and taking the filtrate III as a circulating liquid;

the soaked acorn kernels are directly crushed and then precipitated to prepare acorn starch, or the acorn kernels are dried and crushed to prepare high-purity edible acorn flour.

2. The method for preparing acorn powder and refined tannic acid through membrane filtration separation according to claim 1, wherein in the step a, the acorn kernels refer to refined acorn kernels obtained by removing shells and impurities from acorns or particles with the minimum particle size of not less than 0.2 mm after crushing the refined acorn kernels after the impurities are removed.

3. The method for preparing acorn powder and refined tannic acid through membrane filtration separation according to claim 1, wherein in the step a, the pore size of a filter mesh used for filtration is not less than 100 meshes, and the filter mesh is placed near an outlet of the soak solution.

4. The method for preparing acorn powder and refined tannic acid through membrane filtration separation according to claim 1, wherein in the step a, the water is purified water or circulating water after being added in countercurrent soaking, wherein the countercurrent soaking means that the water adding direction and the circulating water direction are the same, and the soaking time is 0.5 to 24 hours.

5. The method for preparing acorn powder and refined tannic acid through membrane filtration separation according to claim 1, wherein the inorganic salt and the mother liquor I of the macromolecular substance filtered out in the step c are recycled and enriched, and can be directly used as fertilizer or feed or further concentrated to be used as fertilizer or feed.

6. The method for preparing acorn powder and refined tannic acid through membrane filtration separation according to claim 1, wherein in the steps b, c and d, the cycle times of the mother liquor I, the mother liquor II, the filtrate II and the filtrate III are 1 to 10 times.

7. The method for preparing acorn powder and refined tannic acid through membrane filtration separation according to claim 1, wherein in the step e, the soaked acorn kernels can be directly crushed and then precipitated to prepare acorn starch, or dried and then crushed to prepare high-purity edible acorn flour.

8. The method for preparing acorn powder and refined tannic acid through membrane filtration separation according to claim 1, wherein the temperature in the steps a, b, c, d and e is 0-50 ℃.

9. The method for preparing acorn powder and refined tannic acid through membrane filtration separation according to claim 1, wherein in the steps a, b, c, d and e, the pressure is 0.1MPa to 10.0 MPa.

Technical Field

The invention belongs to the technical field of food processing, and particularly relates to an environment-friendly and water-saving method for preparing acorn powder and refined tannic acid by membrane filtration separation.

Background

Acorn is also called acorn, etc., and is a fruit of plant of Quercus genus of Fagaceae family, with hard shell on its outer surface, long round, brownish red, and inner kernel such as peanut kernel. Acorns contain about 60% of starch, are edible and are one of the most important foods in early human; acorn starch can be used as a raw material for sizing in the textile industry; acorns also contain rich amino acid, fat and a plurality of trace elements required by human bodies such as potassium, sodium, calcium, magnesium and the like, and acorns are also rich in tannic acid and are a main factor causing eating difficulty; the acorn shell can also be used for preparing tannin extract. The acorn has biological functional factors which can resist, relieve and prevent the poison of heavy metals such as lead and the like to the human body; acorn can be used as medicine for treating dysentery, enhancing immunity, promoting growth and development, promoting cell metabolism, promoting bone collateral growth, enhancing physiological function, and preventing anemia. China has a long tradition of eating acorn powder; in korea, acorn powder has been widely used to produce foods such as korean cold noodles, acorn bean curd, and the like. Acorn is a wild plant resource with high development and utilization values, and has wide application and wide prospect.

At present, the annual yield of the national acorns is about 700 ten thousand tons, and the yield of the acorns is also rapidly increased along with the rapid recovery of forest resources in China. Along with the improvement of living standard of people, the increase of grain yield and the abundance of varieties, people gradually fade the utilization of acorns: most of acorns are naturally scattered in the field, and part of acorns are picked up manually, most of the acorns are directly used as feed or are used as acorn powder for eating after being subjected to rough treatment; the comprehensive processing technology of acorns is also reported (see CN107348445B, CN108929384A, CN106032391A, CN108976304A and the like), and organic solvents such as alcohol and/or ultrasonic wave assistance and evaporation and the like are utilized.

The existing processing method for acorns has the disadvantages of low yield, large pollution, high resource waste and high comprehensive cost; or the quality of the target product is difficult to control, and the maturity of the adopted technical means is low; or the added value of the product is low and the resource utilization rate is not high. Therefore, the whole processing and utilization of the acorns are restricted.

Disclosure of Invention

Aiming at the comprehensive utilization prospect of acorn resources and the existing technical problems, the invention provides the method for preparing acorn powder and refined tannic acid by membrane filtration separation, which has the advantages of reasonable design, simple structure, energy conservation, high efficiency, simple and convenient technical method, capability of effectively improving the comprehensive utilization of acorns and high purity of target products, environmental protection and water saving. The invention is further popularized and utilized on the basis of the technology of the prior invention (application number 202110772450.2) of the inventor team.

In order to achieve the aim, the invention adopts the technical scheme that the invention provides an environment-friendly and water-saving method for preparing acorn powder and refined tannic acid by membrane filtration separation, which comprises the following effective steps:

a. firstly, placing acorn kernels into a container, adding water, soaking in counter current, and filtering;

b. filtering and separating the filtrate I through a filter screen by a membrane filtering system I;

c. the filtered inorganic salt and macromolecular substance mother liquor I are circularly concentrated to be used as fertilizer or feed, and the filtrate II is used as circulating liquid or is filtered and separated by a membrane filtration system II;

d. circulating, enriching, cooling and recrystallizing the mother liquor II to obtain a high-purity tannic acid product, circulating the recrystallized mother liquor II, and taking the permeate as filtrate III as circulating liquid;

e. the soaked acorn kernels are directly crushed and then precipitated to prepare acorn starch, or the acorn kernels are dried and crushed to prepare high-purity edible acorn flour.

Preferably, in the step a, the acorn kernels refer to refined acorn kernels obtained by removing shells and impurities from acorns or particles with the minimum particle size of not less than 0.2 mm after crushing the refined acorn kernels after removing the impurities.

Preferably, in the step a, a filter screen used for filtering is placed near the outlet of the soak solution, and the diameter of the filter screen is not less than 100 meshes.

Preferably, in the step a, water is added for countercurrent soaking, the water is pure water or circulating water, the countercurrent is that the water adding direction and the circulating water direction are the same, and the soaking time is 0.5 to 24 hours.

Preferably, in the step c, the inorganic salt and the macromolecular substance mother liquor I filtered out can be directly used as fertilizer or feed or further concentrated to be used as fertilizer or feed.

Preferably, in the step b, the step c and the step d, the circulation times of the mother liquor I, the mother liquor II, the filtrate II and the filtrate III are 1 to 10 times.

Preferably, in the step e, the soaked acorn kernels can be directly crushed and then subjected to precipitation filtration to prepare acorn starch, or dried and crushed to prepare high-purity edible acorn flour.

Preferably, in the step a, the step b, the step c and the step d, the temperature is 0 ℃ to 50 ℃.

Preferably, in the step a, the step b, the step c and the step d, the pressure is 0.1MPa to 10.0 MPa.

Compared with the prior art, the invention has the advantages and positive effects that:

1. the invention provides the technical method for preparing the acorn powder and refining the tannic acid by the membrane separation, which has the advantages of reasonable design, simple structure, energy conservation, high efficiency, simple and convenient technical method, capability of effectively improving the comprehensive utilization level of acorns and higher purity of target products, environmental protection and water saving.

2. The mode of filtering for many times by adopting a self-made filter screen and an independently researched and developed membrane material is adopted, beneficial inorganic salt and high molecular substances are effectively and independently separated out to be used as fertilizer or feed, and the whole process can be used for continuous production or intermittent production.

3. The invention is further popularized and utilized on the basis of the technology of the prior invention of the inventor team.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, the present invention will be further described with reference to the following examples. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and thus the present invention is not limited to the specific embodiments of the present disclosure.

Example 1, this example provides an environment-friendly and water-saving method for preparing acorn powder and refined tannic acid by membrane filtration separation:

firstly, a container for containing acorn kernels is provided with a self-made 20-mesh filter screen, and the filter screen and a conveyor belt are fixed together for standby.

And (2) loading a 400D nanofiltration membrane and a 1812 membrane element into an organic membrane separation production experiment machine CINTANG-GM-24H equipment 1, testing the pure water flux at 0.3MPa and 25 ℃ to be 1500L/H, draining the pure water, and constructing a membrane forming and filtering system I for later use.

And (3) loading the 150D nanofiltration membrane and the 1812 membrane element into an organic membrane separation experiment machine CINTANG-GM-24H device 2, testing the pure water flux at 0.3MPa and 25 ℃ to be 1200L/H, draining the pure water, and constructing a membrane forming and filtering system II for later use.

Removing impurities from the dried carefully selected acorns, removing shells, crushing to 200 kg of acorn kernels with the diameter of about 2 mm, filling the container with pure water (1000L) for the first time, and heating to 45 ℃ for later use.

In the technical scheme provided by the invention, nanofiltration membranes within the range of 100D-1000D (D is the molecular weight unit Dalton) and the range are feasible, and only in the embodiment, 400D nanofiltration membranes and 150D nanofiltration membranes are matched for use.

The above steps constitute the completion of the previous preparation.

After soaking for 30 minutes, starting a temperature control circulating device, controlling the filtering temperature to be 45 ℃, ensuring that tannic acid in the acorns is quickly leached and starch is not gelatinized at the temperature of 45 ℃, starting a filtering system I to start circulating filtration, and starting circulation of a mother liquor I.

And starting the discharge port of the mother liquor I, the filtering system II, the circulation of the mother liquor II and a water injection valve at the same time when the concentration of the circulating liquor of the mother liquor I is not changed any more. Regulating pressure regulating valve controlThe filtration pressure of the filtration system I is 1.5MPa, the pressure of 1.5MPa can ensure the optimal retention rate of inorganic salt, polysaccharide, protein and other macromolecular substances under the condition of meeting the requirement of filtration flux, and the filtration flux is 20.0L/(H.m)²) (ii) a The filtering pressure of the filtering system II is controlled to be 2.5MPa by adjusting the pressure regulating valve, and the filtering flux is 30.0L/(H.m)²) (ii) a The water adding speed after the whole system is stable is the same as the discharging speed of the enrichment liquid of the mother liquid I.

Then, the feeding system and the discharging system are started, the feeding rate and the discharging rate are the same, the feeding rate is controlled to be the time required by the whole system to be stable, and the dynamic balance is realized. Drying and crushing the discharged acorn kernels, and bagging to obtain the finished product acorn flour.

In the process, the mother liquor II circulating liquid is saturated, then the temperature is reduced for recrystallization, and high-purity tannic acid is obtained by filtration and separation.

Selecting acorn kernels from quercus acutissima produced in mountain of Funiu in Henan, wherein the total yield of acorn flour is 53.5%; the total yield of the high-purity tannic acid is 7.5 percent, and the purity is more than 90 percent.

The above operation process is continuous production, and pure water can be supplemented appropriately according to the situation.

Example 2, this example provides an environment-friendly and water-saving method for preparing acorn powder and refined tannic acid by membrane filtration separation:

it is to be noted that the method belongs to a batch production process.

Firstly, a self-made 4-mesh filter screen is arranged on a container for containing acorn kernels, and the filter screen and a conveyor belt are fixed together for standby.

And (2) loading 300D nanofiltration membranes and 1812 membrane elements into an organic membrane separation production experiment machine CINTANG-GM-24H equipment 1, testing the pure water flux at 0.4MPa and 25 ℃ to be 1800L/H, draining the pure water, and constructing a membrane forming filtration system I for later use.

And (3) loading RO5 nanofiltration membranes and 1812 membrane elements into an organic membrane separation experiment machine CINTANG-GM-24H equipment 2, testing the pure water flux to be 900L/H at 0.4MPa and 25 ℃, draining the pure water, and constructing a membrane forming filtration system II for later use.

Removing impurities from dried acorns, removing shells, selecting acorn kernels, putting into a container for 200 kg, filling pure water (1000L), and heating to 45 ℃ for later use.

In the technical scheme provided by the invention, nanofiltration membranes within the range of 100D-1000D (D is molecular weight unit Dalton) and the range are feasible, and only in the embodiment, a 300D nanofiltration membrane and a RO5 nanofiltration membrane are matched for use.

The above steps constitute the completion of the previous preparation.

After soaking for 30 minutes, starting a temperature control circulating device, controlling the filtering temperature to be 45 ℃, and starting a filter screen, a filtering system I, a mother liquor I circulation, a filtrate I circulation, a filtering system II, a filtrate II circulation, a mother liquor II circulation and a water injection valve.

And starting a discharge port of the mother liquor I when the concentration of the circulating liquor of the mother liquor I is not changed any more.

The filtering pressure of the filtering system I is controlled to be 2.5MPa by adjusting the pressure regulating valve, and the filtering flux is 20.0L/(H.m)²) (ii) a The filtering pressure of the filtering system II is controlled to be 2.5MPa by adjusting the pressure regulating valve, and the filtering flux is 30.0L/(H.m)²) (ii) a The water adding speed after the whole system is stable is the same as the discharging speed of the enrichment liquid of the mother liquid I.

In the process, the mother liquor II circulating liquid is saturated, then the temperature is reduced for recrystallization, and tannic acid is obtained by filtration and separation.

The circulating filtration process is continued until no precipitate is separated out from the circulating liquid of the mother liquid II; or stopping circulation when the content of tannic acid in the filtrate I is less than 0.001%, or stopping circulation when the content of tannic acid in the acorn is less than 0.01% by sampling detection.

The acorn kernels treated above are dried, crushed and bagged to obtain the finished product acorn flour.

According to the method, oak nuts and acorn flour are selected from quercus acutissima produced in mountain of Henan Funiu, 109 kg of acorn flour is selected, and the yield is 54.5%; the total yield of the high-purity tannic acid is 14.2 kg, the yield is 7.1 percent, and the purity is more than 88 percent.

The above operation may be performed by appropriately supplying pure water according to the circumstances.

Example 3, this example provides an environment-friendly and water-saving method for preparing acorn powder and refined tannic acid by membrane filtration separation:

it is to be noted that the method belongs to a batch production process.

Firstly, a container for containing acorn kernels is provided with a self-made 10-mesh filter screen, and the filter screen and a conveyor belt are fixed together for standby.

And (2) loading 300D nanofiltration membranes and 1812 membrane elements into an organic membrane separation production experiment machine CINTANG-GM-24H equipment 1, testing the pure water flux at 0.4MPa and 25 ℃ to be 1600L/H, draining the pure water, and constructing a membrane forming filtration system I for later use.

And (3) loading RO5 nanofiltration membranes and 1812 membrane elements into an organic membrane separation experiment machine CINTANG-GM-24H equipment 2, testing the pure water flux to be 1000L/H at 0.4MPa and 25 ℃, draining the pure water, and constructing a membrane forming filtration system II for later use.

Removing impurities from dried acorns, removing shells, selecting acorn kernels, putting into a container for 200 kg, filling pure water (about 1000L), and heating to 45 ℃ for later use.

In the technical scheme provided by the invention, nanofiltration membranes within the range of 100D-1000D (D is molecular weight unit Dalton) and the range are feasible, and only in the embodiment, a 300D nanofiltration membrane and a RO5 nanofiltration membrane are matched for use.

The above steps constitute the completion of the previous preparation.

After soaking for 30 minutes, starting a temperature control circulating device, controlling the filtering temperature to be 45 ℃, and starting a filter screen, a filtering system I, a mother liquor I circulation, a filtering system II, a filtrate II circulation mother liquor II circulation and a water injection valve. The filtrate I cycle was closed.

And starting a discharge port of the mother liquor I when the concentration of the circulating liquor of the mother liquor I is not changed any more.

The filtering pressure of the filtering system I is controlled to be 2.5MPa by adjusting the pressure regulating valve, and the filtering flux is 20.0L/(H.m)²) (ii) a The filtering pressure of the filtering system II is controlled to be 2.5MPa by adjusting the pressure regulating valve, and the filtering flux is 30.0L/(H.m)²) (ii) a The water adding speed after the whole system is stable is the same as the discharging speed of the enrichment liquid of the mother liquid I.

In the process, the mother liquor II circulating liquid is saturated, then the temperature is reduced for recrystallization, and tannic acid is obtained by filtration and separation.

The circulating filtration process is continued until no precipitate is separated out from the circulating liquid of the mother liquid II; or stopping circulation when the content of tannic acid in the filtrate I is less than 0.001%, or stopping circulation when the content of tannic acid in the acorn is less than 0.01% by sampling detection.

Directly pulverizing the processed acorn kernels, precipitating, removing supernatant and suspended substances (which can be used as the next production or combined with the mother liquor I enriched solution), and filtering and precipitating with a bag filter to obtain acorn starch.

According to the method, oak nuts are selected from quercus acutissima produced in mountain of Henan Funiu, 92.5 kg of acorn starch is selected, and the yield is 46.3%; the total yield of the high-purity tannic acid is 14.0 kg, the yield is 7.0 percent, and the purity is more than 89 percent.

The above operation may be performed by appropriately supplying pure water according to the circumstances.

The above description is only a preferred embodiment of the present invention, and not intended to limit the present invention in other forms, and any person skilled in the art may apply the above modifications or changes to the equivalent embodiments with equivalent changes, without departing from the technical spirit of the present invention, and any simple modification, equivalent change and change made to the above embodiments according to the technical spirit of the present invention still belong to the protection scope of the technical spirit of the present invention.