阅读说明：本技术 一种马铃薯胰蛋白酶抑制剂的提取工艺 (Extraction process of potato trypsin inhibitor ) 是由 吴常忠 于 2019-11-08 设计创作，主要内容包括：本发明公开了一种马铃薯胰蛋白酶抑制剂的提取工艺,包括如下步骤：第一步,淀粉提取；第二步,泡沫分离工艺；第三步,消泡工艺；第四步,分离过滤工艺；第五步,胰蛋白酶抑制剂活性测定；第六步,马铃薯淀粉制备。本发明属于蛋白酶抑制剂提取技术领域,具体是提供了一种实用性高、将泡沫分离工艺与传统马铃薯淀粉生产工艺相结合,高效简单的提取马铃薯中的胰蛋白酶抑制剂,大大改进了马铃薯蛋白的生产工艺,有效保留了马铃薯蛋白的生物活性,提高马铃薯蛋白的产品价值进而提高马铃薯加工产品的总价值,降低马铃薯加工废液中的化学需氧量COD,减少对环境的污染,促进马铃薯产业的发展的马铃薯胰蛋白酶抑制剂的提取工艺。(The invention discloses an extraction process of a potato trypsin inhibitor, which comprises the following steps: firstly, extracting starch; secondly, a foam separation process; step three, defoaming process; fourthly, separating and filtering; fifthly, measuring the activity of trypsin inhibitor; and sixthly, preparing potato starch. The invention belongs to the technical field of protease inhibitor extraction, and particularly provides a potato trypsin inhibitor extraction process which is high in practicability, combines a foam separation process with a traditional potato starch production process, efficiently and simply extracts a trypsin inhibitor in potatoes, greatly improves the production process of potato protein, effectively retains the biological activity of the potato protein, improves the product value of the potato protein, further improves the total value of processed potato products, reduces the Chemical Oxygen Demand (COD) in waste potato processing liquid, reduces the pollution to the environment, and promotes the development of the potato industry.)

1. A process for extracting potato trypsin inhibitor is characterized by comprising the following steps:

first, starch extraction

Washing the potato raw material to remove stones, then carrying out secondary washing, crushing the washed potatoes, adding water and stirring to obtain a starch extracting solution;

second, foam separation Process

Extracting potato protein from the starch extract obtained in the first step as a feed for foam separation, wherein the parameters of the foam separation are as follows: the temperature is 20-50 ℃, the pH is 6.0-8.0, and the air flow is 9m³/h-20m³/h；

Thirdly, defoaming process

Collecting foam, and defoaming by using a polyether defoamer as a defoamer, wherein the temperature of the defoamer is 20-40 ℃ to obtain a potato protein extract separation liquid;

the fourth step, separation filtration process

Filtering the potato protein extract separation liquid by a filter medium to obtain supernatant, adding an alkaline solution with the pH value of more than 8 into the supernatant for alkali precipitation, then removing the precipitate, taking the supernatant, carrying out centrifugal separation on the supernatant at the rotating speed of 5000-9000 rpm, taking the precipitate, removing the supernatant to obtain a modified potato protein extract, putting the modified potato protein extract into an acidic renaturation buffer solution for renaturation, and carrying out vacuum freeze-drying at the temperature of-10-50 ℃ and under the pressure of 1.3-13 Pa to obtain freeze-dried potato protein;

fifth step, determination of Trypsin inhibitor Activity

Adding substrate solution into two quartz cuvettes, respectively, adding 0.1-0.5mL of 1-5 × 10^{- 3}Taking a mol/L HCl solution as a blank, and adjusting zero at the wavelength of 200-300 nm; adding 0.1-0.5mL of trypsin solution and 0.1-0.5mL of 1-5X 10 solution into another cuvette^-3mixing with HCl solution of mol/L, and reading every 10-20s until the absorbance is up toThe lyophilized potato protein of the fourth step is admixed with 0.1-0.5mL of 1-5X 10^-3Preparing 5-20g/L of inhibitor solution from mol/L of HCl solution, replacing the HCl solution in the step of measuring the activity of trypsin with the inhibitor solution, and representing the activity of the inhibitor by using the change of the activity of the trypsin;

sixth step, potato starch preparation

And (3) preparing the potato starch from the starch extracting solution subjected to foam separation in the first step according to a normal starch extracting process.

2. The process of claim 1, wherein the pH of the foam separation in the second step is 6.5-7.5.

3. The process for extracting potato trypsin inhibitor according to claim 1, wherein the filter medium in the fourth step is polypropylene plate-and-frame filter cloth.

4. The process for extracting potato trypsin inhibitor according to claim 1, wherein the alkaline solution in the fourth step is NaOH solution.

5. The process for extracting potato trypsin inhibitor according to claim 1, wherein the acidic renaturation buffer solution in the fourth step is hydrochloric acid.

Technical Field

The invention belongs to the technical field of protease inhibitor extraction, and particularly relates to a process for extracting a potato trypsin inhibitor.

Background

Potatoes are one of the important crops, are mainly used for producing starch at present, and a large amount of waste water is generated in the process of producing starch from potatoes. As the starch wastewater contains organic matters such as protein, soluble starch and the like, the chemical oxygen demand COD in the starch wastewater is up to 20000 mg/L. If a large amount of starch wastewater is directly discharged, the environment is greatly harmed, in addition, the potato protein contains various amino acids necessary for human bodies, the nutritional value of the potato protein is superior to that of animal protein, the soluble starch is widely applied to the fields of food, chemistry and the like, and the direct discharge of the starch wastewater causes a large amount of waste of valuable organic matters.

Trypsin inhibitors are small molecular polypeptides capable of inhibiting the hydrolytic activity of trypsin, have antiviral, antitumor, antifungal and other activities, and are widely present in plants, animals and microorganisms. The potato protease inhibitor in the potato protein has a plurality of potential application values, can improve the content of cholecystokinin in plasma, can delay gastric emptying, controls the blood sugar concentration of a human body, and reduces food intake through satiety so as to achieve the effect of losing weight. The potato tuber juice contains more than 50% of soluble protein by the content of various protein protease inhibitors. The production process of the potato protein usually needs high-temperature treatment, which leads to protein denaturation and inactivation, and greatly reduces the product value of the potato protein.

Disclosure of Invention

In order to solve the existing problems, the invention provides the extraction process which is high in practicability and simple in operation, combines the foam separation process with the traditional potato starch production process, efficiently and simply extracts the trypsin inhibitor in the potatoes, greatly improves the production process of the potato protein, effectively retains the biological activity of the potato protein, improves the product value of the potato protein and further improves the total value of processed potato products, and meanwhile, reduces the Chemical Oxygen Demand (COD) in the waste potato processing liquid, reduces the environmental pollution, and promotes the development of the potato industry, and is suitable for the potato trypsin inhibitor.

The technical scheme adopted by the invention is as follows: the invention relates to an extraction process of a potato trypsin inhibitor, which comprises the following steps:

first, starch extraction

Washing the potato raw material to remove stones, then carrying out secondary washing, crushing the washed potatoes, adding water and stirring to obtain a starch extracting solution;

second, foam separation Process

Extracting potato protein from the starch extract obtained in the first step as a feed for foam separation, wherein the parameters of the foam separation are as follows: the temperature is 20-50 ℃, the pH is 6.0-8.0, and the air flow is 9m³/h-20m³/h；

Thirdly, defoaming process

Collecting foam, and defoaming by using a polyether defoamer as a defoamer, wherein the temperature of the defoamer is 20-40 ℃ to obtain a potato protein extract separation liquid;

the fourth step, separation filtration process

Filtering the potato protein extract separation liquid by a filter medium to obtain supernatant, adding an alkaline solution with the pH value of more than 8 into the supernatant for alkali precipitation, then removing the precipitate, taking the supernatant, carrying out centrifugal separation on the supernatant at the rotating speed of 5000-9000 rpm, taking the precipitate, removing the supernatant to obtain a modified potato protein extract, putting the modified potato protein extract into an acidic renaturation buffer solution for renaturation, and carrying out vacuum freeze-drying at the temperature of-10-50 ℃ and under the pressure of 1.3-13 Pa to obtain freeze-dried potato protein;

fifth step, determination of Trypsin inhibitor Activity

Adding substrate solution into two quartz cuvettes, respectively, adding 0.1-0.5mL of 1-5 × 10^-3Taking a mol/L HCl solution as a blank, and adjusting zero at the wavelength of 200-300 nm; adding 0.1-0.5mL of trypsin solution and 0.1-0.5mL of 1-5X 10 solution into another cuvette^-3mixing with HCl solution of mol/L, reading every 10-20s until the absorbance does not change basically, mixing the lyophilized potato protein obtained in the fourth step with 0.1-0.5mL of 1-5 × 10^-3Preparing 5-20g/L inhibitor solution from mol/L HCl solution, replacing HCl solution in trypsin activity determination step with inhibitor solution, and changing trypsin activityCharacterization of inhibitory properties;

sixth step, potato starch preparation

And (3) preparing the potato starch from the starch extracting solution subjected to foam separation in the first step according to a normal starch extracting process.

Preferably, the pH of the foam separation in the second step is 6.5-7.5.

Further, the filter medium in the fourth step may be a filter cloth or a ceramic membrane, and preferably, the filter medium is a polypropylene plate frame filter cloth.

Further, the alkaline solution in the fourth step can be NaOH solution or NaCO solution₃Solution, preferably, the alkaline solution is a NaOH solution.

Further, the acidic renaturation buffer solution in the fourth step can be sulfuric acid and hydrochloric acid, and preferably, the acidic renaturation buffer solution is hydrochloric acid.

The invention with the structure has the following beneficial effects: the extraction process of the potato trypsin inhibitor has the advantages of simple structure, reasonable design, low cost, simple and convenient operation, good dissolubility, foamability, emulsibility, water holding capacity and viscoelasticity of potato protein, low investment, low energy consumption and simple operation, can separate or concentrate surface active substances from an extremely thin solution by a foam separation method, combines the foam separation process with the traditional potato starch production process, greatly improves the production process of the potato protein, evaluates the effect of the trypsin inhibitor by using the change of the activity of the trypsin, confirms that the extracted protein has the inhibition effect on the trypsin, retains the biological activity of the potato protein, improves the product value of the potato protein so as to improve the total value of processed products of the potatoes, greatly reduces the COD of waste potato processing liquid, reduces the pollution to the environment, promoting the development of the potato industry.

Drawings

FIG. 1 is a schematic view of the process of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.