CN112279886A

CN112279886A - Method for improving foaming performance of protein isolate of jackfruit seeds by high-pressure steam assisted high-intensity ultrasound

Info

Publication number: CN112279886A
Application number: CN202011010228.0A
Authority: CN
Inventors: 钟俊桢; 周若楠; 周磊; 刘伟; 刘成梅
Original assignee: Nanchang University
Current assignee: Nanchang University
Priority date: 2020-09-23
Filing date: 2020-09-23
Publication date: 2021-01-29

Abstract

The invention discloses a method for improving the foaming performance of jack fruit seed protein isolate. The method comprises the following steps: (1) preparing jack fruit seed protein isolate: crushing, drying and degreasing the jack fruit seeds, adjusting the pH value to 10 by using 1M NaOH, taking supernatant, adjusting the pH value to 4.3 by using 1M HCl, collecting precipitate, dialyzing for 24h, drying the precipitate for 48h to obtain jack fruit seed protein isolate powder (2), treating the jack fruit seed protein isolate solution by using high-pressure steam for 20-40min, rapidly cooling the jack fruit seed protein isolate solution to room temperature in an ice-water bath, and ultrasonically treating the protein solution under the condition of the ice-water bath at the power of 600-1000W for 10-30 min. (4) The protein solution is dried again to obtain the final required protein sample. The experiment found that the foaming capacity of the protein after treatment was increased by 64%. The method is a physical method, and has low processing cost and good safety. The raw materials have wide sources and are easy to popularize.

Description

Method for improving foaming performance of protein isolate of jackfruit seeds by high-pressure steam assisted high-intensity ultrasound

Technical Field

The invention relates to the field of protein foaming performance, in particular to a method for improving the foaming performance of protein separated from jack fruit seeds.

Background

Jackfruit (Artocarpus heterophyllus Lam.) is a normally green arbor belonging to the family of Moraceae, is a typical tropical fruit tree and is known as "tropical fruit queen". In China, the plants mainly grow in tropical and subtropical regions such as Guangdong, Hainan, Guangxi, Fujian and Yunnan (south). The jack fruit seeds are rich in starch and high in protein content, and account for about 20% of the total amount.

Protein is one of the most important nutrients in plants and has been widely studied and used in the food industry. In addition, vegetable proteins are inexpensive and readily available, can replace expensive animal proteins, and have become the primary source of dietary protein in many developing countries. The functional properties of proteins determine the extent of their use in food processing, and the functional properties of vegetable proteins, such as foaming, solubility, emulsifying, gelling, etc., affect the texture and organoleptic properties of the food product.

Foaming is one of the important functional properties of protein, and the foaming agent can be added into food to enable the structure of the food to be fluffy and improve the overall performance of the food. The foaming properties of proteins play a non-negligible role in the food industry, such as some baking, confectionery, desserts and beer. Compared with the foamability of soybean protein, the foamability of the protein isolated from the jack fruit seeds is still in a certain gap, and the application of the jack fruit seeds in the food industry is limited. Therefore, the foamability of the protein isolate of the jack fruit seeds is improved, and the application of the jack fruit seed protein isolate in the food industry is expanded.

Currently, there are many methods for improving protein foaming, and chemical modification may generate or introduce toxic substances or substances affecting food flavor. Enzymatic modification can cause proteins to generate bitter peptides in an enzymolysis process. The physical modification has small loss of the nutritional value of the protein, short time and good safety.

Disclosure of Invention

In order to solve the problems, the invention aims to provide a method for remarkably improving the foaming performance of protein isolate of jack fruit seeds

The above purpose of the invention is realized by the following technical scheme:

a method for remarkably improving the foaming performance of protein isolate from jack fruit seeds comprises the following steps:

crushing jack fruit seeds, carrying out ventilation drying for 1-3 days, sieving, carrying out degreasing for 1-2 times, and carrying out ventilation drying for 12-24 hours to obtain degreased powder;

dissolving the defatted powder in deionized water, adjusting pH to 10 with 1M NaOH, stirring at room temperature for 1-2 hr, centrifuging at 4800rpm for 25-30min, and collecting supernatant;

adjusting pH to 4.3 with 1M HCl, precipitating at 4 deg.C for 2-3 hr, centrifuging at 4800rpm for 25-30min, collecting precipitate, dialyzing for 24 hr, and drying for 48 hr to obtain protein isolated from Jack fruit seed;

dissolving the protein separated from the jack fruit seeds in deionized water at a concentration of 4-7% (v/w), adjusting the pH value to 9 with 1M NaOH, and stirring at room temperature for 1-2h to obtain a protein solution;

performing high-pressure steam treatment on the obtained protein solution for 20-40min, and rapidly cooling to room temperature in an ice water bath;

carrying out ultrasonic treatment on the obtained protein solution under the ice-water bath condition (changing ice water every 10-15 min), wherein the power is 600- & ltwbr/& gt, the time is 10-30min, and drying the obtained sample again to obtain the final required protein sample;

when in use, a protein sample is dissolved in deionized water at 15-25mg/ml, the pH is adjusted to 9 by 1M NaOH, the mixture is stirred for 1-2h at room temperature, 15-25ml of protein liquid is taken and put into a 50ml graduated cylinder, and the mixture is stirred at high speed by a dispersion machine; then, the foamability was measured;

further, the disperser during stirring is a high-speed disperser T25 digital ULTRA-TURRAX, the stirring speed is 15000-.

The invention has the beneficial effects that:

according to the method for improving the foaming property of the jack fruit seed protein isolate, provided by the invention, the jack fruit seed protein isolate is subjected to high-intensity ultrasonic treatment under the assistance of high-pressure steam, so that the foaming property of the protein is obviously improved.

Drawings

FIG. 1 is a graph showing the effect of high pressure steam assisted high intensity ultrasound on protein foaming in an embodiment of the present invention: (A) separating protein from jackfruit seeds; (B) jack fruit seed protein isolate after high-pressure steam and high-intensity ultrasonic treatment

Detailed Description

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Example 1

(1) Crushing jack fruit seeds, carrying out ventilation drying for 1-3 days, sieving, carrying out degreasing for 1-2 times, and carrying out ventilation drying for 12-24 hours to obtain degreased powder;

(2) dissolving the defatted powder in deionized water, adjusting pH to 10 with 1M NaOH, stirring at room temperature for 1-2 hr, centrifuging at 4800rpm for 25-30min, and collecting supernatant.

(3) Adjusting pH to 4.3 with 1M HCl, precipitating at 4 deg.C for 2-3 hr, centrifuging at 4800rpm for 25-30min, collecting precipitate, dialyzing for 24 hr, and drying for 48 hr to obtain protein isolate from Jack fruit seed.

(4) Dissolving a protein sample in deionized water at 15-25mg/ml, adjusting pH to 9 with 1M NaOH, stirring at room temperature for 1-2h, placing 15-25ml of protein liquid into a 50ml graduated cylinder, stirring with a high-speed dispersion machine at 15000-20000rpm/min for 1-2min, and measuring foaming property at 2 min.

The foamability of the jack fruit seed protein isolate is 150.42% through testing.

Example 2

(1) Crushing jack fruit seeds, carrying out ventilation drying for 1-3 days, sieving, degreasing for 1-2 times, and carrying out ventilation drying for 12-24 hours to obtain degreased powder;

(4) Dissolving jack fruit seed protein isolate in deionized water at 4-7% (v/w), stirring at room temperature for 1-2h, subjecting the uniformly stirred protein solution to high-pressure steam treatment for 20-40min, and rapidly cooling to room temperature by using ice water bath.

(5) And (3) treating the protein liquid by using ultrasonic, performing ultrasonic treatment under the ice water bath condition (changing ice water every 10-15 min) with the ultrasonic power of 600- & ltSUB & gt for 1000- & ltSUB & gt, and performing drying treatment on the treated protein liquid for 10-30min to obtain the finally required protein sample.

(6) Dissolving a protein sample in deionized water at 15-25mg/ml, adjusting pH to 9 with 1M NaOH, stirring at room temperature for 1-2h, placing 15-25ml of protein liquid into a 50ml graduated cylinder, stirring with a high-speed dispersion machine at 15000-20000rpm for 1-2min, and measuring foaming property at 2 min.

The foamability of the jack fruit seed protein isolate is 238.35% through testing.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. The present invention is not to be limited by the specific embodiments disclosed herein, and other embodiments that fall within the scope of the claims of the present application are intended to be within the scope of the present invention.

Claims

1. A method for improving the foaming performance of protein isolate of jack fruit seeds by high-pressure steam assisted high-intensity ultrasound is characterized by comprising the following steps:

s1: crushing jack fruit seeds, drying, sieving, degreasing, and carrying out ventilation drying for 12-24h to obtain degreased powder;

s2: dissolving the degreased powder in deionized water, adjusting the pH value to 10 by using 1M NaOH, stirring at room temperature, centrifuging and collecting supernate;

s3: adjusting the pH value to 4.3 by using 1M HCl, precipitating, centrifuging and collecting the precipitate;

s4: dialyzing, and drying the precipitate for 48h to obtain jackfruit seed protein isolate;

s5: dissolving jack fruit seed protein isolate in deionized water at a ratio of 4-7% (v/w), stirring at room temperature for 1-2h, performing high-pressure steam treatment on the uniformly stirred protein solution for 20-40min, and rapidly cooling to room temperature in an ice-water bath;

s6: treating the protein liquid by ultrasonic, wherein the ultrasonic power is 600-;

s7: dissolving the protein sample in deionized water, adjusting pH to 9 with 1M NaOH, stirring at room temperature for 1-2h, placing 15-25ml of protein liquid into a 50ml graduated cylinder, stirring with a high-speed disperser at 15000-20000rpm for 1-2min, and measuring foamability at 2 min.

2. The method for improving the foaming performance of the protein isolate of the jack fruit seeds by the high-pressure steam assisted high-intensity ultrasound according to claim 1, wherein the method comprises the following steps:

ventilating for 1-3 days when drying in the S1; defatting is carried out 1-2 times.

3. The method for improving the foaming performance of the protein isolate of the jack fruit seeds by the high-pressure steam assisted high-intensity ultrasound according to claim 1, wherein the method comprises the following steps:

and in the S2, stirring time is 1-2h at room temperature, the rotating speed is 4800rpm during centrifugation, and the centrifugation time is 25-30 min.

4. The method for improving the foaming performance of the protein isolate of the jack fruit seeds by the high-pressure steam assisted high-intensity ultrasound according to claim 1, wherein the method comprises the following steps:

and the precipitation in the S3 is carried out at the temperature of 4 ℃, the precipitation time is 2-3h, the rotating speed is 4800rpm during centrifugation, and the centrifugation time is 25-30 min.

5. The method for improving the foaming performance of the protein isolate of the jack fruit seeds by the high-pressure steam assisted high-intensity ultrasound according to claim 1, wherein the method comprises the following steps:

the dialysis time in S4 was 24 h.

6. The method for improving the foaming performance of the protein isolate of the jack fruit seeds by the high-pressure steam assisted high-intensity ultrasound according to claim 1, wherein the method comprises the following steps:

the ice water in the S6 under the ice bath condition needs to be replaced every 10-15 min.

7. The method for improving the foaming performance of the protein isolate of the jack fruit seeds by the high-pressure steam assisted high-intensity ultrasound according to claim 1, wherein the method comprises the following steps:

the concentration of the protein dissolved in the deionized water in the S7 is 15-25 mg/ml.