Digestion Absorption And Structure Identification Of Soybean Protein-Isoflavone Complex

Soybean(Glycine max(Linn.)Merr.)is a traditional oil crop in China.Soybean meal after oil extraction is often sold directly as feed,with low added value.Soybean meal retains major nutrients other than oil,such as protein,carbohydrates,and small-molecule soy isoflavones.The flavonoids are mainly produced by the secondary metabolism of plants,have anti-cancer,anti-tumor,osteoporosis and other effects,but the digestion and absorption effect in the human body is poor.In order to better protect soybean isoflavones from being destroyed in the body and increase the digestion and absorption rate of active substances,different extraction methods were used to extract protein and soybean isoflavones from soybean meal,and the complexes were used for simulated digestion to determine the time after different digestion time.Release of isoflavones and analysis of proteins in crude extracts.The aim is to lay the research foundation for the deep processing and further utilization of soybean meal.The main findings of this article are as follows:1.High and low temperature soybean meal was extracted with acid precipitation,ultrasonic assisted extraction,and microwave-assisted extraction to obtain different crude extracts.The contents of crude protein,7s protein and fat in the crude extract of low-temperature soybean meal were higher,and the polysaccharide content of the crude extract obtained by the alkali extraction and precipitation method was higher than that obtained by the other two extraction methods.1.43%;the content of isoflavones in the crude extract of high-temperature soybean meal was higher than that in the crude extract of low-temperature soybean meal.The content of isoflavones in the crude extract obtained by ultrasonic-assisted treatment was 0.41 mg/g,and the use of alkali-extracted acids was achieved.The soy isoflavone content in the crude extract of low temperature soybean meal obtained by Shen method was only 0.29 mg/g.The determination of the content of basic substances in the crude extract of soybean meal provided a certain basis for the subsequent simulation of digestion and protein analysis.2.After gastrointestinal joint digestion experiments,it was found that as the digestion time prolonged,the isoflavones in the digestive juice were increased.By combining with the results of simulated gastric digestion,the best preparation conditions for protecting soybean isoflavones were obtained.It was found that the content of isoflavones in the digestive juice was higher than that of the digestive solution of the crude extract of the low temperature soybean meal after digestive gastrointestinal tract digestive digestion for 8 hours.By analyzing the protein in different crude extracts,the crude extract of high temperature soybean meal was rough under the scanning electron microscope,and the surface of the low temperature soybean meal was smooth;after SDS-PAGE electrophoresis,the positions of the protein bands of different crude extracts were not obvious.Differences,but the protein abundance difference is quite large;after Label-free experiment,high-level soybean meal using ultrasonic and microwave-assisted extraction of crude extract,the protein types are similar,the use of ultrasound-assisted treatment of high and low temperature soybean protein species are similar,and The microwave-assisted extraction of high-and low-temperature soybean protein extracts varied greatly.By comparing the content of soy isoflavones in the digestive juices and the protein content between different crude extracts,it was found that the same kind of soybean meal was obtained by different extraction methods.The crude extracts,compared with each other,the more types of protein increase,after simulated digestion,the higher the content of soy isoflavones in the solution.