Investigation of Enzymatic Hydrolysis Kinetics of Soy Protein Isolate: Laboratory And Semi-Industrial Scale

Soy protein isolate is a worthy substitute for meat protein. However, its low level of digestibility limits its spread to new market niches. This problem can be solved by enzymatic hydrolysis of soy protein to peptides. Several research teams have already been solving this problem, but their results were obtained under laboratory conditions and do not provide information about the reproducibility of the results on an industrial scale. In this paper, we have compared the results of laboratory and semi-industrial experiments of enzymatic hydrolysis of protein. Also the kinetics of the reaction under different conditions is shown, and the final product is characterized. The obtained results of semi-industrial experiments can form the basis of industrial regulations for the production of soy protein hydrolysate as an easily digestible form of dietary protein for athletes and patients with digestive disorders.

Increasing Intestinal Soy Protein Hydrolysate Levels Promotes Colon Inflammation By Affecting Microbial Metabolism and Increases the Protein Expression of Colonic Tight Junction Proteins

Background Increasing intestinal protein levels change the colonic microbial community and metabolic profile of pigs, but the effect of this on colonic inflammation and barrier function in growing pigs remains unclear. Results Sixteen pigs (35.2 ± 0.3 kg) were infused with sterile saline (control) or soy protein hydrolysate (SPH) (70 g/day) through a duodenal fistula twice daily during a 15-day experimental period. The SPH treatment did not affect their average daily feed intake and daily weight gain (P > 0.05), but reduced colon index and length (P < 0.05). Illumina MiSeq sequencing revealed that species richness was increased following SPH intervention (P < 0.05). Furthermore, SPH reduced the abundance of butyrate- and propionate-producing bacteria—such as Lachnospiraceae NK4A136 group, Lachnospiraceae_uncultured, Coprococcus 3 Lachnospiraceae UCG-002, and Anaerovibrio—and increased the abundance of potentially pathogenic bacteria and protein-fermenting bacteria, such as Escherichia-Shigella, Dialister, Veillonella, Prevotella, Candidatus Saccharimonas, Erysipelotrichaceae UCG-006, Prevotellaceae_uncultured, and Prevotellaceae UCG-003 (P < 0.05). In addition, a lower content of total short-chain fatty acids, propionate, and butyrate and a higher concentration of cadaverine, putrescine, total biogenic amines, ammonia, and isovalerate were observed following SPH infusion (P < 0.05). Further analysis revealed that SPH increased the concentration of tumour necrosis factor-α, interleukin (IL)-1β, IL-6, and IL-8 in the colonic mucosa (P < 0.05). Interestingly, SPH intervention increased the expression of occluding, zonula occludens (ZO)-1, and claudin-1 in colonic mucosa (P < 0.05). Correlation analysis showed that different genera were significantly related to the production of metabolites and the concentrations of pro-inflammatory cytokines. Conclusion Overall, increasing intestinal soy protein levels altered the colonic microbial composition and metabolic profile, which may lead to colon inflammation and may also strengthen the colon barrier function.

Study of the antihypertensive peptide from soy protein hydrolysate produced by steam blasting treatment

The purpose of this study was to determine the effect of steam blasting on soybeans and to evaluate the soy protein hydrolysate (SPH) resulting from steam blasting on ace inhibitory activity. Steam blasting works on the principle of heat and pressure. The research conducted begins with a process of pressure treatment and the heating time of soybeans. The pressures used were 2, 3 and 5 bar with heating time (hydrolysis) of 10, 20, 30, 40, 50 and 60 min for each pressure. Furthermore, the soybean resulting from steam blasting was analyzed for the degree of hydrolysis (DH), dissolved protein concentration, protein profile, and also its fractions. Then the ace inhibitory activity was performed on the SPH fraction. The results showed that the higher the pressure and the longer the heating time, the soybean colour from the steam blasting would turn dark brown due to the Maillard reaction. The value of % DH and protein solubility increase with a higher pressure. The % DH values ranged from 76 - 96%. The steam blasting process for soybeans also eliminates anti-nutritional properties and off-flavour compounds in soybeans and cuts protein into peptides/polypeptides. The fractionation results showed that the SPH fraction produced from the soybean steam blasting process had the highest ace inhibitory activity value of 68%, produced by the SPH fraction of 2 bar of 40 min steam blasting treatment. The SPH produced from the steam blasting process can potentially be a source of protein/peptides that can lower blood pressure (hypertension).

HEMATOLOGICAL AND BIOCHEMICAL INDICATORS OF BLOOD IN LINGER CHICKEN WHEN USING A FODDER ADDITIVE OF VEGETABLE ORIGIN

The article presents the results of the use of soy protein hydrolysate in combination with vitamins and microelements «Abiotonic» on laying hens of the cross «Hayseks brown» at the rate of 1 ml/kg of live weight. In order to determine the efficiency of the feed additive, indicators of the clinical status of birds were studied, biochemical and clinical blood tests were carried out. It was found that the feed additive «Abiotonic» in a dose of 1 ml/kg of live weight of hens does not have a negative effect on the physiological indicators of birds. The results of blood tests make it possible to talk about a reliable stimulating effect of feed additives on the metabolic processes, increasing the indicators characterizing hematopoiesis. Accordingly, the feed additive «Abiotonic» can be recommended for use in birds during the period of active growth and development of the organism.