Characterization and biological properties of peptides isolated from dried fermented cow milk products by RP‐HPLC: Amino acid composition, antioxidant, antihypertensive, and antidiabetic properties

Aim. To demonstrate the high adaptive abilities of dairy cattle to various ecosystems and natural zones of the Lower Volga at different times of the year. For the study we selected farms located in the steppe and semi-desert natural zones of the Volgograd region where animals of different breeds are reared.Material and Methods. Analysis was undertaken of the main indicators of raw milk quality, amino acid composition and environmental safety. Animals of all farms studied showed fairly high indicators of milk productivity in the climatic conditions of the Volgograd region, according to the standards of the breeds investigated.Results. The content of essential amino acids in cow milk for all groups varied depending on the breed and period of the year, generally reaching maximum values in winter. The calculation of amino acid scores showed that lysine is a limiting amino acid in animals of the Holstein-Friesian breed in the summer and autumn periods of lactation. The determination of chemical elements in milk during the summer period of lactation showed that all indicators are within acceptable concentrations, including heavy metals (lead, arsenic, cadmium, mercury).Conclusion. The research conducted confirms compliance of raw milk with standards in all farms studied for the main controlled indicators of quality and amino acid composition, content of chemical elements and allows recommendation of the milk produced for the production of all types of dairy and fermented milk products.

Download Full-text

The effect of starter on amino acid composition of fermented milk

Proceedings of the Voronezh State University of Engineering Technologies ◽

10.20914/2310-1202-2021-1-258-262 ◽

2021 ◽

Vol 83 (1) ◽

pp. 258-262

Author(s):

T. N. Zandanova ◽

K. V. Ivanova ◽

T. P. Myryuanova

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Amino Acid Composition ◽

Acid Composition ◽

Microbial Consortium ◽

Essential Amino Acids ◽

Fermented Milk ◽

Lactobacillus Bulgaricus ◽

Cow Milk ◽

Mixed Fermentation

The experimental studies of the amino acid composition of the skimmed cow milk fermented with kefir corns, natural kurunga symbiotic starter and bacterial concentrate of the microbial consortium (BСMC) have been carried out. The bacterial concentrate of the microbial consortium is intended for the preparation of a fermented milk beverage of mixed fermentation – kurunga. The microbial consortium obtained by autoselection of population of kefir corn starter and thermophilic lactobacteriums Lactobacillus bulgaricus and Lactobacillus acidophilum has been used to prepare BCMC. The amino acid analysis of the samples has been carried out by IC method with postcolumn derivatization of amino acids ninhydrin in the acid hydrolyzate of the sample on INGOSAAA-400 amino acid analyzer. The most of essential amino acids has been found in kefir – 434 mg/g of protein. In the samples prepared with natural starter and bacterial concentrate, the total amount of essential amino acids has been 401.84 and 403.8 mg/g of protein, respectively. Exogenous amino acids are essential for the growth of lactics and yeast. The difference in the total amount of the essential amino acids in the samples, probably, caused by the proteolytic activity of the starters and the growth requirements of the microorganisms. The assessment of the bioavailability has been carried out by the method of I.A. Rogov and N.N. Lipatov according to the coefficients of differences between the amino-acid score (CDAS) and bioavailability. The amino-acid scoring studies have shown that the protein in the studied samples is characterized by a complete composition. According to bioavailability, the kurunga samples exceeded kefir by 0.55-0.75%. The obtained results indicate that according to the biochemical activity, the bacterial concentrate of the microbial consortium is practically identical to kurunga prepared with natural starter. It makes possible to obtain a product bioavailably identical to a traditional beverage.

Download Full-text

BioNet: Peptide Mass-Spectrum Prediction

Vestnik NSU Series Information Technologies ◽

10.25205/1818-7900-2020-18-2-31-42 ◽

2020 ◽

Vol 18 (2) ◽

pp. 31-42

Author(s):

Rostislav Yu. Epifanov ◽

Dmitry A. Afonnikov

Keyword(s):

Amino Acid ◽

Amino Acid Composition ◽

Acid Composition ◽

Mass Spectroscopy ◽

Posttranslational Modifications ◽

Mass Spectra ◽

Biological Properties ◽

Peptide Fragmentation ◽

Spectrum Prediction ◽

Peptide Mass

The importance of the biological properties of proteins to cells cause actively exploring their amino acid composition (primary structure). The versatile tool of cell proteome exploring is mass-spectroscopy. The interpretation of massspectroscopy data is complex challenge because it remains uncertain peptide dissociation mechanisms and external factor influence to peptide fragmentation process. Moreover, a lot of mass-spectroscopy data is required to enhancement existing or development novel algorithms to interpret peptide mass-spectra. The article describes development of algorithm for in silico generation peptide mass-spectra covered the problem of influence noncanonical amino acid composition and posttranslational modifications to dissociation process. Developed algorithm was compared with analogues and evaluated over experimental data.

Download Full-text