[Functional food ingredient - chromium complex with protein fermentolysate of bivalve Mactra chinensis for the prevention of hyperlipidemia and obesity].

The creation of specialized food systems capable of correcting body weight and influencing lipid metabolism is an urgent task at the present stage. The main way to create such food systems is to modify product profiles (lipid, protein, carbohydrate, mineral, vitamin, etc.). The aim of the study was to obtain and characterize a new food source of an organic form of chromium for the prevention of hyperlipidemia and obesity in the form of a complex with peptide fractions of fermentolysate proteins of the Mactra chinensis bivalve mollusk from the Far Eastern region. Material and methods. Soft food parts of the Mactra chinensis bivalve mollusk from the Far Eastern region (the motor muscle and mantle) were used as objects of research. Mollusk specimens were collected in the Amur Bay in June - September 2022. Biotechnological modification of soft tissue proteins was carried out using alkaline protease protozyme B with the following parameters: the duration of the process - 12 and 24 hours, pH - 7.0-7.2, temperature 55 °C. The fractional composition of proteins and peptides was determined by medium pressure gel permeation chromatography, the molecular weight (MW) of proteins and peptides was calculated using MW markers by comparing retention volumes. Extraction of free amino acids was carried out with 70% ethanol for 24 hours at a temperature of 20 °C, the composition and quantitative content of amino acids were determined by HPLC. The complexation reaction was carried out by adding to the fermentolysate with stirring a 10% aqueous solution of CrCl3×6H2O in a mass ratio of 6.25 × nitrogen in the liquid fraction : chromium (III) chloride = 20:1. Process conditions: temperature 20-25 °C, time 60 min, pH 7.0-7.1. The chromium content was determined by the atomic absorption method using spectrophotometer. Results. The content of low-molecular fractions increased more significantly over time in the mantle fermentolysate. The content of the high-molecular fraction of peptides weighing more than 160 kDa was minimal for both the muscle and the mantle and didn't exceed 1.1%. Low-molecular fractions weighing no more than 18 kDa in the 24-hour fermentolysate accounted for 79.6% for the muscle and 86.9% for the mantle. The obtained fermentolysates were characterized by a high content of the biologically active amino acid taurine - 25.9% (muscle) and 30.05% (mantle) of the total amino acid content. The high content of such essential amino acids as glycine, alanine, leucine, lysine, and the conditionally essential amino acid arginine was also determined. The obtained fermentolysates of soft tissue proteins of the Mactra chinensis were characterized by a fairly balanced amino acid composition. It has been experimentally established that more than 84% of the total chromium content in muscle fermentolysate and 80.9% in mantle fermentolysate was associated with peptide fractions with molecular weights from 24 to 1.4 kDa, and the highest specific chromium content - 1.67 mg/g protein (muscle) and 1.58 mg/g protein (mantle) was determined in the interval fractions with molecular weights of 18.0-12.5 kDa. The minimum specific content of the trace element was established for high-molecular fractions of 160-67 kDa and low-molecular fraction weighing less than 1.4 kDa. Conclusion. Biotechnological modification of soft tissue proteins of the Mactra chinensis bivalve mollusk from the Far Eastern region made it possible to obtain a balanced amino acid composition fermentolysate with a high content of the free biologically active amino acid taurine. Fortification of the obtained fermentolysate with chromium demonstrated high efficiency of its binding to the amino acid and peptide matrices of the protein hydrolysate. The chromium complex with fermentolysate of proteins of the Mactra chinensis bivalve mollusk can be used as a food source of chromium and taurine, including as a functional ingredient in special food systems for the prevention of hyperlipidemia and obesity.