[In vivo study of the biological value of amaranth protein concentrate and its module with chicken egg protein].

Amaranth (Amaranthus L.), like other pseudocereals as quinoa (Chenopodium quinoa Willd.), chia (Salvia hispanica L.) and buckwheat (Fagopyrum sp.), is a promising source of dietary protein. Depending on the subspecies and breeds of amaranth, the protein content in its grain is estimated from 13.1 to 21.5%, and its amino acid score varies over a significant range and can be limited. The aim of this study was to obtain a protein concentrate from amaranth (Amaranthus L.) grain of the Voronezh breed, enrich it with chicken egg protein, determine the amino acid score of the obtained protein module, and experimentally evaluate in vivo its true digestibility and biological value. Material and methods. The amaranth protein concentrate was obtained from grain according to the technological scheme, including its enzymatic treatment, alkaline extraction, acid precipitation of proteins, microfiltration and lyophilization. The amino acid composition and amino acid score of the concentrate were determined. The protein module was obtained by mixing amaranth protein concentrate and chicken egg protein in a weight ratio of 58:42. The true digestibility and biological value of the protein module has been determined in vivo. The experiment was carried out on 32 Wistar male rats divided into 2 groups (n=16 rats): control group 1 with a body weight of 118.7±3.1 g and experimental group 2 with a body weight of 119.5±3.0 g. Animals of groups 1 and 2 received diets in which egg protein and a protein module were used as a protein source, respectively. Within 15 days of the experiment, individual indicators of food intake and body weight gain of each animal were determined. From the 14th to the 15th day food intake was determined and feces were collected. The amount of nitrogen in the food and feces was determined for each rat using the Kjeldahl method. The true digestibility of the protein was determined according to obtained data. Results. The resulting amaranth protein concentrate contained 70.4±0.6% of protein, 17.0±1.0% fat, 9.8±0.8% carbohydrates, 1.8±0.2% ash, its moisture content was 1.4±0.1%. There were no significant differences in food intake and body weight gain between animals of both groups. The calculated value of the true digestibility of chicken egg protein was 98.8±0.1% for the control group 1, of the protein module was 99.0±0.1% for the experimental group 2, the differences between the groups were not significant. Conclusion. The results of amino acid analysis and the in vivo study of the true digestibility of the protein module (composition amaranth protein/chicken egg protein) indicate the absence of limitation relative to the amino acid scale of the "ideal" protein (FAO/WHO, 2007) and high true digestibility. The biological value of the protein module, calculated according to PDCAAS, is 99.0±0.1%, which confirms the prospects for its inclusion in specialized foods.

[Squid fat as a promising source of polyunsaturated fatty acids].

Omega-3 polyunsaturated fatty acids (ω-3 PUFA) are substances that play an important role in human metabolism. They are essential nutritional factors and can improve the functioning of individual systems and the body as a whole. The main source of ω-3 PUFA has long been fish fat, which contains PUFA in the triglyceride form. A fairly new and promising alternative to fish fat is the liver fat of the Commander squid (Berryteuthis magister), which additionally contains alkylglycerols, contains PUFA in the phospholipid form and can be obtained from squid fishery waste. The objective of the research was to carry out an analysis of scientific data, including the results of studies of the biological activity of squid fat, as well as its components that are part of other similar raw materials, and evaluate the prospects for its use in medical practice. Material and methods. During the study, various sources were analyzed, including scientific literature from electronic databases eLibrary, PubMed, Scopus, Web of Science and electronic search engines Google Academy from 2000 to 2022. Results. It is noted that squid fat has a pronounced biological activity. Its components increase innate immunity, have antitumor potential, improve the state of the body under stress, have hypolipidemiс and hypotensive effect, improve memory and attention, and also positively affect the composition and rheological parameters of blood. In addition to these effects, a positive effect of ω-3 PUFA and alkylglycerols on spermatogenesis, sperm quality and the female reproductive system has been noted. In a number of studies, alkylglycerol esters increased the permeability of the blood-brain barrier and, due to their structure, are able to form vesicles, therefore, they can be considered as raw materials for the production of new dosage forms for targeted therapy of brain tumors. In the available literature, in the case of the use of squid fat and its components, undesirable side effects have not been identified. Conclusion. Squid fat is a complete source of ω-3 PUFA and alkylglycerols, therefore it can be recommended as a dietary supplement, especially in a diet low in ω-3 PUFA.

[Development and validation of methods for the quantitative determination of vitamins B1 and B2 in foods by high performance liquid chromatography with diode array detection].

The main sources of vitamins, which are essential substances, are mainly aliment products, foods for special dietary uses and dietary supplements. Therefore, the study of the native content of vitamins in aliment foods has always been of interest. For the chromatographic separation of vitamins, rather versatile C18 columns are used as a stationary phase, which allow one to obtain reliable results using UV detection for vitamin-enriched foods, dietary supplements and vitamin premixes. However, for unfortified foods, this stationary phase in a UV detection system does not give acceptable results. The aim of the work was to develop a technique for the chromatographic separation of vitamins B1 and B2 in unfortified foods using a diode array detector. Material and methods. To prepare samples of foods, concentrated acid hydrolysis (1.0 g of sample and 4 ml of 0.1 N hydrochloric acid) was carried out in a water bath for 30 min at a temperature of 95 °C, followed by enzymatic hydrolysis and degreasing. Further studies of the samples were carried out on an Agilent Technologies 1100 chromatographic system with diode array detection. For the determination of vitamin B1, a Poroshell 120 Hilic column 4.6×150 mm, grain size 2.7 µm was used. As eluent A, a 10 mM aqueous solution of ammonium acetate with 0.5% acetic acid was used, eluent B was acetonitrile (gradient elution: 0-2 min - 90% B, 8-12 min - 50% B, 14-18 min - 90% B). To determine vitamin B2, a C18 Poroshell column 4.6×250 mm, grain size 5 µm was used. As eluent A, a classical phosphate buffer with pH 2.5 was used, eluent B - acetonitrile (gradient elution: 0-5 min - 0% B, 5-15 min - 90% B, 15-22 min - 90% B, 22-24 min - 0% B, 24-27 min - 0% B). Vitamin B1 was detected at a wavelength of 270 nm, vitamin B2 at 450 nm. Under selected conditions, good retention and efficient separation of vitamins B1 (over 16,000 theoretical plates) and B2 (over 20,000 theoretical plates) was observed. Results. It was demonstrated that the HPLC method with diode array detection can be used to quantify the native content of vitamins B1 and B2 in products with a complex food matrix. For the selective determination of these vitamins, a complex of chromatographic conditions is optimal: reverse-phase HPLC for vitamin B2 and hydrophilic interaction chromatography for vitamin B1. A suitable sample preparation of food products for the content of vitamins B1 and B2 under selected chromatographic conditions is concentrated acid-enzymatic hydrolysis. The limit of quantitation for vitamins B1 and B2 was 40 µg/100 g. Comparison of the enzymatic activity of amylorizin and thermostable α-amylase showed that during long-term hydrolysis for 16 hours (37 °Ð¡) with amylorizin, the degree of vitamin extraction was two fold higher than during hydrolysis (95 °Ð¡, 1 h) with α-amylase. Conclusion. The selected conditions for determining the native content of vitamins B1 and B2 in unfortified and low-fortified foods can be used in practice, which has been proven through their successful validation and practical application on real samples of cereals.