Amino Acid Composition Of Protein Research Articles

Nutritional, biological, and structural properties of bioactive peptides from bellflower, Persian-willow, and bitter-orange pollens.

In this study, the composition of amino acids, nutritional characteristics, degree of hydrolysis (DH), antioxidant properties, and antibacterial activity of proteins and hydrolysates of bellflower (Campanula latifolia), Persian willow (Salix aegyptiaca), and bitter orange (Citrus aurantium L.) were investigated under the influence of different proteases (Alcalase: Al, trypsin: Tr, pancreatin: Pa, and pepsin: Pe). Evaluation of the structural features of the proteins showed amide regions (amide A, B, I-III) and secondary structures. Hydrophobic amino acids (∼38%), antioxidants (∼21%), and essential types (∼46%) form a significant part of the structure of flower pollen. The digestibility and nutritional quality (PER) of the hydrolyzed samples (CP: 1.67; CA: 1.89, and PW: 1.93) were more than the original protein. Among proteins and peptides, the highest degree of hydrolysis (34.6%: Al-PWH), inhibition of free radicals DPPH (84.2%: Al-CPH), ABTS (95.2%: Pa-CPH), OH (86.7%: Tr-CAH), NO (57.8%: Al-CPH), reducing power (1.31: Pa-CPH), total antioxidant activity (1.46: Pa-CPH), and chelation of iron ions (80%: Al-CPH and Al-CAH) and copper (50.3%: Pa-CAH) were affected by protein type, enzyme type, and amino acid composition. Also, the highest inhibition of the growth of Escherichia coli (25 mm) and Bacillus cereus (24 mm) were related to CP and PW hydrolysates, respectively. The results of this research showed that hydrolyzed flower pollens can be used as a rich source of essential amino acids as well as natural antioxidants and antibacterial in food and dietary products. PRACTICAL APPLICATION: Enzymatic hydrolysis of Campanula latifolia, Persian willow, and Citrus aurantium pollen proteins was performed. The hydrolyzed ones had high nutritional quality and digestibility (essential amino acids and PER index). Antioxidant properties and chelation of metal ions of peptides were affected by the type of protein and enzyme. The hydrolysates showed inhibitory activity against the growth of Esherichia coli and Bacillus cereus.

Effects of Food Factors and Processing on Protein Digestibility and Gut Microbiota.

Protein is an essential macronutrient. The nutritional needs of dietary proteins are met by digestion and absorption in the small intestine. Indigestible proteins are further metabolized in the gut and produce metabolites via protein fermentation. Thus, protein indigestibility exerts a wide range of effects on gut microbiota composition and function. This review aims to discuss protein digestibility, the effects of food factors, such as protein sources, intake level, and amino acid composition, and making meat analogues. Besides, it provides an inventory of antinutritional factors and processing techniques that influence protein digestibility and, consequently, the diversity and composition of intestinal microbiota. Future studies are warranted to understand the implication of plant-based analogues on protein digestibility and gut microbiota and to elucidate the mechanisms concerning protein digestibility to host gut microbiota using various omics techniques.

Comparative analysis of the antioxidant capacity of milk from different breeds of cow in Nigeria

Milk is an essential component of human and animal diets, and cattle are a major source of milk for human consumption. Environmental, nutritional, genetic, and physiological factors can affect animal milk composition. This study was aimed at evaluating the antioxidant properties of milk samples from four cattle breeds, namely: White Fulani (WF), Sokoto Gudali (SG), Red Bororo (RB), and the exotic Holstein Friesian (HF) in Sokoto, Nigeria. Fatty acid, amino acid profile, antioxidant vitamins, antioxidant minerals, and antioxidant enzymes activities of the samples were assessed using standard methods. The results of the analysis indicated that milk of SG had the highest values for moisture (85.57%), Vit C (79.24mg/dl), DPPH scavenging activity (80.04%), and FRAP (1083.33mgTE/100g of FW). Milk of RB had the highest ash (4.52%), protein (3.63%), copper (0.19 ppm), zinc (0.16 ppm), iron (3.47 ppm), and antioxidant amino acid composition. The milk of HF had the highest lipid (5.89%), oleic acid (1.17 mg/ml), total polyphenol content (TPC) (0.26 mgTE/100g of FW) and selenium (103.10 ppm) levels. WF had the highest carbohydrate (15.07%), palmitic acid (98.39 mg/ml), stearic acid (35.46 mg/ml), Vit A (55.38 mg/dl), Vit E (52.18 mg/dl) content, catalase (0.02 U/L) and superoxide dismutase (3.00 U/mL) activities. These results show that milk from the WF has better antioxidants and therefore antioxidant capacities than the other breeds. Overall, the study indicates that cow milk is a good source of antioxidants, whose levels vary between the different breeds of cattle. These nutritional differences can be explored during milk sourcing based on nutritional requirements.

Biochemical composition of Hediste diversicolor (OF Müller, 1776) (Annelida: Nereidae) reared on different types of aquaculture sludge

IntroductionSustainable growth of the salmon aquaculture industry is highly dependent on the availability of new feed resources as well as improved management and utilization of waste streams from production. Polychaetes are capable of recapturing and recycling valuable biomolecules contained in aquaculture sludge and at the same time constitute a possible resource for aquafeeds.Material and methodsIn this study, the potential of Hediste diversicolor (OF Müller, 1776) to recover nutrients and energy contained aquaculture sludge was evaluated. Hereby, the effect of two different diets, smolt and post-smolt sludge, and different feed levels on polychaete growth, and biochemical and elemental composition was assessed.Results and discussionSurvival ranged from 80-90%, independent of treatment. Specific growth rates at the highest feed levels were significantly higher than at the lowest feed levels and growth was not affected by the type of diet. Similarly, total lipid and total fatty acid content of polychaetes were positively correlated with feed level while the type of diet had a limited effect. Fatty acid composition of polychaetes reflected feed levels: in both diet groups, polychaetes at lower feed levels showed a higher percentage of saturated fatty acids; monounsaturated fatty acids increased with increased feed supply for smolt sludge-fed group and polychaetes fed post-smolt sludge showed increased polyunsaturated fatty acid content with increasing feed levels. Neither diet nor feed levels affected protein content and amino acid composition of polychaetes. In conclusion, H. diversicolor could be successfully cultivated on both smolt and post-smolt sludge and was rich in proteins and lipids as well as essential amino and fatty acids. The species can be considered a promising candidate for recycling valuable nutrients from different types of side streams salmon aquaculture.

Nutritional aspects and amino acid profiles of tempe from local, imported, and black soybean relating to the functional properties

Soybean (Glycine max L) is a legume rich in protein, fat, vitamins, minerals and fibre. The nutritional value of soybeans and the amino acid profiles of the processed fermented soybean (Tempe) products need to be studied. Soybean and Tempe flour from black soybean, local soybean (Anjasmoro variety) and imported soybean (USA soybean) were analyzed proximately, including carbohydrates (spectrophotometric method), protein (Kjeldahl method), fat (Soxletation method), fiber (gravimetric method), and water content (gravimetric method). The amino acid profile of Tempe flour was measured by UPLC and LC/MS/MS methods. Local soybeans had the highest protein content (45.19%), followed by black and imported soybeans (36.87% and 35.95%, respectively). The protein content of local soybean Tempe flour was the highest (45.83%) compared to other soybean Tempe flour. The fiber content of local and black soybean Tempe flour (14.79% and 13.81%, respectively) was higher than that of imported Tempe. Amino acid profiles test of black soybean Tempe flour, local soybean, and imported soybean showed that the amino acids L-Glutamic Acid, L-Arginine, L-Leucine, and L-Aspartic Acid had the highest amounts compared to other amino acids, ranging from 30-75 thousand ppm. This shows that various soybeans affect the amino acid composition of the soybean protein. The amino acid content of Tempe from local soybeans is higher than the amino acid content of tempe from black and imported soybeans. This may influence the amino acids or peptides’ functional properties, such as antihypertensive and antimicrobial properties. Continuous research in vitro and in vivo should be conducted to explore the functional properties of Tempe flour from local soybean.

Study of Physicochemical and Gelation Properties of Fish Gelatin from Different Sources

Fish gelatin has been increasingly used as a safe alternative to cattle and pig gelatin due to its similar structure, avoiding the health and socio-cultural issues associated with the use of materials of mammalian origin. Fish gelatin can be produced from processed fish products to achieve a high yield at a low cost. Recent studies show that although fish gelatin comes from a wide range of sources, the protein content and amino acid composition of fish gelatin from different sources are different, and some fish gelatin is soft and unstable transglutaminase (TGase) can catalyze the γ-amide group of glutamine residues and the ε-amino group of lysine residues in proteins to form covalent bonds to form a stable protein network structure, improve the strength of the gel so that it can be applied in a more special environment. In this experiment, after screening the raw materials of cold-water fish gelatin M06 and M08, warm-water fish gelatin M03 and M04, a strong fish gelatin was successfully prepared by catalytic modification of cold-water fish gelatin by transglutaminase (TGase), and the excellent performance of TG enzyme-catalyzed modified gelatin was proved through the application effect of chicken salt soluble protein. In this experiment, the protein content of cold-water fish M08 was the highest, which was up to 99.9%, 1.09 times that of warm-water fish. The gelatin content of cold-water fish M08 was the highest of the four kinds of fish gelatin, with a wide proportion of components and rich amino acid composition. Cold-water fish M08 gelatin-derived gel had the highest strength of 253 ± 1 g/cm at 4 °C. It was found that fish gelatin with protein molecular weight distribution and rich amino acid composition had higher gel strength. M08 gelatin is cross-linked by transglutaminase (TGase), which increases the strength of enzyme gels by approximately 200% compared to self-assembled gels. Fish gelatin catalyzed by the TG enzyme improves the gel strength of raw material and makes it more applicable. M08 gelatin also showed good application performance at low temperatures in compound chicken salt-soluble protein gel, with a water retention rate of 95.84% and gel strength of 198.5 g/cm. This study expanded the application range of fish gelatin by TG enzyme and improved the application potential of fish gelatin.

How different amino acid scoring patterns recommended by FAO/WHO can affect the nutritional quality and protein claims of lentils

AbstractAs a nutritious pulse and protein source, lentils play an important role in the plant‐based protein market. Pulses' nutritional quality is influenced by their protein content and amino acid composition. Recommended scoring patterns by FAO/WHO can estimate protein quality for dietary assessment, but different guidelines for protein content in food labeling exist in North America. This study determined the in vitro protein digestibility (IVPD) and amino acid score (AAS) for the protein quality assessment of lentils. The impact of different recommended amino acid scoring patterns by FAO/WHO (1991, 2013) on AAS and AAS corrected for in vitro protein digestibility (AAS‐IVPDC) were evaluated. The impact of AAS‐IVPDC for determining protein content claims for lentils using USA standards was also evaluated. Sulfur AA and tryptophan were the most limiting amino acids. From this work, estimates of lentil protein quality vary with different recommended amino acid scoring patterns. IVPD in lentils was 82.6%, while mean AAS‐IVPDC values ranged from 37.5% to 64.0%. Regarding the protein content claims, if considering a similar interpretation to the protein digestibility–corrected amino acid score (PDCAAS) system (i.e., corrected content is ≥ 5.0 g per RACC), all lentil samples were considered a “good source of protein.” However, if considering a similar interpretation to digestible indispensable amino acid score (DIAAS) system (i.e., corrected content is ≥ 5.0 g per RACC and a claim threshold of 75%), no samples met these protein claims due to the arbitrary cut‐off. The criteria set for making protein content claims should be revised.

Comparison of deep learning models with simple method to assess the problem of antimicrobial peptides prediction.

Antibiotic-resistant strains are an emerging threat to public health. The usage of antimicrobial peptides (AMPs) is one of the promising approaches to solve this problem. For the development of new AMPs, it is necessary to have reliable prediction methods. Recently, deep learning approaches have been used to predict AMP. In this paper, we want to compare simple and complex methods for these purposes. We used the BERT transformer to create sequence embeddings and the multilayer perceptron (MLP) and light attention (LA) approaches for classification. One of them reached about 80 % accuracy and specificity in benchmark testing, which is on par with the best available methods. For comparison, we proposed a simple method using only the amino acid composition of proteins or peptides. This method has shown good results, at the level of the best methods. We have prepared a special server for predicting the ability of AMPs by amino acid composition: http://bioproteom.protres.ru/antimicrob/.

Biochemical composition and nutritional value of green mass of the sainfoin varieties and promising lines

There have been presented the study results of the biochemical composition of the green mass of sandy sainfoin (Onobrychis arenaria) samples developed by the FSBSI Agricultural Research Center “Donskoy”. The purpose of the current study was to identify the variability of the content of raw nutrients: protein, oil, fiber, ash, BEV in the green mass of sainfoin varieties and lines, to determine the amino acid composition of protein and to identify the best samples for the studied traits. The study was carried out in the period of 2017–2021. The variety ‘Zernogradsky 2’ was used as a standard variety. Biochemical analyzes were carried out in the period ‘budding stage – blooming stage’. The chemical composition of the selected samples was carried out in accordance with the methodology and GOSTs. The maximum crude protein percentage was determined in promising lines ‘Sin 8/95’ (15.38 %) and ‘Sin 13/95’ (14.72 %). There was found that the varieties ‘Veles’ (10.6 %), ‘Atamansky’ (14.1 %) and the lines ‘Sin 13/95’ (11.8 %), ‘Sin 8/95’ (16.9 %) were characterized by a high concentration of raw ash. The optimal fiber content was established in the varieties ‘Atamansky’ (29.73 %) and ‘Veles’ (29.61%). As a result of determining the amino acid composition of protein, there was found that the line ‘Sin 8/95’ (68.5 g/kg) and the varieties ‘Zernogradsky 2’ (62.3 g/kg), ‘Veles’ (52.5 g/kg) were distinguished by the collection of essential amino acids. The varieties ‘Veles’ (75.0 g/kg), ‘Zernogradsky 2’ (66.5 g/kg) and the line ‘Sin 8/95’ (66.4 g/kg) were distinguished by the number of non-essential amino acids. The line ‘Sin 8/95’ (134.9 g/kg) and the varieties ‘Veles’ (127.5 g/kg), ‘Zernogradsky 2’ (128.8 g/kg) were characterized by a high total collection of amino acids. There was determined that crude protein percentage (from 4.3–18.4 %), fiber (7.8–16.9 %), dry matter (4.5–13.1 %) and BEV (9.6–15.9 %) were characterized by slight and medium variation in values. The content of crude ash (9.6–25.2 %) and crude oil (7.5–27.8 %) had weak, medium and strong variations depending on the variety and line. The study of the biochemical composition of sainfoin made it possible to establish varietal differences and variability of traits that characterize the nutritional value of the feed. The varieties ‘Veles’, ‘Zernogradsky 2’ and the promising line ‘Sin 8/95’ were found to have the best quality traits, which could be recommended for use in the breeding process as sources of useful traits and properties.

SPIRULINA: A SPOTLIGHT ON ITS NUTRACEUTICAL PROPERTIES AND FOOD PROCESSING APPLICATIONS

Spirulina, blue-green algae is now worldwide used as a dietary supplement owing to its richness in protein (50-60%), antioxidants, essential fatty acids, etc. The amino acid composition of Spirulina protein ranks among the best in the plant world, more than that of soya beans. This review article serves as an overview of why Spirulina is considered as a ‘superfood’. Its methodologies of cultivation, richness in nutrients and bioactive components, therapeutic properties in the health food circuits, and versatile utilization in various food supplements are elaborately introduced. All possible fortification of Spirulina platensis emphasizing the elevation of nutrient levels in bakery products, beverages, dairy products, extruded snacks, energy bars, infant foods, and confectionaries is briefed. Beyond, these algae convert carbon dioxide into organic substances and produce oxygen during their growth in alkaline and saline water thereby not wasting fresh water and allowing the production in barren areas. Such an organism with a plethora of health profits to humans, animals and the environment is limitless and has probably more to offer in the future.

Computational Analysis Predicts Correlations among Amino Acids in SARS-CoV-2 Proteomes.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a serious global challenge requiring urgent and permanent therapeutic solutions. These solutions can only be engineered if the patterns and rate of mutations of the virus can be elucidated. Predicting mutations and the structure of proteins based on these mutations have become necessary for early drug and vaccine design purposes in anticipation of future viral mutations. The amino acid composition (AAC) of proteomes and individual viral proteins provide avenues for exploitation since AACs have been previously used to predict structure, shape and evolutionary rates. Herein, the frequency of amino acid residues found in 1637 complete proteomes belonging to 11 SARS-CoV-2 variants/lineages were analyzed. Leucine is the most abundant amino acid residue in the SARS-CoV-2 with an average AAC of 9.658% while tryptophan had the least abundance of 1.11%. The AAC and ranking of lysine and glycine varied in the proteome. For some variants, glycine had higher frequency and AAC than lysine and vice versa in other variants. Tryptophan was also observed to be the most intolerant to mutation in the various proteomes for the variants used. A correlogram revealed a very strong correlation of 0.999992 between B.1.525 (Eta) and B.1.526 (Iota) variants. Furthermore, isoleucine and threonine were observed to have a very strong negative correlation of -0.912, while cysteine and isoleucine had a very strong positive correlation of 0.835 at p < 0.001. Shapiro-Wilk normality test revealed that AAC values for all the amino acid residues except methionine showed no evidence of non-normality at p < 0.05. Thus, AACs of SARS-CoV-2 variants can be predicted using probability and z-scores. AACs may be beneficial in classifying viral strains, predicting viral disease types, members of protein families, protein interactions and for diagnostic purposes. They may also be used as a feature along with other crucial factors in machine-learning based algorithms to predict viral mutations. These mutation-predicting algorithms may help in developing effective therapeutics and vaccines for SARS-CoV-2.

Molecular Dynamics Simulation as a Tool to Identify Mutual Synergistic Folding Proteins

Mutual synergistic folding (MSF) proteins belong to a recently emerged subclass of disordered proteins, which are disordered in their monomeric forms but become ordered in their oligomeric forms. They can be identified by experimental methods following their unfolding, which happens in a single-step cooperative process, without the presence of stable monomeric intermediates. Only a limited number of experimentally validated MSF proteins are accessible. The amino acid composition of MSF proteins shows high similarity to globular ordered proteins, rather than to disordered ones. However, they have some special structural features, which makes it possible to distinguish them from globular proteins. Even in the possession of their oligomeric three-dimensional structure, classification can only be performed based on unfolding experiments, which are frequently absent. In this work, we demonstrate a simple protocol using molecular dynamics simulations, which is able to indicate that a protein structure belongs to the MSF subclass. The presumption of the known atomic resolution quaternary structure is an obvious limitation of the method, and because of its high computational time requirements, it is not suitable for screening large databases; still, it is a valuable in silico tool for identification of MSF proteins.

Potential Anti-Sarcopenia Effect and Physicochemical and Functional Properties of Rice Protein Hydrolysate Prepared through High-Pressure Processing

Rice protein is a suitable alternative protein source for dairy protein in infant formulas on account of its unique nutrition and hypoallergenicity. Rice protein was isolated through enzymatic hydrolysis (Alcalase, papain, bromelain, Flavourzyme®) in combination with high-pressure processing (HPP) (400 MPa for 15 min at 25 °C) to enhance its functional properties and broaden its food processing applications. The effect of the HPP-treated rice protein hydrolysate on dexamethasone (DEX)-induced atrophy in C2C12 myotubes was also studied. The length of myotubes was observed under a light microscope, and periodic acid Schiff staining. The results showed that even though enzymatic hydrolysis and HPP treatment affected the color of the resulting rice protein, the protein content (3120.31 ± 42.15), branched chain amino acid (BCAA) content (15.12 ± 1.03), peptide content (31.25 ± 0.55), and amino acid composition of the rice protein were significantly increased. Moreover, the combined enzymatic and HPP treatment effectively overcame the problem of limited solubility and water-holding capacity. Rice protein produced through enzymatic and HPP treatment exhibited a higher free radical scavenging activity and oxygen radical absorbance capacity. It also alleviated DEX-induced muscle atrophy in C2C12 myotubes as indicated by the increase in myotube length. In short, the enzymatic and HPP treatment of rice protein not only overcame limitations, but also produced rice protein with high functionality in terms of antioxidant and therapeutic effects on muscle atrophy. The rice protein hydrolysate produced through enzymatic hydrolysis and HPP treatment showed the potential for use as an ingredient for functional foods in the nutraceutical industry.

Accumulation of Minerals in Faba Bean Seeds and Straw in Relation to Sowing Density

Faba beans (Vicia faba L.) are a high-protein legume crop that can be widely cultivated in most climates in Europe. The amino acid composition of the faba bean protein is also beneficial for monogastric animals since it contains a great deal of lysine, an amino acid that is deficient in cereals. Two genotypes of faba beans were cultivated at three sowing densities (45, 60 and 75 seeds per m2) during three growing seasons (years 2013–2015). The aim of the research was to assess accumulation of nutrients (N, P, K, Ca and Mg) of two faba beans in seeds and straw under different sowing densities. A field experiment was conducted in 2013–2015 at fields of Wroclaw University of Environmental and Life Sciences in southwestern Poland from which plant material was used for chemical analysis in terms of determining the accumulation of the following elements—N, P, Mg, K and Ca—in the seeds and straw. The results showed that the genotypes of the faba bean varied greatly in accumulation of nutrients in various sowing densities and in following years of research. However, the average accumulation of nitrogen, calcium and magnesium in seeds for three years (2013–2015) was significantly higher in the Bobas cultivar under 60 seeds per m2 as well as in both tested cultivars using 75 seeds per m2. Accumulation of potassium and phosphorus in seeds was highest in both analyzed cultivars using 60 and 75 seeds per m2 (average for 2013–2015). Considering accumulation of elements in the straw of faba bean, it is shown that the concentration of potassium and calcium was the highest in both tested cultivars under the effect of sowing density at 60 and 75 seeds per m2 while the concentration of nitrogen, phosphorus and magnesium did not differ significantly as an effect of the interaction of cultivar and sowing date (average for 2013–2015). Weather conditions played an important role in accumulation of nutrients of both faba bean genotypes in the years of research (2013–2015).

Associations of DNA microsatellite locus and muscle protein amino acids in &lt;i&gt;Rangifer tarandus&lt;/i&gt; reindeer

Purpose: study the correlations of STR-markers of DNA and amino acids of reindeer meat protein.Materials and methods: Amino acid analysis was performed according to GOST 34132–2017 «Meat and meat products. Method for determining the amino acid composition of animal protein». When setting up multiplex PCR STR, primers and microsatellite DNA loci used for deer (Cervidae) were taken. The nomenclature of loci corresponds to the world standard.Results. Information is provided on the quantitative content of amino acids in the protein of M. longissimus dorsi, on the size of amplicons, the association of amino acids and STR loci in a sample of Chukchi deer. The coefficient of variability of essential amino acids ranged from 7.9 to 11.8 %, which can provide an acceptable level of selection for this trait. Amino acids are associated with each other mainly statistically significantly, the degree of closeness of the relationship varies from medium to strong. Less closely correlated with other amino acids were methionine and proline. Most indicators of the relationship between microsatellite loci and amino acids turned out to be insignificant in magnitude, statistically unreliable and reverse in direction, which practically indicates the absence of a relationship between the traits. At the same time, a significant correlation of individual STR markers with amino acids was revealed. In particular, the NVHRT30 locus is associated with the essential amino acids VAL, LEU, ILE, THR with a coupling coefficient equal to: r1 = -0.322; r2 = -0.290; r3 = -0.272 and r4 = -0.437, respectively.Conclusion. The data obtained fit into the framework of the well-known thesis about the localization of microsatellites mainly in the non-coding regions of the DNA molecule. However, they can also be located in promoter regions and have linkage with candidate genes of quantitative trait loci. It is necessary to continue research in the chosen direction on other populations of the range in order to accumulate more significant amounts of information.

Influence of the Enzymatic Hydrolysis Using Flavourzyme Enzyme on Functional, Secondary Structure, and Antioxidant Characteristics of Protein Hydrolysates Produced from Bighead Carp (Hypophthalmichthys nobilis)

In the current study, bighead carp fish were used in conjunction with the flavourzyme enzyme to obtain (FPH) fish protein hydrolysates. The optimum conditions of the hydrolysis process included an enzyme/substrate ratio of 4% and a temperature of 50 °C and pH of 6.5. The hydrolysis time was studied and investigated at 1, 3, and 6 h, and the (DH) degree of hydrolysis was recorded at 16.56%, 22.23%, and 25.48%, respectively. The greatest yield value was 17.83% at DH 25.48%. By increasing the DH up to 25.48%, the crude protein and total amino acid composition of the hydrolysate were 88.19% and 86.03%, respectively. Moreover, more peptides with low molecular weight were formed during hydrolysis, which could enhance the functional properties of FPH, particularly the solubility property ranging from 85% to 97%. FTIR analysis revealed that enzymatic hydrolysis impacted the protein's secondary structure, as indicated by a remarkable wavelength of amide bands. Additionally, antioxidant activities were investigated and showed high activity of DDPH radical scavenging, and hydroxyl radical scavenging demonstrated remarkable activity. The current findings demonstrate that the functional, structural, and antioxidant characteristics of FPH might make it an excellent source of protein and suggest potential applications in the food industry.

Comparative characteristics of the amino acid composition of protein from traditional sources and entomoprotein: calculated data

The growth of the world population leads to an increase in demand for food consumption. Along with the projected reduction in demand for meat products, a search is underway for a new type of food ("novel food"), one of the promising options for which are insects. In 2023 the European Commission has registered flour made from house cricket (Acheta domesticus) as a "novel food" for human consumption. Currently, the amino acid composition of both new types of food and the diet that includes them is not regulated. Accordingly, the potential amino acid imbalance in the diet when entomoprotein is included need to be further investigated. The aim of the study was to characterize the amino acid composition of a simulated diet using protein obtained from house cricket. Material and methods. To assess the balance of diets in terms of amino acid composition, a comparative analysis was made of the actual diet containing protein from traditional foods (scenario 1) and the diet with the likely replacement of beef, pork and poultry with a product containing A. domesticus protein (entomoprotein) (scenario 2). The volume of food consumption has been calculated based on the results of the assessment of a sample survey of household budgets. The study included foods with an established value of annual consumption, that was calculated as daily consumption. The content of essential amino acids in food sources of protein, as well as in the domestic cricket protein, was evaluated using the data from relevant sources. Dietary balance was assessed by calculating its digestibility using data on amino acid scoring, the utility of essential amino acids, the excess content of individual essential amino acids, and the comparable excess content of essential amino acids. Results. We determined the daily consumption volumes of basic foods, formed consumption scenarios, including with the potential use of a protein product based on entomoprotein. Comparative analysis of the amino acid composition of the diet showed significantly higher content (from 1.4 up to 2.9 times) of amino acids in the diet in scenario 2. The results of calculating the amino acid score and utility coefficient showed that a diet using entomoprotein could provide a better usage of amino acids for protein synthesis compared to the «traditional» diet, however, the digestibility of protein from the traditional diet is higher compared to entomoprotein (96.8 vs 89.1%). Conclusion. Despite the fact that the utility of essential amino acids in the scenario of replacing meat products with a product containing A. domesticus entomoprotein is higher, while the digestibility of protein is lower, the differences identified are insignificant.

Protein content and amino acid composition in seed of bread wheat (Triticum aestivum L.)

The aim of this study was determination of protein content and amino acid composition in seeds of bread wheat, with particular focus of evaluation essential amino acids (EAAs). For analysis used flour samples of grained seed of 10 wheat variety, which selected in different breeding center (in Novi Sad and Kragujevac, Serbia). Kjeldahl method was used for determination of nitrogen (N) contents which value multiplied with coefficient 5.7 for computing protein content (protein contents = 5.7 x % N contents). Amino acids analyses of wheat samples were performed by ion exchange chromatography, followed by the ninhydrin colour reaction and photometric detection at 570 nm and 440 nm (for proline). The results showed that the mean protein content for wheat varied from the lowest value 10.24% in Ljubicevka to the highest 14.21% in Fortuna variety. The mean contents (g 100 g-l protein) of nonessential amino acids (NEAAs) were aspartic acid 5.42%, serine 4.23%, glutamic acid 18.51%, proline 12.18%, glycine 4.17%, alanine 3.64%, tyrosine 2.52%, arginine 5.02%, while mean contents of essential amino acids (EAAs) were threonine 2.86%, valine 4.52%, methionine 1.28%, isoleucine 3.87%, leucine 5.87%, phenylalanine 4.62%, histidine 2.46%, lysine 2.91%. The wheat variety contained relatively high concentration of the most deficient EAAs. The variety Ljubicevka contained relatively high concentration of the most deficient EAAs (threonine, valine, leucine, lysine,). The highest value (29.31 g 100 g-l protein) of total essential amino acids (TEAA), 59.79 g 100 g-l protein of total nonessential amino acids (TNEAA) as well as the highest value (90.35 g 100 g-l protein) of total amino acids (TAA). Obtained results provide variability of wheat variety on the base of amino acid contents and indicate reliable variety for selecting desirable parents in breeding program for improving nutrient quality.

Structural properties of Kudzu protein enzymatic hydrolysate and its repair effect on HepG2 cells damaged by H2O2 oxidation.

We investigated the structural properties, foaming capacity and foaming stability, antioxidant activity, and amino acid composition of Kudzu protein (KP) and Kudzu protein hydrolysate (KPH). The peptide sequence of KPH was analyzed using ultra performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS), and the binding ability of the peptide sequence to Keap1 was predicted through molecular docking simulations. The electrophoresis and molecular weight distribution analysis results showed that the molecular weight of KPH was significantly lower than that of KP, with a mean molecular weight of approximately 2000-5000 Da. The structures and properties were characterized using Fourier transform infrared spectroscopy, relative fluorescence, and circular dichroism. The results showed that KP exposed a large number of hydrophobic groups after enzymatic hydrolysis, and its structure changed from α-helical to random coils. KPH has a higher foaming capacity (200%) and foaming stability (97.5%) than KP, which may be related to the change in structure. These results indicate that moderate hydrolysis can improve the functional properties of KP, providing a new opportunity for its application as a food ingredient. The antioxidant assay results showed that KP and KPH had a good hydroxyl radical, superoxide anion, 1,1-diphenyl-2-picrylhydrazyl (DPPH), and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging capacity and a high reducing capacity. KPH exerted better antioxidant effects than KP. The scavenging rates for DPPH, ABTS, hydroxyl radicals, and superoxide anions were 89.31%, 93.14%, 85.74%, and 58.29%, respectively, and its reducing capacity was 2.191, which may be related to the increase in amino acids with antioxidant activity after enzymolysis. In vitro, KP and KPH could significantly repair H2O2-induced oxidative damage in HepG2 cells, reduce the apoptosis rate, activate the Nrf2-Keap1 signaling pathway, reduce the accumulation of reactive oxygen species and malondialdehyde after oxidative damage, increase the activities of superoxide dismutase and glutathione (GSH) peroxidase, and increase the content of GSH and the total antioxidant capacity. Twenty-one peptide components were identified in KPH using UPLC-MS/MS, and the binding ability of 21 peptide components to Keap1 was analyzed through molecular docking technology. The results showed that all 21 peptides in KPH had good antioxidant activity, and real-time quantitative PCR (qRT-PCR) analysis was conducted to further explain the high antioxidant activity of KPH at the genetic level. These results show that KP and KPH are suitable for preparing antioxidant foods and related health foods to prevent oxidation-related diseases. KPH has more beneficial effects than KP.

Single-cell protein production by Pleurotus ostreatus in submerged fermentation

P. ostreatus biomass could stand as an alternative vegan protein source due to its high protein content and amino acid composition.