Individual Protein Fractions Research Articles

Effect of pore size and temperature on the behaviour of alpha-lactalbumin and the A and B genetic variants of beta-lactoglobulin during protein fractionation microfiltration

The aim of this study was to investigate the influence of membrane pore size and filtration temperature on six individual milk protein fractions (αS-CN, β- CN, κ-CN, α-LA, β-LG A, β-LG A) during the protein fractionation microfiltration process. Pasteurised skimmed milk was microfiltrated using two different pore sizes of spiral-wound membranes, with pore sizes of 0.2 μm and 0.5 μm, at temperatures of 15 °C and 45 °C respectively. The microfiltration process was carried out with a final volume reduction of 66% and a diafiltration volume of 120% (300 L) of the original feed (250 L). It was observed that neither the pore size nor the filtration temperature significantly (p < 0.05) affected the permeation of the α-LA fraction. However, the permeation of the β-LG A and β-LG B fractions can be influenced by membrane pore size and filtration temperature, and the behaviour of the three whey protein fractions, A and B genetic variants of the β-LG and α-LA fractions differs significantly during the microfiltration process. The results of this study could form the basis for the development of new, unique tailor-made milk protein ingredients.

A novel deep eutectic solvent-based green extraction and purification of DPP-IV inhibitory peptides from tilapia (Oreochromis niloticus) viscera hydrolysate

The use of green and low-cost techniques to produce bioactive peptides with anti-diabetic properties from protein-rich fish waste is a sustainable way to manage agro-fishery and food industrial waste. This study investigated a novel ultrasound (UL) assisted deep eutectic solvent (DES) based extraction approach to recover bioactive protein-rich extracts from tilapia fish viscera waste under optimized conditions (52.52% ultrasound amplitude, 1:4 DES molar ratio, 25 min extraction time). The aqueous two-phase system (ATPS) method successfully concentrated the crude proteins in the top phase and back-extracted proteins to the bottom phase with a high recovery yield. Hydrolysis by Alcalase produced tilapia viscera protein hydrolysate (TVPH) with low molecular weight (MW) peptides and low dipeptidyl peptidase (DPP)-IV half-maximal inhibitory concentration (IC50) value of 1.57 ±0.16 mg/mL. Notably, TVPH-3 fraction and TVPH-3-2 sub-fraction exhibited appreciable DPP-IV IC50 values of 1.36 ±0.08 mg/mL and 0.42 ±0.01 mg/mL, respectively. Ultrafiltration combined with RP-HPLC enriched the DPP-IV inhibitory concentration of the individual protein fractions. TVPH-3-2 sub-fraction contained hydrophobic amino acids and peptide sequences with typical DPP-IV inhibitory peptide sequence motifs. The results presented in this study indicate that tilapia viscera biomass is a potential source for protein recovery aided with a green extraction approach, and tilapia viscera protein-derived hydrolysates have potential applications as a potent functional food ingredient for the management of metabolic diseases like type-2 diabetes.

Effect of Different Molecular Weight Hyaluronic Acids on Skim Milk Functional Properties.

Hyaluronic acid (HA), a naturally occurring polysaccharide with recognized health benefits, has gained approval for use in the food industry as a food additive, ingredient, and health supplement in numerous countries. HA can increase viscosity in solutions and is available commercially in various molecular weights (MW) depending on end applications. Nevertheless, no research has explored the impact of different MW HAs on functionality, rheological properties, and texture-building benefits in the dairy product matrix wherein they are incorporated. Therefore, the objective of this study was to evaluate how varying MWs of HA-specifically 8 kDa, 320 kDa, 980 kDa, and 2550 kDa at 0.25% (w/w) concentration-impact rheological characteristics, functional attributes, heat stability, protein stability, protein structure, and protein fractions within skim milk. The addition of HA led to an increase in the apparent viscosity of all samples. A higher G″ value over G' values for all HA samples was observed in frequency sweep, indicating the absence of interparticle interactions between HA particles. Protein stability and heat stability were significantly lower for 980 kDa and 2550 kDa HA as compared to the control and 8 kDa HA samples. As the MW increased, WHC, emulsion properties, and foaming stability notably increased. However, reversed results were found in the case of foaming activity. Moreover, no significant changes were observed in the percent area of individual protein fractions and the hydrodynamic diameter of protein particles. This study would help to understand the effect of HA when incorporated in dairy products for water binding or enhancement in viscosity-based applications.

Blood plasma proteins and the content of metabolites of carbohydrate and lipid metabolism in the hepatopancreas of fish during the action 19-nortestosterone

The aim: study the effect of the synthetic anabolic steroid 19-nortestosterone on the fractional composition of blood plasma proteins, as well as the total protein and albumin content, indicators of the metabolism of carbohydrates, lipids, macro- and microelements in the fish hepatopancreas. Materials and methods. The experiments were conducted on two-year-old carp (Cyprinus carpio L.), which were kept for 24 hours in aquariums with a volume of 40 dm3 with different concentrations of 19-nortestosterone in water at optimal temperature, oxygen content, and pH. Spectrophotometric methods and an automatic biochemical analyzer were used to determine metabolic indicators in fish, and disk electrophoresis in PAGE was used to determine the fractional composition of proteins. Results. It was established that the steroid hormone 19-nortestosterone, the concentration of which in the water of the fish of the experimental groups was 50 and 200 μg/dm3, respectively, increased the level of total protein and albumin, the concentration of glucose, triglycerides, creatinine, inorganic phosphorus and iron in the hepatopancreas and did not affect the calcium content . In the blood plasma of carp, kept in water with a concentration of 19-nortestosterone of 50 μg/dm3, the content of proteins with a molecular weight of 240-231 increases; 215-179; 169-146 and 105-95 kDa, decreases - 35-33 kDa, fractions of proteins with a molecular weight of 228-220 appear; 116-105 and 48-44 kDa. An increase in the concentration of 19-nortestosterone in water to 200 μg/dm3 increased the content of proteins with a molecular weight of 240-231 and 215-179 kDa in the blood plasma of fish, and decreased it by 35-33 kDa, causing the redistribution of individual protein fractions due to the appearance of proteins with a molecular weight of 240 -228; 116-105 and 48-44 kDa in the absence of proteins 42-41; 38-36 and 24-20 kDa. Conclusions. Based on the obtained results, it was concluded that the anabolic synthetic steroid 19-nortestosterone stimulates the biosynthesis of proteins, the metabolism of carbohydrates and lipids, and its effect on the content of minerals in the hepatopancreas and the fractional composition of blood plasma proteins in carp fish was proven

Insight into Organization of Gliadin and Glutenin Extracted from Gluten Modified by Phenolic Acids

The changes in the secondary structure of individual gluten protein fractions (gliadin and glutenin) caused by the supplementation of model dough with eight phenolic acids were analysed. Gliadins and glutenins were extracted from gluten samples obtained from overmixed dough. The changes in the gliadin secondary structure depended on the amount of phenolic acid added to the dough. Higher acid concentrations (0.1% and 0.2%) led to a significant reduction in the amount of α-helices and to the formation of aggregates, non-ordered secondary structures, and antiparallel β-sheets. After the addition of acids at a lower concentration (0.05%), the disaggregation of pseudo-β-sheet structures and the formation of β-turns, hydrogen-bonded β-turns, and antiparallel β-sheets were detected. In the case of glutenin, most of the phenolic acids induced the formation of intermolecular hydrogen bonds between the polypeptide chains, leading to glutenin aggregation. When phenolic acids were added at a concentration of 0.05%, the process of protein folding and regular secondary structure formation was also observed. In this system, antiparallel β-sheets and β-turns were created at the expense of pseudo-β-sheets.

Исследование роли нейротрофических факторов в регуляции регенерационных процессов в поврежденных соматических нервах при действии пептидного препарата «Семакс»

The content of neurotrophic factors in damaged somatic nerves under the action of the drug «Semax» was studied and their role in the regulation of regenerative processes in injured nerve conductors was established. It has been shown that intramuscular administration of the drug is accompanied by a significant increase in the level of NGF and NT-3 both in the proximal and distal parts of the nerve. At the same time, there are no significant changes in the quantitative content of neuroregulin-1 against the background of its use. The data obtained suggest that one of the mechanisms of action of Semax is its ability to interact with Schwann cells and stimulate the release of NGF and NT-3, which facilitate the regeneration of damaged axons and do not affect the synthesis of neuroregulin-1. In addition, the study of the quantitative content of individual protein fractions showed that the drug «Semax» has the most pronounced effect on the level of neurofilament-H in both segments of the nerve conductor, which indicates the important role and activation of the mitogen-activated protein kinase (MAPK / ERK) signalling pathway, which regulates processes of cytoskeletal protein synthesis and axon growth. Nevertheless, it was shown that in the variant of the experiment using Semax, there was a decrease in the level of GAP-43, which is a key marker of axonal growth, both in the proximal and distal segments of the nerve. The data obtained most likely indicate that the intramuscular administration of the drug does not affect the processes of axon growth, but is aimed at maintaining the survival of neurons and accelerated restoration of the functional state of nerve fibres, which is also confirmed by the appearance of an action potential and the ability of the nerve to conduct it against the background of the use of the Semax drug.

The content of total protein and its fractions in the hemolymph and body tis-sues of bees fed with Mg citrate

Mineral elements increase the capacity of organisms for their adaptation to abiotic factors and improve the biological value of animal products. The aim of the experiment was to study the effect of magnesium citrate on the content of total protein in the tissues of the whole organism, the content of soluble protein fractions in hemolymph, and catalase activity. The research was conducted on Carpathian honey bees. They were selected in the apiary at the Institute of Animal Biology of the National Academy of Sciences. The research was conducted in two stages. The first stage of the work was carried out on 5 groups of bees under the conditions of a laboratory thermostat for 20 days. Bees of the control group were fed daily with 1 ml of 50 % sugar syrup (SS) and 1 ml of H2O; group II – 1 ml of SS + 1 ml of 0.4 mg Mg/l nanocitrate; group III – 1 ml of CS + 1 ml of 2 mg Mg/l citrate; group IV – 1 ml of SS + 1 ml of 3 mg Mg/l citrate; group V – 1 ml of SS + 1 ml of 4 mg Mg/l citrate. The second stage of the study was conducted on four groups of bees and lasted 30 days. Bees of the control (I) group were fed daily with 1 ml of 50 % SS and 1 ml of H2O; group II – 1 ml of SS + 1 ml of 0.04 mg Mg/l citrate; group III – 1 ml of SS + 1 ml of 0.02 mg Mg/l citrate; group IV – 1 ml of SS + 1 ml of 0.01 mg Mg/l citrate. At the first stage, a decrease in α1-globulins in the hemolymph of bees of the III – V groups was established. The content of β-globulins increased in the II (P &lt; 0.001), III (P &lt; 0.01), IV (P &lt; 0.001) and V (P &lt; 0.001) experimental groups. The content of γ-globulins decreased in hemolymph of II (P &lt; 0.001) and III (P &lt; 0.01) groups. At the second stage, a decrease in α1–globulins was observed in the hemolymph of bees of the II, III and IV experimental groups compared to the control. The content of α2-globulins was significantly lower in the hemolymph of bees from IV group, and the content of β-globulins was higher in the hemolymph of the bees. An increase in the content of γ-globulins was established in II (P &lt; 0.05), III and IV (P &lt; 0.01) experimental groups. High catalase activity was observed in the hemolymph of bees of all experimental groups (P &lt; 0.001). The highest catalase activity was registered in bees of IV group. The use of 0.01 mg of Mg citrate in addition to sugar syrup feeding changed the ratio of individual hemolymph protein fractions. The relative content of albumin and β-globulin decreased and α2 and γ globulin content increased. An increase in the relative content of α1 and a decrease in β- and γ-globulins in the hemolymph of honey bees of the research groups were caused by Mg citrate in a dose of 0.04 mg.

Complex coacervation of pea protein and pectin: Contribution of different protein fractions to turbidity

Turbidity measurement is commonly used to determine interactions of biopolymers during complex coacervation. However, to investigate the influence of biopolymers with plant-based proteins, results may become affected when turbidity is additionally caused by protein self-aggregation of individual protein fractions. Therefore, the aim of the study was to distinguish between pea protein fractions that mainly are involved in protein-protein interactions and those that are involved in complex formation with pectin. To approach the aim, soluble pea protein (SPP) with low turbidity was fractionated from pea protein concentrate (PP) by isoelectric precipitation. Turbidity development of SPP with pectin was investigated in comparison to the PP with pectin. In mixture, pea protein and pectin, form complex coacervates mainly via electrostatic interactions. The pH-dependent complex formation between pectin and both protein samples respectively was investigated via turbidity measurement. The maximum turbidity of SPP-pectin mixtures was lower in comparison to PP-pectin mixtures. It was shown, that pea globulins influence the turbidity development due to protein self-aggregation, while the SPP fractions showed no influence on turbidity, resulting only in protein-pectin complexes. Analysis of the molecular weight distribution revealed that pea albumin (PA2) and another protein fraction with a low molecular weight (<20 kDa) are the main fractions interacting with pectin. Results from our study showed that protein self-aggregation should not be neglected when investigating the interaction between plant-based proteins and polysaccharides. • Turbidity results from both protein-protein and protein-pectin interactions. • Protein-protein interaction is mainly caused by pea globulin aggregation. • Protein-pectin interaction is dominated by pea albumin, mainly pea albumin 2. • Pea albumin 2 allows studying the effects of pectin structure on complex formation.

Subtractive sequence analysis aided druggable targets mining in Burkholderia cepacia complex and finding inhibitors through bioinformatics approach.

Burkholderia cepacia complex (BCC) is a group of gram-negative bacteria composed of at least 20 different species that cause diseases in plants, animals as well as humans (cystic fibrosis and airway infection). Here, we analyzed the proteomic data of 47 BCC strains by classifying them in three groups. Phylogenetic analyses were performed followed by individual core region identification for each group. Comparative analysis of the three individual core protein fractions resulted in 1766 ortholog/proteins. Non-human homologous proteins from the core region gave 1680 proteins. Essential protein analyses reduced the target list to 37 proteins, which were further compared to a closely related out-group, Burkholderia gladioli ATCC 10,248 strain, resulting in 21 proteins. 3D structure modeling, validation, and druggability step gave six targets that were subjected to further target prioritization parameters which ultimately resulted in two BCC targets. A library of 12,000 ZINC drug-like compounds was screened, where only the top hits were selected for docking orientations. These included ZINC01405842 (against Chorismate synthase aroC) and ZINC06055530 (against Bifunctional N-acetylglucosamine-1-phosphate uridyltransferase/Glucosamine-1-phosphate acetyltransferase glmU). Finally, dynamics simulation (200ns) was performed for each ligand-receptor complex, followed by ADMET profiling. Of these targets, details of their applicability as drug targets have not yet been elucidated experimentally, hence making our predictions novel and it is suggested that further wet-lab experimentations should be conducted to test the identified BCC targets and ZINC scaffolds to inhibit them.

Mass spectrometry in snake venom research

Mass spectrometry allows rapid and reliable identification and characterisation of proteins and peptides in snake venoms. With the increasing availability of transcriptomic and genomic data, there is a growing database of protein sequences that is essential for protein identification. Snake venoms are analysed using a multi-dimensional proteomic approach known as ‚venomics‘. Proteins are first separated by one- or two-dimensional gel electrophoresis or reversed-phase liquid chromatography. The individual protein spots or fractions are digested enzymatically and the resulting peptides are analysed by mass spectrometry. The proteins are identified by comparing the mass spectra of the peptides with those in the database. High-performance mass spectrometers allow the analysis of venoms even without prior separation of the protein mixture. We have analysed the protein composition (proteome) of two European snake venoms of greatest medical interest, the nose-horned viper (Vipera a. ammodytes) and the common adder (Vipera b. berus). The nose-horned viper is the most venomous European snake. Although its bite is rarely fatal, a human wictim often needs to be observed in hospital and treated with an antivenom. The adder is the most widespread European venomous snake and its bite causes milder symptoms than the bite of the nose-horned viper in most cases. To explain the observed differences in the effects of the two venoms at the molecular level, a proteomic study was performed. We also analysed the proteome of the venom of the meadow viper (Vipera ursinii), the most threatened snake species in Europe. It does not pose a threat to humans. In the wild, it feeds mainly on insects, while in captivity it is fed on mice. A comparison of the proteome of the venom of snakes in the wild and snakes in captivity showed clear differences. Thus, the composition of snake venom is diet-dependent. Mass spectrometry is also a very useful tool in the characterisation of antivenoms (antivenomics) to determine their specificity and neutralising power.

Prediction of fresh and ripened cheese yield using detailed milk composition and udder health indicators from individual Brown Swiss cows.

The composition of raw milk is of major importance for dairy products, especially fat, protein, and casein (CN) contents, which are used worldwide in breeding programs for dairy species because of their role in human nutrition and in determining cheese yield (%CY). The aim of the study was to develop formulas based on detailed milk composition to disentangle the role of each milk component on %CY traits. To this end, 1,271 individual milk samples (1.5 L/cow) from Brown Swiss cows were processed according to a laboratory model cheese-making procedure. Fresh %CY (%CYCURD), total solids and water retained in the fresh cheese (%CYSOLIDS and %CYWATER), and 60-days ripened cheese (%CYRIPENED) were the reference traits and were used as response variables. Training-testing linear regression modeling was performed: 80% of observations were randomly assigned to the training set, 20% to the validation set, and the procedure was repeated 10 times. Four groups of predictive equations were identified, in which different combinations of predictors were tested separately to predict %CY traits: (i) basic composition, i.e., fat, protein, and CN, tested individually and in combination; (ii) udder health indicators (UHI), i.e., fat + protein or CN + lactose and/or somatic cell score (SCS); (iii) detailed protein profile, i.e., fat + protein fractions [CN fractions, whey proteins, and nonprotein nitrogen (NPN) compounds]; (iv) detailed protein profile + UHI, i.e., fat + protein fractions + NPN compounds and/or UHI. Aside from the positive effect of fat, protein, and total casein on %CY, our results allowed us to disentangle the role of each casein fraction and whey protein, confirming the central role of β-CN and κ-CN, but also showing α-lactalbumin (α-LA) to have a favorable effect, and β-lactoglobulin (β-LG) a negative effect. Replacing protein or casein with individual milk protein and NPN fractions in the statistical models appreciably increased the validation accuracy of the equations. The cheese industry would benefit from an improvement, through genetic selection, of traits related to cheese yield and this study offers new insights into the quantification of the influence of milk components in composite selection indices with the aim of directly enhancing cheese production.

Role of CSN2, CSN3, and BLG genes and the polygenic background in the cattle milk protein profile

To devise better selection strategies in dairy cattle breeding programs, a deeper knowledge of the role of the major genes encoding for milk protein fractions is required. The aim of the present study was to assess the effect of the CSN2, CSN3, and BLG genotypes on individual protein fractions (αS1-CN, αS2-CN, β-CN, κ-CN, β-LG, α-LA) expressed qualitatively as percentages of total nitrogen content (% N), quantitatively as contents in milk (g/L), and as daily production levels (g/d). Individual milk samples were collected from 1,264 Brown Swiss cows reared in 85 commercial herds in Trento Province (northeast Italy). A total of 989 cows were successfully genotyped using the Illumina Bovine SNP50 v.2 BeadChip (Illumina Inc.), and a genomic relationship matrix was constructed using the 37,519 SNP markers obtained. Milk protein fractions were quantified and the β-CN, κ-CN, and β-LG genetic variants were identified by reversed-phase HPLC (RP-HPLC). All protein fractions were analyzed through a Bayesian multitrait animal model implemented via Gibbs sampling. The effects of days in milk, parity order, and the CSN2, CSN3, and BLG genotypes were assigned flat priors in this model, whereas the effects of herd and animal additive genetic were assigned Gaussian prior distributions, and inverse Wishart distributions were assumed for the respective co-variance matrices. Marginal posterior distributions of the parameters of interest were compared before and after the inclusion of the effects of the 3 major genes in the model. The results showed that a high portion of the genetic variance was controlled by the major genes. This was particularly apparent in the qualitative protein profile, which was found to have a higher heritability than the protein fraction contents in milk and their daily yields. When the genes were included individually in the model, CSN2 was the major gene controlling all the casein fractions except for κ-CN, which was controlled directly by the CSN3 gene. The BLG gene had the most influence on the 2 whey proteins. The genetic correlations showed the major genes had only a small effect on the relationships between the protein fractions, but through comparison of the correlation coefficients of the proteins expressed in different ways they revealed potential mechanisms of regulation and competitive synthesis in the mammary gland. The estimates for the effects of the CSN2 and CSN3 genes on protein profiles showed overexpression of protein synthesis in the presence of the B allele in the genotype. Conversely, the β-LG B variant was associated with a lower concentration of β-LG compared with the β-LG A variant, independently of how the protein fractions were expressed, and it was followed by downregulation (or upregulation in the case of the β-LG B) of all other protein fractions. These results should be borne in mind when seeking to design more efficient selection programs aimed at improving milk quality for the efficiency of dairy industry and the effect of dairy products on human health.

The Effect of Heat Treatment on Cow's Milk Protein Profiles.

Milk is a food of high nutritional value processed by heat treatment. Heat treatment of milk is a technological process designed to inhibit the growth of microorganisms and extend the shelf life of products. The heating process directly affects the molecular structure of whey proteins by the process of denaturation. It leads to the formation of a whey protein–casein polymer complex. Based on these facts, milk heat-treatment conditions should be controlled during milk processing. This work focuses on describing the whey protein denaturation process and formation of the complex of whey protein with casein. The effect of heat treatment on individual milk protein fractions alpha-casein (α-cas), beta-casein (β-cas), kappa-casein (κ-cas), beta-lactoglobulin (β-lg) and alpha-lactalbumin (α-la) was studied by SDS-PAGE. Formation of the whey protein–casein polymer complex increased significantly (p < 0.05) on increasing the temperature and duration of the heat treatment.

Influence of the time of bilberry (Vaccinium myrtillus L.) addition on the phenolic and protein profile of beer.

In recent years, there has been an increased fruit addition to the brewing process, especially in craft breweries. Fruit addition leads to changes in the organoleptic characteristics and chemical composition of beers. Bilberries are rich in phenolic compounds and possess significant antioxidant capacity. The effects of bilberry addition and brewing process parameters on the changes in the phenolic and protein profile of beer have not been sufficiently studied. The aim of this research was to investigate the changes in the individual phenolic compounds and the protein fractions in beer when bilberries were added at different maturation stages. An infusion mashing method was applied for the purpose of obtaining wort with an original extract of 14&deg;P after boiling. Pilsner malt, bitter and aromatic hops 60/40 (Perle and Cascade, respectively), dry yeast Saccharomyces pastorianus (carlsbergensis) Saflager W 34/70, and bilberries (Vaccinium myrtillus L.) were used. All processes were conducted in a Home Brew 50 all-in-one 50 dm3 brewing system. The fermentation was carried out in a stainless steel cylindroconical fermenter at a temperature of 14&deg;C. The &ldquo;green beer&rdquo; was transferred to small stainless-steel fermenters after 60% of the original wort extract had been fermented. The maturation continued for 14 days at 14&deg;C, and the beer lagering for 5 days at 2&deg;C. The bilberries were pasteurised in a water bath for 10 minutes at 70&deg;C. After cooling, they were added to small fermenters at a concentration of 167 g/dm3 at the beginning and on the seventh day of beer maturation. All variants were carried out in duplicate. After lagering, the beer was bottled using a &ldquo;beer gun&rdquo;. The beer samples from the experiments were filtered on the day of bottling and frozen until analysis. HPLC/UV-VIS and electrophoresis were used to determine the phenolics and proteins, respectively. The total monomeric anthocyanins were determined by the pH differential method. The original wort extract and alcohol concentration were evaluated, and the sensory analysis was performed according to EBC standard methods. The changes in 10 phenolic acids, 7 flavonoids, and 10 protein fractions in beer with bilberries added at the beginning and on the seventh day of maturation were studied. The addition of bilberries led to an increase in the phenolic acid (3-fold) and flavonoid (6.2-fold) concentrations. The highest enrichment was observed in terms of rutin, chlorogenic, caffeic, and 3,4-dihydrobenzoic acids. Rosmarinic acid and monomeric anthocyanins were only detected in the bilberry beers. Chlorogenic and neochlorogenic acids, rutin, and catechin dominated in the bilberry beers. Neochlorogenic and gallic acids, epicatechin, and catechin dominated in the bilberry-free beers. The addition of bilberries reduced the protein content by 93 to 96%. The number of protein fractions decreased from 10 to 4. The influence of the bilberry addition time on the phenolics and proteins was different, and it affected the individual protein fractions in a different way. More phenolic acids and flavonoids were determined when bilberries were added at the beginning of maturation. The losses of some protein fractions were higher at the beginning of maturation and of others on the seventh day of maturation, whereas the addition time did not matter for some of the fractions. This study provides new information related to the changes in the phenolic and protein profile of beer with bilberries depending on the time of bilberry addition during beer maturation. The protein concentration and number of protein fractions decreased dramatically. In spite of the significant protein losses, the bilberry addition improved the phenolic profile of the beer and its organoleptic characteristics. The presence of more phenolic compounds is related to the antioxidant capacity respective to the biological value of beer. Further research in this direction is needed.

Фракционный состав белков зерна видов пшениц с разными геномами и уровнем плоидности

The content of storage proteins in the seeds of wheat species with different levels of ploidy and genomic composition was studied. It was shown that in caryopses the protein content varied by three times. Averaging the data for different species and grouping them depending on the ploidy and genomic composition did not reveal significant differences in the total protein content, but the groups of species differed in fractional composition. Diploid and hexaploid species significantly differed in the content of individual protein fractions, while tetraploid species had an intermediate values. Spelt wheat, characterized by a high content and quality of protein, is a promising species for cultivation, however, species with the AbG genomic composition are also of interest. Discriminant analysis of the data showed that the species with the AbG genome (T. timopheevii, T. militinae) differed from other groups of species in the characteristics of the caryopsis protein.

Dual-gating pH-responsive membranes with the heterogeneous structure for whey protein fractionation

Whey protein is a mixture of globular proteins with high nutritional value and excellent functional properties availability. Purified individual whey proteins exhibit better functionality than in their original mixture, thus there is an increasing interest in developing more efficient methods to recover individual whey protein fractions, especially membrane technology. However, whey protein fractionation from the protein mixture is still a huge challenge for membrane separation. Herein, a dual-gating pHresponsive membrane with the heterogeneous structure was developed for whey protein fractionation. The heterogeneous structure of the membranes was obtained by grafting the dimethylaminoethyl methacrylate (DMAEMA) and 4-vinylpyridine (4VP) near the topside and inside the pores of the ethylene vinyl alcohol copolymer (EVAL) membranes based on selective modification of grafting sites. The PDMAEMA and P4VP gates responded to pH individually and provided a multi-stage regulation of the surface charge and sieving property of the membranes. The major whey protein fractionation from the mixture could be achieved by single dual-gating pH-responsive membrane via the sequential stepwise pH gradient from 3.0 to 8.0. The α-Lactalbumin (α-La), β-Lactoglobulin (β-Lg), lactoferrin (LF) and bovine serum albumin (BSA) were separated and enriched in the permeate at pH 3.0, 4.2, 6.4 and 8.0 by the diafiltration process, respectively. This work not only proposed a novel concept of pHresponsive membrane, but also offered a sustainable solution to fractionate the whey protein from the complicated mixture.

Microfiltration and Ultrafiltration Process to Produce Micellar Casein and Milk Protein Concentrates with 80% Crude Protein Content: Partitioning of Various Protein Fractions and Constituents

The objective of the study reported in this research paper was to produce micellar casein concentrate (MCC) and milk protein concentrate (MPC) with 80% crude protein relative to total solids (TS) using MF and UF processes respectively. Additionally, capillary gel electrophoresis (CGE) was used to study the protein fractions in retentate and permeate. For MCC production, 227 L of pasteurized SM was subjected to MF using 0.5-micron spiral wound polyvinylidene fluoride membrane. During the process, diafiltration (DF) water was added at six intervals, totaling 100% of the feed volume. For MPC production, 227 L of pasteurized SM from the same lot was subjected to UF using 10 kDa Polyethersulfone membranes. During the process, DF water was added at four different intervals, with a final total addition of 40% of the feed volume. Both processes used a volume reduction of five. There were significant (p &lt; 0.05) differences in all of the compositional parameters, except fat and casein for the MF retentate (MFR) and UF retentate (UFR). UFR had a higher crude protein (CP), TS, lactose, ash and calcium content as compared to MFR and this affected the CP/TS ratio found in both the retentates. The differences in membrane pore sizes, operating pressures and level of DF used all contributed to the differences in final CP/TS ratio obtained. The CGE analysis of individual protein fractions present in the UFR and MFR showed that UFR has a β-lactaglobulin to α-lactalbumin (α-LA) ratio similar to SM, whereas the MFR has a higher ratio, indicating preferential transmission for α-LA by the MF membrane. The results from this study show that MF and UF processes could be used for production of MCC and MPC with similar CP/TS ratio with careful selection of operating parameters, and that CGE can be used for detailed analysis of various protein fractions.

The effect of glutenins on grain quality as one of the complex polygenic traits in the genus Triticum (a review)

Evaluation of plant breeding material, based on protein markers, gives an opportunity to perform rapid and reliable selection and control the transfer of desired traits from parents to their progeny. A search for new and stable protein markers is needed to identify genotypes with high grain quality. Such storage proteins in wheat as glutenins have been studied profoundly enough. Full characterization of individual protein fractions and components can be found in many scienti fic publications, while studying genetic patterns of protein accumulation in the grain of different wheat cultivars and using high-molecular-weight (HMW) and lowmolecular-weight (LMW) glutenin subunits (GS) for genotype identi fication remain high in the research agenda. This is a comprehensive review of scienti fic publications about the structure and molecular organization of glutenins and a comparative analysis of 22 research papers about the degree of their effect on grain quality indicators: SDS-sedimentation volume (ml), grain/ flour protein content (%; 14% m.b.; 12,5% m.b.), mixing time (min), mixing tolerance (min; mm), bread loaf volume (cm3; ml), dough strength (10 -4 J), and P/L ratio. As a result of reviewing, the best alleles (subunits) of glutenin were identi fied, namely: Glu-A1а, Glu-B1(h, f, b), Glu-D1d, Glu-A3d, and Glu-B3d.

Separation of aggregated β-lactoglobulin with optimised yield in a decanter centrifuge

The interest in individual whey protein fractions, especially the main proteins α-lactalbumin and β-lactoglobulin, has been growing due to their unique nutritional value and their exceptional technofunctional properties. Various fractionation and purification methods have been published. However, none of them achieved highest purity, maximal recovery, and transferability to industrial scale. This study used thermal treatment for selective aggregation of β-lactoglobulin, which was subsequently separated in a pilot-scale decanter centrifuge from the α-lactalbumin-enriched centrate. The aim was to investigate if the centrifugal separation can be improved by pH-induced flocculation of the aggregates compared with non-flocculated suspensions at pH 7.0. With various analytical methods, it was demonstrated that the strongest flocculation occurred at pH 4.4 and facilitated separation of aggregate fragments sized below 20 μm. Finally, separation efficiencies of more than 99% were achieved by aggregate flocculation in the pilot-scale decanter even at low centrifugal forces.

Biomimetic approach for multifarious synthesis of nanoparticles using metal tolerant fungi: A mechanistic perspective

In present study, fungi isolated from metal rich site were explored for metal tolerance capacity and potential of multifarious synthesis of metal nanoparticles (NPs). Total 9 different fungi were isolated from rhizospeheric soils and molecularly characterized. Penicillium janthinellum DJP06 showed maximum metal tolerance capacity and synthesized gold and silver NPs. Detailed characterization confirmed the synthesis of protein capped, crystalline natured, spherical shaped gold and silver NPs. Mechanistic studies suggested involvement of fungal secretome proteins in the NPs synthesis. To find out the active protein(s) responsible for multifarious synthesis of NPs, the dialyzed proteins were fractionated by chromatography technique. Individual protein fractions were separately checked for their ability to synthesize NPs. Results suggested involvement of multiple proteins in an interactive manner for NPs synthesis. Testing the ability of these proteins for multifarious synthesis of other commercially important NPs will be an exciting future possibility.