Limiting Amino Acid Research Articles

Nutritional Evaluation of Milk Thistle Meal as a Protein Feedstuff for Diets of Dairy Cattle.

The objective of this work is to investigate the chemical and nutritional value of milk thistle meal (MTM) in order to improve it and to provide theoretical support for its application in dairy cattle production. MTM was assessed in comparison with seven conventional protein feed sources, namely, soybean meal (SBM), cottonseed meal (CS), canola meal (CN), palm kernel meal (PK), rice bran meal (RB), corn germ meal (CG), and sesame meal (SS). The chemical composition of these feedstuffs was assessed using wet chemical analysis, the Cornell Net Carbohydrate and Protein System was used to evaluate the carbohydrate and protein fractions, and the in situ nylon bag technique and the modified three-step in vitro method were used to assess the rumen degradation and intestinal digestibility. Additionally, Fourier transform infrared technology was used to determine the feedstuff protein spectral molecular structure and its amino acid profile was also assessed. The result showed that MTM acid detergent fiber, lignin, unavailable nitrogen, and non-degradable carbohydrate content were higher than those of the other feedstuffs. It had a 17% and 36% rumen effective degradation rate of neutral detergent fiber and dry matter, respectively, and had the lowest small intestinal rumen undegradable protein digestibility rate. It was low in leucine, histidine, arginine, and proline, but high in methionine. The total area of amide I and amide II in the protein secondary structure was similar to that of CN and CS, and the amide I and II ratio was not different from that of RB. To sum up, MTM has a poor carbohydrate composition and is high in fiber but, in comparison to most other protein feeds, has a higher crude protein rumen effective degradation rate, similar to that of SBM, and it is a good source of methionine, a limiting amino acid. Hence, its nutritional value can be further improved for application in dairy feeding through processes such as microbial or enzymatic fermentation.

Use of Directed Lactic Fermentation to Obtain Plant-Based, Upcycled Beverage from Milk Thistle Endosperm

This study aimed to evaluate the possibility of using milk thistle endosperm (MTE) extract with a protein content of >2 g/100 mL to obtain a fermented product, an alternative to milk beverages. Directed lactic fermentation with Lacticaseibacillus rhamnosus was carried out. The course of the process was monitored. The changes in pH, the saturation of the medium with dissolved oxygen, and temperature were measured. The values of the main nutritional parameters, silymarin content, amino acid profile/content, and the PDCAAS value (Protein Digestibility-Corrected Amino Acid Score) were determined in the extract before and after fermentation. The lactic acid fermentation of the MTE extract took place in four phases, with the activity of L. rhamnosus being the most intense between 4 and 8 h into the process. As a result of fermentation, there were changes in the total amino acid content in the tested medium, suggesting the catabolism of aspartic acid, arginine, proline, and isoleucine via LAB took place. Particularly significant was the increase in the content of lysine and valine (4.95 and 4.68 g/100 g of total AA, respectively), which are the limiting amino acids in MTE. Although MTE contained approximately 1% silymarin, no presence of this flavonolignan complex was found in the extracts.

Nutritional Quality of Early-Generation Kernza Perennial Grain

Grain from improved varieties of the perennial grass Thinopyrum intermedium (Host) Barkworth & D.R. Dewey is marketed under the trade name Kernza (common name intermediate wheatgrass, IWG). While a growing body of evidence is available on the nutritional quality of Kernza, gaps exist for components such vitamins and minerals and protein quality. Therefore, we performed two studies on early-generation breeding program material, characterizing nutritional quality by quantifying macronutrients, sugars, dietary fiber, amino acid profiles, fat composition, vitamins, minerals, carotenoids, antioxidants, and antioxidant activity. The IWG studied frequently had concentrations significantly different from the reference values for whole wheat flour. For example, IWG had 50% higher protein, 129% higher dietary fiber, and 65% higher ash content than reference whole wheat flour. Calcium and selenium were 267% and 492% higher, respectively, in IWG than whole wheat flour. Riboflavin and folate were 43% and 447% higher, respectively, and niacin 74% lower in IWG versus whole wheat flour. We identified lysine as the limiting amino acid, although its concentration was 33% greater in IWG than in whole wheat flour. These results support potential benefits of Kernza for human nutrition. This work supports ongoing studies to further characterize and evaluate nutritional quality during the domestication and breeding process.

Biomarkers for ideal protein: rabbit diet metabolomics varying key amino acids

With the main aim of identifying biomarkers that contribute to defining the concept of ideal protein in growing rabbits under the most diverse conditions possible this work describes two different experiments. Experiment 1: 24 growing rabbits are included at 56 days of age. The rabbits are fed ad libitum one of the two experimental diets only differing in lysine levels. Experiment 2: 53 growing rabbits are included at 46 days of age, under a fasting and eating one of the five experimental diets, with identical chemical composition except for the three typically limiting amino acids (being fed commercial diets ad libitum in both experiments). Blood samples are taken for targeted and untargeted metabolomics analysis. Here we show that the metabolic phenotype undergoes alterations when animals experience a rapid dietary shift in the amino acid levels. While some of the differential metabolites can be attributed directly to changes in specific amino acids, creatinine, urea, hydroxypropionic acid and hydroxyoctadecadienoic acid are suggested as a biomarker of amino acid imbalances in growing rabbits’ diets, since its changes are not attributable to a single amino acid. The fluctuations in their levels suggest intricate amino acid interactions. Consequently, we propose these metabolites as promising biomarkers for further research into the concept of the ideal protein using rabbit as a model.

Effects of single and twin thermal screw extrusion on protein quality of grain-free pet foods formulated with predominantly animal- or plant-based protein ingredients

With the diversification of the pet food industry and increasing market demand, the inclusion of plant protein in companion animal diets has become of interest. Pulses, commonly seen in grain-free diets, are high in protein and could serve as an alternative source of animal-based protein. There has been research on the ingredient about nutrient profiles and effects on canine health. However, little is known about the amino acid availability when pulses are incorporated into diets. In addition, there is lacking in knowledge about the effect of extrusion processing on protein quality and the possible interaction between processing and ingredients. Therefore, the study was conducted to determine the effect of extrusion and pulses on amino acid digestibility and protein quality. Eight grain-free diet formulations were designed: chicken byproduct meal diet (CON), chicken slurry diet (SLR), chicken slurry + yellow pea diet (SLR+YP), yellow pea diet (YP), green lentil diet (GL), garbanzo bean diet (GB), chicken slurry + taurine diet (SLR+TAU), and chicken slurry + yellow pea + taurine diet (SLR+YP+TAU). Two types of extruders were used: single screw and twin screw extruder. Diet samples were taken at 3 processing time points: raw ingredients, at the end of the preconditioner, and at the end of the extruder. The resulting 48 diet samples were analyzed for chemical composition and fed to cecectomized roosters (n=4/treatment) to determine standardized ileal amino acid digestibility and Digestible Indispensable Amino Acid Score (DIAAS)-like values. Even though the diets were mostly similar in chemical composition, methionine content was lower in diets containing yellow pea and green lentil. Extrusion processing did not have negative effect on natural or synthetic taurine in the diets. Preconditioning and extrusion also increased amino acid digestibility and DIAAS-like values in most diets, as processed diets could be considered well-digested and of good protein quality. According to reference protein sources, tryptophan and methionine were the most limiting amino acids in all treatment diet samples. In conclusion, grain-free diet formulation could result in good protein quality in canine diets and extrusion processing increased amino acid digestibility and protein quality.

Metabolic availability of amino acids in humans.

Knowledge of amino acid bioavailability and the effect of combining complementary protein sources are required to determine how to best meet an individual's protein and indispensable amino acid needs. Traditionally, protein quality of foods has been assessed using digestibility data. Digestibility may overestimate bioavailability of some amino acids particularly those more susceptible to heat and processing. The indicator amino acid oxidation (IAAO) method has been validated and applied to determine amino acid bioavailability termed metabolic availability of the first limiting amino acid of a proteinaceous food. The metabolic availability of the limiting amino acid in the test protein is determined as a ratio of the indicator amino acid oxidation response to graded intakes of the test protein compared to the indicator response to a reference protein (crystalline amino acid patterned after egg protein). The IAAO method has also been applied to assess the effect of protein complementation directly in humans on the overall protein quality of the diet. The results demonstrate that protein complementation augments the limiting amino acid supply and increases protein synthesis.

35 Role and mechanism of supplemental methionine in metabolic stress of broilers raised at high ambient temperature or stock density

Abstract Current poultry production practices may render fast-growing broilers prone to metabolic stresses induced by high ambient temperatures and(or) high stocking densities. As the first limiting amino acid of broilers fed corn-soy diets, methionine also serves as a free radical scavenger. Our laboratory has explored metabolic effects and biochemical mechanisms of supplemental methionine in grower and finisher diets for broilers raised at high temperature or high stock density. In Experiment 1, a total of 360 male, 1 d-old Cornish cockerel chicks were fed four diets (10 pens/treatment, 9 chicks/pen): 100 or 130% required methionine in the diets as DL-methionine (DL-MET) or 2-hydroxy-4-(methylthio)butanoate (HMTBA). The room was maintained at 4 to 13oC above the suggested thermoneutral temperature. The 130% DL-MET and HMTBA diets enhanced (P < 0.05) hepatic GSH concentrations of growers and plasma ferric reducing ability of finishers than the 100% diets. The DL-MET-fed growers had greater (P < 0.05%) muscle GSH and hepatic unsaturated fatty acid concentrations than those fed HMTBA. The methionine form and concentration exerted an interaction effect (P < 0.05) on the expression of inflammation-related genes in the liver of finishers. In Experiment 2, we determined if 30% extra DL-MET alleviated adverse effects of a greater stocking density on broilers. A total of 560 male, 1 d-old Cornish cockerels were housed at two stocking densities (9 and 12 birds/m2) and fed two concentrations of DL-MET (grower: 2.90 or 3.77 g/kg and finisher: 2.60 or 3.38 g/kg). The high stocking density decreased (P < 0.05) body weight and growth performance of growers and(or) finishers. Those differences were largely removed or attenuated by the 130% DL-MET diet. There were interaction effects (P < 0.05) between dietary DL-MET concentrations and stocking densities on activities of glutathione S-transferase in the liver of growers and the breast, thigh, and adipose tissue of finishers as well as on activities of glutathione peroxidase and superoxide dismutase in the thigh of growers. The 130% DL-MET diet decreased (P < 0.05) hepatic gene expression of heat shock protein 90 (18%) and malondialdehyde concentrations in the thigh and breast of finishers (35%). In summary, the high ambient temperature-induced metabolic responses of broilers were mediated by the extra methionine supplementation. That function varied with the chicken age and(or) tissue and the methionine form. Meanwhile, the 30% extra DL-MET addition partially reversed adverse effects caused by the greater stocking density, partially via improving tissue redox status. (This research was supported in part by Evonik Nutrition & Care GmbH, and was published: J. Anim. Sci. 97:4883-4894; J. Anim. Sci. 98:skaa092. doi: 10.1093/jas/skaa092).

PSV-2 Digestible indispensable amino acid scores (DIAAS) in pork products

Abstract The “Digestible Indispensable Amino Acid Score” (DIAAS) method measures protein quality in human foods. However, values for DIAAS are not available for some pork products. Therefore, this study aimed to determine DIAAS values for nine pork products. Nine diets contained one pork product (i.e., back ribs, shoulder butt, tenderloin, Coppa ham, prosciutto ham, speck ham, chorizo, Italian sausage, and bratwurst) as the only source of crude protein (CP) and amino acids (AA). Nine ileal cannulated gilts with an initial average body weight of 50.3 ± 3.8 kg were used in a 9 × 6 incomplete Latin square with 9 diets and six 7-d periods. Ileal digesta were collected on d 6 and 7 of each period. There were, therefore, six replicate pigs per diet, but no pig was fed the same diet twice. A nitrogen-free diet was used to measure basal endogenous losses of CP and AA, and this diet was fed to all pigs in one separate 7-d period. The standardized ileal digestibility (SID) and DIAAS of each pork product were calculated. Reference ratios were used for children from 6 mo to 3 yr old and individuals older than 3 yr. Data were analyzed by ANOVA using the MIXED procedure of SAS with pig as the experimental unit. Diet was the fixed effect and replicate pig was the random effect. Results indicated that for both age groups, prosciutto ham had greater (P < 0.05) DIAAS than all other pork products (Table 1), which may be because prosciutto is from the hind leg of the pig, which contains less connective tissue. Prosciutto was also not smoked, which may contribute to the greater DIAAS values for this protein because smoking may reduce DIAAS. For children from 6 mo to 3 yr old, tenderloin, Coppa ham, and Italian sausage had greater (P < 0.05) DIAAS than chorizo and bratwurst sausages, back ribs, and shoulder butt. However, for individuals older than 3 yr, Coppa ham had greater (P < 0.05) DIAAS than all other pork cuts and sausages. The observation that back ribs and shoulder butt had decreased DIAAS than tenderloin is likely because tender cuts with less connective tissues tend to have greater concentrations of indispensable AA with less non-nitrogen content. In addition, for both age groups, there was no limiting AA for all pork products, except that chorizo sausage was limiting in sulfur AA for children from 6 mo to 3 yr old. In conclusion, data from this experiment demonstrated that all pork products have “good” or “excellent” protein quality for individuals older than 6 mo of age, indicating that these food ingredients may be used to complement lower-quality proteins and provide a meal with all indispensable AA.

In vivo protein quality of pistachios (Pistacia vera L.)

Pistachios (Pistacia vera L.), similar to other nuts, fall under the protein foods category, according to the current U.S. Dietary Guidelines and Canada’s Food Guide. When substantiating claims for protein content of pistachios, protein quality data must be available to support these claims. In North America, the Protein Digestibility-Corrected Amino Acid Score (PDCAAS) is used for this purpose, however, Canada requires that this value be used to calculate a Protein Efficiency Ratio (PER). PER can be used for estimating protein quality. The current investigation aimed to offer current assessments of PER and PDCAAS, through the utilization of established in vivo rodent bioassays, for pistachio samples (raw, dry-roasted, and oil-roasted). Amino acid scores established lysine as the most limiting amino acid, with values of 0.933, 1.073, and 1.058 for raw, dry-roasted and oil-roasted pistachios, respectively. PDCAAS values ranged from 83 to 94%, being highest for dry-roasted pistachios. The measured PER values (corrected to casein = 2.50) were 2.53, 2.48, and 2.58 for the raw, dry-roasted, and oil-roasted pistachios, respectively, and were not significantly different from casein. These data support the position that pistachios can be labeled as “good sources of protein” in the U. S. and Canada.

Initial Amino Acid:Codon Assignments and Strength of Codon:Anticodon Binding.

The ribosome brings 3'-aminoacyl-tRNA and 3'-peptidyl-tRNAs together to enable peptidyl transfer by binding them in two major ways. First, their anticodon loops are bound to mRNA, itself anchored at the ribosomal subunit interface, by contiguous anticodon:codon pairing augmented by interactions with the decoding center of the small ribosomal subunit. Second, their acceptor stems are bound by the peptidyl transferase center, which aligns the 3'-aminoacyl- and 3'-peptidyl-termini for optimal interaction of the nucleophilic amino group and electrophilic ester carbonyl group. Reasoning that intrinsic codon:anticodon binding might have been a major contributor to bringing tRNA 3'-termini into proximity at an early stage of ribosomal peptide synthesis, we wondered if primordial amino acids might have been assigned to those codons that bind the corresponding anticodon loops most tightly. By measuring the binding of anticodon stem loops to short oligonucleotides, we determined that family-box codon:anticodon pairings are typically tighter than split-box codon:anticodon pairings. Furthermore, we find that two family-box anticodon stem loops can tightly bind a pair of contiguous codons simultaneously, whereas two split-box anticodon stem loops cannot. The amino acids assigned to family boxes correspond to those accessible by what has been termed cyanosulfidic chemistry, supporting the contention that these limited amino acids might have been the first used in primordial coded peptide synthesis.

Valine in Broiler Diets: A review

Valine (Val) is the 4th limiting amino acid in a corn and soybean meal–based diet for broiler chicken, after methionine, lysine, and threonine. Valine, isoleucine, and leucine represent the branched-chain amino acids (BCAAs) family. It was reported that the performance of broilers is adversely affected by an imbalance of BCAAs in the diet. So, a low crude protein diet must supplement with Val in a range of 0.01–0.20 % for optimal growth performance. The present review reflects on the studies undertaken to assess the effect of dietary levels of Val on growth performance, immunity, gut health, carcass traits, and bone mineralization in broilers. Several studies have revealed that supplementation of valine in higher levels than the present recommendation of NRC (0.72–0.73% in the finisher phase), improves weight gain, feed: gain ratio, intestinal morphology, carcass characteristics, immune response, and increased bone density and strength. According to the data from the literature discussed in this survey, the Val to-lysine ratio recommendation might require reaching 0.86 for high-yielding broilers from 0-15 days of age. It also suggests that the ratio of digestible valine to lysine is between 75 and 84% in growing and finishing. For best feed intake, weight gain, and FCR, studies indicate that 0.903% is the recommended digestible Val level for a better overall performance of 22 to 42 d broilers. This review provides a summary of the addition of valine to the broiler diet and its potential influence on productive performance, immunity, gut health, carcass characteristics, and bone mineralization in birds.

Investigation of the amino acid composition of gluten-free biscuit with carob

The article studies the amino acid composition of the developed biscuit semi-finished products. When developing the recipe for gluten-free products, special attention was paid to the protein composition of the raw materials and the calculation of the amino acid score, since the lack of a certain amino acid affects the ability of gluten formation during the kneading process. In addition, an unbalanced amino acid composition can cause an imbalance in the human body and negatively affect the functioning of muscles, heart, brain and other organs, leading to diseases. The objectives of the research included the following: determination of the amino acid composition of gluten-free biscuit semi-finished products; analysis of amino acid composition and calculation of the amino acid score of gluten-free biscuit products. The amino acid composition was calculated according to well-known methods, taking into account the chemical composition of food products. During the calculation, the biological value of proteins was assessed, the utility coefficient, the amino acid composition balance coefficient, and the amino acid score difference coefficient were determined. It was established that the developed gluten-free biscuit contained a significant amount of threonine, namely 11.38 g per 100 g of protein. As a result of calculations, it was determined that the first limiting amino acid was tryptophan, the second was the compound «phenylalanine + tyrosine», the shares of which in the amino acid score were 0.12 and 0.90, respectively. An assessment of the complex balance of a gluten-free biscuit semi-finished product showed an insufficient level of balance in human nutrition, but the indicators of individual amino acids compared to the control made from wheat flour were higher, for example, valine by 1.8 times, isoleucine, leucine and lysine by 1.1 times, metheonine + cysteine 2.7 times and threonine 2.8 times.

Comparative evaluation of amino acid profiles, fatty acid compositions, and nutritional value of two varieties of head water Porphyra yezoensis: “Jianghaida No. 1” and “Sutong No.1”

Comparative nutritional analysis of Porphyra yezoensis strains “Jianghai No. 1” and “Sutong No.1” revealed significant differences in crude protein, crude fat, crude fiber, crude ash, and total sugar. Both strains contained 16 amino acids, with alanine as the highest and histidine the lowest content. Methionine was determined to be the first limiting amino acid for both strains in both amino acid score and chemical score assessment. They also featured 24 fatty acids, differing notably in four saturated fatty acids and five unsaturated fatty acids. All 12 mineral elements were present, notably differing in sodium, magnesium, potassium, calcium, iron, and zinc. The “Jianghai No. 1” strain stands out with its nutrient-rich profile, featuring high protein content, low fat, and abundant minerals, which could potentially command higher market prices and generate greater economic benefits due to its superior nutritional, and set a strong foundation for its future large-scale promotion and cultivation.

Lysine Distinctively Manipulates Myogenic Regulatory Factors and Wnt/Ca2+ Pathway in Slow and Fast Muscles, and Their Satellite Cells of Postnatal Piglets.

Muscle regeneration, representing an essential homeostatic process, relies mainly on the myogenic progress of resident satellite cells, and it is modulated by multiple physical and nutritional factors. Here, we investigated how myogenic differentiation-related factors and pathways respond to the first limiting amino acid lysine (Lys) in the fast and slow muscles, and their satellite cells (SCs), of swine. Thirty 28-day-old weaned piglets with similar body weights were subjected to three diet regimens: control group (d 0-28: 1.31% Lys, n = 12), Lys-deficient group (d 0-28: 0.83% Lys, n = 12), and Lys rescue group (d 0-14: 0.83% Lys; d 15-28: 1.31% Lys, n = 6). Pigs on d 15 and 29 were selectively slaughtered for muscular parameters evaluation. Satellite cells isolated from fast (semimembranosus) and slow (semitendinosus) muscles were also selected to investigate differentiation ability variations. We found Lys deficiency significantly hindered muscle development in both fast and slow muscles via the distinct manipulation of myogenic regulatory factors and the Wnt/Ca2+ pathway. In the SC model, Lys deficiency suppressed the Wnt/Ca2+ pathways and myosin heavy chain, myogenin, and myogenic regulatory factor 4 in slow muscle SCs but stimulated them in fast muscle SCs. When sufficient Lys was attained, the fast muscle-derived SCs Wnt/Ca2+ pathway (protein kinase C, calcineurin, calcium/calmodulin-dependent protein kinase II, and nuclear factor of activated T cells 1) was repressed, while the Wnt/Ca2+ pathway of its counterpart was stimulated to further the myogenic differentiation. Lys potentially manipulates the differentiation of porcine slow and fast muscle myofibers via the Wnt/Ca2+ pathway in opposite trends.

Effect of Temperature on the Nutritional Quality and Growth Parameters of Yellow Mealworm (Tenebrio molitor L.): A Preliminary Study

The nutritional quality of insects is related to many factors, including their rearing conditions. In this study, the effects of temperature on the contents of crude protein, lipids, ash, and amino acids and the body size and weight of Tenebrio molitor larvae were analysed. The larvae were reared with the occurrence of the first 20 pupae in a laboratory incubator at temperatures of 22, 25, and 28 °C. The results revealed that the weight (from 0.09 to 0.15 g), dry matter (DM) content (from 30.72 to 36.55 g/100 g), and fat concentration (from 22.46 to 36.01 g/100 g DM) of the larvae increased with increasing rearing temperature. In contrast, the crude protein content significantly decreased (from 64.33 to 54.41 g/100 g DM). Methionine was the limiting amino acid. The essential amino acid index ranged from 37% to 45%. Information about the effect of temperature on the growth and nutritional parameters of mealworms may contribute to the optimisation of mealworm-rearing technology.

Characterization of Amino Acid Composition, Nutritional Value, and Taste of Fruits from Different Actinidia arguta Resources

The nutritional value and flavor and texture characteristics of fruits from different Actinidia argute resources were scientifically evaluated and compared. Using 35 A. arguta fruits as materials, the amino acid composition and content were determined by an automatic amino acid analyzer, and differentiation analysis, amino acid nutritional value evaluation, TAV flavor analysis, correlation analysis, PCA comprehensive evaluation, and cluster analysis were conducted to clarify the diversity of A. arguta resources in terms of amino acid content, composition, and flavor characteristics. Analysis of differential results showed that the A. arguta resource fruits contained 17 amino acids with a total amino acid content of 384.20∼2590.56 mg/100 g. The results of the nutritional value evaluation showed that the Leu of the fruits of the A. arguta resources all conformed to the ideal model proposed by FAO/WHO, and the Leu content of all the resources exceeded the human body’s needs, and it was also found that the first limiting amino acid of the Actinidia argute resources was Ile and the second limiting amino acid was Lys. TAV of the flavor-presenting amino acids was calculated to evaluate the flavor-presenting taste characteristics, and the amino acids that influenced the flavor of A. arguta fruit were Glu and Cys. PCA showed that the 2 principal components could better reflect the comprehensive information of amino acids in A. arguta, and the cumulative variance contribution rate was 87.88%, which could represent the main trend of amino acids in A. arguta. A comprehensive amino acid evaluation model was established, and the composite scores indicated that the top 5 excellent resources were S4, S10, S18, S25, and S30. Hierarchical cluster analysis classified the 35 A. arguta resources into 4 categories, which better reflected the differences in amino acid content and composition, nutritional value, and taste characteristics among A. arguta fruits from different collection sites.

Nutritional quality and microbial diversity of Chhurpe from different milk sources: an ethnic fermented food of high-altitude regions of the Western Himalayas

Chhurpe is a naturally fermented traditional dairy food of high altitude Western Himalayan region. They are generally prepared from cow or yak milk and are consumed during harsh winters. The present study was conducted to characterize the different Chhurpe samples traditionally prepared by the ethnic groups utilizing milk from different animal breeds such as cow, yak, Zomo (cow × yak), and Germo (Zomo × yak). Nutritional characterization revealed that 100 g of Chhurpe could completely meet the dietary protein requirements of children and adults with high concentrations of methionine and lysine. Tryptophan and valine were the limiting amino acids among all the Chhurpe samples. Palmitic, stearic, and oleic acids were the predominant fatty acids. The Chhurpe samples were a rich source of micronutrients such as calcium, iron, and zinc meeting above 70% of recommended dietary allowances (RDA) among children (3–10 years) and up to 20% RDA for adults. Culture-independent metagenomic analysis revealed that lactic acid bacteria were the predominant group, consisting of genera such as Lactobacillus, Leuconostoc, Lactococcus, and Streptococcus followed by acetic acid bacteria, mainly Acetobacter. At the species level, Lactobacillus delbrueckii was the abundant strain among all the Chhurpe samples. Species diversity was significantly higher in Chhurpe prepared from Zomo milk. Probiotic bacterial strains such as Lactobacillus helveticus, L. delbrueckii, L. brevis, and Leuconostoc mesenteroides were identified in the Zomo Chhurpe indicating their superior quality. The present study was an attempt to popularize Chhurpe and promote its wider consumption by highlighting its nutritional properties.

Myofibrillar Protein Profile of The Breast Muscle in Turkeys as a Response to The Variable Ratio of Limiting Amino Acids in Feed

The effects of the different dietary levels of Arginine (Arg) in low- and high-methionine (Met) diets on the meat quality and myofibrillar protein profile of breast muscles from turkeys were determined. The experiment had a completely randomized 3 × 2 factorial design with three levels of Arg (90%, 100%, and 110%) relative to the dietary Met levels (30% or 45%). At 42 days of age, eight turkeys from each treatment were sacrificed; the meat pH value was measured at 48 h post-slaughter, and meat color was measured according to the CIE L*a*b* system. The SDS-PAGE method was performed to investigate the myofibrillar protein profile of the breast muscle. The analysis of variance showed a significant effect of the Arg or Met dietary levels on the color parameter b* and the profile of myofibrillar proteins in muscles. The results of the cluster analysis of the myofibrillar protein profile showed that, with a high level of Arg (i.e., 110%), the level of Met 35% or 45% was less important. It can be concluded that the increase in the share of Arg and Met in the diet of turkeys increases the content of some myofibrillar proteins (actinin, desmin, actin) and reduces degradation during the post-slaughter proteolysis of proteins that are considered tenderization indicators.

Dynamic in-vitro system indicates good digestibility characteristics for novel upcycled plant protein; correlation to techno-functional properties

An increasing global population demands the broadening of the plant-based protein portfolio. The high volume of by-products produced across the food industry presents the opportunity to reduce food waste while reclaiming valuable nutrition. The current study examines a novel protein, BRP, extracted from brewers spent grains regarding its techno-functionality and digestibility, in comparison to a variety of proteins including whey, soy, rice and two pea protein sources. Compositional, foaming, emulsifying, structural and rheological properties were examined, while digestion kinetics were determined using the dynamic tiny-TIM in vitro digestion model. BRP performed similarly to whey protein in many respects, demonstrating a high solubility, high nitrogen bioavailability (>90%) and comparable N digestion kinetics, however BRP exhibited no rheological changes over heating. The digestible Indispensable amino acid score for BRP was 67% with lysine as the sole limiting amino acid, a higher value than soy, rice and one of the pea proteins investigated. Industrial relevanceThe production of a protein ingredient from a plentiful and otherwise low-value food processing by-product presents an opportunity for an increased shift towards more sustainable protein sources for the food industry. This protein displays enhanced nutritional characteristics when compared to variety of plant protein sources, and promising functional properties such as a high solubility. This study offers an examination of a novel, upcycled protein ingredient as a potential tool for food manufacturers in the shift towards a more sustainable and secure food future.

Nano casein-pectin complex: exploring physicochemical, organoleptic properties, and LAB viability in skimmed milk and low-fat yoghurt.

Protein complexes with a nutritional value, heat stability, and gelling properties with no negative impact on culture viability have promising application prospects in the fermentation industry. The aim of the study was to investigate the possibility of applying physical modification seeking high-protein-fortified yoghurt production using the nano casein-pectin NCP complex as an active colloidal system with enhanced structural and thermal properties and monitor the quality properties of the physicochemical, heat stability, rheological, starter culture viability and sensory evaluation of fortified products comparing with the plain control throughout the cold storage. High-energy ball milling (HEBM) technique was used to produce nanoparticles of casein powder and smaller particles of pectin individually, and particle size and zeta potential was assessed. Deferent Nano casein-pectin (NCP) complex formulations were prepared, their physicochemical properties were assessed including protein quality via Amino Acid Analyzer (AAA), viscosity, thermogravimetric analysis (TGA), and then used in fortification of skimmed milk and low-fat yoghurt to monitor the fortification effects. The particle sizes showed to be ≈166 nm and 602.6 nm for nano-casein and pectin, respectively. Milk fortification with the NCP complex has significantly increased the nutritional value represented in increased protein content (7.19 g/100 g in NCP5); Ca, P, and S content (2,193.11, 481.21, and 313.77 ppm); and amino acid content with first limiting amino acids; histidine (0.89 mg/g), methionine (0.89 mg/g), and low content of hydrophobic amino acids (HAAs) may cause aggregation. NPC fortification enhanced physicochemical properties announced in enhanced viscosity (62. mP.s in NCP5) and heat stability (up to 200°C) compared with control skimmed milk (SM). NCP yoghurt fortification significantly increased protein content to 11 mg/100 g in T5, enhanced viscosity to 48.44 mP.s in T3, decreased syneresis to 16% in T5, and enhanced LAB viability which was translated in preferable sensorial properties. Applying fortification with nanoparticles of the casein-pectin (NCP) complex balanced the amino acid content and improved physicochemical, rheological, nutritional, and sensorial properties and LAB viability, which can be recommended further in functional food applications.