Protein Source Research Articles (Page 1)

High pathogenicity avian influenza (HPAI) continues to be a major threat to poultry production in Bangladesh, where poultry is a primary source of affordable protein and outbreaks also pose zoonotic risks to humans. We conducted a cross-sectional study in 331 commercial broiler, layer, and Sonali poultry farms to evaluate biosecurity and farm management practices across different poultry production systems in relation to government-recommended biosecurity guidelines, and to identify risk factors associated with avian influenza (AI) outbreaks, as well as to assist in mitigating AI outbreak risks and improving disease prevention in poultry farms. We found that 93.4% of farms were in residential areas and 68.8% of the farms were near waterbodies. A significant number of farms had access to domestic and wild animals, with limited implementation of disinfection and hygiene practices. Overall, most farms did not fully comply with government suggested standard biosecurity and good farm management guidelines. In total, 51 (15.4%) farms reported AI outbreaks with the highest proportion in layer farms (29.1%), followed by broiler (10.6%) and Sonali (7.8%). AI outbreaks were significantly associated with outbreak history on nearby farms, farmers or workers visiting other farms, and farm management by workers or multiple individuals rather than owners. Veterinarian visits were also found to be associated with outbreaks on farms, which may reflect reporting bias rather than causality. Our findings underscore that substantial gaps in biosecurity compliance remain widespread across all farm types. We recommend strengthening biosecurity protocols, addressing environmental risks, and providing comprehensive training programs for farmers to control AI spread, prevent future outbreaks, and ultimately safeguard both poultry and public health.

Totoaba (Totoaba macdonaldi) aquaculture offers economic and ecological advantages. However, its culture still relies on fishmeal in diets because alternative protein sources show reduced productive performance. The current study assessed the impact of low concentrations of methionine and taurine together with alternative proteins, on the productive performance of T. macdonaldi over a 60-day experimental period. Four diets were formulated for this purpose, a basal diet (D-BD), the basal diet with methionine (D-MET), the basal diet with taurine (D-TAU), and the basal diet with methionine and taurine (D-MET + TAU). The present experiment used a randomized design. One hundred forty-four juveniles (41.0 ± 0.5g in weight) were randomly distributed in 12 tanks (500 L) in triplicate groups to assess biological indices, cholesterol content, hepatic gene expression, and the synthesis and transport of taurine. The statistical analysis revealed that the dietary treatments D-MET and D-TAU positively affected the growth rate, whereas their interaction resulted in a significantly higher growth (p < 0.05). The expression of the igf-1 gene in the liver increased and showed a positive interaction. When TAU and MET were limited, there was an observed overexpression of csad in hepatic tissue. Diets supplemented with TAU showed a decrease in total cholesterol level, whereas cholesterol level in the liver increased with MET supplemented alone. Total TAU content in fish tissues was significantly higher when both TAU and MET were supplemented. In conclusion, T. macdonaldi exhibits a limited capacity, for TAU synthesis, and MET limitation appears to restrict growth potential.

With the growing demand for sustainable and high-quality protein sources, evaluating their digestibility and amino acid availability is essential for human nutrition. The objective of this study was to assess the digestibility and Digestible Indispensable Amino Acid Score (DIAAS) of two novel protein sources, barley protein concentrate (BPC) and corn protein concentrate (CPC), using a minipig model as a proxy for human digestion METHODS: A T-cannulated minipig model (n = 6) was employed in a crossover design to measure standardized ileal amino acids (AA) digestibility and calculate DIAAS values, following Food and Agriculture Organization (FAO) guidelines. Each protein source was tested alongside a protein-free diet to estimate basal endogenous AA losses. BPC exhibited a stable AA profile with an overall digestibility of 92.5%, while CPC had a digestibility of 88.9%. Lysine was identified as the most limiting AA in both proteins. The DIAAS values for BPC were 31, 38, and 45 for infants, children, and adults, respectively; for CPC, the values were 45, 54, and 64. These findings highlight the potential of BPC and CPC as valuable protein sources for human consumption.

Goat meat, despite being nutritious and a good source of protein, is susceptible to lipid oxidation, a process that negatively affects its sensory and nutritional quality. This problem, which also occurs in meat products, can be minimized with the use of antioxidants, with rosemary being a promising natural alternative to replace synthetic antioxidants. The objective of this research was to develop a goat meat salami using rosemary extract as a natural antioxidant, partially replacing sodium ascorbate. Three salami formulations were developed with varying concentrations of rosemary extract and sodium ascorbate. The treatments were subjected to physical-chemical, microbiological, and sensory analyses. All formulations complied with the Technical Regulations on Identity and Quality for salamis, presented good microbiological quality, and were well accepted by tasters, emphasizing that the addition of rosemary extract did not interfere with acceptability. The results showed that the use of rosemary extract can be a viable alternative to partially replace synthetic antioxidants in salami without compromsing its nutritional, microbiological, and sensory quality.

Food insecurity remains a pressing issue, particularly in developing countries in sub-Saharan Africa where malnutrition remains a major public health problem. Resources as well as the knowledge to prepare quality over quantity food are limited. Indigenous legumes such as Mucuna pruriens are important dietary components; although the nutrients in the beans are low, fermentation would render them available for absorption and utilization in the body. While affordable, consumption is limited by anti-nutritional factors particularly L-DOPA which reduce nutrient utilization and may cause adverse effects if not properly processed. Mucuna pruriens is a potential alternative protein source. This study evaluated the impact of fermentation on the Mucuna pruriens whole seed form. The primary experimental factor was fermentation, and a Completely Randomized Design (CRD) was used, yielding 27 treatments including unfermented or controls. Factors were variety (Black, White, Mottled), fermentation method (brine at 5% and 10% NaCl, or yeast (Saccharomyces cerevisiae)1 g/500 g), temperature (25°C or 37°C), and time (24 h or 72 h). After fermentation, samples were ground and analysed for proximate and mineral composition using AOAC methods; L-DOPA was quantified by UV-spectrophotometry. Data were analysed in R (ANOVA; Tukey’s HSD at p&lt; 0.05). Carbohydrate content increased significantly (p&lt; 0.05), for example from 54.01% to 64.12% p=0.02 in Black beans and from 56.00% to 63.09% p=0.013 in Mottled beans, while crude fat and fibre were significantly reduced (p &lt; 0.01). Yeast fermentation at 37°C for 72 hours led to a highly significant reduction of L-DOPA by 40 to 60% (p&lt; 0.001) from about 6–8 mg/100g in raw beans to 3–4 mg/100g after fermentation, thereby enhancing the safety of the beans. Mineral content also increased, for Mottled variety, calcium content was (19.57 mg/100g to 23.68 mg/100g, p=0.001), and iron was (0.5mg/100g to 1.17 mg/100g, p=0.001). Brine fermentation at 25°C had minimal effect. Among the tested combinations, yeast fermentation at 37°C for 72 h is recommended as the most effective option for improving the nutritional profile and reducing anti-nutritional factors in Mucuna pruriens seeds, making them a safer and more viable food option. Further research should focus on optimizing fermentation conditions, microbial selection and preservation to promote its sustainable use. Key words: Anti-nutritional factors, Bioavailability, Fermentation, Food security, L-DOPA, Mucuna pruriens

As the global population expands and protein demand also rises, the environmental and ethical issues around traditional animal-based proteins become more important. Conventional proteins are associated with several issues, such as greenhouse gas emissions, deforestation, and extensive use of water and land. However, alternative proteins (APs) originating from plants, microbes, insects, and cultured cells have the potential to overcome such problems. Such proteins not only provide a solution to the growing population but also a sustainable alternative to conventional protein sources. This review focuses on the various sources of alternative proteins, such as plant-based (oil seeds, soybeans, peas), insects (mealworms and crickets), microbial (algae and fungi), and lab-grown proteins. It investigates the extraction and production processes, such as wet and dry fractionation, enzymatic hydrolysis, fermentation, and cell culture, with a focus on efficiency, scalability, and sustainability. Furthermore, the review discusses current consumption trends and commercial acceptance of alternative proteins, taking into account taste, texture, price, and cultural preferences. Despite their potential, alternative proteins are limited by high production costs, regulatory hurdles, and market acceptance issues. The analysis continues by exploring future potential for boosting protein quality, advancing processing technology, and broadening uses in the food and industrial sectors. Overall, AP may play an important role in developing a sustainable food system, providing nutritional safety, and mitigating the environmental effects of conventional protein production.

Egg is a source of animal protein which is cheap and it is very easy to get for consumption. Hence, the quality of egg becomes one of the factors that must be considered in laying hen cultivation. One of the important factors is feeding. Feeding with CGM (Corn Gluten Meal) substitution to laying hens is conducted to know the influence of CGM to the number of eggs, the weight of eggs, feed conversion, and egg-yolk colour. This research was conducted in June-July 2022 in laying hen farming located in Pasuruan, East Java. This research is con-ducted by dividing 40 strain laying hens of Isa Brown into 4 treatment groups, so each group consists of 10 hens. The treatment used is by feeding them with 4 different CGM concentration, namely P0 (CGM 0%), P1 (CGM 5%), P2 (CGM 10%), and P3 (CGM 15%). The obtained data was analysed by using Analysis of Variance (ANOVA). The result of the research shows that CGM substitution does not influence to the number of eggs, but influence the weight of eggs, feed conversion, and egg-yolk colour. The average of the heaviest egg is obtained at treatment group given CGM 10% of feed composition, the average of the littlest feed conversion at group treatment given CGM 15%, and egg yolk colour of laying hens with CGM 15% get the biggest score 13 and the average is 12,33.

Due to the rising protein malnutrition because of high cost of animal protein in many countries in Africa including Nigeria, this renews the interest in legume seeds as potential sources of vegetable protein for human food. Prosopis africana seeds is one of the under used leguminous seeds crops added to food as a condiment called Okpehe. This study was designed to establish optimum conditions for the fermentation of Prosopis africana seeds into vegetable protein based condiment (Okpehe) using Response Surface Methodology (RSM) with four (4) variables namely; fermentation duration (X1), inoculums concentration (X2), pH (X3) and temperature (X4). Prosopis africana seeds were fermented at various temperatures of 35°С, 40°С, 45°С and 50°С for four days (96 hours).The inoculums used for fermentation contained (7.5×108 cells/5ml-1 , 1.5×109 cells/10ml-1 and 2.3×109 cells/15ml-1 into 20g of boil unfermented P. africana seeds. The cell population was calibrated using McFarland standards (No1). The interaction effects of these four variables on the % protein yield were investigated using Central Composite Design (CCD) fractional design of experiments. From experimental data generated by the design of experiment (DOE), using MINITAB 17 software, optimum conditions were obtained at 40⁰C, with inoculum (Bacillus licheniformis) concentration of 1.5×109 cells/10ml-1 with pH 7 at fermentation duration of 96 hours. The adequacy (R2) of the models was highly satisfactory for the processes being 0.90. In conclusion, it was observed that protein content of fermented Prosopis africana seeds were increased during fermentation because, Protein had the highest yield of 44.52 % after 96 hours of fermentation at temperature of 40°С. Key Words: Prosopis africana, fermentation duration, Okpehe and Response Surface Method

Safe feed is vital for animal health, and is a precondition for food safety and human health. Dietary exposure of poultry chickens to aflatoxin-contaminated feeds may result in negative health implications, and may be carried-over into their by-products such as eggs. The aim of this study was to determine the contamination levels of aflatoxins in feed and egg samples from layer chickens, as well as egg samples from free-range chickens from Bafoussam in Cameroon. Levels of crude proteins and total aflatoxin were determined in layer chickens’ feeds (n=9) from nine poultry farms. Additionally, aflatoxin B1 was quantified in eggs (16 pooled egg samples) from the layer chickens that were fed the studied feeds as well as eggs (10 pooled egg samples) from free-range hens in Bafoussam. All studied feed samples revealed levels of crude proteins (mean: 20.4, range: 17.2-25.6 g/100 g of feed) higher than standard (16 g/100 g feed), and levels of total aflatoxin (mean: 107.6, range: 27-178 μg kg-1) higher than the maximum tolerable limit (20 μg/kg) in feed. Levels of aflatoxin B1 in eggs from layer chickens (mean: 0.0005, range: nd-0.0013 μg/kg; 62.5%) and in eggs from free-range hens (mean: 0.0016, range: 0.0009-0.0024 μg/kg; 100%) did not exceed the maximum tolerable limit (2 μg/kg) of aflatoxin B1 in foods destined for human consumption. The direct proposional relationship between crude proteins and total aflatoxins levels speculate that proteins source for feed production may be a critical control point for aflatoxins contamination in feeds. Although levels of aflatoxins B1 in eggs were generally low, the higher occurrence frequencies may be a concern when considering eggs as a part of diet for all age categories in Cameroon.

Pulses and pseudocereals are sustainable protein sources of bioactive peptides (BAPs) with potential antioxidant, antihypertensive, antidiabetic, antimicrobial, and immunomodulatory activities. BAPs are typically liberated during gastrointestinal digestion or through bio-based processes, among which enzymatic hydrolysis and microbial fermentation represent the most widely applied strategies. Enzymatic hydrolysis provides controlled and reproducible release of short peptide motifs; recent advances such as ultrasound- or high-pressure–assisted hydrolysis enhance yield and bioactivity. Fermentation exploits microbial proteolytic activity to generate complex peptide mixtures, while improving sensory quality, reducing antinutritional compounds, and responding to consumer demand for natural and “clean-label” products. In silico tools increasingly complement these approaches by accelerating peptide discovery, predicting interactions with molecular targets, and guiding process design. This review provides an updated overview of bio-based methods to produce BAPs from pulses and pseudocereals, emphasizing the comparative advantages of enzymatic and fermentation technologies and their integration with computational tools. Moreover, it examines regulatory frameworks in the European Union, the United States, Japan, and China, while discussing current challenges for industrial scale-up and application in functional foods and nutraceuticals. These combined strategies offer a promising pathway to unlock the health and sustainability potential of plant proteins.

Background: The association between unprocessed red and processed meat intake and risk of coronary heart disease (CHD) remains controversial, particularly for unprocessed red meat. Moreover, few studies have evaluated the health effects of replacing these meats with different protein sources. Methods: We examined associations between intakes of unprocessed red and processed (red and non-red) meat and CHD risk in a pooled analysis of 25 international prospective cohorts including 1,090,325 women and 673,694 men. Dietary intake was assessed at baseline within each cohort using a food frequency questionnaire. We calculated cohort- and sex-specific hazard ratios (HRs) and 95% confidence intervals (CIs) using proportional hazards regression and pooled estimates using random-effects models. We further conducted isocaloric substitution analyses by comparing coefficients for unprocessed red and processed meat with those of alternative animal- and plant-based protein sources. Results: Over a maximum follow-up ranging from 7 to 30 years across cohorts, we documented 62,336 CHD death. After multivariable adjustment for body mass index, demographic, lifestyle, and medical factors, greater intakes of unprocessed red meat and processed meat were associated with a higher risk of fatal CHD, with stronger associations observed among women (p for heterogeneity due to sex &lt;0.001). The HRs comparing extreme intake categories (≥125 vs. &lt;10 g/d) of unprocessed red meat were 1.34 (95% CI: 1.15, 1.55; p for trend=0.003) for women and 1.06 (95% CI: 0.99, 1.17; p for trend=0.009) for men. For processed meat, the corresponding HRs (comparing ≥50 vs. &lt;2 g/d) were 1.39 (95% CI: 1.22, 1.59; p for trend&lt;0.001) for women and 1.13 (95% CI: 1.03, 1.25; p for trend&lt;0.001) for men. Isocaloric replacement of unprocessed red meat or processed meat with nuts and seeds was associated with a lower fatal CHD risk in both sexes. Additionally, in women, the replacement of processed meat with soy products, poultry, seafood, or dairy products, while the replacement of unprocessed red meat with soy products and dairy products was associated with a lower risk. Conclusions: These findings support global dietary recommendations to limit the intake of unprocessed red meat and processed meat for cardiovascular health, highlighting the benefits of replacing these meats with plant protein sources, particularly among women.

The pursuit of sustainable animal protein sources is critical in light of the environmental, social, and economic challenges associated with conventional livestock production. Although meat, including organic production, remains a valuable source of high-quality protein, diversification is essential to sustainably meet future demand. This review summarizes current knowledge on alternative animal protein sources, with a particular focus on insects and cultured meat in Europe. Insects demonstrate high feed conversion efficiency, require minimal land and water resources, and provide essential amino acids, lipids, and micronutrients, while contributing to circular economy models. Cultured meat presents potential advantages for environmental sustainability and animal welfare; however, its large-scale application depends on technological advances, cost reduction, and supportive regulation. Consumer acceptance remains a challenge influenced by cultural heritage, food neophobia, and product presentation. Policy frameworks, including the European Green Deal and the Farm to Fork Strategy, seek to foster innovation and sustainable food systems. Future perspectives emphasize that conventional and organic meat, insect-based protein, and cultured meat should be regarded as complementary solutions for a balanced and resilient protein supply in Europe.

Concurrently with an exploding interest in the health benefits of a plant-based eating pattern is similar interest in how this pattern could affect athletic performance. In this state-of-the-art review we summarize the current best research on plant-based nutrition and supplements for athletic performance, emphasizing systematic reviews, randomized trials, and comparative studies. A plant-based eating pattern (little or no animal products) is non-inferior to an omnivore diet (no restrictions on meat, dairy, or other animal products) for athletic performance and for muscle protein synthesis when macronutrient content is similar. When sufficient total protein is consumed, plant-based sources are non-inferior to animal-based sources. Most athletes ideally need 1.2 to 2.0grams/kg of body weight/day of protein, preferably split across 3-4 meals to optimize muscle protein synthesis and recovery. Supplements can offer small added benefits, with the strongest evidence for improved performance from caffeine, creatine, protein, and essential amino acids, and the strongest evidence for improved recovery from polyphenols, vitamin E, omega-3 fatty acids. We also discuss plant protein sources, special considerations for masters athletes, and other evidence-based supplements. Our goals are to highlight core principles of plant-based nutrition and supplements while also offering pragmatic advice for athletes of all ages and abilities.

Protein digestion and amino acid absorption kinetics are quantifiable metrics commonly utilized to determine the quality of a protein source. This review critically evaluates recent evidence (primarily from studies that provided commonly consumed protein-rich foods) regarding the relationship between in vivo protein digestion and amino acid absorption rates with the postprandial stimulation of muscle protein synthesis (MPS), with an emphasis on healthy adults and critically ill patients. Ingested protein sources that elicit moderate amino acid bioavailability, including leucine, stimulate MPS rates to a comparable extent as protein sources that elicit high amino acid bioavailability in healthy young adults. Amino acid absorption kinetics appear to be modulated in critically ill patients, leading to a marked reduction in postprandial MPS rates. Preliminary studies demonstrate that enteral feeding of high dose free amino acids increase amino acid bioavailability to a greater extent than intact protein, leading to a positive whole-body net protein balance in critically ill patients. However, in practice, the high osmolarity of free amino acids leads to a high prevalence of diarrhoea and thus limits the clinical application of this intervention. The enteral provision of free amino acids represents a theoretical, but not practically-relevant, clinical nutrition strategy to mitigate the catabolic response to critical illness. Future studies are warranted to establish targeted protein/amino acid-based interventions to mitigate skeletal muscle atrophy during the metabolic care of critically ill patients.

Background Fish and shellfish are valuable sources of high-quality protein, vitamins, and minerals. Their nutrient density and price vary by species. Objectives This study aimed to determine nutrient density and nutrient affordability per unit cost of fish and shellfish in the FAO/INFOODS uFISH database. Methods Two versions of the Nutrient Rich Food (NRF) index were constructed. The NRF was based on a positive subscore, NRn, and a negative subscore, LIM. The NR6 subscore was the sum of percent daily values (%DV) for 6 priority micronutrients widely identified to be lacking in low and middle-income countries, including iron, zinc, calcium, vitamin A, vitamin B12, and folate. The NR9 subscore, specifically tailored to include micronutrients relevant to fish and shellfish, was the sum of %DV for protein, calcium, iron, potassium, magnesium, selenium, vitamin A, vitamin D, and omega-3 fatty acids. The LIM subscore was based on saturated fat and sodium. In both cases NRFn . 2 = NRn − LIM , with %DV calculated per 100 g and capped at 100%. Food prices, obtained from GlobeFish, were converted to the cost per 100 g protein. A new Affordability Index for Aquatic Foods was calculated as nutrient density per unit cost. Results The NRF6.2 score identified mollusks, and especially bivalves, as the best aquatic source of priority micronutrients. The NRF9.2 revealed small pelagic fish as the most nutrient rich, followed by bivalves. Mackerel, tilapia, squid, and mussels provided the most protein, NRF6.2 nutrients, and NRF9.2 nutrients per penny. Conclusion Fish and shellfish are an affordable source of protein, omega-3 fatty acids, and priority micronutrients. However, there were species differences in cost and nutrient density, with mackerel, mussels, tilapia, octopus, and squid scoring the highest for nutrient density at an affordable cost.

The article is devoted to the prospects of using protein fractions of blood plasma as a source of protein in the meat processing industry. The necessity of creation of such products is caused by the current situation in the field of meat processing-insufficient production of meat products.Blood plasma contains a set of essential amino acids necessary for protein synthesis in the human body. Due to high solubility and functional characteristics, plasma proteins are easily integrated into various food matrices, improving their nutritional value and organoleptic properties. Blood plasma proteins have high biological and functional value. Functionality is characterized by such abilities as gelation, foaming, emulsification and stabilization of meat products. In this paper, the consistency and structure forming ability of blood plasma of cattle of different ages was studied. The gelling ability of blood plasma of young cattle, steers aged 1 to 3 years and 6 to 7 years and the effect of lactic acid bacteria concentration on the structuring of blood plasma of cattle were investigated. Further, the consistency obtained from the structured plasma was comparatively evaluated. The aim of this work is to comparatively evaluate the consistency and structuring ability of bovine blood plasma.

Soybean is one of the most economically important crops worldwide and a valuable source of protein for human consumption and animal feed. The use of wild soybean accessions as a source of new alleles for improvement of soybean quality remains challenging owing to linkage drag. Here, using segregating populations derived from a set of wild soybean chromosome segment substitution lines, we fine-mapped quantitative trait loci (QTLs) (qPC-06-1) for seed protein content to a 48.8-Kb interval on chromosome 6. A gene encoding an S-adenosyl- L-methionine-dependent methyltransferase (GmMET) was determined to be the causal gene underlying the qPC-06-1 locus. Three single-nucleotide polymorphism/insertion-deletion markers (SNPs/InDels) in the coding region were found to modulate the methyltransferase activity of different GmMET alleles, thereby influencing seed protein content. Transgenic and multi-omics analyses provided preliminary evidence for the pathways through which GmMET influences seed protein content and exerts pleiotropic effects on seed oil content, oil composition, and related traits. Additional analyses showed that an elite GmMET allele was under selection during soybean domestication and improvement and is now widespread in modern cultivars, particularly in southern China. Our findings thus reveal that a methyltransferase gene affects the protein content of soybean seeds, providing a foundation for the continued development of high-protein soybean cultivars.

Microbial fermentation for succinic acid production has the advantages of a short production cycle, renewable raw materials, and mild reaction conditions, and is recognized as a promising green approach. However, the succinic acid fermentation process is often accompanied by by-products such as formic acid and acetic acid, which increase the cost of subsequent separation and waste resources. This study proposed a green integrated process in which Rhodotorula glutinis As2.703 was used to selectively metabolize formic acid and acetic acid in succinic acid fermentation broth to produce high-value-added single-cell protein (SCP), while succinic acid was retained. The results showed that R. glutinis As2.703 achieved a utilization rate of 100% for formic acid and acetic acid in succinic acid fermentation broth, with a biomass of 7.05g/L and a biomass yield of 0.46g/g. The protein, lipid, and carotenoid contents in SCP were 53.11%, 16.65%, and 194.15µg/g, respectively. SuperPro Designer® was used to simulate the process of producing 54,331 tons of succinic acid annually. After integrating the SCP production module, the process achieved an annual output of 11,935 tons of SCP, with an annual revenue of 19.81million USD. The operating cost for the SCP module was only 8.27million USD/year, resulting in a net annual profit of 11.54million USD. This technology not only reduced the separation cost of succinic acid but also provided a high-quality protein source for the feed industry, significantly improving the economic viability and sustainability of succinic acid production.

Spray-dried plasma (SDP) is a high-quality protein source with functional properties that support gut health, immune function, and digestibility. Although its benefits have been demonstrated in various animal species (e.g., swine, poultry, rodents, and fish), further research is needed to understand its specific effects in extruded diets and canine health. This study evaluated the effects of incorporating SDP from swine, in partial replacement of chicken meal, into extruded diets on nutrient digestibility, fecal metabolites, microbiota composition, serum chemistry, and inflammatory and immune biomarkers in adult dogs. Extrusion processing parameters were also evaluated in diets containing increasing levels of SDP. Four dietary treatments were formulated: a Control diet without SDP, a diet with 4% SDP applied as a coating (4% Coating diet), and diets with 4% or 8% SDP included within the kibble matrix prior to extrusion. Twelve adult Beagles (n = 12) were assigned to the 4 dietary treatments in a replicated 4 × 4 Latin Square design, with each diet fed for 21 days following a 7-day adaptation period. All diets were well accepted by the dogs. Feeding 8% SDP maintained overall nutrient digestibility but reduced total dietary fiber digestibility (P < 0.05). Fecal concentrations of short-chain fatty acids, particularly propionate, were higher in dogs fed the 8% SDP diet (193.8 µmol/g) compared with the Control diet (126.8 µmol/g; P < 0.05). Additionally, a linear reduction in protein fermentation byproducts, mainly indole metabolites, was observed, suggesting a beneficial shift in microbial metabolism (P < 0.05). Inclusion of SDP also modulated fecal microbiota composition, with changes across several genera and increases in beneficial genera such as Lactobacillus, Streptococcus, and Catenibacterium, while also affecting beta-diversity (P < 0.05). Serum chemistry analysis showed lower blood urea nitrogen in dogs fed the 4% Coating SDP (17.8 mg/dL), 4% SDP (18.0 mg/dL), and 8% SDP (16.3 mg/dL) diets compared with the Control diet (19.8 mg/dL; P < 0.05), suggesting improved protein metabolism. Fecal IgA concentrations were higher in dogs fed 8% SDP than the Control diet, indicating potential immunomodulatory effects that may contribute to improved intestinal homeostasis (P < 0.05). These findings support the potential of SDP as a functional ingredient in canine diets, contributing to gut health, metabolic regulation, and immune function in extruded pet food.

Gluten-free (GF) pasta alternatives are frequently limited in variety, availability, and physicochemical qualities when compared with wheat pasta. Egg white protein (EWP) serves as a nutritional and texturizing agent but its role in modulating the structural and functional properties of heat-moisture-treated (HMT) rice-flour based GF pasta remains underexplored. This study aimed to investigate the effects of EWP (2.5%, 5%, 7.5%, and 10%), with and without transglutaminase (TG) (0% and 1%) on the quality of HMT rice-flour-based pasta. The incorporation of egg white protein (with or without TG) restructured the protein-starch matrix, increasing optimal cooking time, water absorption, and swelling index. The EWP-enriched formulation increased firmness and chewiness to wheat-like levels while lowering cooking loss (CL) to less than 8% (threshold for 'good quality' pasta). At 10%, EWP (with or without TG) in the formulation enabled rice pasta to qualify as a protein source under EU regulations with reduced starch digestibility. Microstructurally, EWP with and without TG reduced starch crystallinity but promoted β-sheet network formation. Although TG reinforced the rice-EWP matrix by creating a denser network and delaying starch digestion, the overall pasta properties of EWP with TG remained similar to those without TG, with only minor differences. Overall, this study shows that EWP (with or without TG) can successfully improve HMT rice flour-based pasta, resulting in a wheat-like texture, low CL, and slower starch digestion. These findings support the scalable production of nutritionally enhanced GF pasta, particularly for gluten-sensitive and health-conscious consumers. © 2025 Society of Chemical Industry.