Preparations, characterizations, assembly behaviors, applications, and perspectives of whey protein amyloid fibrils: A review.

Protein supplementation, particularly whey and soy protein, are widely used by individuals engaged in resistance exercise training (RET) to enhance lean body mass (LBM) and muscle strength. However, their effectiveness remain unclear due to conflicting study results. This systematic review and meta-analysis evaluated the effect of whey and soy protein supplementation on amino acid bioavailability, LBM, and strength performance in healthy young adults engaged in RET. Database searches were conducted in Cochrane, EBSCO Host, PubMed, and Scopus from inception to October 19, 2024 using a pre-defined search strategy. Initial screening resulted in a total of 1,813 studies that met the eligibility criteria. The inclusion criteria required participants to be trained or untrained young adults aged 18–30 years engaged in RET and taking either whey or soy protein in the form of concentrate or isolate with the primary outcome of LBM and secondary outcomes of bench press, squat, or plasma essential amino acid (EAA). The studies were assessed for risk of bias using the Cochrane RoB 2 tool, and a meta-analysis was conducted using a random-effects model. A total of 12 studies with 261 participants were included after full-text screening with the main reason for exclusion being wrong population. The analysis found no significant effect of either whey or soy protein supplementation on LBM. However, protein supplement increased peak plasma total EAA with whey protein significantly improved bench press (mean difference [MD] 8.87; 95% CI: 5.95–11.79) and squat performance (MD 9.60; 95% CI: 5.61–13.60), with low to no heterogeneity. These findings suggest whey protein supplementation can enhance strength without significantly altering LBM in young adults. However, further large-scale, high-quality randomized controlled trials are needed to establish definitive conclusions on the effects of protein supplementation RET. The review was registered August 30, 2024 in PROSPERO (CRD42024598070).

4 - Whey proteins

Protein concentrates from lobia seeds, soybean, hyacinth beans and milk (casein and whey) were prepared following isoelectric precipitation. The percent moisture/protein content of these concentrates was 5.01±0.03/84.81±2.19; 5.15±0.06/86.60±1.66; 5.11±0.03/83.28±1.42, 8.19±0.15/86.03±0.68 and10.21±0.04/77.5±0.68 respectively. Acidic and alkaline hydrolysis of these concentrates was carried out in steam under pressure conditions (121°C) at different time intervals (60, 120 and 180 min). Hydrolysis treatment in both the conditions for 180 min resulted into improved separation of amino acids. Identification of essential amino acid with reference to the standard was performed using thin layer chromatography with the help of n-Butanol: acetic acid: water: 4:1:1 and Phenol:Water: 75:25 as solvent systems. Whey and casein protein concentrates were found to be cost effective biologically potential source of essential amino acids hence these were used to fortify wheat flour protein. To Increase essential amino acid content of wheat flour in relation to meet 100% RDA requirement of a complete and balance protein, 15.0 g casein or 23.0 g whey protein per 100 g sample wasrequired. Wheat based products such as chapaties were prepared using specified amount of casein / whey protein concentrates. The resulted product was well acceptable having better nutrition with respect to essential amino acid and protein efficiency ratio. Keywords : Fortification, protein concentrates, RDA, essential amino acid, chapaties Cite this Article Arvind Jaiswal, Dev Kumar Yadav, Patki PE, et al. Supplementing Wheat Protein to Improve and Complement its Nutritional Quality. Research & Reviews: Journal of Food Science and Technology. 2015; 4(2): 13–20p

It is well established that macronutrients and micronutrients modulate responses of muscle kinetics, fatigue and immunity to exercise, although nutritional information have been extremely variable in the sports field. Dietary protein has gained a particular interest in the past few decades with respect to its role in exercise performance and recovery. Amongst the distinct functions of proteins and amino acids in exercise, a superior role in promoting a positive muscle protein balance, characterized with increased muscle protein synthesis and attenuated muscle protein breakdown, was highlighted by numerous studies [1]. A special emphasis on resistance exercise was noted in the majority of these studies, because muscular anabolic responses and muscle damage have been described following high intensity resistance exercise to a greater extent than moderate intensity endurance training. As a means to maximize the anabolic effects of resistance training on skeletal muscles, muscular pool and circulating levels of amino acids should be always maintained. The ingestion of dietary protein and/or amino acids at adequate levels alongside resistance training has been proven to be an effective way to increase protein synthesis rates and consequently skeletal muscle hypertrophy over time. Although ingestion of essential and non-essential amino acids increases plasma amino acid concentrations up to 3 hours, the availability of essential amino acids is the primary promoter of muscle protein synthesis [2]. Studies have demonstrated greater increases in muscle protein synthesis rates when essential amino acids were ingested after resistance exercise rather than when essential amino acids ingested at rest or when resistance exercise performed in the fasting state [3]. However, it seems that a threshold exists above which essential amino acids do not induce further increments in protein synthesis. In the study of Tipton et al. [4], ingestion of either 40 g of essential amino acids or 40 g of a mixed amino acid mixture composed of 21.4 g of essential amino acids an hour after a resistance exercise bout similarly increased amino acid concentrations by 2.5-fold and protein synthesis by 70%. Skeletal muscle kinetic responses were also found to depend on the quality of ingested dietary proteins. Consumption of various types of proteins was found to affect differently the amplitude and possibly the duration of muscle protein synthesis after resistance exercise [5]. Dairy proteins appeared to be more beneficial during high intensity resistance training when compared to other protein types. Milk proteins promoted greater protein accretion in comparison to an isonitrogenous and isoenergetic soy protein when ingested after resistance training in healthy young men [6]. With the immediate provision of 25 g of whey protein, a major protein constituent of milk, following resistance exercise, a sustained enhancement of myofibrillar protein synthesis and anabolic intramuscular signaling responses was reported up to 3-5 hours in recreationally active men [7]. Even as part of a whole-food dairy product, the benefits of whey proteins in enhancing resistance exercise-induced muscle anabolism have been shown. After 45-min of a bout of endurance exercise, the consumption of fat-free chocolate milk revealed unique benefits including enhanced muscle protein fractional synthetic rate, reduced whole body proteolysis, improved skeletal muscle protein turnover and increased time to exhaustion compared to a non-nitrogenous isocaloric carbohydrate control beverage in male runners [8]. Dairy proteins are rich sources of branched-chain amino acids including leucine, isoleucine and valine, which are among the few amino acids that can be actively metabolized in the skeletal muscle during exercise [9]. The anabolic stimulus of branched-chain amino acids on muscle protein kinetics has been mainly attributed to leucine [10], although the importance of leucine relative to the other essential amino acids in regulating muscle kinetics is still not clear. The benefit of leucine in stimulating muscle protein synthesis was consistently established in well-controlled cell culture and animal studies [11]. Animal studies have shown that leucine can independently stimulate muscle protein synthesis by phosphorylating proteins involved in mRNA translation initiation such as through the mammalian target of rapamycin (mTOR) signaling cascade [12], a critical mediator of both contraction- and essential amino acidsmediated increase in muscle protein synthesis [13-14]. However, inconsistencies in findings were reported in humans. In the study of Glynn et al. [15] on young men and women, the consumption of an essential amino acid mixture (10 g) containing a higher concentration of leucine (3.5 g) did not improve net protein anabolism beyond that of the mixture containing the lower amount of leucine (1.85 g) under resting conditions. Furthermore, compared to an isonitrogenous whey protein drink providing an adequate mixture of essential amino acids (69 g total protein containing 4.7 g leucine), the addition of leucine to the whey protein drink (69 g total protein containing 17.6 g leucine) failed to further enhance muscle protein synthesis when consumed over a 6-hour period after performing a 30-minute bout of moderate exercise in older adults [16]. In the study of Churchward-Venne et al. [17], a relatively small amount of leucine (0.75 g) was found to be sufficient to achieve maximal stimulation of muscle protein synthesis when other essential amino acids were provided in larger quantities (8.5 g) following a bout of resistance exercise. Thus, at rest and during recovery from resistance exercise, an essential amino acid profile at adequate doses and of high quality can maximally stimulate muscle protein synthesis with any added leucine providing no further benefits. Caution must be taken since leucine was always supplemented as part of an amino acid mixture. It should be thus clarified whether leucine could be beneficial if used alone or whether its effects on protein balance regulation are linked to the presence of other essential amino acids in the same amino acid mixture. In addition, it is still unclear whether the intracellular or the extracellular availability of leucine and/ or essential amino acids is the major contributor to muscle protein synthesis regulation. Although some studies showed that postprandial stimulation of muscle protein synthesis is directly proportional only to the rise in blood leucine [18], others found that peak activation

Loss of skeletal muscle mass with ageing (sarcopenia) is a problem for which anabolic neutraceutical interventions could hold therapeutic promise. Older women are understudied with recommendations based on studies in older men inappropriate given that women exhibit distinct protein metabolism (i.e. reduced responses to feeding).We previously showed that increases in muscle protein synthesis (MPS) were identical in older women fed 3 g of 40% leucine‐enriched essential amino acids (LEAA) vs. 20 g whey protein (WP). Here we tested whether lower or higher doses of LEAA and WP modified this response.We recruited 24 older women (64±0.7 y) who received (N=8/group) 1.5 g LEAA, 6 g LEAA or 40 g WP while undergoing a primed constant I.V infusion of 13C6 phenylalanine. Using a unilateral resistance exercise model (6×8 leg extensions; 75% 1‐RM) we determined the effects of feeding (FED) and feeding‐plus‐exercise (FED‐EX) over a 2 and 4 h period upon MPS, microvascular blood flow (MBF) and plasma insulin. Muscle biopsies were taken from the vastus lateralis at baseline, 2.5 h later (BASAL) and then at 2 and 4 h in both the rest and exercised legs. MPS was determined by mass spectrometry, MBF by contrast‐enhanced ultrasound (CEUS) and plasma insulin by ELISA. Data were analyzed by 2‐way repeated measures ANOVA with Bonferroni post‐hoc testing; a P‐value of <0.05 was considered significant.We found that FED increased MPS similarly in response to 1.5 g LEAA (0.061±0.003 vs. 0.086±0.005 %/h, P<0.05), 6 g LEAA (0.066±0.006 vs. 0.090±0.007 %/h, P<0.05) and 40 g WP (0.056±0.004 vs. 0.084±0.011 %/h, P<0.01) over 0–2 h, whereas at 2–4 h this was not significantly different to baseline under each condition. Only 40g WP maintained FED responses at 0–4 h.At 0–2 h FED‐EX increased MPS only in response to 40 g WP (0.056±0.004 vs. 0.089±0.017 %/h, P<0.05), however over 0–4 h increases in MPS were similar across the groups (1.5 g, 0.061±0.003 vs. 0.091±0.007 %/h, P<0.01; 6 g, 0.066±0.006 vs. 0.097±0.007 %/h, P<0.01 and 40 g WP, 0.56±0.004 vs. 0.104±0.011 %/h, P<0.001).No significant increases in MBF were evident in response to FED, whilst only WP elicited increases with FED‐EX (0.13±0.04 vs. 0.31±0.09 AU, P<0.05). Plasma insulin increased in response to 1.5 g LEAA (peak: 11.50±1.83 uU/mL), 6 g LEAA (peak: 12.76±1.61 uU/mL) and 40 g WP (peak: 21.03±3.62 uU/mL, all P<0.01). However, both the peak and area under the curve (AUC: 74.62±11.8 vs. 45.6±10.4 (1.5 g LEAA), 33.79±3.0 (6 g LEAA), P<0.05) was markedly greater in response to WP.We conclude there does not exist a bona fide dose‐response of MPS to FED in older women as 1.5 g of LEAA (equating to 0.6 g leucine and 0.9 g other EAA) maximally stimulated MPS in relation to 40 g WP. Similar was true following FED‐EX. The lack of increase in MBF is consistent with reports in older men while the heightened insulin response to WP vs. LEAA would not be expected to modify MPS given the permissive role of insulin in MPS. We conclude LEAA strategies have anabolic potential in older women; nonetheless longer‐term studies are needed to determine how “one‐off” MPS responses reflect myo‐anabolic and functional outcomes.Support or Funding InformationThis work was funded by Ajinomoto Company Incorporation

SummaryBackground & aimsImpaired anabolic responses to nutrition and exercise contribute to loss of skeletal muscle mass with ageing (sarcopenia). Here, we tested responses of muscle protein synthesis (MPS), in the under represented group of older women, to leucine-enriched essential amino acids (EAA) in comparison to a large bolus of whey protein (WP).MethodsTwenty-four older women (65 ± 1 y) received (N = 8/group) 1.5 g leucine-enriched EAA supplements (LEAA_1.5), 6 g LEAA (LEAA_6) in comparison to 40 g WP. A primed constant I.V infusion of 13C6-phenylalanine was used to determine MPS at baseline and in response to feeding (FED) and feeding-plus-exercise (FED-EX; 6 × 8 unilateral leg extensions; 75%1-RM). We quantified plasma insulin/AA concentrations, leg femoral blood flow (LBF)/muscle microvascular blood flow (MBF), and anabolic signalling via immunoblotting.ResultsPlasma insulineamia and EAAemia were greater and more prolonged with WP than LEAA, although LEAA_6 peaked at similar levels to WP. Neither LEAA or WP modified LBF or MBF. FED increased MPS similarly in the LEAA_1.5, LEAA_6 and WP (P < 0.05) groups over 0–2 h, with MPS significantly higher than basal in the LEAA_6 and WP groups only over 0–4 h. However, FED-EX increased MPS similarly across all the groups from 0 to 4 h (P < 0.05). Only p-p70S6K1 increased with WP at 2 h in FED (P < 0.05), and at 2/4 h in FED-EX (P < 0.05).ConclusionsIn conclusion, LEAA_1.5, despite only providing 0.6 g of leucine, robustly (perhaps maximally) stimulated MPS, with negligible trophic advantage of greater doses of LEAA or even to 40 g WP. Highlighting that composition of EAA, in particular the presence of leucine rather than amount is most crucial for anabolism.

Deficiencies in protein and energy intakes are partly responsible for age-related sarcopenia. We investigated the effects of supplements matched in essential amino acid (EAA) content (7.5 g) on energy intake and appetite. Ten women aged 69.2 ± 2.7 years completed 3 trials in a randomised, crossover design. Composite appetite scores, peptide-YY (PYY), and insulin responses to a 200-mL whey protein (WP) isolate (275 kJ), a 50-mL EAA gel (GEL, 478 kJ), or nothing as the control (CON) condition were investigated over 1 h, followed by an ad libitum breakfast. Energy intake at breakfast (CON, 1957 ± 713; WP, 1413 ± 623; GEL, 1963 ± 611 kJ) was higher in CON and GEL than in WP (both P = 0.006). After accounting for supplement energy content, energy intake in GEL was higher than in CON (P = 0.0006) and WP (P = 0.0008). Time-averaged area under the curve for composite appetite scores (CON, 74 ± 20; WP, 50 ± 22; GEL, 60 ± 16 mm) was higher in CON than WP (P = 0.015). Time-averaged area under the curve for PYY (CON, 87 ± 13; WP, 119 ± 27; GEL, 97 ± 22 pg·mL-1) was higher in WP than CON (P = 0.009) and GEL (P = 0.012). In conclusion, supplementation with WP facilitated an increase in protein intake, whereas supplementation with GEL increases in both energy and protein intakes, when consumed before an ad libitum breakfast. Such findings highlight potential gel-based EAA supplementation intake for addressing age-related sarcopenia.

Canola protein is a rapeseed-derived protein that contains all essential amino acids in proportions that meet the WHO amino acid scoring requirements, making it an interesting protein for human food applications. It is currently unknown whether canola protein processing modulates postprandial plasma amino acid bioavailability in vivo in humans. This study compared postprandial plasma amino acid profiles following the ingestion of unprocessed (native) canola, processed canola, and whey protein isolate in healthy, young, females. In a randomized, clinical, cross-over design, 15 healthy young females (25 ± 3 y) participated in four test days on which they consumed 20 g protein as either native canola, enzyme processed or heat processed canola protein, or 20 g whey protein. Blood samples were collected for 5 h following protein ingestion to assess plasma amino acid concentrations. Ingestion of native canola protein resulted in lower increases in plasma total amino acid (TAA) concentrations compared to whey protein (3191 ± 794 vs. 4429 ± 84 µmol∙L− 1, P < 0.001). Canola protein processing resulted in greater peak plasma total amino acids concentrations, reaching statistical significance for enzyme (3599 ± 687 µmol∙L− 1, P = 0.045) but not heat (3565 ± 722 µmol∙L− 1, P = 0.166) treated compared to native canola protein. Plasma total amino acid availability, expressed as incremental area under the curve over a 5 h postprandial period, did not differ between treatments and averaged 163 ± 81, 171 ± 76, 194 ± 82, and 207 ± 85 mmol∙300 min∙L− 1 following ingestion of native, enzyme- and heat processed canola, and whey protein, respectively (P > 0.05). Ingestion of whey protein allows for a more rapid postprandial rise in circulating essential and non-essential amino acids and greater postprandial plasma total amino acid availability when compared to the ingestion of native canola protein. Ingestion of enzyme- or heat processed canola protein accelerates the postprandial rise in circulating amino acids but does not further augment overall plasma amino acid availability throughout a 5 h postprandial period when compared to the ingestion of native canola protein.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00726-025-03482-1.

Background: The rate of protein digestion and amino acid (AA) absorption determines the postprandial rise in circulating AA and modulates postprandial muscle protein synthesis (MPS) rates. Furthermore, it is necessary to consider the timing of protein ingestion, along with its quantity and quality, to regulate the blood AA concentration. Chicken breasts are a popular food among athletes as they are a good source of animal protein, containing sufficient essential amino acids (EAAs) and branched-chain amino acids (BCAAs). Low-molecular-weight chicken peptides (Cpep), a novel protein supplement, were isolated from chicken breasts. Blood AA dynamics, which have a significant influence on MPS rates, were observed and compared with commercially available whey- and soy-derived protein supplements.Objectives: We evaluated blood AA dynamics after Cpep intake compared with whey protein (WP), and soy protein (SP).Methods: Three groups of six healthy adult men volunteers (age 39 ± 10 years) ingested 0.3 g/kg (protein/body weight) of Cpep, WP, and SP. The concentrations of AA in the plasma were measured before and after the ingestion period and their kinetics were compared.Results: Cpep comprises free amino acids or peptides, and their average molecular weights are lower than those of WP and SP. The absorption dynamics of AA in the plasma were evaluated. After Cpep intake, EAA and BCAA concentrations peaked at 30 min and levels of EAA and BCAA were higher than those after WP and SP ingestion at 15 and 30 min, respectively. Conversely, the levels of total AA, EAA, and BCAA decreased 45 min after Cpep intake compared with WP and SP intakes. In contrast, WP and SP showed similar blood AA dynamics with a peak at 60 min.Conclusions: Cpep is absorbed significantly faster than WP and SP, making it a useful option for efficient protein intake to maintain and increase muscle mass.Keywords: chicken-derived peptides, blood amino acid dynamics, branched-chain amino acid, muscle protein synthesis

Leucine: a nutrient 'trigger' for muscle anabolism, but what more?

Wheat bread is a widely consumed commodity around the world. It is poor and imbalanced in some essential amino acids. The aim of this study is to fortify wheat bread with whey proteins (WP), in order to inhence its nutri-tional value and to improve the balance of its essential amino acids. The composition of the different flours and breads enriched with WP was deter-mined by standard methods. The alveograph’s results show that the tenacity increases and the deformation energy decreases with increasing incorpora-tion of WP. The addition of WP leads to a dough that is resistant to defor-mation, extensible for incorporation rates of 2.5% and 3% and less extensible for 10% and 20%. The results on the composition of the different breads show that the addition of WP contributes to the improvement of the amino acid profiles of the breads, especially for P10 and P20. It corrects, especially, the deficit and imbalance of the bread in essential amino acids. The assess-ments of the organoleptic characteristics show that the majority of the tast-ers find the P2.5 and P3 breads are very close to the commercial breads and sometimes better. These loaves have a nice external appearance, regular shape, crispy golden crust, light texture, good taste and smell. The develop-ment of the breads during vacuum storage is very satisfactory. They keep their crispness and a good crumbliness after 7 days.

Studies on egg albumen and whey protein interactions by FT-Raman spectroscopy and rheology

Whey protein-derived exosomes increase protein synthesis and hypertrophy in C2­C12 myotubes

Background: Protein is an essential portion of food that exerts beneficial effects on body composition and metabolism. However, protein-rich foods are costly and scarcely available in developing countries, and protein deficiency is a significant public health concern. In this situation, searching for additional dietary protein sources is of utmost importance due to decreasing resources because of the growing global population. The current literature review is about whey protein as it is the cheapest, readily available protein source. Methods: Milk is formed of two proteins, casein and whey. Whey is different from the casein in milk and is formed as a by-product of the cheese-making process. Whey (the liquid left after milk curdling) was deemed a waste by the dairy industry for decades. However, it is the cheapest protein source for the poor growing populations in developing countries. Whey protein is a complete protein as it contains all nine essential amino acids. It is low in lactose content. Conclusion: Human body cannot make essential amino acids, so it is necessary to get enough of them from the diet. Due to the availability of carbohydrates, fat, immunoglobulins, lactose, and minerals, including essential amino acids in whey protein, it is necessary for human energy. There are many benefits related to whey protein consumption, such as muscle building and loss of fat. New possible therapeutic properties of whey protein have to be investigated further for the full utility to humans.

Biochemical and clinical effects of Whey protein supplementation in Parkinson's disease: A pilot study