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Resistance exercise training (RET) is a well-known stimulus for muscle protein synthesis. Protein supplementation, in conjunction with RET, has been shown to yield greater accretion of lean body mass than RET alone. Few studies have compared two multi-ingredient, isonitrogenous supplements of differing quality protein. Therefore, the purpose of the current study was to determine whether there was an augmented effect of a high-quality whey protein multi-ingredient nutritional supplement on hypertrophy in young adults following a RET program. We hypothesized that the multi-ingredient supplement would induce hypertrophy to a greater extent than the control supplement in young adults. Twenty-six (13 male, 13 female) healthy young adults (22 ± 2 years [mean ± SD]) were randomly assigned to either the multi-ingredient nutritional supplement (SUPP, n=12: 20g whey protein, 2g leucine, 2.5g creatine monohydrate, 300mg calcium citrate, 1000IU vitamin D) or control beverage (CON, n=12: 20g collagen protein, 1.4g alanine, 0.6g glycine) groups, ingesting their respective supplements twice daily. Measurements were obtained prior to and after a 10-week linear RET program. Dual-energy X-ray absorptiometry (DXA), ultrasound, one-rep maximum (1RM), and biopsies from the vastus lateralis muscle were performed. A 2-way ANOVA (time by supplement) revealed significantly larger increases in lean body mass (LBM), as assessed via DXA, from the active supplement compared to the control (SUPP: +4.1 ± 1.3kg CON: +2.8 ± 1.7kg, p=0.004). We conclude that the consumption of a multi-ingredient nutritional supplement increased lean body mass to a greater extent than to that observed in the CON group in healthy young adults. / Thesis / Master of Science in Kinesiology / Resistance exercise training (RET) is known to augment muscle size, a process known as hypertrophy. Several factors may affect hypertrophy, such as supplementation with protein and amino acids, increasing an individual’s potential to maximize muscle hypertrophy beyond RET-induced gains. However, little is known regarding the effectiveness of multi-ingredient supplements and the synergistic effects they may exhibit on hypertrophy and strength gains. The present thesis shows the effect of a specific multi-ingredient supplement that contained: whey protein, creatine, calcium, vitamin D, and leucine, compared to a low-quality collagen-based supplement, on measures of hypertrophy and strength in young adults. Interestingly, the active supplement (SUPP) induced greater gains in lean body mass (LBM), type II muscle fibre CSA, and bicep CSA and thickness compared to the control (CON), but not strength. These findings provide insight into a novel formulation of ingredients on exercise-induced increases in hypertrophy in young adults.

Recent research suggests that [beta]-hydroxy-[beta]-methylbutyrate (HMB), a metabolite of leucine (Leu), increases muscle mass and attenuates muscle damage during resistance training. Although Leu acts as a potent stimulator of protein synthesis, HMB, but not Leu, has been reported to be effective in suppressing proteolysis in skeletal muscle. However, mechanisms for the effects of HMB on cell signaling pathways controlling muscle protein turnover during rest and after endurance exercise are still poorly understood. Furthermore, the effects of HMB on cell signaling pathways controlling protein synthesis and degradation under normal in vivo conditions warrant further investigation. For optimal gains in muscle mass, the appropriate type and amount of protein (PRO) is required for positive protein balance to occur in skeletal muscle. Therefore, this dissertation was designed to determine the effect of HMB, PRO and Leu, individually and in combination, on the regulation of cellular signaling pathways controlling muscle protein turnover during sedentary and post-exercise conditions. Study 1 demonstrated that, compared with HMB and PRO alone, the combination of HMB and PRO was more effective in activating the mTOR signaling pathway, which controls protein synthesis, and inhibiting FOXO3A, a major regulator of the ubiquitin-proteasome proteolytic signaling pathway. Study 2 demonstrated that, compared with its individual components, a novel HMB/PRO/Leu supplement better activated protein-synthetic signals and inhibited proteolytic signals in skeletal muscle, and these effects were better sustained. Finally, Study 3 demonstrated that adding Leu to PRO-enriched mixtures after exercise additively activated protein-synthetic signals in a fiber type-specific manner, and adding HMB clearly inhibited proteolytic signaling proteins. Furthermore, provision of an HMB/PRO/Leu supplement after exercise was found to favorably modulate signaling pathways controlling both protein synthesis and degradation. Taken together, the results of these studies suggest that a novel nutrient supplement, composed of HMB, Leu and PRO, additively enhances the intracellular signaling proteins controlling protein synthesis and attenuates signaling proteins controlling proteolysis in skeletal muscle during sedentary and post-exercise recovery. Therefore, such a supplement may be beneficial for both athletic and therapeutic purposes. / text

Poly(ethylene oxide) (PEO) is known for facilitating the electrospinning of biopolymer solutions, that are otherwise not electrospinnable. The objective of this study was to investigate the mechanism by which PEO enables the formation of whey protein isolate (WPI) electrospun fibers under different pH conditions. This investigation revealed that the addition of PEO increased the viscosity of WPI/PEO (10% w/w WPI; 0.4% w/w PEO) solutions. Difference in pH levels of the polymer solutions affected electrospinnability and fiber morphology. Acidic solutions resulted in smooth fibers (700 ± 105 nm) while neutral solutions produced spheres (2.0 ± 1.0 um) linked with ultrafine fibers (138 ± 32 nm). In comparison, alkaline solutions produced fibers (191 ± 38 nm) that were embedded with spindle-like beads (1.0 ± 0.5 um). Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analyses revealed that the native globular configuration of WPI was not altered under neutral conditions. By contrast, the electrophoresis and spectrometry data indicated that WPI was denatured and hydrolyzed under acidic conditions, which facilitated the formation of smooth fibers. C13 nuclear magnetic resonance (NMR) and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopies showed that the increase random coil and a-helix secondary structures in WPI contributed to the formation of bead-less electrospun fibers. Also, C13 NMR analysis showed no evidence of chemical interaction between WPI and PEO. Scanning transmission electron microscopy coupled with energy dispersive X-rays (STEM-EDAX) revealed that WPI was uniformly distributed within WPI/PEO electrospun fibers. Observations by scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM) indicated that fibers possessed a solid core. All these findings suggested that PEO enables the formation of WPI/PEO electrospun fibers by entanglement/entrapment/deposition. Preliminary studies were conducted on hydroxypropyl methyl cellulose (HPMC). In the absence of PEO, HPMC enabled the formation of WPI electrospun fibers under acidic conditions (124 ± 46 nm). FTIR analyses indicated that there was no interaction between HPMC and WPI, suggesting that HPMC aided in the electrospinning of WPI fibers, also by entanglement/entrapment/deposition. Hence, HPMC and PEO aid in the electrospinning of WPI fibers by entanglement/entrapment/deposition, which can be manipulated by alterations in the protein configuration and solution properties. / Natural Sciences and Engineering Research Council (NSERC) of Canada and the Dairy Farmers of Ontario (DFO)

Hydrolysis of casein using chymotrypsin results in the formation of polypeptides (CH) with a hydrophobic aromatic amino acid on one end of the chain because the enzyme selectively cleaves the adjacent peptide-bond. Due to resonance of the aromatic micro-domain, thiols become redox-sensitive and actively participate in electron transfer. These types of amphipathic peptides also tend to be membrane-lytic. The two prong approach of this investigation was to, (1) assess antibacterial effect of the CH in beef steak, and (2), to determine its antioxidative efficacy as a constituent of Cheddar whey based edible coating mix. The edible coating prevented coliform growth even at a minute concentration range of 0.15-0.2 % (w/v). Marked antioxidative efficacy of the CH, particularly at a concentration of 0.3% (w/v), was also evident from its remarkable free radical scavenging ability and extended resilience in an abusive model system saturated with peroxyl-radicals generated through controlled pyrolysis.

Orientador: Celio Kenji Miyasaka / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-15T19:03:10Z (GMT). No. of bitstreams: 1 Abecia-Soria_MariaInes_D.pdf: 1397720 bytes, checksum: efabd9293a2a8d45841c5d131da10056 (MD5) Previous issue date: 2010 / Resumo: As proteínas do soro de leite são consideradas de alto valor nutritivo. Elas têm escore químico superior às de outras proteínas de origem animal, possuem elevadas concentrações de aminoácidos de cadeia ramificada (BCAA), com excelente balanço e biodisponibilidade de aminoácidos essenciais. As proteínas de soro de leite vêm sendo largamente utilizadas pela indústria de alimentos como suplemento na alimentação de esportistas, devido às suas características fisiológicas e funcionais, destacando-se o uso dos hidrolisados, que tem sido recomendado para situações de estresse metabólico como o exercício físico em que a reposição de proteínas no organismo se torna necessária. O presente trabalho teve como objetivo avaliar alterações metabólicas induzidas pelo consumo de proteínas do soro de leite [isolado (ISL) e seu hidrolisado (HSL) com grau de hidrólise 10%] em comparação com a dieta padrão [caseína (CAS)], utilizadas como única fonte protéica em ratos submetidos ao exercício físico. Foram utilizados 96 ratos machos Wistar (~100g) divididos em grupos segundo o tipo de dieta (CAS, ISL e HSL) e a intensidade do exercício físico [treinados (T), treinados exaustos (TEX), sedentários (S) e sedentários exaustos (SEX)] durante 35 dias. Os seguintes parâmetros foram analisados: tempo de exaustão, concentração de lactato no sangue, glicogênio hepático (GH) e muscular (GM), atividade das enzimas marcadoras de lesão tecidual, incluindo lactato desidrogenase (LDH), creatina quinase (CK), alanina e aspartato aminotranferase (ALT e AST, respectivamente). Os animais alimentados com HSL nos grupos TEX e SEX conseguiram correr por muito mais tempo até atingir a exaustão em relação aos que receberam as dietas com CAS e ISL (p<0.05). O tempo de exaustão em relação à dieta CAS foi 72 min maior no grupo TEX e 44 min maior no grupo SEX. A diferença no tempo de exaustão entre os animais alimentados com as dietas de HSL e ISL foi de 40 min. no grupo TEX e de 13 min no grupo SEX. A concentração de lactato dos animais alimentados com ISL e HSL foi significativamente menor em relação aos alimentados com CAS nos grupos T e S (p<0,05). A concentração de glicogênio hepático dos animais que receberam as dietas com ISL e HSL foi estatisticamente superior em comparação com os que consumiram CAS nos grupos T(46%) e S (61%). A concentração de glicogênio muscular não apresentou diferenças significativas entre as três dietas nos diferentes grupos de treinamento (TEX, SEX, T e S). A atividade da ALT dos animais que consumiram HSL nos grupos SEX e S foi estatisticamente menor que os que receberam CAS. A atividade da AST dos animais alimentados com HSL foi significativamente menor que a dos que consumiram a dieta com CAS nos diferentes grupos de treinamento (TEX, SEX, T e S). A atividade da CK e LDH dos ratos que receberam a dieta com HSL foi estatisticamente menor que dos alimentados com CAS em todos os grupos de treinamento exceto no grupo S. Dos resultados obtidos neste trabalho pode-se concluir que o uso das proteínas do soro de leite [principalmente o hidrolisado (10% grau de hidrólise)] em relação à proteína padrão (CAS) como única fonte protéica em ratos submetidos a exercício físico, promoveu a) menor ganho de peso em todos os grupos, b) maior resistência à exaustão tanto no grupo TEX como no SEX, c) maior concentração de glicogênio hepático nos grupos T e S e d) maior proteção contra possíveis lesões hepáticas e musculares nos diferentes grupos estudados (TEX, SEX, T e S) / Abstract: The milk whey proteins are considered to be of high nutritive value and superior chemical score in comparison to other proteins of animal origin. They have high concentrations of branched-chain amino acids (BCAA) with excellent balance and bioavailability of essential amino acids. The milk whey proteins are widely used in the food industry as supplements for sportsmen due to their physiological and functional properties, and their hydrolysates are thought to be more efficient in the recovery of debilitated organisms under pronounced catabolic state because of their great stimulation to protein synthesis. In view of the energy value of proteins in exhaustive exercise, several studies on exercise and protein metabolism have been carried out in the attempt to elucidate the proper amount of protein that must be consumed by sportsmen. The present work had the objective of evaluating the metabolic changes induced by consumption of milk whey proteins [isolate (WPI) and its hydrolysate (WPH) with hydrolysis degree 10%] used as the only protein source in comparison to the standard diet [casein (CAS)] in rats submitted to physical exercise. 96 male Wistar rats (~100g) were divided in groups according to the type of diet (CAS, ISL and HSL) and the intensity of physical exercise [trained (T), trained taken to exhaustion (TEX), sedentary (S) and sedentary exhausted (SEX)] during 35 days. The following parameters were analyzed: time of exhaustion (min.), blood lactate concentration (mmol/L), liver glycogen (LG) and muscular glycogen (MG) (g/100g of tissue), activity of tissue injury marker enzymes (U/L) including lactate desidrogenase (LDH), creatine kinase (CK) and alanine and aspartate aminotranferase (ALT and AST respectively). The results showed that the animals fed with HSL in the groups TEX and SEX ran for much longer times until exhaustion in relation to the ones that received the diets with CAS and ISL (p<0.05). The exhaustion time in relation to the CAS diet was 72 min longer for the TEX group and 44 min longer for the SEX group. The difference in exhaustion time between the animals fed with the WPH and WPI diets was of 40 min for the group TEX and 13 min for the SEX group. The lactate concentration in the animals fed with WPI and WPH was statistically lower than in the ones fed with CAS in the groups T and S (p99<0,05). The concentration of liver glycogen in the animals that received the diets with WPI and WPH was statistically higher than in the animals that consumed CAS in the groups T (46%) and S (61%). The concentration of muscular glycogen did not have significant differences between the three types of diet in the different groups of training (TEX, SEX, T and S). The activity of the ALT of the animals that consumed WPH in the groups SEX and S was statistically lower than that of the animals that received CAS. The activity of the AST of the animals fed with WPH was significantly lower than that of the animals that consumed the diet with CAS in all of the groups of training (TEX, SEX, T and S). The activity of CK and LDH in the rats fed with HSL diet was statistical lower than in the ones fed with CAS in all of the groups of training except in the group S. From the results obtained in this work it can be concluded that the use of milk whey proteins [mainly the whey protein hydrolysate (10% hydrolysis degree)] in relation to the standard protein (CAS) as the only protein source in rats submitted to physical exercise promoted a) lesser weight gain in all of the groups, b) higher resistance to exhaustion in groups TEX and SEX, c) higher hepatic glycogen concentration in groups T and S and d) higher protection against possible hepatic and muscular injuries in all of the studied groups (TEX, SEX, T and S) / Doutorado / Nutrição Experimental e Aplicada à Tecnologia de Alimentos / Doutor em Alimentos e Nutrição

Master of Science / Department of Food Science / Karen A. Schmidt / Milk proteins are excellent sources of sulfur-containing amino acids methionine and cysteine, in particular whey proteins. Cysteine is synthesized from methionine by γ-cystathionase. However, cysteine has to be included in the diets of certain subpopulations due to diminished γ-cystathionase activity. Cysteine, a heat- liable amino acid, may lose bioavailability during thermal processing. The objective of this research was to enhance cysteine content in yogurt while maintaining its quality. First, yogurt mixes were formulated to a total solids content of 12.5% with nonfat dry milk (NDM) (N) or a combination of NDM (10%) and whey protein isolate (WPI) (2.5%) (W), and processed at 70°C (20 min) (70) or 90°C (7 min) (90). Yogurt was prepared and maintained at 4oC for 60 days. Three replications were performed and data were analyzed using SAS®. The W mixes had 65%, 32% and 190% more cysteine, true protein and whey protein contents respectively, compared to N mixes prior to processing. However in day 1 yogurt, the highest cysteine content (398.3 mg/L) was found in the W70 yogurt and its gel quality was comparable to the N90 yogurt except for firmness. During a 60 day storage period the W70 and N90 were similar in gel quality except for firmness. Secondly, a hedonic test was done on the W70 (HC) and N90 (LC) yogurts which had been reformulated to contain sugar and vanillin. One replication was performed and data were analyzed using SAS®. The LC and HC yogurts did not vary in liking of flavor (6.1), aftertaste (6.1) and overall acceptability (6.3) corresponding to the words of “like slightly” when compared. However, the appearance of the LC yogurt was liked more than the HC yogurt (6.7 vs. 6.1) whereas the thickness of HC yogurt was liked more than the LC yogurt (6.4 vs. 5.8). These results suggest that addition of WPI along with lower process treatment resulted in yogurt with enhanced cysteine; however, further studies may be needed to optimize the WPI addition to improve the visual characteristics of the yogurt for consumer acceptance.

Whey proteins are mainly a group of small globular proteins. Their structures can be modified by physical, chemical and other means to improve their functionality. The objectives of this study were to investigate the effect of radiation on protein-protein interaction, microstructure, and microbiological properties of whey protein-water solutions. Whey protein isolate (WPI) solutions (27-36% protein) were treated with different dosages (10-35 KGy) of gamma radiation. The protein solutions were analyzed for viscosity, turbidity, soluble nitrogen, total plate count, and yeast and mold counts. The interactions between whey proteins were also analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and scanning electron microscopy (SEM). The viscosity of protein solution (27%, w/w) was increased from 2.19 for the control to 4.78 mPa*s for the sample treated at 25 KGy, respectively, and viscosity also increased during storage at 23°C. The soluble nitrogen (10%, w/w) was decreased from 100% to 54.7% for control and the sample treated at 35 KGy. The effects of gamma radiation and storage time on viscosity of whey protein solutions were significant (p

Carbohydrate plus additional protein supplementation provided immediately after exercise has been found to increase the rate of muscle glycogen restoration compared to carbohydrate alone. To examine whether leucine, and/or β-hydroxy-β-methylbutyrate (HMB) to carbohydrate plus protein supplementation affects short-term recovery (45 min) of muscle glycogen, we compared plasma glucose and insulin, the muscle glycogen concentration, and the cellular signaling proteins controlling muscle glycogen synthesis 45 min after supplementation. Rats (n=35) underwent high-intensity resistance exercise followed by supplementation with carbohydrate (CHO: 1.2g/kg body weight), carbohydrate with whey protein (CP: 1.2g CHO + 375mg whey protein/kg body weight), carbohydrate with whey protein plus HMB (CPH: 1.2g CHO + 375mg whey protein + 400mg HMB/kg body weight), carbohydrate with whey protein, HMB plus leucine (CPHL: 1.2g CHO + 375mg whey protein + 400mg HMB + 444mg leucine/kg body weight) or exercise only (CON). Blood samples were collected immediately after exercise and 45 min after supplementations. Muscle samples of plantaris were excised immediately and 45 min post-exercise. Plasma glucose was increased by CHO and CPH supplementation and reduced by CPHL at 45 min post-exercise. Plasma insulin was elevated by CP and CPHL treatments compare to CHO. Muscle glycogen concentration was unaffected by all treatments and did not differ from CON. Phosphorylation of Akt/PKB, GSK3α/β, and GS at 45 min of recovery for all supplements was not significant difference from CON. Phosphorylation of mTOR was significantly increased by CPHL and CP supplementation compared to CON, CHO, and CPH. Phosphorylation of AS160 was markedly reduced by CPH supplementation compared to CON. These results suggest that supplementing with carbohydrate plus protein with or without leucine and its metabolite, HMB, to enhance muscle glycogen replenishment following exercise may not provide an advantage during the early phase of recovery (45 min). Furthermore, there is some indication that HMB may elicit insulin resistance, and this needs further evaluation. / text