Efectos de la proteína whey, leucina y entrenamiento de fuerza en la composición corporal / Effects of whey protein, leucine and resistance training on body composition

INTRODUCCIÓN: Los deportistas y las personas activas que entrenan la fuerza para lograr un aumento de su masa muscular tienen requerimientos calóricos y proteicos aumentados, por esta razón emplean diversas estrategias como la suplementación con proteína whey aislada y aminoácidos aislados como la leucina después del entrenamiento sustentados en la premisa de que promueven el incremento en la síntesis de proteínas musculares, y por ende un aumento de la masa magra. OBJETIVO: Comparar cambios de la composición corporal aplicando el método de Absorciometría Dual de Rayos X (DEXA) en personas físicamente activas expuestas a un programa de entrenamiento de la fuerza con la suplementación de proteína whey aislada y/o leucina durante 12 semanas. METODOLOGÍA: estudio aleatorizado prospectivo longitudinal en un grupo de 10 varones físicamente activos, los cuales fueron asignados al azar en 3 grupos de suplementación con proteína whey aislada, leucina o la mezcla de ambas bajo el mismo protocolo de entrenamiento de la fuerza. Se evaluó la composición corporal en 3 momentos: semana 0, semana 6 y semana 12 de la intervención. RESULTADOS: En las condiciones evaluadas no se observaron cambios estadísticamente significativos de las variables de composición corporal y fuerza en los diferentes protocolos de suplementación: leucina, proteína whey aislada con leucina y proteína whey aislada. CONCLUSIONES: Se observaron resultados superiores de la masa magra y la fuerza en el grupo de la suplementación de proteína whey aislada con leucina con respecto a los demás grupos, cabe aclarar que por el tamaño de muestra no alcanzó a ser estadísticamente significativo.

INTRODUCTION: Athletes and active people who work hard to increase their muscle mass have increased caloric and protein requirements. For this reason, they use different strategies such as whey protein isolate supplementation and/or branched-chain amino acids after sustained training on the premise that they promote an increase in muscle protein synthesis, and therefore an increase in lean mass. OBJECTIVE: To compare body composition changes in physically active people exposed to a strength training program withwhey protein isolate and/or leucine supplementation for 12 weeks. METHODS: Longitudinal prospective randomized study in a group of 10 physically active males, which were randomly assigned to 3 supplementation groups with whey protein isolate, leucine, or a mixture of both, under the same strength training protocol. Body composition was evaluated in 3 moments: week 0, week 6 and week 12 of the intervention. RESULTS: In the evaluated conditions, no statistically significant changes were observed in the variables of body composition and strength based on the different supplementation protocols: Leucine, protein with leucine and protein. CONCLUSIONS: Compared with the other groups, higher results were observed in lean mass and strength in group using the whey protein isolate supplementation with leucine. It should be noted that due to the size of the sample, the difference was not statistically significant.

Preparation and Characterization of Berberine Hydrochloride Ternary Complexes / 世界科学技术-中医药现代化

The debitterizing effect of ternary complexes was appraised and characterization of ternary complexes was made by infrared spectrum (IR) and differential scanning calorimetry (DSC). The ternary complexes (β-CD/BH/WPI90) of berberine hydrochloride (BH),β-cyclodextrin)β-CD (and whey protein isolate (WPI90) were prepared with adopting coprecipitation preparation. The results showed that the ternary complexesβ-CD/BH/WPI90 can sig-nificantly reduced the bitterness of BH. The content of BH in the ternary complexes was 3.20%. It was concluded that the ternary complexesβ-CD/BH/WPI90 had significant effect in reducing the bitterness of BH. IR and DSC of the ternary complexesβ-CD/BH/WPI90 were different from the simple physical mixture.

Caracterização químico-nutricional de um isolado protéico de soro de leite, um hidrolisado de colágeno bovino e misturas dos dois produtos / Chemical-nutritional characterization of a whey protein isolate, a bovine collagen hydrolysate and mixtures of the two products

OBJETIVO:Estudar química e nutricionalmente um isolado protéico de soro de leite bovino, um hidrolisado de colágeno bovino e misturas dos dois produtos visando elevado valor nutritivo e funcional. MÉTODOS: Realizaram-se análises da composição centesimal e do perfil de aminoácidos dos dois materiais protéicos, para cálculo da melhor adequação dos aminoácidos essenciais, com base no perfil recomendado pela Organização Mundial de Saúde. Os índices de valor nutritivo para o isolado de soro de leite, o hidrolisado de colágeno e as misturas foram determinados em ratos, a partir de ensaios de crescimento e de balanço de nitrogênio. Os resultados dos parâmetros nutricionais foram submetidos à análise de variância e ao teste de Tukey para a verificação de diferenças entre médias (p<0,05). RESULTADOS: O isolado protéico de soro de leite mostrou-se completo quanto aos aminoácidos essenciais pelo padrão de referência da Organização Mundial de Saúde enquanto que o hidrolisado de colágeno bovino mostrou-se deficiente em todos os aminoácidos essenciais, com agravante de completa ausência de triptofano. A caseína mostrou-se mais eficaz que o isolado de soro e as misturas quanto ao poder de promover crescimento em ratos. Não houve diferença estatística no crescimento dos ratos entre o isolado protéico de soro e a mistura 60 por cento isolado de soro e 40 por cento hidrolisado de colágeno. Nos demais índices de valor protéico a mistura 60 por cento isolado de soro: 40 por cento hidrolisado de colágeno mostrou-se igual ou superior à caseína e ao isolado (100 por cento). CONCLUSÃO: A mistura 60 por cento isolado de soro mais 40 por cento hidrolisado de colágeno bovino apresentou elevado valor nutritivo e alto índice de solubilidade em água, mostrando-se promissora como ingrediente na formulação de alimentos dietéticos para idosos, inclusive pelas propriedades funcionais já descritas para essas proteínas.

OBJECTIVE:The objective was the chemical and nutritional study of a bovine whey protein isolate, a bovine collagen hydrolysate and mixtures of the two products aiming at high nutritional and functional value. METHODS: Centesimal composition and amino acid analyses were performed on both proteinaceous materials for the calculation of an adequate amino acid profile based on the Food and Agriculture Organization/World Health Organization recommendation. The nutritive value indexes for the whey protein isolate, the collagen hydrolysate and mixtures of both proteins were determined in rats through growth assay and nitrogen balance. The experimental parameters from nutritional assays were submitted to analysis of variance and the Tukey test applied for differences among means (p<0.05). RESULTS: The whey protein isolate met all the requirements of the Food and Agriculture Organization/World Health Organization reference for essential amino acids while the collagen hydrolysate showed deficiency in all essential amino acids and complete absence of tryptophan. The casein showed higher efficiency than the whey isolate and mixtures of both proteins in promoting growth in the rat. There was no statistical difference in growth between the whey protein isolate and the mixture of 60 percent whey protein isolate and 40 percent collagen hydrolysate. In all other indexes of protein nutritive value the mixture 60 percent whey protein isolate and 40 percent collagen hydrolysate revealed itself equal or superior to casein and the 100 percent whey isolate. CONCLUSION: The protein mixture 60 percent whey protein isolate and 40 percent collagen hydrolysate showed high nutritive value and water solubility indexes, considered favorable properties as an ingredient for the formulation of dietetic products for elderly people.