Modificació del valor nutritiu, l'estabilitat oxidativa i la qualitat sensorial de la carn de pollastre mitjançant la dieta
ENGLISH ASTRACT: One of the goals of food scientist is to increase the nutritional value of foods without compromising sensory quality. In this regard, chicken meat can be increased in n-3 polyunsaturated fatty acids. However, these fatty acids are very prone to oxidation, and, consequently may produce off-tastes and off-odours. This work shows several dietary strategies to achieve enriched meat in n-3 polyunsaturated fatty acids without compromising oxidative stability and consumer acceptability. In relation to this, broilers fed 1.25% of fish oil and 70 mg/kg of alpha-tocopheryl acetate led to meat with an increased content in n-3 polyunsaturated fatty acids as well as meat with good oxidative stability and accepted by consumers. Moreover, the replacement of dietary fish oil for linseed oil or animal fat 5 days before slaughter modified the fatty acid composition. Animals fed this linseed oil replacement led to meat with the highest content in n-3 polyunsaturated fatty acids whereas animals fed the animal fat replacement led to meat with similar amount in eicosapentaenoic acid and docosahexanoic acid to those fed fish oil throughout the period. Little attention has been devoted to mineral enrichment. In this regard, we studied the effect of Zn and Se dietary supplements on the composition, oxidative stability and sensory quality of chicken meat. The inorganic Se supplement did not increase this element content in chicken meat. However, organic Se and Zn supplementation provoked an increased Se content. On the contrary, Fe, Zn and Cu content were not affected by any of the dietary factors. In addition, neither Zn supplements nor Se supplements affect chicken meat stability or sensory quality. In relation to elements determination, a mineralization procedure was validated for determining Fe, Zn, Se and Cu in chicken meat and feed samples. This procedure avoids Se volatilization losses. Finally, this work also dealt with the effects of feeding different types of oxidized oils on nutritional value, oxidative stability and sensory quality. There were not significant differences in sensory quality or meat oxidation variables from chickens fed oxidized oils. However, alpha-tocopheryl acetate supplementation led to meat with an increased oxidative stability and a decreased rancidity.
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Advisor:Guardiola Ibarz, Francesc; López Sabater, María Carmen; Codony Salcedo, Rafael
School:Universitat de Barcelona
Source Type:Master's Thesis
Keywords:nutrició i bromatologia
Date of Publication:05/26/2005