Mejora genética de la composición de la grasa en porcino

[EN] This thesis is framed in the field of breeding for fat composition in pig, specifically using ratios as indicators of stearoyl-CoA desaturase and Elovl6 enzyme activity, which are involved in lipid metabolism, for the estimation of genetic parameters.[ES] La tesis está enmarcada en el campo de la mejora genética de la composición de la grasa en porcino, específicamente utilizando ratios como indicadores de la actividad de las enzimas estearoil-CoA desaturasa y Elovl6, las cuales están involucradas en el metabolismo lipídico, para la estima de parámetros genéticos.Henríquez Rodríguez, E. (2013). Mejora genética de la composición de la grasa en porcino. http://hdl.handle.net/10251/44846Archivo delegad

Carcass lean-yield effects on the fatty acid and amino acid composition of Duroc pork and its technological quality after vacuum-ageing

Eighty purebred Duroc castrated male pigs slaughtered at 210 days of age were used to evaluate the effect of lean yield (European Union carcass grading based on lean content; or R, O and P classes) on the fatty acid and amino acid composition of raw pork (Day 1 post-mortem), and technological meat quality after vacuum aging up to 4, 6 and 8 days. A strong relationship between slaughter weight and carcass lean-yield was observed. Carcasses graded as having a lower lean yield were fatter with higher intramuscular fat concentration, and differences in proportions of fatty acids with increased monounsaturated fatty acid and decreased polyunsaturated fatty acid percentage, but without adverse effect on ultimate pH, drip loss or colour attributes. There were no effects of carcass lean-yield on amino acid composition of raw pork, with valine being the limiting amino acid relative to lysine by ~30–35%. Vacuum aging did not reduce the shear force of raw pork, which may not be indicative of cooked pork response. The lipid oxidation had an inverse relationship with the polyunsaturated fatty acid content of each pork class, and it did not increase due to vacuum aging up to 8 days. Meat fatness did not affect its amino acid balance and technological quality (colour, drip loss, shear force and lipid stability) but modified intramuscular fat composition.The authors thank T. Giró, A. Ñaco and L. Villagrasa for their technical assistance during collection and analyses of samples. This work was supported by the Ministry of Economy and Competitiveness of Spain and the European Union Regional Development Funds (AGL2012–33529 and AGL2015–65846-R)