Nutritional and functional quality, and oxidative status of Pampa Rocha pork in an outdoor vs. a confined system: Doctoral thesis abstract

Abstract

The chemical, nutritional and functional composition of Pampa Rocha pork, produced in two systems, outdoors with pastures and deep bed, was studied. The animals in the outdoor system showed improvements in some carcass and meat parameters. In both systems, the meat was adequate from the nutritional and technological point of view, for consumption and processing, fresh or preserved. Meat from outdoor had a lower pH, was darker, and had higher drip loss. Longissimus longissimus thoracis had a higher pH, and drip loss, was less red and lighter than psoas major, regardless of the production system. The aged meat presented a stable pH, but it was redder and yellower, and with a higher drip loss than fresh meat. Muscle glycogen and lactate were not affected by the production system, the type of muscle or the sex of the animals. The oxidative stability of lipids and proteins was similar for both systems, but it depended on the type of muscle, with the psoas major being a more fragile muscle against oxidation. The fatty acid profile was similar in both systems, but the psoas major had a higher lipid content than the longissimus. The latter, produced outdoors, presents a moderate improvement in the fatty acid profile, particularly with alpha-linolenic acid (C18:3n-3), and a lower n-6/n-3 ratio. The production system had an impact on the iron content, particularly bioavailable iron, with the heme iron/total iron ratio being higher in meat produced on pastures, considering the longissimus and psoas muscles, and the hindquarters, gluteus medius, semitendinosus, biceps femoral, and quadriceps femoris. In this thesis, knowledge was generated about the particularity of each muscle, in terms of its nutritional and technological attributes, regardless of the productive system. The outdoor system presents some advantages that enhance the genetic type in an environment that may interest consumers with particular requirements.