Resumo

BOROSKY, J.C. et al. Longissimus dorsi miofibre characteristics and meat quality in four pork lines. Arch. zootec. [online]. 2010, vol.59, n.226, pp.277-286. ISSN 1885-4494.

The aim of this paper was to analyze the myofiber characteristics of four distinct genetic pork groups and correlate them with the meat quality. 46 animals (23 barrows and 23 females) from four genetic lines were used, representing the experimental treatments: high-lean commercial cross-bred line; commercial cross-bred line selected for ends of prolificacy, non selected genetic line and crossbred animals (Landrace x Large White). Were analyzed the sarcomere length, myofiber differentiation, myofiber number and diameter and meat quality (colour, marbling and dripping loss). It was used a complete randomized design with a 4x2 factorial arrangement (4 genetic lines and 2 sexes). The high-lean commercial cross-bred line, commercial cross-bred line selected for ends of prolificacy and Landrace x Large White animals presented greater myofiber number than non selected animals (p<0.05). Landrace x Large White animals presented the greatest cell diameter and non selected animals and commercial cross-bred line selected for ends of prolificacy animals presented the smallest averages for this trait (p<0.05). There were no differences among genetic lines for sarcomere length. The commercial cross-bred line selected for ends of prolificacy animals had less glicolitic fibers percentage and more intermediate fiber percentage (p<0.05) than the other genetic groups. The high-lean commercial cross-bred line and commercial cross-bred line selected for ends of prolificacy had the greatest (p<0.05) and the smallest (p<0.05) dripping loss values, respectively. Non selected animals presented the greatest marbling value and the darkest meat (p<0.05), while they showed more intramuscular-fat than high-lean commercial cross-bred line animals (p<0.05) and showed the darker meat (p<0.05). Barrows presented lighter paler meat than females. The correlation analysis indicates that the myofiber number was positively associated with dripping loss values and lightness. It also indicates that muscle with greater glicolitic fiber present greater marbling value. In this way we conclude that the myofiber number and type are related with meat quality characteristics. Breeds with greater myofiber number have less intramuscular fat, lighter muscles and smaller water holding capacity, but it was not observed correlation among myofiber number and glicolitic fiber percentage.

Palavras-chave : Muscle cell; Dripping loss.

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