The Influence of Feeding and Aging on Pork Quality

Tikk, K. 2007. The influence of feeding and aging on pork quality. Doctoral thesis. ISSN 1652-6880, ISBN 978-91-576-7390-9 The objective of the present thesis was to obtain a more basic understanding on how production factors such as feeding strategies and aging of the meat influence consumerrelated pork quality attributes. Especially, post mortem colour characteristics of fresh pork and flavour development including warmed-over flavour in cooked pork as a function of feeding strategies have been further elucidated in the present thesis. It was found that diet-induced progress in early post mortem muscle temperature development affects the colour and colour stability of pork during aging. Moreover, postmortem colour development progressed differently in M. longissimus dorsi (LD) and in M. semimembranosus (SM). A gradual increase in the extent of blooming took place throughout aging in vacuum in the SM muscle; in contrast to a more complex colour progress during aging in the LD muscle. Moreover, discoloration was found to proceed faster in chops of SM compared to LD, especially after extended aging in vacuum. The observed diet and muscle effects might be coupled to the diet-induced change in post mortem temperature progress in the meat, which affects the activity of the inherent enzyme systems. Thus, dietary treatment and aging of the meat have a pronounced effect on colour and colour stability of pork. Moreover, it was found that diets with different sources of vegetable oil influence the fatty acid composition in pork without any pronounced effect on overall meat quality. However, positive correlations between specific fatty acids in the phospholipid fraction of LD and single sensory traits in pork from female pigs were established with polyunsaturated fatty acids and C18:2n-6 correlating to fried meat odour and sweet odour and with monounsaturated fatty acids and C18:1n-9 correlating to piggy flavour and sourish odour in freshly cooked pork. Finally, sensory attributes associated to warmed-over flavour and secondary lipid oxidation products formed during re-heating of cooked pork were positively correlated with gas-sensor responses (using electronic nose for detection of volatiles), and this supports the potential of e-nose systems as a quality control tool in the meat industry in the future.