Influence of stress factors on nutritional characteristics of pork meat

Abstract

Qualitative alterations in pork – PSE (pale, soft, exudative) - are an accompanying feature of intensive breeding. Changes in internal biological conditions lead to an increased sensitivity of high yielding pigs to stress. Our investigations focused on changes in nutritional characteristics (total proteins and amino acids) of normal quality pork (m. longissimus dorsi) and pork with abnormal course of ageing and on subsequent qualitative changes - PSE. The following methods were used to identify PSE meat (n=6): - pH determination; - colour radiance determination; - loss of meat juice determination. Quantitative determination of total amino acids was carried out after acid hydrolysis at 110o C for 24 hours. According to our findings, pork meat with PSE, regarding total proteins and amino acids, is not nutritionally less valuable than that qualitatively unchanged. The results showed higher values of essential amino acids isoleucine, treonine, valine, leucine and phenylalanine, non essential ones being tyrosine, glutamic acid, cystine, aspartic acid and alanine in the fresh musculature of pigs with PSE meat. The findings were confirmed by the sum of essential amino acids in the PSE meat and correlated with (P< 0.05) higher values of total proteins in the PSE meat.