Influence of aging temperature on bovine sarcoplasmic proteins

Graduation date: 1967Effects of high temperature aging upon certain characteristics\ud of bovine l. dorsi muscle were studied. Paired wholesale ribs of\ud carcasses were obtained subsequent to slaughter. The left rib of\ud each pair was held at 30°C for 24 hours, then stored at 3°C.\ud Analogous right ribs were immediately stored at 3°C. A sampling\ud schedule of 0, 1, 2, 3, 4, 7, and 10 days was followed.\ud Muscles held at only the 3°C temperature showed slightly\ud higher pH levels and superior water binding capacity than those\ud subjected to the high temperature aging treatment.\ud Up to three days storage, extractability of water soluble protein\ud was greatest from muscles held at the elevated temperature. After\ud the third day, however, extractability was greater for muscles held\ud at 3°C. Also during the first three days of aging, tyrosine-\ud tryptophan index ratios indicated protein breakdown to be greatest\ud in muscles subjected to the elevated temperature. Thereafter, proteolysis appeared to occur more rapidly in the muscles held at\ud 3°C.\ud Color differences between muscles treated via the two storage\ud temperatures were marked. Spectrophotometric ratios (422/280 mμ)\ud of extracts showed that muscles held at the high temperature had\ud higher extractable levels of oxymyoglobin than ribs held at 3°C.\ud This difference remained apparent throughout the aging period.\ud Results of DEAE-cellulose ion exchange chromatography of\ud the sarcoplasmic proteins showed only minor variations in profiles\ud between the two aging treatments. Alterations did appear with time.\ud Profile alterations did not appear related to anticipated increases in\ud tenderness