STUDIES IN MEAT TENDERNESS .4. CHANGES IN EXTRACTABILITY OF MYOFIBRILLAR PROTEINS DURING MEAT AGING

SUMMARY— Changes during aging in the extractability of the myofibrillar proteins of meat from beef and rabbit carcasses have been examined, using a buffer which dissociates the actomyosin complex of the muscle cell. Approximately 52% of the myofibrillar proteins of unaged meat is extracted in 40 min at 2°C whereas from aged meat as much as 78% is extracted. The rate and extent of these changes are determined largely by the ultimate pH value of the meat. Similar increases in protein extraction, displaying the same pH dependence, occur during the aging of well‐washed myofibrillar preparations. The increase in the percentage of myofibrillar protein extracted during aging results from either a progressive weakening of the fibrous protein linkages with the insoluble stroma of the meat cell, or from a disintegration of the insoluble stroma itself. Copyright © 1968, Wiley Blackwell. All rights reserved