Treatment of meats with ionising radiations. VIII.—pH, water-binding capacity and proteolysis of irradiated raw beef and pork during storage, and the ATP-ase activity of irradiated rabbit muscle

Journal Article · Wed Nov 01 04:00:00 EST 1961 · Journal of the Science of Food and Agriculture

DOI:https://doi.org/10.1002/jsfa.2740121104· OSTI ID:4825878

Lawrie, R. A.; Sharp, J. G.; Bendall, J. R.; Coleby, B.

The immediate effects of 5-Mrad ionizing radiation on beef and pork longissimus dorsi muscles were an increase in pH, a decrease in water-holding capacity, in increment in gel-volume for a given pH rise, and in soluble protein, and increased resistance to low- and high-speed homogenization. The indications of cross-binding induced by irradiation were supported by studies of isolated myofibrils from rabbit psoas muscle. Irradiation markedly reduced the syneresis (18 deg , mu = 0.04) and the swelling (0 deg , mu = 0.25) induced by ATP and, to a lesser extent, over-all fibrillar ATP-ase activity (the initial fast phase being depressed more than the slower second phase of the reaction). On storage (at -20 deg +37 deg pH and water-binding capacity increased generally with increase of temperature. Changes in pH occurred earlier with pork and to a greater extent than with beef. In sterile beef longissimus dorsi (irradiated or unirradiated) there was a decrease in soluble protein during storage for 60-90 days at 37- (indicating denaturation) and lncreases in TCA-soluble nitrogen and tyrosine (indicating proteolysis, which was more marked in unirradiated samples). The absence of soluble hydroxyproline and the presence of clearly marked cross- striations indicated that the autolysis must have involved sarcoplasmic and not fibrillar or connective tissue protein.

• Research Organization: Low Temperature Research Station, Cambridge, Eng.
• Sponsoring Organization: USDOE
• NSA Number: NSA-16-004019
• OSTI ID: 4825878
• Journal Information: Journal of the Science of Food and Agriculture, Journal Name: Journal of the Science of Food and Agriculture Journal Issue: 11 Vol. 12; ISSN 0022-5142
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BIOLOGY AND MEDICINE
ENZYMES
IRRADIATION
MEAT
PROTEINS
QUANTITY RATIO
RABBITS
STORAGE
TEMPERATURE
WATER