ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
SUMMARY– A study was done on the effects of in vitro storage of purified α-actinin, troponin, tropomyosin, and the tropomyosin-troponin complex on the activity of these protein fractions in the ATPase and superprecipitation assays. Storage was done at various combinations of temperatures between 0 and 40°C and pH values between 5.7 and 7.0. Even after 40 hr of storage, activities of purified tropomyosin and the tropomyosin-troponin complex were not affected by any combination of temperature and pH included in this study, but activities of purified α-actinin and troponin were almost completely lost after 16 hr at 40°C and pH 5.7. Storage for 40 hr at low pH (5.7) and low temperatures (0°C) did not affect the activity of either α-actinin or troponin, but 40 hr of storage at high temperatures (40°C) and neutral pH caused some loss in activity for both these proteins. This loss of activity caused by 40°C, pH 7.0 storage was much more noticeable in the case of troponin than in the case of α-actinin. Storage periods of 40 hr or longer were required before any loss of α-actinin activity could be detected at pH 7.0 and 40°C. Since most meat animal carcasses are chilled soon after exsanguination and attain muscle temperatures of 25°C or lower before the pH falls below 6.2, it is probable that α-actinin and tropomyosin-troponin activity remain almost unchanged in meat handled through normal market channels. However, myofibrillar tissue in those porcine animals whose musculature undergoes a very rapid post-mortem decline in pH so that values of 5.7 or less are reached while muscle temperatures are still 37°C or higher may lose much of its α-actinin and tropomyosin-troponin activity during the first 24 hr post-mortem.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1970.tb01977.x
