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 carried out with light and electron microscopic techniques to discover the effect of heating and carcass maturity upon the connective tissue and myofibrillar proteins of longissimus from veal (5–6 months), A (12–20 months) and D (54–60 months) maturities. Longissimus was heated to internal temperatures of 1) 50°C; 2) 60°C; 3) 70°C; 4) 80°C and 5) 90°C. Light microscopy indicated that connective tissue fibers increased in size and degree of aggregation with carcass maturity. Also, the more aggregated fibers from D maturity were more heat resistant than the less aggregated fibers of veal and A maturity. Endomysial connective tissue shrinkage was initiated at 50°C and it was completed at approximately 70°C. On the other hand, perimysial connective tissue shrinkage required internal temperatures of 70°C and higher before any significant fiber changes were observed. However, if endomysial and perimysial connective tissue fibers showed similar degrees of aggregation, they appeared to react similarly to heat regardless of maturity group. Electron and phase contrast microscopy showed that myofibrillar proteins compressed and sarcomeres shortened at 50°C. Heating to 60°C caused loss of M-line structure, initiation of disintegration and coagulation of thin and thick filaments and further myofibrillar protein shrinkage. Heating to 70 and 80°C caused more disintegration of thin filaments and coagulation of thick filaments. At 90°C, an amorphous structure resulted, but regardless of the internal temperature the principal banding features of the sarcomere could be identified. These changes are discussed in relationship to changes in meat tenderness.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1971.tb02049.x
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