ACTION OF CATHEPSIN-B ON INTRAMUSCULAR COLLAGEN UNDER CONDITIONS SIMULATING CONVENTIONAL AGING OF MEAT - A CALORIMETRIC STUDY

Beef pectoralis profundus muscle was stored either under conventional conditions of aging during 2 d (A) or 8 d (B), or after freezing-thawi ng and 8 d of aging (C). Intramuscular connective tissue was then extr acted and incubated with purified cathepsin B at 37-degrees-C for h, o r 10-degrees-C for 7 days, or 4-degrees-C for 14 d. Denaturation tempe ratures decreased with aging time (A>B) and with intensity of aging tr eatment (C). The observed decrease was significantly larger when the c ollagen extract was incubated in presence of cathepsin B. However, den aturation temperatures were not different, whatever the time/temperatu re conditions of incubation: equal low denaturation temperatures were obtained at 4-degrees-C during 14 d or at 37-degrees-C during 48 h. Th e practical implications of this result are considerable, since cathep sin B was shown to act on intramuscular collagen under conditions prev ailing in conventional aging of meat.