Comparison of Constant and Fluctuating Temperatures on Activity of Lipase B

Effect of Fluctuating Temperature Treatment on Milk Coagulation and Inactivation of Soybean Trypsin Inhibitor

“…The results imply that if the optimal temperature of a process is far from the transition temperature of the catalyst and the process is at the optimal reaction rate due to the nature of the substrate, FTT treatment around the optimal temperature can bring about a lower activation energy without hastening the inactivation rate of the catalyst, and consequently, results in a faster reaction over the optimum under CTT. Both this study and previous studies (Chang and Powers, 1974;Wu et al, 1974;Wu et al, 1975) also showed that below the optimal temperature, enzymic reactions are usually enhanced by the FTT. In this regard, FTT can possibly be used in hastening the process involving enzyme modifications or enzyme processes involving microbial transformation.…”

“…In the enzyme systems used by Chang and Powers (1974) and Wu et al (1974Wu et al ( , 1975 the optimal temperature for reactions under FTT was shifted approximately 4'C lower than those under CTT. However, in this experiment the temperature optima under both temperature treatments were nearly the same.…”

“…Among such studies are those on the growth of microorganisms (Howell et al, 1971) and activities of lipase (Chang and Powers,19,7,4), invertase (Wu et al, 1974) and lysozyme and chymotrypsm (Wu et al, 1975). A definite enhancement of heat inactivation was shown for these enzymes under FTT (Chang and Powers, 1974;Wu et al, 1974Wu et al, , 1975 suggesting that FTT might find practical applications in this respect.…”

Yields From Chymotrypsin and Lysozyme Under Fluctuating Temperature Treatments

“…When heat inactivation was apparent, e.g., 50°C region for lysozyme, the slower frequency and the cycle-down mode resulted in greater inactivation as well as greater activation; yet, the former effect can probably overshadow the latter effect and result in a lower yield. This is supported by the previous finding that the effect of fluctuating temperature on heat inactivation can overshadow the effect on heat activation (Chang and Powers, 1974;Wu et al, 1974). The effect of cycling amplitude coincides with previous findings with invertase (Wu et al, 1974).…”

“…The effect of fluctuating temperature on lipase activity was studied by Chang and Powers ( 1974), and on invertase activity and stability by Wu et al (1974). Results of these investigations indicated that fluctuating temperature reaction rates depended upon the relationship of the temperature region under study to the transition temperature of the enzyme, the cycling-mode (up or down-shifted), the frequency, and amplitude of cycling.…”