Chemical reaction kinetics in relation to glass transition temperatures in frozen food polymer solutions

Abstract

Abstract The hydrolysis of disodium‐p‐nitrophenyl phosphate (catalyzed by alkaline phosphatase) in frozen sugar and maltodextrin solutions was studied, with emphasis on how the rate of hydrolysis could be related to the glass transition temperature (T′ g ). Reaction rates decreased with storage temperature and approached zero at temperatures below ‐ 15°C. Arrhenius plots of the data were non‐linear, and the slopes of the best‐fitting lines differed from one solution to another. The data also did not fit the equation of Williams et al (J Am Chem Soc 77 (1955) 3701–3706) that describes diffusional processes as a function of the temperature difference (T‐T′ g ). However, when placed into similarly composed groups, log(rate) was linearly correlated with the temperature difference (T‐ T’ g ).