Kinetic analysis of freeze denaturation of soyprotein by a generalized theoretical model for freeze-acceleration reaction. (December 2016)

• Record Type: Journal Article
• Authors: Miyawaki, Osato; Nishino, Hiroki
• Is Part Of: Journal of food engineering. Volume 190(2016:Dec.)
• Page Start: 109
• Page End: 115
• Publication Date: 2016-12
• Subjects: Protein freeze denaturation -- Freeze-acceleration -- Freeze-concentration effect -- Fraction of frozen water -- Freezing point depression -- Cryoprotectant; Food industry and trade -- Periodicals; Food -- Analysis -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Analyse -- Périodiques; Aliments -- Recherche -- Périodiques; 664.005
• DOI: 10.1016/j.jfoodeng.2016.06.017
• Languages: English
• ISSNs: 0260-8774

Abstract

Abstract: A generalized n -th order reaction model was proposed to explain the reaction rate acceleration in the frozen state in dilute systems. The mechanism for the rate acceleration existed in the freeze-concentration effect, which was represented by a concentration factor, α . The α was theoretically related to the freezing point depression and was estimated from the analysis on the fraction of frozen water. The theoretical model was effectively applied to describe the freeze-denaturation of soyprotein. Changes in native and denatured protein concentrations during freeze-preservation were described by the model to obtain kinetic parameters, which suggested the reaction order very likely to be 2. When the preservation temperature was changed from −5 to −40 °C, the denaturation equilibrium was the highest at −5° C but the apparent kinetic parameter was the highest at −18° C. The addition of sucrose proved theoretically and experimentally to be very effective to suppress the freeze-denaturation of protein as a cryoprotectant. Highlights: Generalized n-th order reaction model was proposed for freeze-acceleration reaction. Freeze-concentration effect was theoretically related to fraction of frozen water. Reaction model was very effective to describe freeze-denaturation of soyprotein. Reaction order was estimated to be 2 from the kinetic analysis. Cryoprotectant effect of sucrose was explained theoretically and experimentally.