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Thermally accelerated oxidative degradation of wolfberry pulp was kinetically monitored using model-free and model-based approaches. Kinetic calculations were performed based on simultaneous thermal analysis measurements in an air at four different heating rates. From kinetic analysis, new developed mechanistic scheme which is responsible for wolfberries anti-oxidative behavior was proposed. It was found that thermo-oxidative process proceeds through multiplestep mechanism including sum of two independent reaction sets, via consecutive and competitive steps. It was established that rutoside degradation pathway to flavonol through hydrolysis reaction is rate-determining step of considered process. Furthermore, it was found that key flavonol compound degraded by competitive reactions mechanism forming such kinetic branches, which lead to compounds responsible for wolfberries antioxidant activity. It was established that flavonol oxidative cleavage reaction and oxidative polymerization are main chemical routes which are very important in a complex antioxidant mechanism for scavenging free radicals in wolfberries oxidative stress response.

Kinetics of degradation for Aronia melanocarpa fresh fruits in argon and air atmospheres were investigated. The investigation was based on probability distributions of apparent activation energy of counterparts (ea). Isoconversional analysis results indicated that the degradation process in an inert atmosphere was governed by decomposition reactions of esterified compounds. Also, based on same kinetics approach, it was assumed that in an air atmosphere, the primary compound in degradation pathways could be anthocyanins, which undergo rapid chemical reactions. A new model of reactivity demonstrated that, under inert atmospheres, expectation values for ea occured at levels of statistical probability. These values corresponded to decomposition processes in which polyphenolic compounds might be involved. sa values obeyed laws of binomial distribution. It was established that, for thermo-oxidative degradation, Poisson distribution represented a very successful approximation for sa values where there was additional mechanistic complexity and the binomial distribution was no longer valid. (C) 2017 Elsevier Ltd. All rights reserved.