The effect of pressure on degradation kinetics of polyphenols: Impact of polyphenol structure at hyperbaric storage conditions

Abstract

Understanding reaction kinetics at elevated pressures is essential for developing efficient pressure-based technologies. It is especially vital for hyperbaric storage (HS), where pressure is applied for long durations. In single and multi-component models, the influence of pressure on the degradation kinetics of different catechins and anthocyanins was studied at accelerated conditions using neutral pH at pressures up to 200 MPa (HS levels) for several hours. In the neutral baroresistant buffer, pressure enhanced the degradation of all tested flavonoids with a negative activation volume. Despite the significant structural variety and major differences in the degradation rates within each tested subgroup, no significant structure-dependent effect of pressure on the activation volume was observed, which is suggestive of a similar mechanism by which pressure accelerates the degradation. The antioxidant capacity of catechins was not affected by pressure compared to control samples when the concentration of the original catechin was similar. Industrial relevanceA better understanding of pressure effects on the degradation reaction kinetics of food components can contribute to the general understanding of mechanisms related to food component degradation under high-pressure treatments. Plant-based foods are rich in polyphenolic compounds and responsible for sensory characteristics and their related health-promoting properties. In conditions similar to HS, that are known to inhibit and even, in some cases, inactivate microorganisms, when food is exposed to high pressures for a long time, it is imperative to investigate the effect of pressure on polyphenol degradation kinetics, which can lead to differences in the polyphenol compositions during the pressurized storage. However, the impact of pressure on polyphenol degradation kinetics is often overlooked. This study provides fundamental information regarding the polyphenol structure-dependent degradation kinetics of catechins and anthocyanins under pressure while taking into account the often overlooked pressure-induced pH shifts. The presented work can promote the development of novel storage and processing technologies based on high pressure that will better preserve oxidation-liable compounds with lower energetic costs.