Effect of pulsed electric field, mild thermal pretreatment and calcium on texture changes of potato (Solanum tuberosum L.) during subsequent cooking

Abstract

The effect of pulsed electric field (PEF) and/or mild thermal processing at 60 °C (T60) on the cooking behaviour of potato tissue in media with different Ca2+ concentrations (0–0.5%) was investigated. The rate constant for texture degradation during cooking seemed to decrease after the different pretreatments in the order Untreated > T60 > PEF > PEF-T60, but only a significant effect (α = 0.05) could be found in the case of the combination pretreatment in 0.5% Ca2+ medium. These texture changes were linked with changes in pectin degree of methylesterification (DM) and Ca2+ crosslinking obtained after the pretreatments. The mild thermal pretreatment has little effect on the pectin DM but promotes ionic crosslinking. Both the PEF and combination pretreatment reduce the pectin DM and increase ionic crosslinking significantly. An exponential correlation was found between the texture degradation rate constant and the pectin properties studied.