Degradation of sesame hull pectin during roasting: catalytic effects of four inorganic chloride salts

Abstract

SummarySesame seed hull contains a substantial concentration of minerals. During the roasting, these minerals assume a catalytic function in the degradation of the sesame seed hull pectin. In this work, the effect of four inorganic chloride salts on the structure and thermal degradation products of sesame hull pectin during heating was investigated. The results indicated that, during roasting, chloride salts catalysed the degradation of pectin polysaccharide side chain regions more than the linear main chain. The introduction of chloride salts reduced the rate of mass loss from sesame hull pectin and resulted in a shift of the main peak towards a lower temperature range. The introduction of KCl and NaCl resulted in a significant decrease in the yield of furans and an increase in the proportion of small molecules such as acids and aldehydes in the thermal degradation products of sesame peel pectin, suggesting that the presence of KCl and NaCl facilitated the fragmentation of the sugar units. In contrast, MgCl2 and CaCl2 clearly facilitated the formation of furans and exhibited a discernible catalytic effect on the degradation of acidic substances. This study contributes to the understanding of the effect of minerals on the degradation behaviours of pectin in sesame hulls during sesame processing.