Effect of hydrothermal-calcium chloride treatment on pectin characteristics and related quality in green peppers during storage.

Effects of hydrothermal (HT)-calcium chloride (CaCl2) treatment on pectin characteristics and related quality in green peppers during storage were assessed. The results showed that the changes of physicochemical quality in all green peppers were similar during storage. Weight loss percentage increased, firmness, the content of free water and bound water decreased during storage. Water-soluble pectin (WSP) notably increased, but sodium carbonate-soluble pectin (SSP) and chelate-soluble pectin (CSP) decreased. Galacturonic acid (GalUA), rhamnose (Rha), galactose (Gal), and arabinose (Ara) were the crucial compositions in the backbone and branched chains of pectin in green peppers. Rha and Gal increased, but Ara decreased in pectin after storage. The changes in the ratio of Rha/GalUA, Ara/Gal, and (Gal + Ara)/Rha represented that the backbone and branched chains of pectin in green peppers depolymerized to some extent after storage. Comparing with other green peppers, HT-CaCl2 treated green peppers posed lower weight loss percentage and WSP content, higher firmness, the content of free water, bound water, SSP, and CSP during storage. Otherwise, most pectin compositions in HT-CaCl2 treated green peppers showed high molar ratio after storage. Hence, HT-CaCl2 treatment was an effective way to retain pectin characteristics and related quality of green peppers, and further inhibited the softening of green peppers during storage. © Association of Food Scientists & Technologists (India) 2020.