Basic Physicochemical Properties of Pectin from Underutilized Chili Peppers Subjected to Different Heating Regimes

Brown Jalapeno peppers (BPs) are accidentally harvested and discarded at different points of the postharvest handling and processing lines because they are not visually attractive to consumers. Water-, chelator-, and alkali-soluble pectins (WSP, CSP, and NSP) were extracted from raw and heat-treated BPs and evaluated for basic physicochemical properties. Heat treatment increased the yield of WSP with the concomitant decrease in CSP and NSP. The extracted pectins were classified as low-methoxyl pectins, as only CSP from raw peppers showed a degree of methyl esterification slightly above 50%. Heat treatment decreased (13.5-86.2%) the molecular weight of the most abundant fraction in all pectins. It also decreased the degree of methyl esterification and Gal and Man contents in all pectins. The viscosity of WSP solutions decreased (28-41%) with heat treatment. Heat treatment negatively affected the color of pectin.