Pectin from lemon and mango peel: Extraction, characterisation and application in biodegradable film

Abstract

The food wastes have significant amount of functional ingredients that have valorization potential. Citrus limon (lemon), Mangifera Indica (mango) peels are maximally used as waste in food industries in all over the worlds. This work aimed to extract pectin from mango and pectin peels at different conditions, and pectin yield, degree of esterification (DE), intrinsic viscosity (η) and molecular weight (Mw) were determined. The best conditions of extraction were pH 2, temperature 80 °C, time 4 h for lemon and 5 h for mango, where pectin yields were 30.60 ± 0.95 and 31.70 ± 1.04%, respectively. At this condition, DE, η, Mw were 42.02%, 0.177 and 42,316 g/mol for lemon peel while 30.60%, 0.05 and 8364.01 g/mol for mango peel, respectively. The extracted pectin under optimal conditions was used to fabricate pectin-silica based film. All the composition of films showed considerable mechanical properties due to the presence of silica. The highest values of tensile strength and young modulus were found 61.31 MPa and 16.49 MPa, respectively, at the silica percentage of 1.25% (w/v) where toughness and elongation at break were decreased due to the more bonding between pectin and silica. This study demonstrated that incorporating silica at 1.25% (w/v) can improve the physicochemical properties of pectin film.