A COMPARATIVE STUDY ON CHARACTERISTICS OF PECTINS FROM VARIOUS FRUIT PEEL WASTES EXTRACTED USING ACID AND MICROBIAL ENZYMES

Abstract

The potential of microbial enzyme-aided extraction of pectin from fruit processing wastes was evaluated to assess its possible use as an environment friendly alternative to acid extraction methods. Peel wastes from yellow passion fruit (Passiflora edulis Slims var. flavicarpa), ‘Saba’ banana (Musa ‘saba’ [Musa acuminata x Musa balbisiana]), ‘Carabao’mango (Mangifera indica L. cv. ‘Carabao’) and soursop ‘guyabano’(Annona muricata) were extracted of pectin using different microbial enzymes namely cellulase, xylanase, pectinase and α-amylase. The efficiency of the enzymatic extraction as well as pectin quality were compared with acid extraction. Generally, high yields were obtained using cellulase and α-amylase. The yields from enzymatic extractions were however significantly lower compared with the acid extraction. Highest yields were obtained from ‘Carabao’ mango peels. The chemical properties of the pectins extracted from the fruit peels highly varied depending on the fruit and the extraction method. Pectin from yellow passion fruit peels was classified as low methoxyl (LM) based on the degree of esterification values while the rest of the pectins were classified as high methoxyl(HM). Analyses of the anhydrouronic acid (AUA) content showed that ‘Carabao’ mango peel pectins had high purity while the pectins from the other fruits had low purities. Equivalent weights of the fruit peel pectins from microbial extraction were significantly higher than that from acid extraction and from commercial citrus peel pectin. ‘Carabao’mango, ‘Saba’ banana, yellow passion fruit and soursop ‘guyabano’ peels are potential sources of pectin for food applications. Acid extraction was found to be more efficient compared with microbial enzyme-aided extraction.