Chemical composition and physicochemical properties of mango juice extracted using polygalacturonase produced by Aspergillus awamori CICC 2040 on pretreated orange peel

Abstract

This study investigated the effect of combined NaOH and microwave pretreatment of orange peel on the efficacy of polygalacturonase, produced by Aspergillus awamori CICC 2040, in mango juice extraction. Mango juice extracted with polygalacturonase produced using pretreated orange peel (PUE) had a higher yield than CRE (mango juice extracted with polygalacturonase produced using untreated orange peel) and CME (mango juice extracted with commercial polygalacturonase). Significantly (p < 0.05) higher soluble solids, total sugar, total carotenoid and phenolic contents, and percentage transmittance were recorded for PUE compared to CRE. However, CRE had a higher reducing sugar, pH, vitamin C, and pectin. Rheological characterization using Power Law, Herschel-Bulkley, and Casson models showed that PUE had better flow characteristics than CRE. The sensory evaluation result showed that PUE was more preferred than CRE and compared favourably with CME in terms of colour, mouthfeel, and overall acceptability. This study showed that the pretreatment of orange peel enhanced the efficacy of polygalacturonase in mango juice extraction.