Comparative study on the characterization and antioxidant properties of bael (Aegle marmelos) pulp, shell and seed pectin

Abstract

The present study is focused on the extraction and characterization of pectin from different parts of Aegle marmelos (bael) fruit such as pulp, shells and seeds by using two different acids i.e. HCl and H2SO4 on the dry and wet basis. Moreover, the comparative analysis of the extracted pectin from different fruit parts was also performed by using various parameters. The percentage yield of the extracted pectin was found to be slightly higher by using HCl. Physicochemical properties, antioxidant activity and functional group analysis were carried out on the extracted pectin. In the present study, the % yield of bael seed pectin was found to be higher as compared to bael pulp pectin and bael shell pectin. The equivalent weight, methoxyl content, total anhydrouronic acid content (AUA), degree of esterification (on dry basis) of bael pulp, shell and seed pectin were found to be 1119.52±14.57, 1095±13.94 and 1071.53±13.35, 7.25±0.10%, 6.77±0.03% and 7.39±0.07%, 56.9±0.81%, 54.56±0.35% and 58.43±0.60%, 72.37±0.03, 70.53±0.22 and 71.88±0.05, respectively. On the other hand, the moisture content and ash content of bael pulp, shell and seed pectin were found to be 10.23±0.52%, 8.33±2.08% and 9.9±0.99% and 6.77±0.5%, 7±1.01% and 6.55±0.83%, respectively which was in the acceptance range of purity. The functional group of extracted pectin was determined by Fourier transform infrared (FTIR) spectral analysis. Extracted bael pulp pectin demonstrated higher antioxidant activity with IC50 10.6 µg/ml as compared to bael seed pectin (33.47µg/ml) and bael shell pectin (53.08µg/ml). Total phenolic content of bael pulp pectin was also found to be maximum (43.5 mg GAE/g) in comparison with bael seed pectin (33.5 mg GAE/g) and bael shell pectin (23.5 mg GAE/g). These results suggest that various parts of bael fruit is having a good quality of pectin and can be utilised as a functional ingredient in biomedical and nutraceutical compounds.