Total phenolics, radical scavenging capacity and antimicrobial property of fruit peels.
Lorsuwan P., Rechtanapun C., Chantanawarangoon S.
Author Affiliation: Department of Food Science and Technology, Faculty of Agro-Industry, Kasetsart University, Bangkok, Thailand.
: 554-561
Abstract : The total phenolic contents, and antioxidant and antimicrobial activities of mangosteen, mango, banana, durian, longgong [longan], pawpaw, orange and pineapple peel extracts were studied. The mangosteen and mango peel extracts showed the highest total phenolic contents, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobiz(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities. The mangosteen peel extract also had the highest contents of flavonoids. The mangosteen and mango peel extracts exhibited greater antimicrobial properties than the other extracts. Gram-positive bacteria were more sensitive to the peel extracts than the Gram-negative bacteria. The mangosteen peel extract also had significant inhibitory effect on Aspergillus flavus. The preparation of samples (freeze dried or fibre form) had significant effects on the total phenolic and flavonoid contents, DPPH and ABTS radical scavenging activities, and antimicrobial properties of the extracts.