Mexican lime peel: Comparative study on contents of dietary fibre and associated antioxidant activity

High dietary fibre (DF) powders from Persian and Mexican lime peels were prepared and their dietary fibre composition and antioxidant capacities determined. The total dietary fibre (TDF) contents of both varieties were high; 70.4% and 66.7%, respectively. Both lime peel varieties had an appropriate ratio of soluble/insoluble fractions. The water-holding capacities (WHC) of DF concentrates are high (6.96-12.8 g/g). The WHC was related to the soluble dietary fibre (SDF) which was higher in the DF concentrate of Mexican lime. As part of this analysis, the antioxidant activity (AA) of total extractable polyphenols (TEP) was studied, using three methods: azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) ABTS radical-scavenging activity, alpha,alpha-diphenyl-picrythydrazyl (DPPH) and beta-carotene-linoleic acid antioxidant assay. DF concentrates of Persian lime peel had greater polyphenol contents than those of Mexican lime peel. The polyphenols associated with the DF in both lime peel varieties showed a good AA. From a nutritional standpoint, DF lime concentrates may be suitable as food additives. (C) 2004 Elsevier Ltd. All rights reserved.