Antioxidants in processed fruit, essential oil, and seed oils of feijoa

Abstract

The degradation of nutraceutical properties during processing of the fruits of feijoa (Acca sellowiana), and the characterization of seed oils, and volatile compounds were evaluated. In feijoa fruit dehydrated by a standard convective air process, the total phenols and total flavonoids declined 42%, and the antioxidant capacity determined by ABTS, DPPH, and FRAP declined 26% with respect to lyophilized fruit. In feijoa jam, the reduction of total phenols and flavonoids was 52%, and the reduction in antioxidant capacity was 72%. Vitamin C in the jam was also reduced by the processing. Feijoa seeds had 69.4% unsaturated fatty acids, mainly linoleic (46.2%) and linolenic (3.7%) acids. Behenic acid was also detected in the seeds but in small amounts (0.91%). The feijoa skin had 31 volatile compounds in two orchards with different climate, one in a tropical highland and the other in a temperate zone. The extraction yield was on average 0.45%. The major compounds in the essential oil of the feijoa skin were 3-hexen-1-yl benzoate, elixene, spathulenol, D-germacrene and alpha-cadinol. In general, the concentration of volatile oils was higher in the temperate zone.

Keywords

• Acca sellowiana; linoleic acid; nutraceutical foods; phenols in jam; volatile oil