Biothiols, taurine, and lipid-soluble antioxidants in the edible pulp of Sicilian cactus pear (Opuntia ficus-indica) fruits and changes of bioactive juice components upon industrial processing

摘要

Biothiols, taurine, and flavonols, as well as tocopherols and carotenoids have been assessed in theudedible pulp of Sicilian red (Sanguigna), yellow (Surfarina), and white (Muscaredda) cultivars of cactusudpear. The yellow cultivar has the highest level of reduced glutathione (GSH, 8.1 ( 0.78 mg/100 gudpulp), whereas the white cultivar showed the highest amount of cysteine (1.21 ( 0.12 mg/100 gudpulp). Taurine accounted for 11.7 ( 1.0 mg/100 g in the yellow pulp, while lower levels were measuredudin the others. With the exception of kaempferol in the yellow cultivar (2.7 ( 0.2 íg/100 g pulp), theudedible pulp of cactus pear was not a source of flavonols. Very low amounts of lipid-soluble antioxidantudvitamins such as vitamin E and carotenoids were measured in all cultivars. As a consequence ofudindustrial processing, a total loss of GSH and â-carotene and a net decrease of vitamin C and cysteineudwere revealed in the fruit juice, whereas betalains, taurine, and vitamin E appeared to be lessudsusceptible to degradation.