Sweetened nopal flakes: a functional snack

Abstract

Nopal (Opuntia spp. and Nopalea spp. genera) is a crop, recognized for its nutritional and medicinal properties; however, there are some underused species, despite the great genetic diversity in Mexico. The genus Opuntia spp. is the most consumed nopal, whereas Nopalea spp. has low commercial demand, possibly because their nutraceutical attributes are unknown. Additionally, the nopal pads or cladodes are little accepted by many consumers, due to their texture and flavor.

The study objectives were 1) evaluate the nutraceutical content and antioxidant activity of four nopal cultivars: Nopalea cochenillifera cv. Texas (NT) and Opuntia ficus-indica cv. Jade (OJ), Milpa Alta (OMA), and Atlixco (OA); 2) develop nopal flakes, sweetened with rebaudioside A, from the cultivar with the best nutraceutical quality and sensory acceptability. Ascorbic acid, total phenolics, and total flavonoids were determined by spectrophotometric methods, individual flavonoids (quercetin, kaempferol, and isorhamnetin) by HPLC, and antioxidant activity by the DPPH assay. OA was the cultivar with the best nutraceutical quality.

The sweetened nopal flakes of OA, at a concentration of 1.1 mg g^-1 rebaudioside A, had the highest sensory acceptability by the panelists in intensity and sweetness preference. The addition of rebaudioside A improved the product’s flavor and contributed to preserve the flavonoids and antioxidant activity. These results will contribute to the chemotaxonomy of O. ficus-indica and N. cochellinifera species,and to the utilization of nopals as functional foods, due to their nutraceutical quality.