Effect of Ripening Stage at Harvest on Phytochemical Composition of Huamiche (Ferocactus histrix) Fruit

Ferocactus histrix, a member of the Cactaceae family, is an important underutilized barrel cacti from the central arid part of México. The stem, floral bottoms and fruit (huamiches) have been traditionally consumed by rural communities, however, its phytochemical composition and nutraceutical potential is still unknown. Phytochemical and physicochemical characterization of the fruits could enhance sustainable production of F. histrix in arid and semiarid regions. The fruits from these cacti present an oval shaped, a characteristic bittersweet flavor, and yellow or red external colour attributed to betalain pigments: betaxanthins and betacyanins. In this work, total phenolic, flavonoid and betalain (betaxanthins,  betacyanins) contents, DPPH  antioxidant capacity, colour parameters (L*, a*, b*), titrable acidity, pH, TSS, weight and size were measured in red and yellow F. histrix fruits of two ripening stages  (ripe and unripe) collected at San Luis de la Paz, Guanajuato, Mex. (N 21° 16´48.43¨, W 100° 30´16.68¨). Overall, yellow fruits were larger and heavier than red ones, and the phytochemical contents and physicochemical variables were affected by the ripening stage. The highest phenolic and flavonoid contents were observed in unripe red fruits, 15,1 ± 2,7 mg EAG/g and 10,8 ± 1,9 mg EC/g respectively. Total betalain contents were also higher in unripe fruit (≈ 20%) despite the color. Maximum betacianin and betaxanthin contents were observed for red and yellow unripe fruits respectively. F. histrix fruits have similar or higher phytochemical contents compared to other cacti fruits, and could represent a source of nutraceutical food in arid and semiarid regions of México.