Abstract

Cactaceae had always attracted attention by their strange shapes and important adaptability supporting extreme temperatures ranging from -10 to 65°C. For this reasons, morphological and biochemical prospection of three Tunisian cultivars of prickly pear (Thorny, Gialla and Rossa) were established. Results show significant differences between the cultivars. The source of this variation was probably genetic without excluding the geographic effects. The thorny cultivar showed small fruit dimensions with 74.25 g of weight, 6.67 cm length and 3.94 cm of diameter. In contrast, Rossa and Gialla were respectively about 140 g. Gialla and Rossa fruits, although larger, contained few seeds; about 235 seeds per fruit, while Thorny cultivar contained 256 seeds per fruit. pH, acidity and sugar juice levels were also studied. High levels of juice (44.77 and 55.43 ml) were obtained with Gialla and Rossa cultivars, respectively. Total sugars of the three cultivars were quite similar and pH was close to neutrality. Concerning the performance of oil seeds, values averaging was about 7.30%. This value is an important indication of the potentially nutraceutical, economic and industrial utility of seeds of cactus fruit as a new source of oils. The seeds of prickly pear are deficient in protein with the higher percentage of the total protein for Gialla cultivar.

Key words: Cactus (Opuntia ficus-indica), fruit, juice, acidity, sugar, seeds, lipids, proteins.