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Food security is threatened in Southern Africa, because of unpredictable droughts and higher summer temperatures brought on by climate change and global warming. Durable and hardy plants that grow easily and quickly in such conditions must be adopted to ensure sustainable and reliable food supplies. The young cladodes (nopalitos) from the cactus pear plant, which adapts to hot and dry climates, is an underutilised alternative food source that can serve as a healthy vegetable. It thrives in many environments such as deserts, below sea level, high altitude regions and tropical regions with temperatures above 50°C. Nopalitos are a traditional staple vegetable and have been consumed in Mexico for over 9000 years. However, it is underutilised and unknown as an alternative vegetable in Africa. Research on the physiochemical and nutritional content has been conducted. However, the information on harvesting nopalitos from cultivars available in South Africa for optimal edible quality is not available. Good quality nopalitos are young, thin, bright green, soft, fresh and not too sour or slimy. This paper aims to identify the effect of and the interaction between size, cultivar and harvesting season to obtain optimal eating quality. Data were obtained for two cultivars (Morado and Fusicaulis) at 9 cm, 12 cm, 15 cm, 18 cm, 21 cm and 24 cm, which were harvested in spring (October) and autumn (March) over two years. The quality characteristics were translated into the measurable attributes of morphology (weight, width, diameter, volume and surface area), texture (firmness and compressibility), colour (L*, a*, b*, C*and h°), turgidity (moisture content, mucilage yield and viscosity) and gustatory (percentage titratable acidity, pH and total soluble solids). ANOVA and Principal Component Analyses were performed to determine significant differences and interactions between the length groups, two cultivars and two seasons. The results showed that the size, cultivar and season influenced the edible characteristics. Both cultivars were most tender at 15 cm and presented the best edible qualities in spring. Morado showed better colour, turgidity and gustatory qualities. Morado was thinner, a brighter green colour, less sour and less slimy compared to Fusicaulis nopalitos. • Nopalito quality is highly influenced by harvest size, cultivar and season. • At 15 cm, nopalitos from both Morado and Fusicaulis were the most tender. • Morado nopalitos was the preferred cultivar, but Fusicaulis also performed satisfactorily. • Spring harvest was preferable, but autumn harvest nopalitos were acceptable. • Morado was thinner, a brighter green colour, less sour and less slimy. [ABSTRACT FROM AUTHOR]

Several studies have reported remarkable hypoglycemic property of the aqueous extract of different varieties of the fruit of Curcubita ficifolia . The purpose of this paper was to conduct a comparative study of the genetic diversity of C. ficifolia leaves collected in some regions of Mexico by AFLP and to determine if the aqueous extracts of the fruits with distinct phenotypic characteristics have similar hypoglycemic effects. The leaves and fruits of chilacayote from Hidalgo, Tlaxcala, Michoacán, Puebla and Mexico City were gathered. The DNA samples of the leaves were analyzed using AFLP. A binary matrix of presence-absence was built, and a dendrogram was obtained with the UPGMA method. For the evaluation of the hypoglycemic effect, the aqueous extract of the fruits was prepared and administrated to normal CD-1 male mice. Molecular analysis by AFLP exhibited an 89.4–99.4% of similarity in the genome of the all analyzed samples from different regions. However, the dendogram reached two groups with different morphological characteristics. Independent of the region and the morphological characteristics, all the fruits showed hypoglycemic effect, which in some cases was more effective compared to glibenclamide, as it was the case of the fruits from Ixtapaluca, State of Mexico. The data obtained provide information about the potential of C. ficifolia fruits for development of functional food or nutraceutical product, or a phytomedicine. [ABSTRACT FROM AUTHOR]