IDENTIFICATION, NUTRITIONAL AND PHYTOCHEMICAL DESCRIPTION OF EDIBLE WILD CACTUS VARIETIES FROM KENYA

Abstract

Edible cactus is considered to have a promising commercial application in the food industry due to its nutritive composition and drought resistant nature. However, knowledge on the nutritive composition of edible cactus varieties and their distribution in Kenya is still limited. This study sought to prospect for edible cactus varieties in Kenya and determine their physicochemical characteristics in order to unlock their industrial potential. Five samples were collected in four Arid and Semi-Arid lands (ASALs) counties of Kenya namely; Makueni, Machakos, Baringo, and Laikipia. Structured questionnaires were used to identify and differentiate edible from non-edible cactus varieties. Morphological and physicochemical characteristics of the fruits, and their juice extractability were determined. The juice was characterized in terms of pH, Total Titratable Acidity (TTA), Total Soluble Solids (TSS), proximate content, minerals, total sugars, and phytochemicals. Three edible cactus varieties were identified namely the purple type (Opuntia ficus-indica) in Baringo and Makueni, the green type (Opuntia monacantha) in Makueni and Machakos, and the yellow type (Opuntia megacantha) in Laikipia based on the Food and Agricultural Organization (FAO) cactus plant descriptors and taxonomic knowledge. The purple variety (O.ficus-indica) was the highest yielding with yields over 11kg/ m². At the mature ripe stage, the juice recovery rate for the purple and yellow varieties was above 50%. All the samples were a rich source of crude fiber (1.41-1.71g/ 100g), Calcium (295.56-342.42 g/100g), and Zinc (2.30-2.39g/100g). The sugar content was predominantly glucose (1.26- 4.59 g/100g) and fructose (1.45-2.66/100g). The fruits exhibited substantial amount of total phenolics (1.79-2.52g/100g G.A.E.) and high antioxidant activity (0.59-1.83 mg/ml). Generally, the yellow variety was most nutritious, had highest sugar and phytochemical content. Therefore, the fruits are recommended for use either in isolation or with other food ingredients in the food industry.

Key words: Cactus varieties, physicochemical properties, juice extractability, phytochemical, yields