Storage Potential of the Cactus Pear (Opuntia ficus-indica) Fruit Juice and Its Biological and Chemical Evaluation during Fermentation into Cactus Pear Wine

Abstract

The cactus pear (Opuntia ficus-indica) fruit is widely cultivated and grown naturally in arid regions because it is adaptive to a wide range of soil and environments. The pear fruit is inhabited by different micro-organisms and has chemical composition suitable for wine making. Profiling the contributing micro-organisms and evaluating the chemical parameters of cactus pear wine can assist in selecting reliable microbes for use as starter cultures. Spontaneous fermentation was carried out for 13 days and followed by three months of cold storage. Fermenting microbes were isolated, characterised and identified. The chemical parameters, namely, sugar concentration, ethanol concentration, pH and total acidity, were analysed. A total of 22 micro-organisms were identified, among which nine yeast species, two acetic acid bacteria (Gluconobacter spp.) and eight Bacillus spp. were isolated. The simple sugars were used up, and ethanol was produced to a high concentration of 50.9 g/L. The pH ranged between 2.8 and 2.9; hence, a maximum total acidity of ±25 g/100 mL was achieved. At least 78% of the available tannins were used in the early stages of fermentation. Potassium and magnesium were the highest minerals obtained, and zinc was the lowest. The highest ash content obtained was 7.9 g/100 mL. The vitamin C content was retained and gradually increased throughout the fermentation process. The findings indicate that lasting flavoured wine can be developed from cactus pear fruit because of the fermenting microbes and the chemical composition of the fruit.