Evaluation of Microbial and Chemical Composition of Fermented Beverages Produced from Tiger nut (Cyperus esculentus) and Beetroot (Beta vulgaris)

Abstract

Consumption of fruits, vegetables, and nuts is essential for human health because of their minerals, vitamins, antioxidants and dietary fibre contents. Two types of beverages were prepared (tiger nut beverage and tiger nut/beetroot beverage). 200 g tiger nut was homogenized in 1 L of sterile water to prepare tiger nut beverage while 200 g of tiger nut with 20 g of beetroot to prepare tiger nut/beetroot beverage were homogenized with 1 L of sterile water. The prepared products were pasteurized at 80 °C for 5 min and left to ferment at room temperature (28±2 °C) for 4 days. The products were analyzed for chemical composition and microbial load. Results obtained showed no significant differences in the moisture, ash and protein content products. However, significant differences existed in fibre, fat and carbohydrate contents. Leuconostoc mesenteroides, Lactobacillus plantarum, Lactobacillus acidophilus, Streptococcus lactis, Saccharomyces cerevisiae, Saccharomyces exiguus, Saccharomyces stellatus and Candida pseudotropicalis were isolated from products. The number of bacteria in Tiger nut beverages increased from 0.85×103 to 1.83×107 and 0.97×103 to 1.78×107 in the Tiger/beetroot beverage. Mould and yeast counts in the tiger nut beverage increased from 0.32×102 to 1.06×104 while in the mixed product, the increase was from 0.30×102 to 1.18×104. There were no significant differences in pH and titratable acidity throughout days of fermentation. The tiger nut/beetroot beverage has high overall acceptability. The beverages could serve as a good material for the production of quality yoghurt in place of animal milk that is mostly used for yoghurt production.

Keywords

• beverage
• chemical
• fermentation
• microorganisms
• plants