Assessment of Cashew Apple Juice on Fermentative Activity of Two Lactic Bacteria in Production of Yoghurt

Abstract

Cashew apple is not practically used such as cashew nut which is one of most traded agricultural export products from Northern Ivory Coast. This work focus on the use of cashew apple juice as food additive in production of yoghurt. The aim of this study is to evaluate physicochemical parameters of cashew apple juice and its effect on fermentative activity of two lactic bacteria (Lactobacillus delbrueckii subsp bulgaricus and Streptococcus salivarius subsp thermophilus). Various types of yoghurt were formulated with incorporation of different proportions (0%, 5%, 10%, 15%, 25%, 35% and 40%) of cashew apple juice in milk (v/v). Each formulation was fermented with lactic ferment containing the above two lactic bacteria. Effect of juice on fermentative activity of the two bacteria was carried out by pH, titratable acidity with duration of fermentation to obtain 80 Dornic degrees. Results of phytochemical analysis (p<0.05) showed that cashew apple juice have an acid pH with value of 3.96 ± 0.03 and titratable acidity of 0.41 ± 0.01%. This juice contains a high level of moisture (77.48 ± 0.09%) and vitamin C (124.74 ± 1.17 mg/100ml) but a low concentration of reducing sugars (1.46 ± 0.03 g/100ml). The study of effect of cashew apple juice incorporated into milk, showed that the formulations with 5% and 10% improved fermentative activity of lactic bacteria tested. These two formulations (5% and 10%) reduced fermentation time (180 min) compared to control (220 min). This study suggests that cashew apple juice could be a food additive in production of yoghurts as a source of vitamin C and catalyst for fermentation. In perspective, we plan to assess toxicity and shelf of yoghurt with cashew apple juice.