Evaluation of the physico-chemical and microbiological quality of tshui wine made from the fruit of Grewia coriacea Mast

This study focused on the variability of physico-chemical and microbiological quality properties of wine made from the traditional fruit juice of Grewia coriacea Mast) commonly known as "tshui", widely consumed and appreciated in Congo Brazzaville.  Samples of sweet must (intermediate product) taken every 5 days for 30 days during alcoholic fermentation were used for the various physico-chemical and microbiological analyses. These analyses were carried out using standard physicochemical and microbiological methods. Physicochemical results showed that the wine obtained had a density of 1.04±0.2, a pH of 3.2 ±0.4, a total acidity of 1.3 ± 0.2, a Brix degree of 13.7±2.1%, an alcohol degree of 5.2± 1.6%, a vitamin C content of 1.7 ± 0.2 (Kcal/100 ml) and a temperature of 26.2±0.5 °C. Polyphenols and anthocyanins in the wine increased as a result of the high alcohol content and yeast-induced acidification. Microbiological analysis revealed that yeasts, with 1.7×108 cfu/mL, were the dominant microflora in the wine, while the lactic acid bacteria isolated belonged to the Lactobacillus and Leuconostoc genera.