A Tamarind Local Variety from Garoua, Cameroon: Physicochemical Characterization, Fruit Pulp Fermentation and Extraction of Tartaric Acid from the Fruit Pulp Winery Waste

Abstract

Objective: Tamarind is known for the tart taste that is characteristic of Tartaric acid. The fruit pulp is in high demand in both the domestic and industrial settings due to its high food value. It contains fatty acids, vitamins, roughage, phytosterols and many other phytochemicals necessary for good health. To the best of our knowledge, very little has been reported on the processing of this nutritional fruit and the results reported so far show variability as a function of the botanical origin of the plant. No literature exists on the Tamarind variety from Cameroon and no study combining wine production and extraction of Tartaric acid from the waste residue has so far been reported. We are taking this advantage to explore wine fermentation from Tamarind fruit pulp by focusing on the effects of different parameters such as time of treatment for juice extraction, yeast inoculate for wine fermentation and secondary fermentation on wine quality, and to extract Tartaric acid from the winery solid waste residue. Methods:The main fermentation was done at 2°C in 13d and 1w secondary fermentation was done in 1 week. The wine was characterized for alcoholic content, pH, titratable acidity, soluble dry matter and consumer acceptability. The winery solid waste residue (potassium bitartrate precipitate) was used to extract crystalline L-Tartaric acid which was characterized by Fourier transform infrared spectroscopy, melting point and crystallinity by powder X-ray diffraction. Results:The Tamarind pulp wine produced was of acceptable quality. It was clear, sweet, sparkling, smooth and well-flavored. The drink had a pH of 3.04 and an alcohol content of 16%. The Tartaric acid was crystalline, and it reflected all characteristic functional groups of Tartaric acid, with a melting point of 189.8-196.4°C (laboratory grade). Conclusion:It is very possible to couple Tamarind fruit pulp wine production with chemical synthesis of pure crystalline Tartaric acid using solid winery waste from Tamarind fruit pulp. The method used in this study is simple, straightforward, ecofriendly and cost effective.