Microbiological and Physicochemical Variations during Spontaneous Fermentation of Plantain Must.

Abstract

Major losses are recorded every year in the plantain production sector in Côte d'Ivoire. These losses are mainly due to poor harvesting, transport, and storage conditions. Local processing of this food crop into other products could help limit postharvest losses. The aim of this study was to evaluate some microbiological and physicochemical parameters during the fermentation of plantain must for the production of an alcoholic beverage. Physicochemical parameters such as pH, titratable acidity, and reducing sugars were measured using a pH meter by titration and the Bernfeld method, respectively. Refractometric dry extract and alcohol content were measured using a refractometer. Loads of mesophilic aerobic germs, total coliforms, streptococci, and yeasts were determined by standard microbiological methods. Values for refractometric dry extract (10°B-4.5°B), reducing sugars (8.25-0 mg/mL), and pH (4.37-3.36) decrease during fermentation. The highest alcohol content (11%) is obtained after four days of fermentation of plantain must. In contrast to total coliforms (5.27-3.61 log₁₀ cfu/mL), loads of mesophilic aerobic germs (4.84-9.8 log₁₀ cfu/mL) increase during fermentation. Yeast and streptococci loads reach their peaks at 7.81 log₁₀ cfu/mL and 8.15 log₁₀ cfu/mL, respectively, after six (6) days of fermentation before dropping off. Plantain must could be used to produce distilled alcoholic beverages.