Study on the changes during the fermentation of the wine prepared from palm (Phoenix sylvestris) sap.

ABSTRACT

The sugary sap of different palm trees is fermented to create palm wine, an alcoholic beverage. This work was aimed at studying the changes that occur during the fermentation process of wine made from the sap of the wild date palm species Phoenix sylvestris. At first, the best age of the palm tree was determined by observing total soluble solid and sap yield for 24 h and was found to be middle-aged palm plants (15-40 years old). Pure wine yeast (Saccharomyces cerevisiae SC22) and a natural starter culture were added to the palm saps, adjusting the total soluble solid (TSS) to 21.5° brix (°Bx). Total titratable acidity, pH, volatile acidity, reducing sugar, non-reducing sugar, total sugar, alcohol content, ester content, and aldehyde contents were the parameters under investigation. The statistical analysis showed significant (p ≤ 0.05) changes in the physico-chemical and volatile constituents of palm sap during the fermentation process in both systems. Sensory evaluation revealed that palm wine fermented with pure yeast culture was significantly superior to natural, spontaneously fermented wine. The acceptability test showed that the ideal characteristics of palm wine are cloudy in appearance, fruity in aroma, and sweet in taste.