Thesis (BS Food Technology) -- University of the Philippines Mindanao, 2010

A study of the natural fermentation and alcohol production potential of two laocal palm saps was done. Selected physico-chemical parameters such as pH, total soluble solids, sugar (sucrose, glucoseand fructose) content; ethanol, organic acids (lactic aand acetic acid)concentration and microbial populationwere monitored for the 48 hours natural fermentation of coconut (C. nucifera) and fishtail (Caryotasp.)saps. An attempt to control ethanol production using the 12hour substrate (harvested palm sap) was made by inoculating the saps separately with three different commercial yeast strains S. bayanus (Red Star Cote des blancs), and S. cerevisiae var ellipsoideus BIOTECH 2815. Theoritically, every one (1) gram glucose yeilds 0.511gram ethanol and ethanol conversion efficiency (Y E/glu) is expressed as teh ratio of the yeild of ethanol to total sugars consumed (as gram ethanol/gram glucose). This is usually expressed in percent. For coconut sap, Y E/glu for each treatment were 0.37 g/g, 0.26 g/g and 0.31g/g or 36.67%, 26.20% and 30.87% respectively. For fishtail palm sap Y E/glu for each treatement were 0.34g/g, 0.25g/g and 0.23 g/g or 36.74%. 24.65% and 23.10% respectively. The ethanol production of palm saps can be improved by using commercial yeasts, provided that, after a harvest period of 12 hours, the sap is immediately pasteurized at a holding temperature of 60'C for 30 minutes to inhibit or slow down the activity of other microorganisms present in its natural microflora, prior to inoculation. The above results will still be subject to further potimization on order to improved ethanol conversion efficiency.