ABSTRACT

Palm wine sample (Raphia hookeri) with different salt concentration (O.6g, 0.7g, 0.8g and 0.9g salt) was subjected to ohmic heating to determine the extent of yeast destruction. The treatment was at 120 volts for 5, 10, 15 and 20 minutes and the treated samples were allowed to stand on the shelf for 21 days. Analysis of the yeast count, Alcohol content, Brix level, pH, ionic strength and titratable acidity were conducted on the fresh sample, ohmic heated sample and stored sample on the 7th , 14th and 21st day. Result of the analysis showed that ohmic heating with addition of salt showed a destruction rate that increased with increase in salt concentration. Destruction rate (0.6g — 0.9g salt) was (3.5 16 — 3. 190) x (cells/mi) 1mm and the yeast cells were destroyed within 20 minutes of heating. The alcohol content of the non-ohmic sample (ctrl 1) increased from 2.16% to 13.06% on the 7th day while the ohmic heated samples showed slight increase (1.6 1% — 2.16%). The brix level, iomic strength and pH of the non ohmic heated sample (ctrl 1) reduced drastically while there was slight reduction in the ohmic heated samples. Sensory test conducted on the 2 1st day produced acceptable colour, flavour and taste of the ohmic heated wine samples with addition of salt while the ohmic heated wine sample without salt was the most undesired in terms of taste. Ohmic heating with NaCI is therefore recommended for palm wine preservation.