Effect of Cold Storage on the Nutritive and Microbiological Quality of Fermented Soy Drink from Tamarind and Nono

Abstract

The effect of cold storage on fermented soy drink from tamarind and nono was assessed. Soymilk was produced by milk extraction from whole soybean seeds and pasteurized at 76oC for 30 minutes. The soymilk was divided into two portions. One portion inoculated with tamarind pulp containing 5.3×103 cfu/mL and the other with nono containing 11.6×103 cfu/mL. They were incubated at 42oC for 12 hours, fermentation was harvested by stirring, packaged, refrigerated at 5oC and subjected to microbial analysis using standard method. Preservation of drink by refrigeration method increased the microbial load of sample A from day 0 (8.7×103 cfu/mL) to day 9 (15.0×103 cfu/mL) but decreased on day 12 (11×103 cfu/mL). Similar results were recorded for samples B and C. However, sample A had neither coliform nor fungal growth. Sample A and B had no significant (p>0.05) difference in energy value (41.91±0.89 and 42.50±1.14) but sample C had the highest energy (96.69±2.03- 77.80±1.17), ash (4.10±0.13- 96.69±2.03), crude protein (0.51±0.01- 0.55±0.03), oil extract (3.44±0.17- 3.65±0.15) and NFE (7.61±0.14- 11.16±0.17) but lowest in moisture (79.84±1.07- 80.27±1.30) contents on day 6– 12. However, sample B had high moisture content ranged (84.43±1.17- 87.15±2.3) but lower in other parameters. Statistical analysis for the vitamin C, potassium and calcium of sample’s A, B and C were carried to determine their significant differences. Refrigeration slows down the bacterial activity hence reducing spoilage thus making fermented soy drink a good source of desired protein in Nigeria.