Journal de la transformation et de la technologie des aliments

Abstrait

Osmotic Dehydration of Garden Egg (Solanum aethiopicum): The Shrinkage and Mass Transfer Phenomena

DK Adekeye, OI Aremu, OK Popoola, EO Fadunmade, IS Adedotun, AA Araromi

Osmotic dehydration is usually employed to lower the water activity of fruits and vegetables and thus has a wide range of applications in food preservation. This study investigates the osmotic dehydration of garden egg (Solanum aethiopicum) using sodium chloride solution (NaCl) of varying concentrations (20, 40 and 60)% w/w as osmotic solutions. Different parameters such as percentage water loss (%WL), weight reduction (%WR) and solid gain (%SG) were investigated at different solution temperature (25, 35, 45, 55, and 65)°C, agitation time (20, 40, 60, 80, 100, 120, 140, 160 and 180) min and osmotic solution concentration (20, 40 and 60)% w/w to ascertain the optimum dehydration performance of the process. The performance efficiency of the process was evaluated at different osmotic solution concentrations (20, 40 and 60)% w/w with respect to time (20-180) min at a constant temperature of 40°C. The performance efficiency of the process was also evaluated at different osmotic solution concentrations (20, 40 and 60)% w/w with respect to temperature (25, 35, 45, 55, and 65)°C at the constant time (180 min). The results of this study showed that %SG and %WL increased with increase in concentration with respect to time whereby the optimum values for these parameters being 157% and 45.80% respectively were achieved at 60% w/w osmotic solution concentration, while optimum %WR (34.70%) with respect to time was achieved at 40% w/w osmotic solution concentration. Therefore, the order of %SG and %WL by the garden egg with respect to time was (60>40>20)% w/w. The optimum %SG, %WL, and %WR were achieved at 65°C in 60% w/w osmotic solution with the values of (133, 53.11 and 40.10)% respectively. The results from this study, therefore, showed that osmotic dehydration could potentially reduce the water activity of the garden egg.