Quality prediction of nipa palm fruit during osmotic dehydration and drying process
2017
Pojchananaphasiri, W. | Lertworasirikul, S.
This research aimed to develop osmotic dehydrated (OD) nipa palm fruit, study mass transfer and develop regression models for quality prediction of dried OD nipa palm fruit during the OD and drying processes. The samples in size 1.5x1x0.2 cm3 were immersed in 65% sucrose solution at 25 oC in a water bath with the ratio of sample to solution 1:5 (w/w). During the OD, when the immersion time increased, the moisture content (MC) of OD nipa palm fruit was decreased, while solid gain (SG) and water loss (WL) were increased. OD process of nipa palm fruit reached the equilibrium point in 12 h with 26% SG. Initial MC of samples was 85.98-86.36% (wet basis). After the OD, MC, WL and SG were in the range of 39.64-44.50%,62.28-62.86% and 25.89-26.47%, respectively. The exponential models were the best models to predict MC, WL and SG. The OD nipa palm fruit was dried in a hot air oven at 50, 60 and 70°C for 240 min. The effects of SG and drying temperature on the qualities of OD nipa palm fruit were studied. The results showed that the drying time was in the range of 180-240 min so that the MC and water activity (aw) were lower than 18% and 0.75, respectively. Based on the high coefficient of determination and low average mean squared error, the 2nd order polynomial type was suitable to predict MC, aw and hardness of the dried OD nipa palm fruit during the drying process.
显示更多 [+] 显示较少 [-]