Rehydration Kinetics of Green Pea Grains Dried at Different Microwave Powers

In this study, both untreated and pre-treated green pea grain samples dried at different microwave output powers (90, 180, and 360 W) were rehydrated at three different temperatures (30ºC, 50ºC, and 70ºC). The rehydration kinetics of dried peas were analyzed using both the Peleg and the first-order kinetic models. Observations revealed that the Peleg model exhibited better agreement with the experimental data. As both microwave power and rehydration temperature increased, the rehydration capacity also increased in both pre-treated and untreated peas. The highest moisture content was observed after rehydration in pre-treated peas dried at 360 W microwave power (2.80 g water/g dry matter and 213.40% mass gain), while the lowest moisture content was recorded in pre-treated samples dried at 90 W microwave power (1.66 g water/g dry matter and 119.30% mass gain). However, the samples were unable to reach the moisture level (3.10 g water/g dry matter) before drying at all rehydration temperatures. The activation energy of rehydration varied between 10.75 and 37.39 kJ/mol. The color properties of rehydrated green pea grains were significantly influenced by both microwave power and rehydration temperature. As these two parameters increased, the color differences of rehydrated peas compared to fresh peas also increased. The maximum total color difference (E = 17.66) in rehydrated peas compared to fresh peas was observed at 360 W microwave power and 70ºC rehydration temperature with untreated green peas, while the least total color difference (E = 8.69) occurred at 90 W microwave power and 30ºC rehydration temperature with pre-treated green peas.