| Popis: |
Drying is well-known as an effective process for food preservation. The main benefits of the drying process are restricted growth of microorganisms, reduced degradation reactions related to moisture content, and decreased mass during transportation [1]. Among the advantages of using microwaves in drying, two of them stand out. First, an increase in drying rate with a reduction in time of processing, due to faster diffusion and better heat transfer. Second, the ability to improve quality, including eliminated case hardening and better sensory attributes, appearance, colour, and texture [2]. This study aimed to examine the effect of convective drying combined with microwaves on drying kinetics and the colour of pumpkin pulp (Cucurbita maxima). Hybrid drying of pumpkin pulp were performed at five microwave powers (119 W, 336 W, 462 W, 595 W, 700 W) for 2 minutes coupled with hot air drying (60 °C, air velocity 1 ms-1). The results show that microwave- assisted hot air convective drying significantly affects drying kinetics and colour. Higher microwave power shortens the drying time. Total colour difference is increasing due to the increase in microwave power. Increasing the microwave power results in a decrease in lightness (L*) and yellowness (b*). The hybrid drying can be accepted as an alternative drying process for pumpkin pulp. |
