Effects of different drying methods on Phyllanthus emblica pomace and modeling of relationship between moisture and water activity

Phyllanthus emblica pomace，which was rich in fiber，was beneficial raw material for the production of dietary fiber. Fresh P. emblica pomace with high moisture content was suitable for the bacteria breeding and would be corrupted. In order to decrease resources waste，the appropriate drying method was selected to reduce water content of P. emblica pomace. Under safety moisture content，the pomace storage time would be delayed to apply to dietary fiber processing. Model establishment exhibited the relationship between moisture content and water activity. The model could determine the maximum moisture content at safety water activity. The results showed that the relationship between moisture and water activity was Y=Exp（0.920-12.312/x+8.194/x2-0.03x）. The safety water activity was 0.6 and its correspondence moisture was 10.25%. Under 10.25%，microbe was hard to parasitism. Fluidized bed drying method had the shortest time with 5 min. The sample，which was porosity，showed the smallest hardness（21 N），followed by 105℃ vacuum drying sample. Polymerization was significantly affected by the method of 50℃ hot-air drying