标题：OPTIMIZATION OF COMBINED HEAT PUMP AND MICROWAVE DRYING OF YACON (SMALLANTHUS SONCHIFOLIUS) USING RESPONSE SURFACE METHODOLOGY
作者：Shi, Qilong; Zheng, Yaqin; Zhao, Ya
作者机构：[Shi, Qilong; Zheng, Yaqin; Zhao, Ya] Shandong Univ Technol, Sch Agr Engn & Food Sci, Zibo 255049, Shandong, Peoples R China.
通讯作者地址：[Shi, QL]Shandong Univ Technol, Sch Agr Engn & Food Sci, Zhang Zhou Rd, Zibo 255049, Shandong, Peoples R China.
来源：JOURNAL OF FOOD PROCESSING AND PRESERVATION
摘要：Response surface methodology was employed to investigate the effects of drying temperature (15.0-45.0C), air velocity (1.00-2.00 m/s), moisture content at conversion point (40.0-60.0%) and microwave (MW) power (1.0-3.0 W/g) on the average drying rate (DR), specific moisture evaporation rate (SMER), total color difference (E), rehydration ratio (R-R) and shrinkage ratio (S-R) of yacon dried by combined heat pump (HP) and MW methods. A central composite rotatable design was used to develop models for responses. The coefficients of determination R-2 of DR, SMER and E were higher than 0.7. However, R-2 of R-R and S-R were 0.540 and 0.343, respectively. Based on response surface and desirability functions, the optimum conditions for combined HP and MW drying of yacon were drying temperature of 42.7C, air velocity of 1.69m/s, moisture content at conversion point of 50% and MW power of 2.0W/g. At this optimum point, DR, SMER and Delta E were 0.262 kg(H2O)/kg((d.b.)).h, 0.222kg/kW.h and 23.59, respectively.