Division of Food Science and Technology, Faculty of Agro-industry Chiang Mai University, Chiang Mai, Thailand.
Division of Product Development Technology, Faculty of Agro-industry Chiang Mai University, Chiang Mai, Thailand.
J Food Sci Technol. 2014 Sep;51(9):2127-33. doi: 10.1007/s13197-012-0709-9. Epub 2012 May 4.
This study investigated the effect of microwave power (2,400-4,000 W) and drying times (10-30 min) on the quality of dried turmeric in terms of colour (L, a*, b*), moisture content, water activity (aw), ash, antioxidant activity (2,2-dipheneyl-1-picrylhydrazyl; DPPH), total phenolic and curcuminoids content. In addition, Response Surface Methodology (RSM) was implemented to optimize the drying conditions for turmeric. A range of quality parameters, microwave power (W) and time (min) were fitted to quadratic models using a central composite design. The Analysis of Variance (ANOVA) statistic results suggested that the optimal qualities (i.e., aw, value, moisture content, phenolic content, curcuminoid content and EC50 and L value) of dried turmeric were achieved at high vacuum-microwave power (3,500-4,000 W) and long duration (27-30 min). The improvement in the quality of dried turmeric microwave-vacuum drying in these conditions was illustrated through the enzymatic browning reaction via inhibition of polyphenol oxidase which suppressed the formation of the brown pigments and increased the phenol substrates.
本研究探讨了微波功率（2400-4000W）和干燥时间（10-30 分钟）对干燥姜黄质量的影响，包括颜色（L、a*、b*）、水分含量、水分活度（aw）、灰分、抗氧化活性（2,2-二苯基-1-苦基肼；DPPH）、总酚和姜黄素含量。此外，还采用响应面法（RSM）对姜黄的干燥条件进行了优化。采用中心复合设计，将一系列质量参数（微波功率（W）和时间（min））拟合到二次模型中。方差分析（ANOVA）统计结果表明，在高真空-微波功率（3500-4000W）和长时间（27-30 分钟）下，可获得干燥姜黄的最佳质量（即 aw 值、色泽、水分含量、酚类含量、姜黄素含量和 EC50 和 L 值）。在这些条件下，通过抑制多酚氧化酶的酶促褐变反应，提高了干燥姜黄的质量，抑制了棕色色素的形成，增加了酚类底物。
