Behera G, Sutar P P, Aditya S
Department of Food Process Engineering, National Institute of Technology, Rourkela, Sundergarh, Odisha 769008 India.
Department of Food Engineering and Technology, Tezpur University, Napaam, Sonitpur 784028 India.
J Food Sci Technol. 2017 Nov;54(12):4078-4091. doi: 10.1007/s13197-017-2882-3. Epub 2017 Oct 6.
The commercially available dry turmeric powder at 10.34% d.b. moisture content was decontaminated using microwaves at high power density for short time. To avoid the loss of moisture from turmeric due to high microwave power, the drying kinetics were modelled and considered during optimization of microwave decontamination process. The effect of microwave power density (10, 33.5 and 57 W g), exposure time (10, 20 and 30 s) and thickness of turmeric layer (1, 2 and 3 mm) on total plate, total yeast and mold (YMC) counts, color change (∆E), average final temperature of the product (T), water activity (a), Page model rate constant (k) and total moisture loss (ML) was studied. The perturbation analysis was carried out for all variables. It was found that to achieve more than one log reduction in yeast and mold count, a substantial reduction in moisture content takes place leading to the reduced output. The microwave power density significantly affected the YMC, T and a of turmeric powder. But the thickness of sample and microwave exposure time showed effect only on T, a and ML. The colour of turmeric and Page model rate constant were not significantly changed during the process as anticipated. The numerical optimization was done at 57.00 W g power density, 1.64 mm thickness of sample layer and 30 s exposure time. It resulted into 1.6 × 10 CFU g YMC, 82.71 °C T, 0.383 a and 8.41% (d.b.) final moisture content.
将含水量为10.34%（干基）的市售干姜黄粉在高功率密度下用微波进行短时间去污处理。为避免由于高微波功率导致姜黄水分流失，在微波去污工艺优化过程中对干燥动力学进行了建模并加以考虑。研究了微波功率密度（10、33.5和57 W/g）、暴露时间（10、20和30 s）以及姜黄层厚度（1、2和3 mm）对总平板计数、总酵母和霉菌（YMC）计数、颜色变化（∆E）、产品平均最终温度（T）、水分活度（a）、佩奇模型速率常数（k）和总水分损失（ML）的影响。对所有变量进行了扰动分析。结果发现，要使酵母和霉菌计数降低超过一个对数单位，水分含量会大幅降低，从而导致产量下降。微波功率密度对姜黄粉的YMC、T和a有显著影响。但样品厚度和微波暴露时间仅对T、a和ML有影响。如预期的那样，在该过程中姜黄的颜色和佩奇模型速率常数没有显著变化。在功率密度为57.00 W/g、样品层厚度为1.64 mm、暴露时间为30 s的条件下进行了数值优化。结果得到YMC为1.6×10 CFU/g、T为82.71°C、a为0.383、最终水分含量为8.41%（干基）。
