Li Khu Say, Ali M Abbas, Muhammad Ida Idayu, Othman Noor Hidayu, Noor Ahmadilfitri Md
Department of Bioprocess and Polymer Engineering, Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia.
Department of Chemistry, Rajshahi University of Engineering & Technology.
J Oleo Sci. 2018 May 1;67(5):497-505. doi: 10.5650/jos.ess17203. Epub 2018 Apr 9.
The impact of microwave roasting on the thermooxidative degradation of perah seed oil (PSO) was evaluated during heating at a frying temperature (170°C). The roasting resulted significantly lower increment of the values of oxidative indices such as free acidity, peroxide value, p-anisidine, total oxidation (TOTOX), specific extinctions and thiobarbituric acid in oils during heating. The colour L* (lightness) value dropped gradually as the heating time increased up to 12 h, whereas a*(redness) and b* (yellowness) tended to increase. The viscosity and total polar compound in roasted PSO was lower as compared to that in unroasted one at each heating times. The tocol retention was also high in roasted samples throughout the heating period. The relative contents of polyunsaturated fatty acids (PUFAs) were decreased to 94.42% and saturated fatty acids (SFAs) were increased to 110.20% in unroasted sample, after 12 h of heating. On the other hand, in 3 min roasted samples, the relative contents of PUFAs were decreased to 98.08% and of SFAs were increased to 103.41% after 12 h of heating. Outcome from analyses showed that microwave roasting reduced the oxidative deteriorations of PSO during heating.
在油炸温度（170°C）加热过程中，评估了微波烘焙对辣木籽油（PSO）热氧化降解的影响。烘焙导致加热过程中油的氧化指标（如游离酸度、过氧化值、对茴香胺、总氧化值（TOTOX）、比消光值和硫代巴比妥酸）的增量显著降低。随着加热时间延长至12小时，颜色L*（明度）值逐渐下降，而a*（红色度）和b*（黄色度）趋于增加。在每个加热时间点，烘焙后的PSO的粘度和总极性化合物含量均低于未烘焙的PSO。在整个加热期间，烘焙样品中的生育酚保留率也很高。加热12小时后，未烘焙样品中多不饱和脂肪酸（PUFA）的相对含量降至94.42%，饱和脂肪酸（SFA）的相对含量增至110.20%。另一方面，在烘焙3分钟的样品中，加热12小时后，PUFA的相对含量降至98.08%，SFA的相对含量增至103.41%。分析结果表明，微波烘焙减少了加热过程中PSO的氧化劣化。
