Abbas Ali M, Anowarul Islam M, Othman Noor Hidayu, Noor Ahmadilfitri Md
Department of Chemistry, Rajshahi University of Engineering & Technology, Rajshahi, 6204 Bangladesh.
Department of Processing Technology, Oils & Fats, Sime Darby Research Sdn. Bhd., Carey Island, Selangor Malaysia.
J Food Sci Technol. 2017 Dec;54(13):4335-4343. doi: 10.1007/s13197-017-2904-1. Epub 2017 Oct 20.
The oxidative stability and fatty acid composition of groundnut seed oil (GSO) exposed to microwaves were evaluated during heating at 170 °C. During heating, the oxidative indices such as free fatty acid, peroxide value, -anisidine value, TOTOX, thiobarbituric acid value, specific extinctions, and color value were increased. The increments were found to be higher in unroasted seed oils compared to roasted ones indicating lower release of lipid oxidation products in roasted GSO. After 9 h heating, the relative content of polyunsaturated fatty acid (PUFA) decreased to 89.53% and that of saturated fatty acid (SFA) increased to 117.46% in unroasted sample. The relative content of PUFA decreased to 92.05% and that of SFA increased to 105.76% in 7.5 min roasted sample after 9 h of heating. However, the roasting process slowed down the oxidative deterioration of PUFA. With increased heating times, an appreciable loss was more apparent in the triacylglycerol species OLL and OOL in unroasted samples compared to roasted ones. In FTIR, the peak intensities in unroasted samples were markedly changed in comparison with roasted samples during heating. The roasting of groundnut seed prior to the oil extraction reduced the oxidative degradation of oil samples; thereby increasing heat stability.
在170°C加热过程中，对经微波处理的花生油（GSO）的氧化稳定性和脂肪酸组成进行了评估。加热过程中，游离脂肪酸、过氧化值、对茴香胺值、TOTOX、硫代巴比妥酸值、比消光值和颜色值等氧化指标均升高。结果发现，未烘焙的种子油中的增幅高于烘焙过的种子油，这表明烘焙过的GSO中脂质氧化产物的释放量较低。加热9小时后，未烘焙样品中多不饱和脂肪酸（PUFA）的相对含量降至89.53%，饱和脂肪酸（SFA）的相对含量升至117.46%。加热9小时后，7.5分钟烘焙样品中PUFA的相对含量降至92.05%，SFA的相对含量升至105.76%。然而，烘焙过程减缓了PUFA的氧化劣化。随着加热时间的增加，与烘焙样品相比，未烘焙样品中三酰甘油种类OLL和OOL的明显损失更为明显。在傅里叶变换红外光谱（FTIR）中，与烘焙样品相比，未烘焙样品在加热过程中的峰强度发生了明显变化。在榨油前对花生种子进行烘焙可减少油样的氧化降解，从而提高热稳定性。
