Effects of Different Storage Conditions on the Flavor and Overall Quality of Superfine Fragrant Peanut Oil
DENG Jinliang, LIU Yulan, WANG Xiaolei, CHEN Ning, SONG Lili
Related Articles |
To shed light on the effects of different storage conditions on the flavor and overall quality of peanut oil, superfine fragrant peanut oil contained in stainless steel oil tanks under normal conditions, with the addition of tertiary butylhydroquinone (TBHQ) or in a nitrogen atmosphere was sampled periodically during 18 months of storage in the natural outdoor environment for quantitative analysis of volatile flavor compounds by headspace solid phase microextraction followed by gas chromatography-mass spectrometry (SPME-GC-MS), flavor evaluation by gas chromatography-olfactometry (GC-O), and measurement of acid value, peroxide value, vitamin E content and physterol content. The results showed that 64 volatile flavor compounds belonging to 9 chemical classes were isolated and identified in superfine fragrant peanut oil with pyrazines and aldehydes accounting for more than half of the total amount, and both volatile flavor compounds constituted the basic flavor of superfine fragrant peanut oil including nutty, roasted, and sweet aromas. After 18 months of storage, the relative content of pyrazines decreased from 36.42% to 16.33%, 21.92% and 27.02% under normal conditions, with the addition of TBHQ, and in the nitrogen atmosphere respectively, whereas the relative content of aldehydes increased from 23.82% to 24.61%, 2.26% and 17.52%, respectively. The nutty, roasted, and sweet aromas and the overall flavor were obviously weakened, and the oil became rancid. Added TBHQ and nitrogen atmosphere storage could effectively delay the loss of the characteristic flavor compounds, vitamin E and physterols in peanut oil, and extend the shelf life to more than 18 and 10 months, respectively, but in peanut oil with added TBHQ, 2-tert-butyl-1,4-benzoquinone was detected as its oxidative decomposition product after storage. Therefore, nitrogen atmosphere storage can not only avoid the pollution of oils by added antioxidants, but also can achieve the purpose of quality and freshness preservation.