Sinapic acid derivatives in microwave-pretreated rapeseeds and minor components in oils

Publication date: Available online 20 December 2019Source: Journal of Food Composition and AnalysisAuthor(s): Yanxia Cong, Mingming Zheng, Fenghong Huang, Changsheng Liu, Chang ZhengAbstractMicrowave pretreatment has been considered to improve the quality of rapeseed oil for canolol generation. Canolol is assumed to be formed by the decarboxylation of sinapic acid (SA). In this work, sinapic acid derivatives in 39 microwave-pretreated rapeseeds and their roles in the enhanced oxidative stability of rapeseed oils were investigated. The average contents of sinapic acid derivatives in rapeseeds, including (from high to low) sinapine, sinapoyl glucoside (SG), disinapoyl gentiobioside (DSG), quercetin-sinapoyl-di-hexosepentose (QSDG), sinapoyl malate (SM), disinapoyl glucoside (DDSG) and SA, were determined. After microwave pretreatment, the canolol content in rapeseed increased from nil to 6.16-76.1 mg/100 g, while sinapic acid derivatives contents decreased. The degradation rates of SG, DDSG, DSG, SM, SA and sinapine were 59.1%, 40.2%, 33.7%, 27.4%, 14.4% and 11.3%, respectively. There was no correlation relationship between sinapine and canolol. However, SG, DSG, SM and DDSG were regarded to be the precursor substances of canolol. Additionally, the tocopherols, sterols and canolol contents, along with the induction period (IP) of microwaved rapeseed oil increased by 3.79%, 10.0%, 76.8 times and 38.7%, respectively. There was a significant positive correlation between IP and...
Source: Journal of Food Composition and Analysis - Category: Food Science Source Type: research