Evaluation and comparison of antibacterial activities of edible vegetable oils in China

To evaluate antibacterial activities of edible vegetable oils in China for healthy consumption, we investigated the antibacterial activities of extracts from 6 edible vegetable oils and rapeseed oils at different refining levels on 4 bactria (Staphylococcus aureus,Bacillus subtilis, Escherichia coli and Pseudomonas strains) by disc diffusion test. Results showed that camellia oil had considerable antibacterial activity against E. coli with antibacterial rate of 108.3%. Perilla oil, sunflower seed oil, and flaxseed oil showed the highest antibacterial activities against B. subtilis with the antibacterial rates of 108.3%, 102.8%and94.4%respectively. Moreover, the extracts of rapeseed oils obtained by different processing technologies showed significantly different antibacterial effects. Two crude oils and grade4 rapeseed oil showed antibacterial rates of more than 40%, whereas grade 1 and 2 rapeseed oils showed antibacterial rates of less than 20%. Therefore, it was recommended to use rapeseed oil rather than refined rapeseed oil because of higher antibacterial activities. It was suggested that proper refining processes should be taken to obtain the edible oils with higher antibacterial activities.

Porous metal-organic framework as sorbent and LC-MS/MS as detector to identify aflatoxins in peanut

Aflatoxins are the most potent spontaneous carcinogen known as secondary metabolite. Aflatoxins detection in peanut is challenging on account of inherent complexity of high fatty matrices. A modified Quick Easy Cheap Effective Rugged Safe (QuECh-ERS) method couple with liquid chromatograph-mass spectrometer (LC-MS/MS) has been developed to monitor aflatoxins in peanut. It?s a simple and rapid sample preparation for aflatoxins analysis compared with common method. Microporous metal-organic framework MIL-101 (Cr) was used as absorbent in this research. Promising properties of high porosity and surface area endowed MIL-101 (Cr) with efficiently aflatoxin enrichment with other matrix exclusion from high fatty sample. Negligible matrix effect was observed due to efficient extract clean up with MIL-101 sorbent. Recoveries ranged from 73.5% to 98.4% for aflatoxins, with relative standard deviations less than 7%. Limit of detection (LOD) and limit of quantitation (LOQ) for aflatoxins in peanut were 0.05-0.1 μg/kg and 0.2-0.6 μg/kg respectively.By using method described in this research, 15 real samples were successfully analyzed in which 6 samples were contaminated. MIL-101(Cr) was used to reduce matrix effect and develop a quick and effective method for aflatoxins detection in peanut via LC-MS/MS for the first time.

Comparison of anthocyanin and fatty acid in black and ordinary peanuts

In this study, anthocyanin and fatty acid compositions between black and ordinary peanuts were compared. Results showed that black peanuts contained 93.90±18.36 μg/g of cyanidin, which was significantly higher than that of ordinary peanuts. In addition, although both of black and ordinary peanuts shared some specific fatty acids, 4 fatty acids in black peanuts were significantly different from those in ordinary peanuts, which could be used as markers to distinguish black peanut from ordinary ones. This study might serve as a reference for authenticity identification and further nutritional researches on black peanut.