Volatile Substances, Quality and Non-Targeted Metabolomics Analysis of Commercially Available Selenium-Enriched Rice

Selenium is an essential trace element for the human body. However, its intake is usually low. Therefore, the production and utilization of selenium-enriched food are currently a research hotspot. Despite the remarkable scientific interest in this topic, only a few of the numerous studies focus on commercially available products. This study examined the nutritional quality, physical and chemical properties, cooking characteristics, and eating quality of four commercially available hot-selling rice types, both selenium-enriched and non-selenium-enriched, and discovered that selenium-enriched rice outperforms ordinary rice in terms of both nutritional quality and taste. In addition, we employed the gas chromatography-ion mobility spectrometry (GC-IMS) technique to evaluate the volatile chemicals of rice. Some of the chemicals that made selenium-rich rice taste different from regular rice were pentanal, (E)-2-Hexen-1-ol, ethyl-3-methyl butanoate, 2-furan methanol acetate, ethyl heptanoate, ethyl hexanoate, methyl hexanoate, isopentyl pentanoate, and ethyl butyrate. We looked into the metabolite profiles of rice using LC-MS-based untargeted metabolomics to obtain a better idea of the different metabolites that are found in selenium-enriched rice compared to regular rice. We identified a total of 522 metabolites and screened 182, 227, and 100 differential metabolites in selenium-enriched (A) vs. non-selenium-enriched rice (B/C/D) groups, respectively. This study revealed that selenium primarily influenced the metabolism of D-amino acids, starch, sucrose, and linoleic acid in rice. This study systematically analyzed the quality differences between selenium-enriched and non-selenium-enriched rice available on the market. For consumers, it is essential to understand the quality of selenium-rich rice on the market to guide the purchase of rice.