The formation approaches of volatile compounds in Chinese traditional hot-pressed fragrant rapeseed oil

Hot-pressed fragrant rapeseed oil (HFRO) is a traditional edible oil in China, prized for its special flavor, which includes fresh, spicy, pungent and roasted fragrance. The fresh fragrance is mainly brought by aldehydes, ketones, esters, alcohols and other substances produced by fat oxidation. The pungent fragrance is mainly caused by thiocyanates and isothiocyanates produced by the degradation of glucosinolates. Roasting aroma is usually brought by pyrazines and furans produced by Maillard reaction. Both the composition of the rapeseed and the processing techniques employed are critical in shaping these flavor components. An optimal processing temperature for HFRO is around 150°C. Rapeseed varieties with higher glucosinolates content are preferred for producing oils with a pronounced spicy, whereas those with lower glucosinolates levels are suitable for a stronger roasted aroma. The moisture content of the rapeseed should ideally be maintained between 10% and 15% to optimize flavor development. This study elucidates the primary pathways for volatile compound production in HFRO and discusses future prospects and research directions for the enhancement of rapeseed oil, offering a scientific foundation for the modern processing and quality control of rapeseed oil.