Abstract: [Objective] The oxidation and antioxidation of oil during roasting process and the shelf life at room temperature were studied by optimizing soaking process and adding antioxidant TBHQ to Torreya grandis seeds to clarify the occurrence and regulation mechanism of quality deterioration of T. grandis seeds and lay a theoretical foundation for improving the yield of T. grandis seeds and accelerating the development of T. grandis industry.[Method] The seeds were soaked in 5% and 20% of NaCl for 0, 5, 10, and 20 min, respectively, and 0.02% of tertbutyl hydroquinone (TBHQ) was added to the soaking media. The peroxide value, acid value, inhibition rate of linoleic acid lipid peroxidation system, total phenol and DPPH free radical scavenging activity with other indicators were measured to determine the appropriate salt leaching time. The lipid oxidation and antioxidant activity of T. grandis during roasting process, followed by a shelving time for 60 days at room temperature were investigated.[Results] The optimal soaking conditions of T. grandis in roasting process for alleviating lipid oxidation and improvement of antioxidant capacity were to soak for 10 min in 20% NaCl solution, at which the peroxide values, acidity, and inhibitory activity of lipid oxidation were the lowest, and the total phenolic contents and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity were the highest. The addition of TBHQ to the 20% NaCl solution led to higher DPPH scavenging activity and contents of total phenolic and vitamin E (V_E). The treatment also resulted in lower peroxide, acidity, and p-anisidine levels after soaking, and maintained higher quality during shelf life at room temperature than the seeds without antioxidants.[Conclusion] Soaking in 20% NaCl solution for 10 min can alleviate the decline of the quality of T. grandis. TBHQ can reduce lipid oxidation of T. grandis seeds during baking and storage at room temperature and improve oxidative stability, to improve the processing and storage technology of T. grandis.

Key words: Torreya grandis, soaking condition, lipid oxidation, antioxidant capacity, tertbutyl hydroquinone