Preheating detoxification of flaxseed and its impact on the quality of flaxseed

Aiming to provide a theoretical basis for possible uses of flaxseed as a food supplement and functional ingredient,the heat treatment of flaxseed was carried out using steaming, roasting, and microwave methods to investigate the detoxification effects of these three pretreatment methods on flaxseed, as well as the impact of the three methods on the quality of flaxseed. The results showed that all three pretreatment methods had better detoxification effects on flaxseed,in which, microwave treatment was the most effective method. After 5 min of microwave treatment, the hydrogen cyanide (HCN) content in flaxseed decreased from (94.65±1.68) mg/kg to (7.80±0.57) mg/kg. All three pretreatment methods significantly reduced the water content in flaxseed but had a weaker effect on protein, fat, and ash contents. After pretreatment by the three methods, the polyphenol content, peroxide value (POV), and a* value of flaxseed increased significantly, thiobarbituric acid reactive substances (TBARS) increased, while polyunsaturated fatty acids (PUFA) content, amino acid content, and L*, W*, and b* values decreased, with varying degrees of wrinkles and cracks appearing on the surface of flaxseed, and the overall signal pattern of FTIR spectra did not change much. During the 40 ℃ accelerated storage process, the quality of flaxseed treated by all three preheating methods generally declined, and correlation analysis revealed that color change was a good indicator of quality changes in flaxseed. Notably, all three pretreatment methods extended the shelf -life of flaxseed. Compared with steaming (120 ℃ for 20 min) and roasting (100 ℃ for 40 min), microwave (560 W for 4 min) is recommended to remove cyanogenic glycosides and improve the stability and quality characteristics of flaxseed.