Effect of thermal pre‐treatment on the phenolic and protein profiles and oil oxidation dynamics of golden flaxseeds

Abstract

Summary The food industry is interested in the application of thermally pre‐treated flaxseeds because the treatment improves their sensory acceptability and reduces anti‐nutrient contents. However, it may influence the health benefits of flaxseed compounds. The changes in the phenolic and protein profiles, and in situ oil oxidation dynamics after steaming or roasting of flaxseeds were analysed to study this effect. The results showed that the pre‐treatment of flaxseeds did not affect the content of major flaxseed phenolics. Steaming and roasting considerably changed the flaxseed protein profile. The thermally induced protein aggregation and/or cross‐linking occurred. The most significant changes were found for the 13 and 53 kDa proteins. Flaxseed roasting deteriorated the oil oxidative stability significantly more than steaming. These changes may decrease the nutritional quality and shelf life of roasted or steamed flaxseeds. They should be monitored when pre‐treated flaxseeds are intended to be used as a food ingredient.