Comparison of wheat germ and oil characteristics and stability by different stabilization techniques

Abstract

In this study, the effects of four stabilization techniques (vibrated fluidized bed, oven, microwave, and extrusion) on the characteristics and stability of wheat germ and its oil were evaluated. The results showed that all methods were highly effective in inactivating lipoxygenase activity, although significant differences were observed in their ability to inactivate lipase activity. Among the techniques, extrusion was found to be the most effective, reducing residual lipase and lipoxygenase activity to less than 5% of that of fresh wheat germ. Acid value remained stable in the stabilized samples after 6 weeks of storage at 37 °C. However, the extrusion, oven, and microwave-treated samples showed rapid oxidation and/or significant losses of tocopherols (84.9%, 99.6%, and 33.9%, respectively). In contrast, wheat germ treated with the vibrated fluidized bed technique exhibited the best lipid stability, attributed to the suitable aw and few structural changes. Consequently, vibrated fluidized bed technique is recommended as the most suitable method for stabilizing wheat germ and producing high-quality wheat germ oil.