Effect of oil oxidation on aggregation of wheat gluten–peanut oil complexes during extrusion

SUMMARY To better understand the aggregation mechanism of wheat gluten–peanut oil complex (WPE), the oxidation properties of peanut oil and wheat gluten at different extrusion temperatures were investigated. With the increase in extrusion temperature from 100 to 180 °C, the total oxidation value of peanut oil in WPE increased from 5.04 ± 0.26 to 10.01 ± 0.87, and the carbonyls content of gluten increased from 21.73 ± 0.62 to 31.43 ± 0.58 nmol mg −1 . The results of surface hydrophobicity and carbonyls content indicated that peanut oil could induce gluten oxidation in WPE. The morphology of the extrudates showed that the addition of peanut oil promoted the aggregation of gluten protein. These results enhance our understanding of the interactions between peanut oil and gluten in extrudates and provide a theoretical basis for gluten-based extrudates with favourable textural properties.