Intervention of microwave irradiation on structure and quality characteristics of quinoa protein aggregates

This study sought approaches to improve the textural properties of quinoa protein (QP) from the perspective of processing methods. The effect of microwave (MW) heating on the aggregation changes and gel properties of QP was investigated. The QP was treated with water bath and MW at the same heating rate. Ultraviolet absorption spectrum, intrinsic fluorescence spectrum and circular dichroism showed that MW accelerated the denaturation and unfolding of protein structure, thus more hydrophobic residues were exposed and the surface hydrophobicity was enhanced. The significant depression of free sulfhydryl groups and solubility indicated that MW promoted the production of protein aggregates. Larger protein aggregates observed in turbidity, particle size and atomic force microscopy images. MW treatment improved the gel strength and maintained the water holding capacity of QP gel. This study provided a theoretical reference for the application of MW in gluten-free foods.