Effects of Ultrasonic-Assisted Macroporous Resin Treatment on the Color, Rheological, Emulsifying Properties, and Structure of Sunflower Meal Protein

Abstract

Sunflower meal protein (SMP) has been considered as a high-quality source of plant protein. However, because the chlorogenic acid (CA) contained in sunflower seed meal was prone to oxidation reactions under traditional alkali extraction conditions, the extracted protein has a dark color and some poor functional properties. To this end, this study used ultrasound-assisted macroporous resin treatment to extract SMP. The effects of different ultrasonic powers (100, 300, and 500 W) assisted macroporous resin treatment on the color, functional properties, and structure of SMP were studied. Results showed that compared with untreated sunflower meal protein (USMP), the CA content of SMP treated with ultrasound-assisted macroporous resin decreased and the color was significantly improved. Moreover, solubility, emulsifying properties, and rheological properties were improved. In addition, ultrasound-assisted macroporous resin treatment can effectively change the secondary and tertiary structures of SMP. Ultrasonic power of 300 W was the optimal ultrasonic parameter, which has a more obvious effect on protein color, emulsifying, and rheological properties. However, higher ultrasound power (500 W) can cause protein aggregation and reduce protein color and some functional properties. This study provides a potential strategy for extracting SMP with higher quality and functional properties.

Keywords: Sunflower meal protein, Ultrasound-assisted macroporous resin, Rheological property, Structure, Emulsifying property.