Hybrid protein systems of whey protein concentrate and microfluidized corn gluten meal: Colloidal and emulsifying...

The partial or total replacement of proteins from animal sources by those from plant sources is a useful strategy to increase sustainability aspects of diets. Thus, the production of hybrid protein systems is relevant in this context of food transition. Aiming to increase the industrial relevance of corn gluten meal (CGM), a co-product of corn starch production, microfluidization was used and CGM colloidal and emulsifying properties were evaluated alone and in combination with whey protein concentrate (WPC). Microfluidization significantly improved the dispersibility of CGM (reduction of D₉₀ in around 97 %). Dispersions (2 % w/ w, pH 7.0) of microfluidized CGM, WPC and a balanced mixture of these two proteins (50:50) were studied before and after heat treatment (90 °C per 15 min). Before heat treatment, the emulsifying properties of WPC were significantly (p < 0.05) better than those of CGM, for all evaluated parameters. Under these circumstances, the emulsifying properties of the hybrid system containing the two protein sources were dictated by the WPC. After heat treatment, the aggregation of the whey proteins led to a significant reduction in the emulsifying properties of the WPC. Consequently, CGM proteins began to coexist with whey proteins at the oil-water interface of the hybrid emulsions. Despite the overall superior emulsifying properties of WPC, the results suggest that microfluidized CGM may contribute to the development of hybrid protein systems with WPC for applications involving severe heat treatments.