Whey protein-based particles in Pickering foams and clean label frozen desserts

Abstract

[EMBARGOED UNTIL 12/01/2024] Traditional emulsifiers and stabilizers are used in ice creams and frozen desserts to create a microstructure which improves the texture and stability during storage. These ingredients typically function by stabilizing the air bubbles and increasing the viscosity of the unfrozen matrix. Their functions are critical to the properties and quality of frozen desserts. The ongoing clean label trend leads the industry to search for ingredients that can replace synthetic emulsifiers and certain types of stabilizers. Recently, there has been growing interest in Pickering stabilization of food emulsions and foams by biopolymer microgels. One important advantage of Pickering stabilization is that the Pickering particles can provide long-term stability to emulsions and foams. The overall goal of this study was to determine the effects of whey protein gel particles on the physical and foaming properties of frozen yogurt mixes as well as the physical, foaming, and sensory properties of frozen yogurt. Whey protein gel particles were formed by heating whey protein concentrate (WPC) (pH 7.0, 85 [degrees] C, 30 min) followed by disintegration of the protein gels using sonication and adjusting pH to 4.0, 4.5, and 5.0. Replacing non-fat dry milk (NFDM) in frozen yogurt mixes with WPC gel particles (P4.0, P4.5 and P5.0) led to significant improvement in emulsification properties as shown by decreased fat globule sizes (P < 0.05), a significant increase in overrun (P < 0.05) and a drastic improvement in foam stability. The most significant effect of WPC gel particles in frozen yogurt was an improvement in melting properties as shown by a significant increase in induction time and drip-through rate (P < 0.05). Descriptive sensory evaluation reveals an improvement in meltdown rate with frozen yogurt made with WPC-gel particles; however, an increase in cardboard aroma, cardboard flavor, and astringency was also observed. It is likely that improved foaming properties were due to the ability of the gel particles to increase viscosity and function as Pickering stabilizer of emulsion and foam.