Effect of erythritol on physicochemical properties of reformulated high protein meringues obtained from whey protein isolate
Maciej Nastaj, Bartosz G. Sołowiej, Konrad Terpiłowski, Stanisław Mleko
Abstract
Whey protein isolate (WPI) dispersions (15, 20 and 25%, w/v) were prepared. After whipping, erythritol was added to obtain WPI/erythritol ratios of 1:0, 1:1 and 1:2. Surface tension of the pre-foam solutions, foam overrun and their rheological properties were determined. Foam stability was evaluated in a Turbiscan. Liquid foams were solidified at 130 °C for 2 h. For solid foams, texture, surface (roughness and spreading kinetics) and microstructural properties were determined. Protein/erythritol at a ratio of 1:2 was detrimental for overrun and rheological properties of liquid foams; however, it improved their stability. Higher concentrations of erythritol produced a smoothing effect on meringue surfaces. At higher protein and erythritol concentrations, hardness and fracturability increased. The samples without erythritol demonstrated the greatest kinetics of spreading. The 1:1 protein/erythritol ratio was the most effective in maintaining an aerated structure; however, the ratio 1:2 resulted in an increase of final meringue volume.