This study reports the possibility of obtaining the WPI-based meringues with the small sucrose content (0–15%). The whey protein isolate (WPI) solution (20%, w/v) was whipped and sucrose was added to foam at the concentrations of 5, 10 and 15%. The surface tension, viscosity, zeta potential of the pre-foam solutions, foam overrun, foam stability and their rheological properties (G′, G″ and tan (δ)) were evaluated. To produce meringues, liquid foams were solidified at 130 °C for 2 h. The surface properties (roughness, contact angles, apparent free surface energy) as well as microstructural ones were determined for the solid foams (meringues). The 15% sugar concentration was detrimental for overrun, stability and rheological properties of liquid foams. The meringue production without sugar was infeasible. The addition of the smallest amount of sucrose (5%) enabled preservation of the aerated structure of the liquid foam during solidification. The 10% sugar concentration increased the stability of liquid foam, its rheology and it was the most effective for air bubbles stabilization during the foam solidification, however, its largest addition (15%) resulted in an increase in the final meringue volume. Larger sucrose concentrations produced a smoothing effect on the meringue surfaces.

The dairy industry is actively seeking new applications for various types of whey. One promising direction is the development of nutritious ice cream, using a blend of different whey proteins. However, the production of whey ice cream is hindered by the occurrence of quality issues, primarily stemming from a low content of solids, particularly fat and protein. The development of natural components with distinctive technological attributes, such as the ability to bind excess moisture, enhance foaming properties, and replicate the taste of milk fat, is of significant relevance in food science. In this work, we investigated the influence of plant-based structuring ingredients on the viscoelastic characteristics of whey-based ice creams. Notably, mixes such as 0.4% Vianoks C45 + 0.75% oat β-glucan, 0.4% Vianoks C45 + 0.5% yeast β-glucan, and 0.4% Vianoks C45 + 3% whey protein complex + 10% vegetable purée from table beet have been proven to be effective stabilizing compositions. However, attempts to combine the whey protein complex with other types of vegetable purées like zucchini and broccoli did not yield satisfactory results. It has also been found that β-glucan from the yeast Saccharomyces cerevisiae and κ-carrageenan, a component of the Vianoks C45 stabilization system, forms a robust gel within the system. Analysis of the aqueous phase in whey-based ice creams revealed a consistent correlation between water activity, surface tension, and rheological behavior. Finally, the ice creams that exhibited the best viscoelastic characteristics also had the best sensory attributes.

The aim of the research was to use low-mineral egg white albumin isolate to obtain aerated calcium ion-induced gels and to investigate their aptitude as matrices for active ingredients release. Aerated gels were prepared by adding calcium ions to pre-heated protein dispersions with simultaneous aeration. 20 mM calcium concentration was an optimal concentration at which the maximum viscosity and hardness of the gels were found. For higher concentrations of calcium ions (25–30 mM), aerated gels were characterized by lower values of the moduli and tangent of the phase angle was larger for aerated gels which indicated more viscous character than that of non-aerated gels. Increased ions concentration causes higher aggregation of protein matrix and less smooth microstructure of the interface between the gel and air. An increase in calcium concentration from 5 to 30 mM caused an increase in an average bubble size. The release of calcium ions from aerated gels was measured in an artificial stomach. It occurred by Fickian diffusion through the swelling matrix and it was faster for the gels with higher concentration of calcium. An increase in calcium concentration caused an increase in surface roughness of the aerated gels. There were linear correlations between the quadratic mean of the surface roughness and “n” coefficient from the Ritger and Peppas equation and between the maximum roughness size and “n”. The increased calcium concentration made the gel microstructure more particulate and the surface rougher, which enabled faster proteolysis of the gel in an artificial stomach and faster diffusion of calcium ions.

The aim of this study was to investigate the gelation process of binary mixes of pumpkin-seed and egg-white proteins. The substitution of pumpkin-seed proteins with egg-white proteins improved the rheological properties of the obtained gels, i.e., a higher storage modulus, lower tangent delta, and larger ultrasound viscosity and hardness. Gels with a larger egg-white protein content were more elastic and more resistant to breaking structure. A higher concentration of pumpkin-seed protein changed the gel microstructure to a rougher and more particulate one. The microstructure was less homogenous, with a tendency to break at the pumpkin/egg-white protein gel interface. The decrease in the intensity of the amide II band with an increase in the pumpkin-seed protein concentration showed that the secondary structure of this protein evolved more toward a linear amino acid chain compared with the egg-white protein, which could have an impact on the microstructure. The supplementation of pumpkin-seed proteins with egg-white proteins caused a decrease in water activity from 0.985 to 0.928, which had important implications for the microbiological stability of the obtained gels. Strong correlations were found between the water activity and rheological properties of the gels; an improvement of their rheological properties resulted in a decrease in water activity. The supplementation of pumpkin-seed proteins with egg-white proteins resulted in more homogenous gels with a stronger microstructure and better water binding.