Utilização de concentrado proteico de leite no desenvolvimento de sorvetes sabor chocolate com diferentes conteúdos de proteínas

Abstract

Milk-based ice cream is considered a nutritious and palatable food that appeals to individuals of different ages and social classes. Milk protein concentrate (MPC) is an excellent source of protein, which preserves the proportion of dairy proteins (80% caseins and 20% seroproteins), as well as other milk nutrients, with significant technological, functional and sensory qualities in the development of new products. The objective of this work was to develop two formulations of chocolate-flavoured ice cream, which meet the criteria of source and double of proteins, added to MPC with 70% protein (MPC 70), using as a base a formulation commercially produced by an industry, and to evaluate its physicochemical, microbiological and microstructural characteristics. Three treatments were performed: "control" (base formulation used in the industry), "double" protein (about control) and "source" of protein, according to specific legislation. The treatment production process followed the methodology adopted by the ice cream industry in four replications. Analyses of overrun, microstructure, proximate composition, pH and acidity of the solution were performed. The texture profile, colour and pH of the ice creams were evaluated during storage (02, 15 and 30 days). The microbiological and microstructure analyses of the ice creams were performed at 02 days of storage and the melting analysis at 30 days. Significant differences (P < 0.05) were observed among the treatments for the average moisture levels, proteins, moisture, pH and acidity, demonstrating that adding MPC directly interfered with these parameters. There was no statistical difference (P > 0.05) in relation to the amount of air incorporated into the different ice creams (overrun). The total melting rate was highest in the "control" sample, followed by the ice cream with the "double" and "source" of proteins. Regarding the texture profile, only the hardness and elasticity parameters did not differ (P > 0.05) among the treatments, with adhesion, cohesiveness and chewiness showing, in general, higher values for the treatments with higher protein content. Over time, the texture attributes showed different results. The colour of the ice creams (L*, a* and b*) showed no statistical difference (P > 0.05) among the treatments, as well as L* throughout storage. The results of the microbiological analyses showed that the formulations met the legal standards established for the ice cream trade. Microscopic analyses (photonic and electronic) revealed no observable differences in syrup and ice cream. The analysis of the scanning electromicrographs showed no observable differences among the three ice cream samples. There was no statistical difference (P > 0.05) among the treatments in terms of the zeta potential and the polydispersivity index of the mixtures. The mean hydrodynamic diameter of the particles was statistically higher (P < 0.05) in the "control" sample compared to the "double" and "source" samples, which did not differ from each other (P > 0.05). The addition of MPC 70 contributed significantly to the increase in protein content, a good alternative for producing high-protein ice creams.