Specific features of structure formation of foam-like emulsions for muffins

Diet-related noncommunicable diseases (NCDs) are a major global health problem. One of the main strategies for NCDs prevention is an increase in a range of available food products, including flour confectionery, with the beneficial nutrient profile. In this paper the character of structure formation in foam-like emulsions for muffins was investigated. The properties of emulsions determine quality of finished products. The recipe composition of muffins was modified by reducing added sugar and fat and incorporating whole and skim milk powders and whey powder. The incorporation of these powders caused an increase in the viscosity of emulsions. The emulsion with whole milk powder had the highest viscosity of undisturbed structure (162.8 ± 8.1 Pa · s), which was 4.5 times higher than that in the control sample (36.1 ± 1.8 Pa · s). The main decrease in viscosity of all samples was noticed at low ranges of shear rate (up to g = 3 s –1 ), that pointed to low structure strength of emulsions. The values of the dynamic yield strength for all emulsions with powdered raw materials exceeded the value in the control sample (22.4 ± 1.1 Pa). This indicated a change in the flow behavior of the modified systems due to the formation of stronger structural properties. In this study, the rheological model of flow for the samples of emulsions with the modified composition and the control sample was determined and mathematical equations of this process were obtained. It was found that the use of dry milk products and whey powder, and the developed techniques ensured the formation of the necessary amount of structure-forming air phase in the food system. Density of the experimental samples changed insignificantly compared to the control (590 ± 5.3 kg/m 3 ) and was higher than this value in the control by 2 % in the emulsion with whole milk powder (600 ± 5.6 kg/m 3 ), by 3 % — with skim milk powder (610 ± 5.5 kg/m 3 ) and by 5 % — with whey powder (620 ± 5.6 kg/m 3 ). The research results form the basis for the development of technology for muffins with the reduced content of the critically important ingredients according to the principles of healthy nutrition.