Mandiuk O. Improving the Technologies of Sour Cream and Sour Cream Products with Low Fat Content

A dissertation for obtaining the degree of Doctor of Philosophy in speciality 181 “Food Technologies” – National University of Food Technologies, Ministry of Education and Science of Ukraine, Kyiv, 2025. The dissertation is dedicated to the enhancement of technologies for sour cream and sour cream products with low fat content through the application of functional and technological ingredients (whey protein and protein-carbohydrate concentrates, as well as polysaccharides), the development of an energy-saving method for cream heating, the formulation of new product types with natural ingredients, as well as the refinement of technological parameters for their production. The scientific justification for selecting protein-containing ingredients to develop a set of quality indicators for sour cream and sour cream products has been provided. The technological feasibility of using whey protein ingredients in the composition of 10% fat sour cream has been demonstrated. Based on a set of organoleptic and physicochemical indicators (acidity, degree of syneresis, microstructure), as well as fermentation duration, the optimal content of skimmed milk powder (1%), sodium caseinate (0.5%), calcium caseinate (0.75%), whey protein concentrate WPC (1.0%) and hydrolyzed whey concentrate with 40% dry substance content (30%) was determined. These components ensure a protein content in the final product ranging from 3.0% to 3.4%. The application of protein-containing ingredients in the determined rational doses allows to stabilize the titratable and active acidity of 10% fat sour cream during five-day-storage period. According to organoleptic evaluation results, as well as water-holding and structuring capacity, the highest sour cream quality level was detected in sour cream containing 1% WPC and 30% hydrolyzed whey concentrate. The potential for intensifying the Maillard reaction was studied to provide the final product’s with distinctive flavor, aroma, and color. Based on the analysis of the average color characteristics of baked milk, the following CIE Lab system colour criteria were established for 10% clotted cream: “a” – coordinate – from 1.5 to 2.0 units, “b” – coordinate – from 11.5 to 13.0 units. A significant reduction in the cream heating process was determined with whey protein and carbohydrate ingredients: at least 21 minutes for cream with whey protein concentrate and at least 28 minutes for cream with hydrolyzed whey concentrate. The results of analysis of protein-enriched baled sour cream indicator quality confirmed the feasibility of the approved technological solutions. During the development of formulations for low-fat sour cream products with the aim of their additional structuring, the functional-technological properties of guar gum were proven to be significantly superior to those of β-glucan at a concentration of 0.5%. The parameters of the cream homogenization process as a critical technological step in sour cream technology were optimized. It was established that an effective viscosity value of sour cream not lower than 80 mPa∙s during rotation measurements and at a shear rate gradient of 0.1 s-1 in the presence of whey protein concentrate and hydrolyzed whey concentrate can be achieved over a wide range of pressure (5-25 MPa) and temperature (40-80⁰С) owing to the structuring ability of protein-containing ingredients. As a result, the homogenization parameters for cream with β-glucan were significantly narrowed to 10-15 MPa and a temperature of 60-70⁰С, while for cream with guar gum, a distinctive low temperature range of 40-80⁰С was viable. According to the analysis results of the set of experimental samples quality indicators with varied chemical compositions, an original formulation for a protein-enriched sour cream product containing guar gum and turmeric was developed. The technological parameters for producing of sour cream and sour cream products wit low-fat concentration were refined. The specifics of the fermentation process for new product types with natural functional-technological ingredients were identified. The regulatory quality indicators of sour cream and sour cream products with natural ingredients were examined. The social impact of implementing enhanced technologies for low-fat sour cream and sour cream products lies in the expansion of the assortment of fermented dairy products with enhanced nutritional value, exclusively based on natural raw materials. The economic effect results from the conservation of animal-derived raw materials and reduced energy consumption due to the shorter technological cycle of production. The reliability of the obtained results is confirmed by the application of modern methodology and research methods, appropriate equipment and mathematical tools for data processing. The scientific novelty of the research findings is substantiated by a utility model patent.