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Expanding the assortment of lactose-free dairy products, namely, ice cream for people who cannot tolerate lactose is a promising direction of research. The purpose of the work is to develop the technology of milk lactose-free synbiotic yogurt ice cream based on buttermilk protein-lipid concentrate, obtained by ultrafiltration/diafiltration, with the addition of natural flavoring and food additives, and the study of its quality indicators. A protein-lipid concentrate of buttermilk with a low lactose content was obtained by ultrafiltration/diafiltration, and its quality indicators were determined. The concentrate has a high protein content (16.01%) and a low lactose content (1.28%). Protein-lipid concentrate fermented with synbiotic sourdough is the main component included in the formulation of lactosefree synbiotic yogurt ice cream. The main physico-chemical parameters of the obtained fermented protein-lipid concentrate were determined, which ensures a rational content of the main components of the chemical composition in the finished lactose-free ice cream (it does not contain lactose, the protein content is 8.46%) and a high content of useful microflora (bifido- and lactobacilli). A mixture for lactose-free synbiotic yogurt ice cream was obtained according to a scientifically based recipe. A sample of lactose-free ice cream was made from the mixture using traditional technology, and organoleptic, physico-chemical and microbiological quality indicators were investigated. A comparison of the quality indicators of the studied sample with the control, which was taken as classic yogurt ice cream, was carried out. The mass fraction of lactose in samples of lactose-free ice cream is 0,011%. The developed lactosefree synbiotic yogurt ice cream has high probiotic activity (contains lacto- (3.0×108 CFU/g) and bifidobacteria (3.5×109 CFU/g)) [ABSTRACT FROM AUTHOR]

Removing lactose from buttermilk and other dairy products is a topical problem, as there is a significant increase in morbidity rates due to lactose intolerance. In many cases, milk and dairy products containing lactose can not be completely excluded from the diet. These products have a number of valuable components. There are several ways to remove lactose from milk or other dairy products. They are based on separation methods of processing and on the use of enzymes. Among the separation methods, membrane treatment, including diafiltration, is of particular importance. A technique of engineering calculation of cleaning an ultrafiltration buttermilk concentrate is suggested. As a solvent that reduces the concentration of lactose, a nanofiltrate permeate of buttermilk ultrafiltration is used. This method allows preserving the chemical composition of the concentrate with lactose effectively removed. Basing on the experimental data of membrane productivity and their selectivity for lactose, the main characteristics of diafiltration are calculated for various practical applications. For practical purposes, it is advisable to use a buttermilk permeate nanofiltrate using highly selective lactose membranes. Selectivity for salts should be minimal. When comparing the different diafiltration variants, the most suitable is a periodic method, with continuous dilution, and a continuous method with a crossflow and reverse flow of the nanofiltrate. The smallest amount of a nanofiltrate is observed in the case of a continuous countercurrent. The time for diafiltration treatment depends on the membrane’s specific parameters, process operating parameters, and the selected lactose purification variant. The most cost-effective is the continuous variant with a countercurrent nanofiltrate. However, it can not be recommended because of the considerable duration of the process. The suggested technique for calculating diafiltration allows quick evaluation of possible options of purifying the product from lactose, and concludes which one is optimal. [ABSTRACT FROM AUTHOR]