The influence of concentration methods on powdered milk technological properties

Milk powder (MP) is a widely spread ingredient used in the production of various types of food products in dry or reconstituted form, the condition and technological properties of which the quality of the finished product depends. One of significant factors influencing the quality characteristics of the MP and the formation of its technological properties are undoubtedly the processes used in its manufacture, including such mandatory production step as preliminary concentration (evaporation). The study of scientific and technical materials revealed the demand for updating knowledge and structuring information, considering the impact of various concentration methods on the MP quality. The aim of the research was to analyze and systematize the information on the effect of concentration methods used in dairy industry as a preliminary stage of milk condensation before spray drying on the MP technological properties. The following methods were considered: vacuum evaporation, hyperfiltration, cryoconcentration. A brief description was given. The main MP technological properties (recoverability, thermal stability, cheese suitability) depended on the composition, size and form of dry particles, solubility, dispersibility, wettability, etc. The process of vacuum evaporation had long been widely used on an industrial scale for various MP types' manufacture. Progressive evaporation methods (hyperfiltration and cryoconcentration) were increasingly used, but mainly in instant skimmed milk powder production. Physicochemical parameters of the MP, developed using studied concentration types, corresponded to standardized norms. The MP obtained using cryoconcentration consisted of agglomerated particles, which contributed to its better solubility. None of the evaporators' kinds had any significant impact on the dispersibility and wettability. Thermal stability was also almost the same with some minor differences when cryoconcentration was applied. Heat treatment before evaporating and drying had a dominant influence on thermal stability and cheese suitability. To expand the understanding of the pre-evaporating effect on the MP technological properties, additional research is required, especially on milk concentrate in dry whole milk production, obtained by modern concentration methods.