OPTIMAL MODES OF VACUUM-SUBLIMATION DRYING

DOI 10.12737/2073-0462-2025-87-95 УДК 637.146

Abstract

The aim of the study is to identify optimal drying modes for camel milk using a built-in vacuumsublimation drying unit and to analyze the main quality indicators of the final finished product. The objects of the study – fresh whole camel milk and a vacuum-sublimation dryer Model: ZLGJ-300. The sublimation dryer has a preliminary freezing function and removes up to 90% of moisture at temperatures below 0°C, moving from a solid state of ice to a gaseous state. The quality studies of raw and dry camel milk were conducted in accordance with the requirements of GOST 3626-73, ST RK 166-2015, ST RK 3386-2019, TR CU 033/2013. Five drying temperature modes with different thicknesses of the camel milk layer (from 0.9 to 1.5 cm) and step-by-step temperature exposure were studied - from deep freezing (-55°C) to the final stage of drying at positive temperatures (+ 50°C). Mode IV (layer thickness of 0.9 cm) was recognized as the most effective, which provided the optimal combination of the quality of the finished product and the duration of drying (22 hours). The results confirm that maintaining a thin layer and a gradual temperature increase contribute to obtaining a product with preserved nutritional properties in accordance with the requirements of ST RK 3386-2019. In dry milk, the moisture content is from 2.5 to 5%, which makes it impossible for microorganisms to develop. The studied camel milk microbiologically complies with the requirements of TR CU 033/2013, which indicates the health of animals not susceptible to infectious diseases. Chemical analysis of fresh milk showed: fat - 4.56%, SNF - 6.23%, protein - 2.93%, density - 26.8%, which corresponds to the standard. In dry milk obtained according to the optimal mode, after reconstitution, the fat content is 6.75%, SNF - 7.50%, protein - 3.42%, water - 10.3%, which confirms its high quality and compliance with standards.