Determining the influence of pre-preparation of blueberries (Vaccinium corymbosum L.) on the total duration of drying

Comprehensive studies into the influence of various types of preliminary preparation of blueberry berries for drying have established the amount of wax coating, color, and the total duration of dehydration of raw materials. A comparison of 2 types of preliminary preparation was made: hygrothermal treatment and infrared radiation treatment directly during drying. It was established that after treatment with infrared radiation, 53 times more wax plaque came off the berries than after hygrothermal treatment. Microscopic studies of sections of the parenchymal part of berries recorded the state of the cell membranes and the color of the raw materials without prior processing, with pretreatment, and after drying. It was found that berries dried without pretreatment (mode parameters of heat carrier: t=70 °C, v=2 m/s, d=10 g/kg dry air. Win=85 %, ) have partially destroyed cell membranes but the color of the dried material is preserved to the maximum. It was observed that the berries after hygrothermal treatment have partially destroyed parts of the cell membrane, which makes it possible to more intensively release moisture from the material after drying, the maximum color of the product is also preserved. In berries, after treatment with infrared radiation of 100 W for 10 minutes, the cells remain convex with partial destruction of the shell of some cells but, after pretreatment, the intensity of color decreases. Studies into the kinetics of drying blueberry berries have confirmed that the use of infrared radiation with a capacity of 100 W for 10 minutes with simultaneous drying under the regime parameters of the heat carrier t=60 °C, v=3 m/s, d=10 g/kg dry air. makes it possible to reduce wax coating on blueberry berries and to intensify thermal moisture exchange during drying of berries better than using hygrothermal treatmen