The Application of Osmotic Dehydration in the Technology of Producing Candied Root Vegetables

Abstract

The improved technology of the production of candied table and sugar beet, carrot, parsnip, root celery, and rutabaga was offered. The technology is based on increasing the osmotic pressure in the cells of plant raw materials by increasing the concentration of solids. The advanced technology involves the use of the process of osmotic dehydration in 70 % sugar solution of the temperature of 50 °C as an alternative to the process of blanching. This ensures the reduction of drying time up to 1 hour due to the partial transition of water from root cells into the sugar solution. Inactivation of enzymes, which occurs during dehydration, positively influences the organoleptic quality indicators of candied vegetables. Candied vegetables have a good smell, characteristic natural color, and can be used as a ready-made dessert dish and fillers in the production of fermented milk products and confectionery.

The influence of the traditional methods for processing plant raw materials on its nutritional and biological value was analyzed. The methods of making candied vegetables were studied and the shortcomings of these methods were revealed. A dataset on the modes of maintenance of dehydration and drying processes was obtained. The technology which includes: crushing raw material, osmotic dehydration, drying in vacuum drying chambers was proposed. The technology involves crushing raw material into cubes with the dimensions of 5/5/5 mm. Osmotic dehydration of raw materials occurs in the oversaturated sugar solution for 2.5 hours at the temperature of 50 °C with subsequent drying in vacuum drying chambers for 1 hour at 50 °C.

The design of the apparatus for osmotic dehydration, which ensures maintenance of the assigned temperature mode, preparation, and stirring the sugar solution, constant stirring of raw materials with the purpose of mass exchange intensification was developed.

The organoleptic (appearance, consistency, taste, smell, color) and physical and chemical quality indicators (mass fraction of sucrose, moisture, total ash) of candied table beets manufactured according to the improved technology were analyzed. Their compliance with the requirements of DSTU 6075:2009 was established.

Keywords: osmotic dehydration; vacuum drying chambers; candied table beets; root vegetables; mass fraction of sucrose