Zamorazhivanie yagod klubniki pri vozdeystvii akusticheskikh mikrovibratsiy

The impact of microvibrations on the strawberry structure was studied. Two methods were used to freeze strawberries: half of strawberries were frozen by traditional method at -30 оС under conditions of convection of heat, the second part was frozen under the same conditions but additionally the strawberries were exposed to microvibrations generated in the air medium of the freezing chamber using a specific program. A digital frequency synthesizer generating the electromagnetic field at 250 W/m3 power with rectangular pulse packages in the range of frequencies from 10 mHz to 5000 kHz was used. The microstructure of frozen samples was studied. The number of cells that kept their structure as well as their structural and mechanical characteristics was defined. Strawberries frozen by the traditional method kept 25-30% of cells. When using microvibrations 65-70% of cells of their total number were kept. The results of penetration and limit shear stress definition showed that strawberries frozen using microvibrations were 10-15% firmer. So, the application of microvibrations influences positively the strawberry structure, and allows improving their preservation during transportation and packing.

клубника, методика замораживания, микроструктурный анализ