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Effects of intermittent CO 2 convection under far‐infrared radiation on vacuum drying of pre‐osmodehydrated watermelon
Author(s) -
Chakraborty Rajat,
Mondal Pijus
Publication year - 2017
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.8246
Subject(s) - tray , dehydration , osmotic dehydration , chemistry , thermal diffusivity , moisture , water content , convection , food science , infrared , horticulture , botany , meteorology , thermodynamics , physics , biology , biochemistry , geotechnical engineering , organic chemistry , engineering , optics
BACKGROUND Watermelon, a tropical seasonal fruit with high nutrient content, requires preservation through drying due to its perishable nature. Nevertheless, drying of watermelon through conventional processes has a negative impact either on the drying time or on the final product quality. In this work, osmotic dehydration of watermelon followed by far‐infrared radiation‐assisted vacuum drying ( FIRRAVD ) was optimized to develop dehydrated watermelon with minimum moisture content. Significantly, during FIRRAVD , an attempt was made to further intensify the drying rate by forced convection through intermittent CO 2 injection. Drying kinetics of each operation and physicochemical qualities of dried products were evaluated. RESULTS FIRRAVD was a viable method of watermelon drying with appreciably high moisture diffusivity ( D eff,m ) of 4.97 × 10 −10 to 1.49 × 10 −9 m 2 s −1 compared to conventional tray drying. Moreover, intermittent CO 2 convection during FIRRAVD ( ICFIRRAVD ) resulted in appreciable intensification of drying rate, with enhanced D eff,m (9.93 × 10 −10 to 1.99 × 10 −9 m 2 s −1 ). Significantly, ICFIRRAVD required less energy and approximately 16% less time compared to FIRRAVD . The quality of the final dehydrated watermelon was superior compared to conventional drying protocols. CONCLUSIONS The novel CO 2 convective drying of watermelon in the presence of far‐infrared radiation demonstrated an energy‐efficient and time‐saving operation rendering a dehydrated watermelon with acceptable quality parameters. © 2017 Society of Chemical Industry