Microwave Drying of Grapes in a Single Mode Cavity at 2450 Mhz - 11: Quality and Energy Aspects
T.N. Tulasidas, G.S.V. Raghavan, A.S. Mujumdar
Drying Technology
Abstract
ABSTRACT Drying studies were conducted to optimize process parameters (air temperature T. microwave power density P and air velocity u) for quality and energy in microwave drying of grapes using a single mode cavity applicator at 2450 MHz. Thc quality was assessed by several attributes like colour. damage, darkness, crystallized sugar, stickiness and non-uniformity. Colour and damage attributes provided more preeise predietability when compared to the other quality attributes. Microwave dried raisins were lighter in colour and hence were superior to hot air dried samples. Quality attributes were sipnificantlv dependent on T. P and u. Increase in air velocitv resulted in better Quality raisins where as P and T had the opposite effect. Optimum selection of T, P and u was found to be critical to achieve an energy efficient process for a quality product. Response surface models in terms of temperature m d micowave power were obtained for each of the quality attributes. Process optimization of the operating variables through response surface method was performed by imposing certain constraint levels on quality attributes
Extracted Claims
4 claims extracted from this paper into the knowledge graph
microwave drying of grapes results in lighter colour
“Microwave dried raisins were lighter in colour and hence were superior to hot air dried samples.”
microwave drying of grapes decreases quality
“Increase in air velocity resulted in better quality raisins where as P and T had the opposite effect.”
microwave drying of grapes improves quality
“Increase in air velocity resulted in better quality raisins.”