1Indian Institute of Crop Processing Technology, Kelappaji College of Agricultural Engineering and Technology, Kerala Agriculturl University, Kerala, India
2Department of Food and Agricultural Process Engineering, Kelappaji College of Agricultural Engineering and Technology, Kerala Agriculturl University, Kerala, India
*Email: dileep.sean7@gmail.com
Online published on 24 February, 2017.
In this study an ultraviolet radiation assisted ohmic heating system for preservation of fruit juices was developed and successfully fabricated. The fabricated instrument was tested for its effectiveness in pasteurization of pineapple juice. It was found that the synergistic effect of UV radiation assisted by ohmic heating could improve the microbial lethality in pineapple juice, and it was presumed that the UV light could effectively penetrate and damage the cellular structure through the cell pores opened by electroporation of ohmic process. The process parameters of the developed system were optimized by considering the important process variables. It was established that a combined UV assisted ohmic heating process with ohmic heating temperature of 50°C and a UV radiation dosage of 1200 mJ/cm2 could bring out a 5 log reduction in bacteria causing minimum changes in the nutritional and sensory quality and thus the overall acceptability of the pineapple juice. In order to further validate the developed system, a storage study was also carried out with pineapple juice treated in the fabricated system with the optimized process parameters and compared the same with that of fresh untreated juice. It was revealed that system could effectively treat the juice which could give a shelf life of 25 days under a refrigeration temperature at 4°C retaining its biochemical characteristics while keeping the microbial level safe.
Ohmic heating, Ultraviolet radiation, Electrophoresis, Microbial inactivation, Pineapple juice
