Nutritional Quantification and Shelf Life Analysis of Non-thermal Processed Coconut Juice

¹ Bioprocess Engineering and Biotechnology Center, Department of Biotechnology, Faculty of Applied Science, King Mongkut’s University of Technology North Bangkok, Bangkok, Thailand
² Department of Electrical and Computer Engineering, Faculty of Engineering, King Mongkut’s University of Technology North Bangkok, Bangkok, Thailand

^* Corresponding author: sasithorn.k@sci.kmutnb.ac.th

Abstract

Nonthermal processing methods are attracted by many food and beverage industry because it can kill the microbial contamination under mild temperatures used in thermal processing; They can sustain flavours, essential nutrients, and vitamins undergo minimal changes. The objective of this research was to evaluate nonthermal processing as the high current impulse generator (HCIG) and investigate the reduction the contaminated microorganism in coconut juice under the batch and continuous treatment of HCIG. The physical, biochemical and nutritional changes of treated coconut juice were also investigated. The application of the direct electricity through cathode of high current impulse generator (HCIG) in 1,170 chambers contained the contaminated coconut juice. Significantly reduction both Saccharomyces cerevisiae and Escherichia coli as 5-log were found when treatments were applied with impulses at 5.17 kA. Comparison of nutritional value of non-thermal processes before and after high current impulse was showed no significant differences between main nutritional values and free amino acid. For the continuous HCIG treatment under the treatment of 5.17 kA current with 9, 15 and 30 pulses with 5 L coconut juice at the flow rate of 1 L/min, results from initial concentration at 1.41 × 10⁵ CFU/mL showed that S. cerevisiae reductions were found 78%, 66% and 96% as increasing number of pulses as 9, 15 and 30 pulses, respectively. The increment of microbial reduction with the increasing number of pulses was also detected as 78 %, 82 % and 96 % from 1.11 × 10⁵ CFU/ml E. coli. Results revealed that the microbial reduction with HCIG under batch treatment were successful preserved the nutritional components of the coconut juice without significant physicochemical changes.