Impact of Nonthermal Pulsed Electric Field on Bioactive Compounds and Browning Activity in Emblica officinalis Juice

The effect of nonthermal pulsed electric field (PEF) and thermal treatment (900C for 60s) was studied on quality parameters of Emblica officinalis juice for the period of 6 weeks at 40C using monopolar rectangular pulse of 1μs width. The PEF treatment was given using static chamber at 24kV/cm for 500μs. The quality of Emblica officinalis juice was investigated in terms of non enzymatic browning index (NEBI), 5-hydroxymethyl-2-furfural (HMF), total polyphenol content and antioxidant capacity. 0Brix, pH and conductivity were evaluated as physical parameters. The aim of the work was to investigate the effect of PEF on the retention of bioactive compounds and retardation of browning activity. The results showed that conventional thermal treatment had led to a significant (p<0.05) decrease of 48.15% in polyphenol content (129.56 mg of GAE L), with higher NEBI and HMF formation (p < 0.05) whilst PEF suppressed NEBI and retained higher polyphenol compounds (168.59mg GAE L) with limiting the loss to 32.56% along maximum free radical scavenging activity (92.07%). However, pH, 0brix and electrical conductivity of treated juice samples remain unaffected. Therefore, PEF can be considered as an effective nonthermal treatment for retaining bioactive compounds along suppressing browning of emblica juice. Keywords—Emblica officinalis juice, Free radical scavenging activity, Pulsed electric field, Total polyphenol content.