Pulsed electric field processing of functional drink based on tender coconut water (Cococus nucifera L.) - nannari (Hemidesmus indicus) blended beverage

摘要

Tender coconut water (Cocos nucifera L.) Nannari extract (Hemidesmus indicus L.) ready-to serve (RTS) blended beverage were optimised. Response Surface Methodology (RSM) was employed to optimize the levels of independent variables (levels of tender coconut water, nannari extract and sugar). The responses of pH, oBrix, CIE colour (L*, a* and b*) value and OAA were studied. The data obtained were analysed by multiple regression technique to generate suitable mathematical models. The developed blended beverage was processed using pulsed electric field (PEF) with electric field 31.2 kV/cm, 20 pulse widths at 100 Hz frequency to minimise nutritional and sensory attributes losses and compared with conventional thermal pasteurization (96 oC for 360 s) with p-value of 8.03. Thermal pasteurization showed a significant (p0.05) decrease in colour value, radical scavenging activity and overall acceptability after treatment and also during storage, when compared to PEF treated tender coconut water-nannari blended beverage. PEF treatment also achieved a 3.01 ± 0.69 log inactivation, similar to thermal pasteurization of native micro flora. PEF treated tender coconut water-nannari blended beverage was stable up to 120 days under ambient storage condition (27-30 °C).