Effect of PEF and heat pasteurization on the physical-chemical characteristics of blended orange and carrot juice.

摘要

The effect of different Pulsed Electric Fields (PEF) intensities (25 kV/cm and 280 micro s, P1; and 25 kV/cm and 330 micro s, P2) and conventional HTST treatment (98 degrees C, 21 s, T) on quality characteristics (pH, degrees Brix, total acidity, turbidity, hydroxymethylfurfural (HMF), color, microbial flora, pectinmethylesterase (PME) activity, and sensory analysis) of blended orange and carrot juice were investigated. HMF, L* (luminosity) and C* (saturation or chrome) color parameters did not vary with any of the treatments. Total acidity and turbidity were slightly higher after HTST treatment. Sensory characteristics of the PEF-treated juice were more similar to the untreated juice than the HTST-pasteurized juice. Nevertheless, heat pasteurization (98 degrees C, 21 s) was more efficient in inactivating microbial flora and PME and preventing the growth of microbial flora and reactivation of PME at 2 and 12 degrees C for 10 weeks. However, the shelf-life of the PEF-treated juice was established as 4 weeks at 2 degrees C. This appears to be a reasonable shelf-life for this type of foodstuff..