Avoiding Non-enzymatic Browning By High-intensity Pulsed Electric Fields In Strawberry, Tomato And Watermelon Juices

摘要

Changes in color and 5-hydroxymethyl furfural (HMF) of strawberry, tomato and watermelon juices were evaluated after high-intensity pulsed electric field (HIPEF) processing using a response surface methodology and compared to the thermally-treated and unprocessed juices. HIPEF-processed juices retained the color better, and had lower HMF concentration than those treated by heat. The influence of pulse frequency, pulse width and polarity on color difference (△E) and HMF content of the juices were well fitted through second-order models. In the three products, monopolar mode and frequencies below 100 Hz promoted few changes on △E, keeping constant the initial amount of HMF. In addition, it was feasible to minimize non-enzymatic browning by the application of pulse widths beyond 4.5 μs for strawberry juice and up to 2.5 μs for tomato and watermelon juices.