2.4. Thermal treatment
Orange juice and gazpacho were heat-pasteurized (90 C,
1 min) to compare the effects of HIPEF versus a conventional
thermal treatment on vitamin C content and antioxidant
capacity. Typical heat treatments of juices vary from
95 C to 90 C for 15–60 s (Nagy, Chen, & Shaw, 1993).
Products were thermally processed in a continuous flow
tubular heat-exchanger (Universitat de Lleida, Lleida,
Spain). A gear pump was used to maintain the juice flow
rate at 60 ml/min through a stainless steel heat-exchange
coil, which was immersed in a hot water shaking bath.
After thermal processing, the products were immediately
cooled in a heat-exchange coil which was immersed in an
ice-water bath.