Influence of ultra high pressure homogenization processing on bioactive compounds and antioxidant activity of orange juice

The purpose of this study was to evaluate the effect of ultra high pressure homogenization (UHPH) treatments on bioactive compounds and antioxidant activity of orange juice. Fresh squeezed orange juice was pre-warmed at two inlet temperatures (10 and 20 degrees C) and processed at 100, 200 and 300 MPa. The level of depletion of both L-ascorbic acid and carotenoids significantly depended (P<0.05) on the pressure applied during processing and even strongly on the maximal temperature achieved during the UHPH treatment, although the inlet temperature did not significantly influenced on any of the parameters evaluated. Nevertheless, the remaining content of L-ascorbic acid in the UHPH treated samples at any pressure was significantly higher (P<0.05) than in the thermal pasteurized one. On the other hand, the flavanone content increased with the UHPH treatments, more specifically the amounts of hesperidin, achieving its highest concentration on the samples treated at 200 and 300 MPa. No significant differences were observed on the total polyphenol content and antioxidant capacity values between the fresh and the UHPH treated orange juice samples while these values where significantly lower in the thermal pasteurized one. Industrial relevance: Nowadays, food researchers are testing alternative treatment technologies to heat pasteurization due to the increased interest in achieving high levels of food safety while producing high nutritive quality products. Ultra high pressure of homogenization (UHPH) is an emerging technology based on the dynamic application of high pressure allowing the processing of fluid foods continuously, which has been proposed as an alternative to thermal pasteurization for foods with heat-sensitive properties. The recent improvements in the UHPH equipments are design to apply semi-industrial treatments at pressures above 350 MPa, with a better temperature control. The successful application of UHPH treatments may provide with a new generation of minimally processed products, hopefully closer to the fresh ones in organoleptic and nutritive properties, but as safe and lasting as the pasteurized ones. (C) 2013 Elsevier Ltd. All rights reserved.