SURVIVAL OF SACCHAROMYCES CEREVISIAE IN REFRIGERATED FRESH ORANGE JUICE TREATED WITH CINNAMON LEAF ESSENTIAL OIL AND THERMO-SONICATION

摘要

The survival of Saccharomyces cerevisiae in refrigerated fresh orange juice processed by combined use ofthermo-sonication and cinnamon leaf essential oil (CLEO) was evaluated. The concentration of CLEOaccepted by consumers in orange juice was determined by sensory analysis as 20 ppm. The resistance of S.Cerevisiae cells to the action of ultrasound (24 KHz; 33.31 W mL~(-1); 30 minutes) at 50℃ in orange juice withCLEO was analyzed. The survival of S. cerevisiae in the fresh orange juice untreated (control) and treatedwith thermo-sonication, or thermo-sonication plus 20 ppm CLEO and kept under refrigeration (5℃) for 28days was studied. The best result was obtained with thermo-sonication and 20 ppm CLEO treatment. Thistreatment produced a reduction from an initial population of 5.18 log of S. cerevisiae in fresh orange juice to2.60 ± 0.26 log after 30 min of sonication at 50℃. The best result of inhibition obtained during refrigerationwas achieved with orange juice treated with 30 min of sonication at 50℃ and 20 ppm CLEO because thetreated juice kept under refrigeration at 5ºC for 28 days diminished the S. cerevisiae population 1.33 ± 0.17log.