KINETICS OF ASEPTIC CONCENTRATED ORANGE JUICE QUALITY CHANGES DURING COMMERCIAL PROCESSING AND STORAGE

Aseptically concentrated orange juice (COJ) was processed commercially at three holding temperatures (84, 87 and 90 degrees C, 72 s) and sto red for up to 7 weeks at 32 degrees C and 15 weeks at 22 degrees C. No differences were found in nonenzymic browning (NEB), vitamin C, sucro se, fructose and glucose, furfural, HMF (5-hydroxymethyl furfural), an d DMHF (2,5-dimethyl-4-hydroxy-3(2H)-furanon) concentrations due to th e different thermal treatment. The dominating factors affecting vitami n C retention and NEB were time and storage temperature. A lag-time wa s observed in NEB formation and its length depended on storage tempera ture. Furfural concentration was below 1 ppm. HMF reached c. 11 ppm af ter 7 weeks at 32 degrees C. DMHF concentration decreased throughout t he storage period. Sensory evaluation showed a nonsignificant preferen ce for COJ processed at the lower temperature.