Effects of thermal pasteurization on quality of Kozan misket and Valencia orange juices

At this work, we researched that effect of different pasteurisation temperatures (75, 80 and 85 oC) on carotenoids, phenolic compounds, ascorbic acid, antioxidant activity, sensory quality, total phenolic compound, hydroxyl methyl furfural (HMF) and color parameters of Valencia and Kozan Misket orange juice. According to results of color analyses, it was not found important differences between control and pasteurized juice samples when varieties of orange juice were evaluated in different groups. The highest value of HMF was found in pasteurized at 85 oC of Kozan Misket orange juices. The differences of antioxidant activity samples were not evaluated as important between varieties and applications. Ascorbic acid content were between 1131.43 and 1374.99 mg/l in Valencia orange juices and between 574.24 and 711.01 mg/l in Kozan Misket orange juices. According to results, hesperidin was found as major flavonoid in Valencia orange juices (51.69?89.00 mg/l) but in Kozan Yerlisi orange juices, hesperidin was determined as major flavonoid (63.08?73.87 mg/l). The major carotenoids of Valencia and Kozan Misket orange juices were zeaxanthine (% 38) ve ß-carotene (% 34), respectively and the principal losses among carotenoids were observed in ß-xanthopyll (% 6) and xanthopyll (% 35.7), respectively. In accordance with sensory analyses, Kozan Misket was the most desirable variety.