Determination of effects of heat treatment on carotenoid compounds of orange juices made from local oranges

The carotenoid composition and heat treatment related changes on carotenoid composition and some properties important for fruit juice technology of native oranges ?Kozan Yerli, Dörtyol Yerli, Finike Yerli and Alanya Dilimlisi? was searched in this study.After heat treatment, the least decrease in total carotenoid composition was found in Finike Yerli orange juice (5-14%), and the most decrease was found in Alanya Dilimlisi orange juice (15-25%).Approximately half amount of the identified and amount determined carotenoids (Xantophyll, Zeaxanthin, ß-apo-8-carotenal, ?-cryptoxanthin, ß-cryptoxanthin,?-carotene and ß-carotene) were ß-carotene (38.08-55.06%). With the effect of heat treatment (120 seconds at 70oC and 80oC, 15 seconds at 90oC), the decrease in carotenoids that has provitamin A effeciency (ß-cryptoxanthin, ?-carotene and ß-carotene) was determined. As the result of heat treatment the decreases of ß-carotene in Dörtyol Yerli orange respectively 45.06%, 66.11 and 66.70%, in Alanya Dilimlisi orange respectively 32.10%, 33.79% and 37.76% and in Finike Yerli and Kozan Yerli oranges 10.62-28.18% was determined. After the heat treatment (120 seconds at 70oC and 80oC, 15 seconds at 90oC) in orange juice the decrease in ?-carotene amount was found respectively 23-55%, 32-65% and 52-88%. The decrease in ß-cryptoxanthin content after heat treatment was found 8.7%, 44% and 48% respectively in Dörtyol Yerli orange, 6-37% in Alanya Dilimlisi and Finike Yerli oranges, but a decrease was also found in Kozan Yerli orange at 12-69% level.On pH, titration acidity, and water soluble solids values effect of heat treatment was not found significant. On the other hand total pectic substances, cloudiness, precipitated pulp, citric acid, ascorbic acid and oxalic acid values were decreased and visible viscosity, and total phenolic substances amount were increased.Keywords: Orange, Orange juice, Pasteurization, Carotenoid, beta-carotene Ascorbic Acid