Vitamin C Retention in Orange Juice Imitation Orange Juice, and Orange Beverage from Frozen Concentrates

The susceptibility of ascorbic acid to aerobic oxidation and possible loss of vitamin activity prompted a study to (1) determine if the vitamin C content of reconstituted frozen orange juice prepared using an electric blender is different from that prepared by stirring, and (2) to ascer tain the stability of vitamin C in reconstituted frozen orange concentrates (both pure and syn thetic) stored in a refrigerator for up to one week. Two cans of three brands of frozen concentrated orange juice and one brand of frozen con centrated orange beverage were reconstituted, one using an electric blender and the other by stirring. One can of imitation orange juice was reconstituted by stirring only. The beverages were analyzed immediately after reconstituting, after 3 days, and after 7 days of storage in a refrigerator at 0 ± 1°C (30°–34°F). Method of preparation did not have a significant effect on vitamin C (ascorbic acid plus dehydro‐ascorbic acid) levels. Both time and product affected vitamin C levels. The syn thetically derived orange concentrates were higher in vitamin C (62 mg/100 ml) compared with the orange juices (52 mg/100 ml). All reconstituted concentrates studied were similar in retention of vitamin C, retaining 94 percent or more after 3 days and 91 percent or more after 7 days.