Vitamin C Content of Ready-To-Drink Orange Juice in Different Storage Conditions

The vitamin C contents of ready-to-drink orange juices in doy pack, tetra wedge and plastic bottle stored at room (31 320C) and refrigerated (4 50C) temperatures for a month were determined using the dichloroindophenol titration procedure. All the orange juice samples stored at room temperature showed higher vitamin C lost (1.45 4.09 mg/100ml) compared to orange juice samples stored inside the refrigerator (1.18 2.91 mg/100ml). The differences in the amounts of vitamin C lost in the orange juice samples stored at different temperatures were insignificant. At room temperature storage, higher amount of vitamin C was lost in the doy pack orange juice sample (4.09 mg/100ml), followed by juice sample in plastic bottle (2.35 mg/100ml) and in tetra wedge (1.45 mg/100ml). At refrigeration, the amounts of vitamin C lost in orange juice sample were as follows, doy pack (2.91 mg/100ml) > tetra wedge (1.18 mg/100ml) > plastic bottle (0.99 mg/100ml). The amounts of vitamin C lost in refrigerated orange juice samples contained in tetra wedge and plastic bottle were not significantly different. The use of container with thick inner layer, and lesser headspace oxygen content and storage at cool temperature are recommended for retention of vitamin C in ready-to-drink orange juice. Introduction The National Nutrition food consumption survey conducted in 2013 showed low consumption of vitamin C among Filipinos. The adult average daily per capita intake of vitamin C was noted to decrease from 46.7 mg in 1993 to 44.7 mg in 2008. The diminishing intake was attributed to factors such as high food prices and lack of food supply due to seasonality of sources. Vitamin C is white, crystalline, odorless water soluble compound that is acidic, has reducing properties and naturally occurred in plants but not in humans. Therefore, humans acquire this vitamin from consuming plant sources. The primary functions of vitamin C is to act as coenzymes in energy metabolism and in reactions that build and maintain body tissues like bones, muscles, collagen and red blood cells. It also helps enhance iron absorption, fight infections and combat diseases caused by free radicals by operating as an active antioxidant. Rich sources of Vitamin C are fruits, specifically citrus fruits, kiwi, guava, strawberries, grapefruits and vegetables such as the green leafy, green peppers, asparagus and broccoli. Vitamin C deficiency results to bleeding gums, easy bruising, poor wound healing, slow recovery from infection, fatigue and depression. The Philippine recommended vitamin C intake for female and male adults is 60 and 70 mg/day, respectively [1]. Ready to drink fruit juices are significant source of vitamin C commonly available in the market, nowadays. Fruit juices are liquid naturally contained in fruit or vegetable tissues. Codex Alimentarius defines juice as “unfermented but fermentable juice, intended for direct consumption, obtained by the mechanical process from sound, ripe fruits, preserved exclusively by physical means. The juice may be turbid or clear. The juice may have been concentrated and later reconstituted with water suitable for the purpose of maintaining the essential composition and quality factors of the juice. The addition of sugars or acids can be permitted but must be endorsed in the individual standard. ” [2]. All citrus juices are abundant in vitamin C, containing twice as much as the recommended daily allowance per eight-ounce glass.