engleski

Vitamin C in fruits and commercial fruit juices: HPLC content analysis and contribution to recommended dietary intake

Generic descriptor vitamin C encompasses the group of compounds, including oxidation products, esters and synthetic forms of L-ascorbic acid, with biological activity equivalent to the L-ascorbic acid. Vitamin C is one of the most important antioxidants in human nutrition. Since humans are not able to synthetize vitamin C, an adequate intake of vitamin C from foods and/or supplements is necessary for normal physiological functioning. Due to the wide choice of products available in the market and their high consumption, fruit juices together with fresh fruits and vegetables have become the most import source of vitamin C. High sensitivity and precision in obtaining results set the chromatographic (HPLC) method as the most reliable for the vitamin C determination in fruits and their products. The method was validated and found to be fit for purpose. Vitamin C was determined in commercial orange, apple and pineapple juices and fruits of the same species. The highest vitamin C content was found in orange juices (mean 35.32 ±7.43 mg/100 mL) followed by pineapple juices (16.62±10.48 mg/100 mL), while only 3 of 10 apple juice samples had detectable amount of vitamin C (from 38.94 to 54.00 mg/100mL). Fresh oranges and pineapples had higher vitamin C content compared to the commercial juices while fresh apples showed no detectable concentrations of vitamin C. Based on the recommendations for daily fruit intake (2 - 3 portions) it was concluded that contribution of fresh fruit and juices to daily vitamin C intake varies from none up to above the recommendations in dependence on choice with fresh orange being the best choice.

vitamin C; HPLC analysis; dietary intake; commercial fruit juices; fruits

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