DETERMINATION OF VITAMIN C CONTENT IN FRUITS AND VEGETABLES

ABSTRACT Vitamin C is an essential water-soluble antioxidant required for immune function, collagen synthesis, and protection against oxidative stress, and the prevention and treatment of scurvy, a deficiency disease marked by fatigue, swollen gums, and impaired wound healing. This research project was carried out to determine the vitamin C (ascorbic acid) content in various fruits and vegetables commonly consumed, with the aim of evaluating their nutritional value and biochemical significance. The analysis was performed using a UV-Visible spectrophotometer, with absorbance readings taken at 491 nm a wavelengths. Standard ascorbic acid solutions were used to prepare a calibration curve for accurate quantification of the vitamin C in the test samples. Fresh samples including mango, grape, beetroot, cucumber, pineapple, orange, carrot, banana, pawpaw, lemon, apple, green bell pepper, habanero, bitter leaf, onion, garden egg, chilli pepper, green beans, beetroot, cucumber, and carrot were extracted, filtered, and analyzed under standard conditions. The vitamin C concentrations were calculated based on their absorbance values using calibration curve. The results revealed that all tested fruits and vegetables contained measurable levels of vitamin C, ranging from 1.63 mg/100g in pineapple to 2.2 mg/100g in green beans. Among the fruits, orange (2.17 mg/100g) and lemon (2.14 mg/100g) had the highest values while pineapple (1.63 mg/100g) and watermelon (1.83 mg/100g) had the lowest. Among the vegetables, green bell pepper (2.23 mg/100g), green beans (2.20 mg/100g), and chilli pepper (2.20 mg/100g) recorded the highest concentrations. These findings demonstrate that fruits and vegetables are rich and diverse natural sources of vitamin C and confirm their important contribution to dietary antioxidant intake. The spectrophotometric method used was simple, effective, and reliable for routine ascorbic acid determination. This research confirmed the nutritional importance of consuming a variety of fresh fruits and vegetables and supported dietary recommendations for vitamin C intake.