Titrimetric Determination of Ascorbic Acid Levels in Some Citrus Fruits of Kurgwi, Plateau State Nigeria

Citrus samples of three different fruits, sweet orange (Citrus sinensis) lime (Citrus aurantifolia) and lemon (Citrus lemon) were picked fresh from the trees at intervals of seven days, from September to November at different locations in Kurgwi, washed and kept in the refrigerator at 4 o C pending analysis. Two stages of fruit development, Ripe and Unripe, were considered during sampling. The bark of these fruits were peeled off with sterile knife and sliced into half, then manually compressed into a 250cm 3 beaker and filtered off with glass wool in to a 100cm 3 beaker to remove the pulps which could block pipette jets. The Standard Methods of the Association of Official Analytical Chemists, AOAC methods, 939.13 and 966.18 were used for the determination of ascorbic acid in the fruit juice. Results of these determinations showed that sweet orange (Citrus sinensis) lemon (Citrus lemon) and lime (Citrus aurantifolia) have concentration range of 50.23mg/100mL - 56. 26mg/100mL, 51.33 mg/100mL - 53.47 mg/100mL and 34.12mg/100mL - 35.62mg/100mL, respectively. The unripe species of all the fruits tend to have higher ascorbic acid content as shown in the results obtained, with sweet orange and lemon having almost twice the level of ascorbic acid than lime. Patients with diabetes, stroke, heart diseases and cancer etc could take more of sweet orange and lemon, which have higher levels of ascorbic acid than lime as revealed by this research.