Quantitative Analysis of Vitamin C and Minerals in Processed Tropical Fruit Juices Sold in Ibadan, South West Nigeria

Commercially processed fruit juices are marketed as nutrient-rich beverages, but processing conditions, packaging materials, and storage duration can significantly reduce their vitamin and mineral content, affecting nutritional claims. This study quantifies vitamin C and selected mineral concentrations in ten commercially available tropical fruit juice brands (pineapple, orange, and mango) sold in supermarkets and open markets in Ibadan, Oyo State, South West Nigeria. Vitamin C content is determined by iodometric titration and verified by high-performance liquid chromatography. Mineral content for calcium, potassium, magnesium, iron, and zinc is measured by atomic absorption spectrophotometry. Samples include both imported brands and locally manufactured products to enable comparative assessment. The study also examines correlations between packaging type and nutrient retention. Results are compared against product label declarations and recommended daily allowances to assess labelling accuracy. Statistical analysis uses descriptive statistics and one-way analysis of variance. Preliminary evidence from the literature suggests that local brands may have lower vitamin C retention due to less advanced preservation technology. Findings contribute to consumer information and support regulatory enforcement of nutritional labelling standards by the National Agency for Food and Drug Administration and Control in the South West zone. Keywords: vitamin C, minerals, processed fruit juices, Ibadan, nutritional analysis