Determination of ascorbic acid and its influence on the bioavailability of iron, zinc and calcium in Fijian food samples

The total content of ascorbic acid (AA) determined in selected Fijian foods from different food groups of cereals [long grain rice, brown rice, white bread, wholemeal bread, weet-Bix, oats and flours], pulses [yellow split, black eye beans, chickpea, green gram/moong whole, bengal gram/chana dal, spilt red gram/toor dal, blue peas, red kidney beans], poultry/meat products [chicken breast, lamb chops, fish and egg] and dairy products [milk powders and cheese] was in the range 24.54 ± 1.37 to 1.87 ± 0.69 mg/100 g. Further, the influence of AA on the bioavailability of Fe, Zn and Ca was determined using in vitro gastrointestinal digestion method by addition of (5 or 10 mg) AA in 2 g food sample. Pulses showed low content of AA whereas green leafy vegetables showed high content but AA was not detected in cereals, poultry/meat and dairy products. Our study confirmed that AA in chickpea reduced Fe bioavailability from 38.69 to 22.77% but increased in red kidney beans from 1.04 to 11.57%, in green gram (whole moong) 1.79 to 6.48% and wholemeal bread 2.44 to 8.76% whereas bioavailability of Zn and Ca was increased.