Comparison of Iron Absorption – Inhibited Substances in Local Thai Vegetables

Abstract

Seventy-five samples of local Thai vegetables which popularly consumed as fresh vegetable are chosen from various menu foods. They are selected and classified into direct components in food dish, eg. Som tum, Kua yum etc, including consumed as fresh vegetable together with chilli paste such as Nuam prig. In report of analysis, the iron absorption - inhibited substances of various local vegetables which take to balance iron are 114.46–244.66 mg of phytate 100 g 455.72–1407.23 mg of oxalic acid 100 g 209.60–528.90 mg of phosphate100 g 175.03–453.06 mg of tannin 100 g and 1.0852–2.7273 g of crude fiber100 g by statistical interval estimation (minimum – maximun) at 95% confidence level. In part of edible vegetables, they are found that fruit group has crude fiber content more than the others while edible leaf group has high oxalic acid and tannin content. Tannin of creeper, herb and tree which are orderly average 240, 314 and 584 mg/100g have significantly difference by statistic at ∝=0.01. Comparison on Pearson ’s correlations between oxalic acid with phosphate and tannin with phosphate are Rxy = 0.77 and 0.598 respectively at 99% confidence level.