Use of ascorbic and citric acids to increase dialyzable iron from vinal (Prosopis ruscifolia) pulp

Vinal (Prosopis ruscifolia) is an ecologically important wild leguminous tree that grows spontaneously in Argentine deforested lands, the fruit of which is consumed by humans and animals. Because considerable iron content with low to intermediate availability has been previously reported in vinal pulps, its enhancement would be of interest. Iron availability was determined as iron dialyzability using an in vitro technique. Response surface methodology was used to evaluate iron availability increase after adding ascorbic and/or citric acids to vinal pulp at different mM acid/mM Fe ratios. Those ratios ranged from 0.05:1 to 9.95:1 and from 0.5:1 to 99.5:1 for ascorbic acid/Fe (AA:Fe) and citric acid/Fe (CA:Fe), respectively. The obtained second- and first-order polynomial equations showed that AA:Fe and CA:Fe molar ratios linear terms had a significant effect on iron dialyzability increase (P < or = 0.05). It was possible to enhance iron availability to a maximum of 4.6 times. Additional confirmatory experiments were made adding the same organic acids to different vinal pulps and to a traditional cake prepared with vinal pulp called "patay." There were no significant differences (p > 0.05) between predicted values obtained by the model and experimental results.