Effect of different degrees of decortication on pearl millet flour shelf life, iron and zinc content

Grain decortication is used commercially to extend the shelf life of pearl millet flour over the world. This is the first study in pearl millet to assess the effects of various degrees of decortication on the rancidity developing parameters and provide insight for its commercial application. Present study is evaluating the impact of different degree of decortication on the shelf life of pearl millet flour and percent loss of micronutrients abundant (iron and zinc) in pearl millet. Eight pearl millet genotypes belong to low, medium and high rancid category were subjected to three different level of decortication. On the basis of percent weight loss by decortication, up to 1-3% was designated as low (LD), 3.1-6% as medium (MD) and 6.1 to 10% as high (HD) level of decortication. Analysis of rancidity measuring parameters revealed that only LD is effective in improving the shelf life of pearl millet flour by reducing the lipoxygenase (LOX) activity and lipid oxidation as compared to control sample and also the loss of essential micronutrient due to decortication was minimal. As the degree of decortication increases, at MD and HD level, the lipid oxidation rate increases through non enzymatic method and also the loss of essential micronutrients was observed to be high. To conclude, LD is an effective approach for regulating the rancidity and improving the shelf life of pearl millet flour.