Assessment of nutritional loss in finger millet during abrasive decortication using principal component analysis and clustering approach

Abstract

The decortication process of finger millet processing involves the removal of the seed covering from the endosperm. Excessive decortication removes portions of the endosperm, lowering the nutritional value of the grain. An investigation was carried out to study the effects of decortication on the milling, nutritional, and functional aspects of finger millet. The experiment was carried out using a full factorial design with grain moisture content (8,10, and 12%) and polishing time (8, 10, and 12 min) as independent variables. Higher polishing time and moisture content reduced endosperm yield. Considerable loss in the nutritional components was observed along with dry matter loss, which gradually increased with moisture content and polishing time. Tannins and phytates both reduced with increased polishing time due to the gradual elimination of aleurone layers of the grain. PCA demonstrated high association between proteins and crude fibre as well as ash, fat, WAC, OAC, and antinutrients. The data were effectively clustered into distinct groups using HCA and neural network clustering methods. The findings indicated that the polishing conditions significantly influenced the responses, and samples belonging to the same cluster were more similar to each other than to those from different clusters.