Chemical composition and physical properties of sorghum flour prepared from different sorghum hybrids grown in Argentina

Abstract

This work analyzed the physical, chemical, and thermal properties of sorghum flour and the relationships among these, in order to evaluate its suitability for the development of food products. Sorghum flour was obtained through roller dry milling from 20 commercial hybrids grown in Argentina with the average chemical composition of the samples being: 0.68% ash, 3.67% fat, 12.21% protein, 83.45% total carbohydrates, 79.77% starch (amylose 26.6%), and 34.9 mg of tannic acid per 100 g of flour. A high degree of variability among evaluated properties was found, particularly in the pasting properties peak viscosity (2809–5184 mPa/s), breakdown (1169–3170 mPa/s), and final viscosity (3030–4401 mPa/s) with onset temperature (To) and gelatinization enthalpy (ΔH) varying between 66.8 and 72.6°C, and 5.38 and 8.48 J/g, respectively. A principal component analysis demonstrated that the grain color did not influence the chemical composition of the flour. Cluster analysis permitted the separation of flour into three different groups with different thermal and physicochemical characteristics, and enabled the selection of hybrids. Thus, sorghum flour is a versatile ingredient and can be used in several food and non-food applications.