Grain characteristics and composition of maize specialty hybrids

Abstract

Improved nutritive and technological maize grain value is very important for its use in diets. In this work, the chemical composition and potential beneficial components, including total and soluble proteins, tryptophan, starch, sugars (sucrose and reducing sugars), and fibres were investigated in flour of eight specialty maize hybrids from Maize Research Institute Zemun Polje (ZP): two sweet, popping, red, white, waxy, yellow semiflint and yellow dent maize hybrids. In addition, digestibility of grain dry matter and viscosity of maize flour were determined. The highest nutritive value was recorded in sweet maize hybrids ZP 504su and ZP 531su which had the highest content of total protein, albumin, tryptophan, sugars and dietary fibres. Besides, low content of starch (55.32% and 54.59%, respectively) and lignin (0.39% and 0.45%) affected the highest dry matter digestibility (92.69% and 91.07%) of sweet maize flour. However, functional properties of ZP sweet hybrids were not satisfactory for food and industrial applications. In contrast, flour of ZP waxy maize hybrid was characterised by a clear and a high peak viscosity. All hybrids could be classified according to the sucrose content in three groups: a) > 4% (sweet and red hybrids-ZP 504su, ZP Rumenka), b) from 3 to 4% (waxy, standard dent and semi flint hybrids-ZP 704wx, ZP 434, ZP 633) and c) from 2 to 3% (sweet, white and popping maize hybrids-ZP 531su, ZP 74b, ZP 611k).alpha-Zein was the dominant protein fraction in all genotypes except the sweet maize hybrids, making 22.45% to 29.25% of the total protein content.