Changes in chemical composition of whole fl ours from grains amaranth a fter different thermal treatments

Abstract

The use of heat is an alternative to ensure the safety, improve sensory characteristics and increase digestibility of vegetables, making them suitable for children consumption. However, severe heat conditions may alter its nutritional composition. The objective of this study was to evaluate the effect of dry or humid heat before milling in chemical composition of whole amaranth (Amaranthus cruentus) grain fl ours. The fl ours were produced from in nature whole grains (UGF), toasted (PGF), cooking and dried (CDF) and popping (PGF). The heat treatmentsapplied to grains did not affect the mineral contents of the fl our, with the exception of Cu and Ca. However, the treatment elevated the levels of lipids (12-19%) and soluble fiber (18-35%) and reduced the insoluble fiber (5.8-8.5%) of the fl our when compared to in nature. The sulfur amino acids were fi rst limiting in UGF, for 1-10 years old and the popping reduced the quality of the amino acids which has become limiting, too, in lysine, for all ages. The toasting and cooking improved the balance of amino acids of fl ours obtained and the sulfur amino acids ceased to be the limiting for children over three years.