POPPING CAPACITY OF AMARANTH (Amaranthus spp.) GRAIN WITH CONTRASTING PERISPERM

Abstract

Popping capacity of amaranth depends on the genotype, seed size, moisture and starch composition. In this study, the frequency of perisperm type with glutinous starch (GS) and non-glutinous starch (NGS) and the effect of perisperm type on grain popping capacity were determined in amaranth germplasm from Mexico. One hundred and two accessions of the species Amaranthus hypochondriacus L. and A. cruentus L. were used for characterization of perisperm type and 38 near-isogenic lines to observe the effect of starch type on popping capacity. The lines were planted under a randomized complete block design with three replications. The starch type of each genotype was identified with a colorimetric indicator and morphological characteristics of the whole and popped grain were observed through scanning microscopy images. Results showed that 90 % of the amaranth germplasm presents opaque perisperm with glutinous starch, low amylose content, low test weight and high popping volume compared to seeds with non-glutinous starch, while amaranth with crystalline perisperm showed non-glutinous starch with low amylopectin content by staining and the presence of a lipoprotein matrix that influences lower popping volume but higher grain weight. Therefore, it is suggested that the type of perisperm is a function of the composition of the starch, and influences its physicochemical properties and the popping capacity of the amaranth seed.