Structural and quantitative changes of starch in seed of Trigonella persica during germination

Starch, the most abundant carbohydrate reserve in plant seeds, is synthesized and stored in the cotyledons of some plants. In seeds of Trigonella persica (Fabaceae), starch appears during germination and forms granules that are composed of amylose and/or amylopectin. In this study, both quantitative and qualitative traits of starch were evaluated during the germination of T. persica seed. The quantitative assay and microscopic imaging showed that there was a low-amylose starch in the cotyledons and its amount reached the highest at 48 h after imbibition (HAI). According to the SEM images of hydrogels, FT-IR spectra, and analysis of extracted starches, the purity of this starch was decreased during germination. So that the extracted starch from cotyledons of non-germinated seeds (ESCN), with the highest purity and the lowest protein content, was different from all the extracted starches. Therefore, it seems that ESCN was an amylopectin rich type starch, which had low amylose to amylopectin ratio and as waxy starch typically, it can have a cohesive and gummy texture compared with ordinary starch.