A PRACTICAL APPLICATION OF STARCH DETERMINATION IN VEGETATIVE PLANT-MATERIAL

Starch determination in plant matter is necessary because of the importance of the carbohydrate pool in combination of the nitrogen pool in crop growth and development. This analysis is complicated in vegetative materials by contamination with non-starch containing material. Starch is not a homogenous material, so the content of amylose and amylopectin varies from the different growth stages and from crop to crop. Therefore standard methods of starch estimation give no exact result. The method described here based on a pretreatment of the plant material with dilute alkali before hydrolysis with amyloglucosidase and the estimation of the glucose content. Therefore this procedure was first tested on amylose, amylopectin, soluble starch, three commercially available starches, and was then applied to vegetative rape material. Recoveries of amylose and three commercial starches were between 98 and 100 % after a additional ultrasonic treatment. The method is advantageous because it is simple, quick and reproducible.