Qualitative and Quantitative Determination of Starch by a Colorimetric Method

Abstract

A method for the qualitative and quantitative determination of low amounts of starch and its components, amylose and amylopectin, was worked out. It combines the extraction of starch with HCI, staining with KJ/J2 and measurement of the absorbancies at two wavelengths, 605 and 530 nm, the absorption maxima of amylose and amylopectin, respectively. The determination of the amylose fraction and the quantification of the starch were done according to two evaluated equations. Phenolic substances did not influence the method. The method proved to be useful for sensitive starch determination and characterisation in plant material.

Microstructure and elastic modulus of phase-separated gelatin–starch hydrogels containing dispersed oil droplets

“…The end points of the tie-lines resided on the compatibility curve and gave the compositions of the phases coexisting at equilibrium (Tolstoguzov, 2008). The Bradford (Kruger, 2002) and iodine (Magel, 1991) colorimetric assays were used to determine the gelatin and starch concentrations in the gelatin-rich and starch-rich phases. For the protein assay, the Bradford reagent was made by dissolving 100 mg of Coomassie blue G250 in 50 mL of anhydrous ethyl alcohol followed by addition of 100 mL of 85.3% phosphoric acid and completion to 1 L with distilled water.…”

Dynamic Plastid Redox Signals Integrate Gene Expression and Metabolism to Induce Distinct Metabolic States in Photosynthetic Acclimation inArabidopsis

“…Starch, proteins, and lipids were determined by standard methods (Magel, 1991). ATP, ADP, NADP reduction state, and NADP-MDH activation state were determined and calculated as described (Kaiser and Urbach, 1977;Dietz and Heber, 1986).…”

Relationships between starch pattern indices and starch concentrations in four apple cultivars

“…The percentage amylose (% AM) in total starch was determined using a semi-quantitative method as described by Magel (1991) and Fan et al (1995). This method is an improved approach of the Hovenkamp-Hermelink et al (1988) method.…”

“…The calculation was based on the ratio of absorbance (R) as described by Hovenkamp-Hermelink et al (1988) and Magel (1991) as:…”