A method for routine measurements of total sugar and starch content in woody plant tissues

Abstract

Several extraction and measurement methods currently employed in the determination of total sugar and starch contents in plant tissues were investigated with the view to streamline the process of total sugar and starch determination. Depending on the type and source of tissue, total sugar and starch contents estimated from samples extracted with 80% hot ethanol were significantly greater than from samples extracted with a methanol:chloroform:water solution. The residual ethanol did not interfere with the sugar and starch determination, rendering the removal of ethanol from samples unnecessary. The use of phenol-sulfuric acid with a phenol concentration of 2% provided a relatively simple and reliable colorimetric method to quantify the total soluble-sugar concentration. Performing parallel sugar assays with and without phenol was more useful for accounting for the interfering effects of other substances present in plant tissue than using chloroform. For starch determination, an enzyme mixture of 1000 U alpha-amylase and 5 U amyloglucosidase digested starch in plant tissue samples more rapidly and completely than previously recommended enzyme doses. Dilute sulfuric acid (0.005 N) was less suitable for starch digestion than enzymatic hydrolysis because the acid also broke down structural carbohydrates, resulting in overestimates of starch content. After the enzymatic digestion of starch, the glucose hydrolyzate obtained was measured with a peroxidase-glucose oxidase/o-dianisidine reagent; absorbance being read at 525 nm after the addition of sulfuric acid. With the help of this series of studies, we developed a refined and shortened method suitable for the rapid measurement of total sugar and starch contents in woody plant tissues.

Starch determination in Chlorella vulgaris—a comparison between acid and enzymatic methods

“…It has been reported (Esposito et al 2006) that the protein content in green microalgae is about threefold higher in nitrogensufficient cells with respect to nitrogen-starved cells. According to Chow and Landhäusser (2004), watersoluble compounds such as proteins react with the concentrated sulfuric acid in the glucose assay and, therefore, significantly interfere with the absorbance reading. Tables 2 and 3 also show that the enzymatic method EM1 had the best precision in starch quantification, while method AM3 yielded the highest percentage relative standard deviation.…”

Production and role of epicormic shoots in pruned hybrid poplar: effects of clone, pruning season and intensity

“…Phenol-sulfuric acid was used to analyze the ethanol extract for total sugar concentration. Starch was digested using an enzyme mixture of α-amylase and amyloglucosidase followed by the colorimetric measurement of the glucose hydrolysate using a peroxidase-glucose oxidase-o-dianisidine reagent (Chow and Landhäusser 2004).…”

Effect of exogenous abscisic acid on the level of antioxidants in Atractylodes macrocephala Koidz under lead stress

“…Estimation of soluble sugar content Total soluble sugar was extracted following the method of Chow and Landhäusser (2004). Fresh ground samples (0.5 g) were extracted by boiling in 80 % neutral aqueous ethanol for 6 h. The extract was filtered through Whatman filter paper no.…”