Direct determination of cellulosic glucan content in starch-containing samples

Abstract

A simple and highly selective analytical procedure is presented for the determination of cellulosic glucan content in samples that contain both cellulose and starch. This method eliminates the unacceptably large compounding errors of current two-measurement methods. If both starch and cellulose are present before analytical hydrolysis, both will be hydrolyzed to glucose causing bias and inaccuracy in the method. To prevent this interference, the removal of starch prior to cellulosic quantification is crucial. The method presented here is a concise in-series procedure with minimal measurements, eliminating large compounding errors. Sample preparation consists of a starch extraction employing enzymatic hydrolysis followed by a simple filtration and wash. The samples are then subjected to a two-stage acid hydrolysis. The concentration of glucose is determined by ion exchange high-performance liquid chromatography with a Pb2+ column and a refractive index detector. The cellulosic glucan content is calculated based on the initial dry weight of the starting material. Data for the native biomass materials studied show excellent reproducibility, with coefficients of variance of 3.0% or less associated with the method. This selectivity for cellulosic glucan by the procedure was validated with several analytical techniques such as liquid chromatography coupled with mass spectrometry (LC–MS), Raman spectroscopy, and nuclear magnetic resonance.

Banana MaNAC1 activates secondary cell wall cellulose biosynthesis to enhance chilling resistance in fruit

“…Wax and other pigments were eliminated using acetone‐ethanol extraction (V acetone :V ethanol = 2:1) by a Soxhlet extractor after grinding into powder (Qin et al ., 2020 ). We also removed the starch from the powder due to the high starch content in the banana with refer to the Sluiter procedure (Sluiter et al ., 2021 ). To completely hydrolyse the powder, an incubation process with 4% diluted sulfuric acid was performed at a temperature of 121 °C for a duration of 60 min.…”

Current Trends in HPLC for Quality Control of Spices

“…Starch quantification is carried out by first extracting the sample with water or ethanol followed by filtration and subjection into the HPLC column. The column is typically equipped with a refractive index detector (RID), which detects changes in the refractive index of the eluent as the sample components pass through the column [103,104]. Excessive fillers destroy the authenticity of the spices, and to detect the fillers in the powdered spices, HPLC is an alternate solution.…”

Technologies for valorization of municipal solid wastes

“…It is worth clarifying that glucan, as a polysaccharide made from glucose units and commonly referred as cellulose, can be found in cellulosic or starch form (José Pablo 50 ). Owing to the importance of distinguishing between types of glucan, National Renewable Energy Laboratory (NREL) has recently standardized a novel method for determining the starch glucan content, 51 complementing the commercial assay kits. The distinction between cellulosic and starch glucan offers an array of possibilities for the optimization of engineering processes and enzyme formulation 52…”