Page 12 - Application Notebook - Solution for Food Development

LAAN-A-LC-E283

Application High Performance Liquid Chromatography

News Analysis of Low Molecular Weight Soluble Dietary

Fiber by Prominence-i
No.L507

Research into the physiological effects of dietary fiber step "*" in Fig. 1), samples would normally require
has been ongoing since the results of epidemiological ethanol precipitation and filtration steps. However, these
research showing dietary fiber reduces incidence of steps can be omitted when analyzing samples that
diseases that include digestive system disorders, clearly contain only low molecular weight soluble dietary
circulatory system disorders, and diabetes. This research fiber. The steps were omitted for both the beverages
has revealed a variety of effects of dietary fiber, analyzed, since they were presumed to contain only low
including the reduced absorption of lipids like molecular weight soluble dietary fiber. Samples were
cholesterol from the intestines, and assistance with then passed through an ion-exchange column before
adsorption and excretion of harmful substances. This being used as the HPLC sample solution. Please refer to
1)
functionality has garnered interest in recent years, with the analytical method for further information.
chemically synthesized dietary fiber being added to an
increasing number of processed foods. Some of
nutritional labeling of foods show dietary fiber content, Sample 10.0 g
and such labeling is a regulatory obligation in some 0.1 mL Ћ-amylase
countries. 50 mL 0.08 mol/L phosphate buffer (pH 6.0)
Many substances can be classified as dietary fiber, with
definitions varying by country and policy. Dietary fiber Boiling water bath for 30 min with shaking
mainly refers to: cellulose, hemicellulose, and lignin that
make up cell walls; animal polysaccharides like chitin Cool to room temperature
and chitosan (insoluble dietary fiber), polysaccharides
like pectin (high molecular weight soluble dietary fiber), Adjust pH 7.5 ±0.1 with 0.275 mol/L NaOH
and chemically synthesized polysaccharides like 0.1 mL protease
polydextrose and indigestible dextrin (low molecular
weight soluble dietary fiber). Water bath at 60 ˚C for 30 min with shaking
Dietary fiber is normally measured using an enzymatic-
gravimetric method (prosky method). This involves Cool to room temperature
subjecting a sample to an enzymatic reaction, filtering
the sample, and measuring the weight of residue as the Adjust pH 4.3 ±0.2 with 0.325 mol/L HCl
amount of dietary fiber. A problem with this method is
its low rate of recovery for low molecular weight 0.1 mL amyloglucosidase
soluble dietary fiber, such as polydextrose and
indigestible dextrin. Total dietary fiber is obtained by Water bath at 60 ˚C for 30 min with shaking
adding the quantitative result obtained by the
enzymatic-gravimetric method to the quantitative result Cool to room temperature (*)
obtained by HPLC analysis of filtrate obtained from the
enzymatic-gravimetric method. Japan's food labeling
standards (Cabinet Office Ordinance No. 10, dated Elute by ion exchange column (300 mm L. × 20 mm I.D.,
March 20, 2015) specify dietary fiber to be measured containing 25 g each, thoroughly mixed,
of ion-exchange resins “AMBERLITEä IRA-67”
by a prosky method or HPLC method. and “AMBERLITEä 200CT”)
This application news describes an analysis of the
amount of low molecular weight soluble dietary fiber
by an enzymatic-HPLC method, based on the Food Extract through the column with water
Labeling Standards Š Appendix: Methods of analysis of
1)
nutritional composition . Collect 200 mL eluent
The instrument used was a Prominence-i integrated Evaporate
HPLC system installed with an RID-20A differential
refractive index detector. Water
Filtrate
Q Pretreatment of Low Molecular Weight Soluble
Dietary Fiber in a Beverage HPLC
Two types of cold beverages containing indigestible Fig. 1 Pretreatment Procedure
dextrin were prepared according to the analytical TM
1)
method . The pretreatment procedure is shown in Fig. 1. AMBERLITE is a trademark of the Dow Chemical Company (Dow) or
an affiliated company of Dow.
After treatment with three different enzymes (after the