Related Experiment Video
Updated: Jan 23, 2026
07:04
Determination of the Glycogen Content in Cyanobacteria
Published on: July 17, 2017
13.6K
An improved method to determine the hydroxypropyl content in modified starches by 1H NMR
Weiwei Wang1, Zhenhua Sun1, Yong-Cheng Shi1
1Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506, USA.
Food Chemistry
|June 9, 2019
Summary
This study optimized acid hydrolysis for hydroxypropyl (HP) starches, enabling accurate HP content determination using 1H NMR. The improved method enhances analysis of modified starches for food applications.
Area of Science:
- Food Chemistry
- Analytical Chemistry
- Polymer Science
Background:
- Hydroxypropyl (HP) starches are vital food thickeners and stabilizers.
- HP starch properties depend on the degree of hydroxypropylation.
- Accurate determination of HP content is crucial for quality control.
Purpose of the Study:
- To develop an improved acid hydrolysis method for HP starches.
- To enable accurate HP content determination by 1H NMR.
- To optimize hydrolysis conditions for modified starches.
Main Methods:
- Investigated effects of DCl concentration and temperature on hydrolysis.
- Determined optimal conditions: 10% starch, 3.5% DCl in D2O, 90°C for 1h.
- Utilized sodium acetate as an internal standard and TFA-d as a water-peak shifter.
Main Results:
- Successfully degraded and solubilized HP starches.
- Achieved HP content results consistent with enzyme-catalyzed methods.
- Validated the method on six HP starches and two cross-linked HP starches.
Conclusions:
- The developed acid hydrolysis method is effective for HP starch analysis.
- This method provides a reliable alternative for determining HP content.
- Optimized conditions facilitate accurate characterization of modified starches.
Related Concept Videos
02:16Stereotype Content Model
15.4K
The Stereotype Content Model (SCM) was first proposed by Susan Fiske and her colleagues (Fiske, Cuddy, Glick & Xu, 2002; see also Fiske, 2012 and Fiske, 2017). The SCM specifies that when someone encounters a new group, they will stereotype them based on two metrics: warmth—or that group’s perceived intent, and how likely they are to provide help or inflict harm—and competence—or their ability to carry out that objective. Depending on the warmth-competence...
15.4K
01:04¹³C NMR: ¹H–¹³C Decoupling
1.8K
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
1.8K
01:22Protein-Drug Binding: Determination Methods
632
Determining protein-drug binding can be achieved through indirect and direct methods, each providing valuable insights into the interaction between proteins and drugs.
Indirect methods involve isolating the bound drug from its free form in biological samples such as blood, serum, or plasma. These techniques aim to measure the percentage of drugs bound to proteins. Equilibrium dialysis is a commonly used method where the free drug concentration at equilibrium is measured by separating the bound...
Indirect methods involve isolating the bound drug from its free form in biological samples such as blood, serum, or plasma. These techniques aim to measure the percentage of drugs bound to proteins. Equilibrium dialysis is a commonly used method where the free drug concentration at equilibrium is measured by separating the bound...
632
01:15¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
1.7K
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
1.7K
01:21Dose Size and Dosing Frequency: Determination Methods
285
Determining the optimal dose size and dosing frequency in pharmacotherapy is crucial for achieving therapeutic effectiveness while minimizing adverse effects. This article explores the methodologies employed in determining these parameters, focusing on their significance and interplay to tailor dosing regimens.Dose Size: Dose size refers to the amount of a drug administered in a single dose. It is determined based on the drug's pharmacodynamics and pharmacokinetics properties and...
285
01:19Dosage Interval and Administration Route: Determination Methods
228
A medication’s effectiveness largely depends on its appropriate dosage and the route of administration. Dosage ensures that a sufficient drug concentration is maintained in the bloodstream to elicit the desired therapeutic effect without causing toxicity. The route of administration affects the drug's bioavailability, rate of absorption, and onset of action, which are crucial for achieving optimal therapeutic outcomes. Drug dosage calculations are critical to tailoring therapy to...
228