Insights into maize starch degradation by sulfuric acid from molecular structure changes

Area of Science:

• Carbohydrate Chemistry
• Polymer Science
• Biochemistry

Background:

• Maize starch is a complex polysaccharide with significant industrial applications.
• Understanding the molecular structure of starch is crucial for optimizing its processing and functionality.
• Acid hydrolysis is a common method for modifying starch properties.

Purpose of the Study:

• To analyze the molecular structure of maize starch after sulfuric acid hydrolysis.
• To characterize the changes in chain-length distribution (CLD) and molecular size.
• To investigate the degradation patterns of different chain lengths over time.

Main Methods:

• Acid hydrolysis of maize starch using sulfuric acid.
• Characterization of chain-length distribution (CLD) using advanced analytical techniques.
• Quantification of molecular size reduction and amylose content changes.
• Comparative analysis of hydrolyzed and native starch CLDs.

Main Results:

• Molecular size was dramatically reduced within 1 hour of acid hydrolysis.
• Amylose content decreased from 28.3% to 4.6% with prolonged hydrolysis time.
• Long chains (DP ~500-30000) degraded rapidly, followed by shorter amylose and amylopectin chains.
• Hydrolyzed starch molecular size strongly correlated with CLD subtraction parameters.

Conclusions:

• Sulfuric acid hydrolysis effectively modifies maize starch at a molecular level.
• The degradation process targets longer chains initially, then progresses to shorter chains.
• The study provides insights into the relationship between CLD and molecular size in modified starch.