Eliminating protein interference when quantifying potato reducing sugars with the miniaturized Somogyi-Nelson assay

Area of Science:

• Agricultural Chemistry
• Food Science
• Analytical Chemistry

Background:

• Reducing sugar (RS) content is critical for potato quality, acrylamide formation, and crop management.
• Accurate RS quantification is vital for the potato industry, impacting quality and development.
• Soluble proteins in potato matrices interfere with standard Somogyi-Nelson (SN) analysis.

Purpose of the Study:

• To develop a deproteinization method for potato samples compatible with miniaturized Somogyi-Nelson (SN) analysis.
• To ensure the deproteinization procedure does not compromise the accuracy of RS quantification.
• To provide a simpler and effective alternative to existing protein removal techniques.

Main Methods:

• A miniaturized Somogyi-Nelson (SN) assay was employed for reducing sugar quantification.
• Ethanol was investigated as a deproteinization agent for potato samples.
• High-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) was used for validation.

Main Results:

• Ethanol effectively removed soluble proteins from potato samples without affecting SN assay accuracy.
• The ethanol-based deproteinization procedure proved simpler than methods involving salts, acids, heating, or pH adjustment.
• RS content measured by the ethanol-deproteinized SN assay was precise and validated against HPAEC-PAD.
• A common biochemical analyzer underestimated RS content due to its inability to detect fructose.

Conclusions:

• The ethanol-based deproteinization method is a reliable and simple approach for preparing potato samples for accurate RS quantification using the SN assay.
• This optimized SN assay provides a more accurate measure of total reducing sugars compared to some conventional biochemical analyzers.
• The findings support the widespread adoption of this improved method for potato industry applications.