Method for Glucose and Fructose Quantitation in Beverages Using an Off-the-Shelf Glucose Test Strip

Area of Science:

• Analytical Chemistry
• Biochemistry

Background:

• Accurate quantification of sugars like glucose and fructose is crucial in food analysis and agricultural applications.
• Traditional methods for sugar analysis can be complex and time-consuming.

Purpose of the Study:

• To develop a simple, cost-effective method for simultaneously quantifying glucose and fructose.
• To apply this method for assessing grape ripeness through sugar content analysis.

Main Methods:

• Utilized commercially available glucose test strips and a mini-potentiostat.
• Employed enzymatic conversion of fructose to glucose using glucose isomerase to determine total sugar concentration.
• Calculated fructose concentration by subtracting initial glucose levels from total sugar levels.

Main Results:

• Achieved a limit of detection of 0.047 g L⁻¹ for glucose and 0.49 g L⁻¹ for fructose.
• Successfully applied the method to analyze grape juice samples with high sugar concentrations (>60 g L⁻¹).
• Demonstrated the method's potential for determining grape ripeness based on the glucose-to-fructose ratio.

Conclusions:

• The developed method offers a reliable approach for quantifying glucose and fructose in complex matrices like grape juice.
• This technique provides a valuable tool for viticulture, assisting in optimal grape harvesting decisions.