Validation of Enzytec™ Liquid Combi Sucrose/D-Glucose for Enzymatic Determination of Sucrose and D-Glucose in Selected Foods and Beverages: First Action 2024.05.

Background: Sucrose is produced in the greatest quantity of all industrially produced organic substances and can be used in almost all processed foods. Glucose is the most abundant monosaccharide and contained in many foodstuffs naturally or added as an ingredient.

Objective: To validate the performance of the Enzytec™ Liquid Combi Sucrose/D-Glucose test kit for the determination of sucrose and D-glucose in juices, chocolate, breakfast cereals, ice cream, sweetened condensed milk, wine, beer, and soft drinks.

Methods: The kit contains all reagents in a ready-to-use format and is suitable for automation. Sucrose is cleaved by β-fructosidase. The resulting D-glucose from sucrose and glucose originally in the sample are phosphorylated and react in a NADH-generating reaction afterwards. β-Fructosidase is not present in the glucose system. The amount NADH produced is equivalent to the amounts of sucrose and D-glucose and is measured at 340 nm within 30 minutes.

Results: The linear measurement range for 100 µL test volume is from 17 mg/L to 2500 mg/L sucrose and 4 mg/L to 2000 mg/L D-glucose. Trueness was checked by using four CRMs and resulted in recoveries from 96% to 105%. Spiking of juices, ice cream, sweetened condensed milk, and shandy resulted in recoveries between 98% and 106% for both systems. Intermediate precision was at 3% or lower for sucrose and glucose.For automation, three applications with different test volumes were validated. Linearity is given from 3.8 mg/L to 9500 mg/L for sucrose and 2.4 mg/L up to 10000 mg/L for glucose.

Conclusions: The method is robust and accurate for manual and automated applications. The method was approved as AOAC Official Method of Analysis℠.

Highlights: The ready-to-use components of the test kit have a shelf of at least 29 months.