Determination of Edible Sugar in Fruit Juice Using Evaporative Light Scattering Detector and BEH Amide Column

Mark E. Benvenuti and Jennifer Burgess

purpose

The sugar content of various juices was successfully determined in a cost-effective manner by a simple sample preparation in a short analysis time.

background

In recent years, studies have shown that sugary soft drinks are associated with obesity, coronary heart disease and type 2 diabetes. Therefore, the use of pure juice instead of sugary soft drinks is highly recommended. In addition, it has been reported that certain juices such as pomegranate juice are beneficial to health due to the presence of antioxidants, resulting in higher prices for such products.

To ensure product quality and compliance with regulatory requirements, the juice industry must test products to meet specific standards. One of the indicators is the sugar content. Fructose, sucrose and glucose are important analytes in juice analysis. Their content and relative ratio are different and can be used as markers to identify different varieties.

HPLC combined with evaporative light scattering (ELS) detectors has long been recognized as an effective technique for performing such analyses. Amino columns have long been used for sugar separation. However, this may result in the formation of a Schiff base, resulting in a shortened column life and inaccurate sugar quantitation.

The use of reliable XBridge ™ BEH Amide column binding proven Alliance ^® HPLC system technology, five kinds of sugar consumption and rapid quantitative analysis.

The Waters ^® patented amido column prevents the formation of Schiff bases and eliminates these problems. This study demonstrates the versatility of the Waters XBridge BEH Amide XP column for sugar analysis.

solution

Various juices are purchased in the local market. Sample preparation only requires: these juice samples are centrifuged at high speed to remove pulp and other insoluble materials. A portion of the supernatant of each juice was taken and diluted with a 1:50 water/acetonitrile mixture.

Analysis was performed using an Alliance HPLC system equipped with a 2424 evaporative light scattering detector. Since the target analyte has no chromophore, it is not suitable for UV and fluorescence detection, and a more suitable ELS detection is used. Gradient elution can be performed to separate related compounds such as other sugars, sugar alcohols (sorbitol), and high carbon oligomers. The column used was an XBridge BEH Amide XP 4.6 x 100 mm, 2.5 μm column. The binary mobile phase used for the gradient elution consisted of water and acetonitrile with triethylamine (TEA) as the modifier. A standard curve of six points was established using a dilution of the sugar mixed stock solution to quantify the sample. Figure 2 shows the separation of four edible sugars and sorbitol, a sugar alcohol that can be used as a marker for non-conforming products in certain varieties. The analysis results of various juices are shown in Figure 3. It is worth noting that apple juice contains traces of sorbitol.

to sum up

The sugar analysis in the juice can be done in less than 7.5 minutes using the XBridge BEH Amide column. Accurate quantitative analysis of sugar in juice using the proven XBridge BEH Amide XP column with reference to this method. The proven Alliance HPLC system technology accurately quantifies sugar in juice for accurate solvent delivery and Repeated injection performance and the ability to create non-linear gradients and perform simple ELS inspections meets the goals of simplified sample preparation, reduced analysis time and cost-effectiveness.