Current methods for lactose measurement in dairy products are time consuming and tedious and may require expensive equipment and skilled technicians. The aim of this research was to develop a novel and rapid method for the routine measurement of lactose in dairy products. The proposed method is based on the rapid hydrolysis of lactose using β-galactosidase and subsequently measuring glucose using a blood glucose meter. Blood glucose meters were developed after decades of research and clinical trials and are used extensively worldwide by individuals with diabetes to monitor their blood glucose levels. The method was developed and validated in a series of experiments. In the first experiment, temperature and time required for the near-complete hydrolysis of lactose were determined. Subsequently, the influence of glucose meters and their test strip lots were evaluated. We found that meters were not significantly different. However, the test strip lots were significantly different from each other. In the second experiment, the proposed method was validated using different concentrations of lactose solutions (1.9-6.5%) and compared with a HPLC-based reference method. In the third experiment, the proposed method was used to determine the lactose content of raw milk. The proposed method shows potential for rapid, routine, and low-cost measurement of lactose in milk and other dairy products.
Bibliographical noteFunding Information:
We thank Midwest Dairy Association (St. Paul, MN), and Dairy Management Inc. (Rosemont, IL) as administered by Dairy Research Institute for their financial support. We are also thankful to Ruplal Choudhary (Southern Illinois University, Carbondale) and Kartik Shah (South Dakota State University, Brookings) for their help in the HPLC analysis of samples.
Copyright 2012 Elsevier B.V., All rights reserved.
- Blood glucose meter
- Rapid method