A Comparative Study on Sugar Content in Sugar-Free Fruit Juices Using Volumetric and Instrumental Methods

Abstract:

Sugar-free fruit juices are increasingly consumed as healthier alternatives to conventional beverages due to rising concerns over excessive sugar intake and associated health risks. However, the presence of naturally occurring sugars in such products necessitates scientific evaluation to verify labeling claims. The present study aims to determine the sugar content in commercially available sugar-free fruit juices using both classical volumetric and instrumental methods. Fehling’s titration based on the Lane–Eynon principle was employed for the estimation of reducing sugars, while UV–Visible spectrophotometry was used for quantitative analysis through calibration curves. In addition, physicochemical parameters such as viscosity and pH were measured to understand their relationship with sugar concentration and beverage quality. The results are expected to reveal the presence of detectable levels of reducing sugars even in sugar-free labeled juices, primarily due to natural sources. Comparative analysis indicates that spectrophotometric methods offer higher sensitivity and precision, whereas volumetric methods remain simple and cost-effective for routine analysis. The study highlights the importance of analytical validation of sugar-free claims and demonstrates the applicability of accessible laboratory techniques in food quality assessment.