Application of optical spectroscopy techniques in fruit juice analysis: A review

Abstract Fruit juices are widely consumed for their nutritional value and sensory appeal, but concerns regarding quality, adulteration and authenticity necessitate reliable, rapid and non-destructive analytical techniques. This review explores applications of UV-Visible spectroscopy (UV-Vis), infrared spectroscopy, fluorescence spectroscopy and Raman spectroscopy in fruit juice analysis. Literature was retrieved from Scopus, Web of Science and Google Scholar using predefined search terms. The working principles, instrumentation, and performance of these techniques are discussed, UV-Vis detection of pomegranate juice adulteration ( R 2 up to 0.99), NIR prediction of Ca (RPD = 3.92), and ATR-FTIR sugar quantification ( R 2 > 0.99). Applications include detecting and quantifying nutrients, adulterants, toxic elements and verifying quality attributes such as color, phenolic content and acidity. Integration with chemometrics and Artificial Intelligence (AI) enhances accuracy and predictive power, while miniaturization and multimodal approaches enable real-time, in-field monitoring. Despite challenges such as matrix effects and calibration complexity, optical spectroscopy shows strong potential for ensuring fruit juice safety, quality and authenticity.