SPECTROSCOPIC DETERMINATION OF ACID AND SUGAR CONTENT IN FRUIT JUICE

摘要

We conducted the fundamental studies to understand the ultraviolet (UV), visible (VIS), near-infrared (NIR), mid-infrared (MIR) and fluorescent spectroscopic characteristics of acid and sugar component in fruit juice. Satsuma mandarin (orange; Citrus unshu) juice obtained after reaming and filtration was used as the test fruit juice. In addition, we selected citric acid as the typical acid and fructose, glucose and sucrose as the important sugar components. Consequently, it was suggested that the modification of MIR spectroscopy or the NIR application based on the MIR spectroscopic analysis could contribute the acid and sugar quantification.