Penetapan Kadar Glukosa Total Hasil Hidrolisis Limbah Air Kelapa Tua (Cocos Nucifera L.) Secara Spektrofotometri UV-Vis

Abstrak

This study was conducted to identify and quantify the glucose content present in waste from old coconut water (Cocos nucifera L.) employing the phenol–sulfuric acid method analyzed by UV–Vis spectrophotometry. Prior to measurement, the sample underwent hydrolysis using 3% HCl, followed by neutralization and clarification. Qualitative analysis was carried out with Fehling’s reagent, whereas quantitative determination was performed at a wavelength of 490 nm using glucose standard solutions within the concentration range of 0.01–0.05 mg/mL. The resulting calibration curve demonstrated a strong linear correlation, described by the regression equation ŷ = 9.25x + 0.3587 with a correlation coefficient (r) of 0.9794. The glucose level in the old coconut water waste was determined to be 2.11% ± 0.015% (w/v). These findings suggest that the phenol–sulfuric acid method offers adequate sensitivity and accuracy, making it appropriate for glucose determination in old coconut water waste samples.