CHARACTERISTICS OF SAPPAN WOOD (Caesalpinia sappan L.) EXTRACTION USING THE HYDRODYNAMIC CAVITATION METHOD AND ITS POTENTIAL AS AN INDICATOR FOR AMMONIA ANALYSIS

Abstract

Sappan wood (Caesalpinia sappan L.) contains phenolic compounds, such as brazilin, that can be used as colour indicators. Thebioactive ngredient of sappan wood will decrease its sensitivity as a colour indicator if it experiences oxidation due to heating, so selecting an appropriate extraction method is necessary. Extraction using hydrodynamic cavitation (HC) is considere environmentally friendly because it requires less energy, extraction process without heating, cheaper equipment, and can be easily scaled up for large-scale production. In a hydrodynamic system, cavitation is caused by a pressure drop through a narrow  gap in a closed loop. This study investigated how extraction time, airflow rate, and ethanol concentration affect HC extraction results from Sappan wood. The HC extracts were characterized using total phenolic content (TPC) measurements, Fourier Transform Infrared (FTIR), UV-Visible (UV-Vis) spectrophotometer, and  High performance liquid chromatography (HPLC). Results showed that an extraction time of 60 min, an airflow rate of 2L/min, and 60% ethanol  as the solvent yielded the best TPC result of 8.22 ± 0.07%. The FT-IR spectrum of the HC extract showed several peaks, especially at 1,029 cm-1, 1,455 cm-1, 1,603 cm-1, 2,921 cm-1, and 3,320 cm-1, which characterized phenolic compounds. The UV-VIS spectrum of the HC extract shows two maximum absorption wavelengths (λ max), recorded at 450 and 540 nm in the initial form of the extract at pH 5.25. Brazilin content in sappan wood extract by HPLC was 70.63 ± 0.76 mg/g. HC extraction yielded a higher TPC content than the maceration method. Using the HC extract as a colour indicator in ammonia analysis produced good results, with an analysis recovery rate (%R) ranging from 101 to 105%.

Keywords:
colour indicator, extraction, hydrodynamic cavitation, sappan wood