This study aims to quantify anthocyanins in castor bean plants using UV/Vis spectroscopy. Four extraction methods are compared: 1) using varying ethanol/HCl solutions adjusted to pH 1, 2) adjusting solutions to pH 1 and 4.5 before and after shaking and centrifuging, 3) preparing methanol/HCl solutions and extracting over multiple shakes, and 4) using a commercial INA method. Castor bean leaves and stems were collected, freeze-dried, and ground before anthocyanins were extracted and concentrations measured via spectroscopy. The optimal method will be determined for quantifying anthocyanins and evaluating chemical defense strategies in castor beans.