Separation of proanthocyanidin from red sorghum seed extract using macroporous resin

Abstract

Abstract Proanthocyanidin has been extracted from red sorghum seed with Ultrasound-Assisted Extraction using an aqueous-based solvent. Proanthocyanidin concentration in the extract is relatively low mixing with other compounds. The adsorption method was chosen to separate proanthocyanidin compounds due to the relatively simple operation to recover targeted solutes from low concentration solutions. The purpose of this study was to find an efficient adsorbent for separating proanthocyanidin from red sorghum seed extract. Two types of macropore resin were investigated, namely macropore resin AB-8 and D101. Besides the slight difference in average pores diameter, D101 is non-polar while AB-08 is weak polar resin. The initial concentration of proanthocyanidin compounds in the extract was 0.872 mg/ml. Adsorption processes were performed to reach equilibrium. AB-8 and D101 macropore resins showed adsorption capacity of 34.65 mg/g and 30.36 mg/g with the percent recovery of 79.64% and 69.79%, respectively. Macropore resin AB-8 offers a higher adsorption capacity than macropore resin D101. Additionally, adsorption with AB-8 could reach equilibrium after 24 hours, while D101 took significantly longer to reach equilibrium after 48 hours. While both AB-8 and D101 macropore resins demonstrated reasonable performance as potential adsorbents for recovering proanthocyanidin from red sorghum extract, AB-8 showed better performance in terms of capacity and adsorption rate.