Process for Purification of Litchi γ-Aminobutyric Acid

ZHOU Junping; XU Yujuan; WU Jijun; DU Bing; YIN Xiaomeng; WANG Jin; LI Chuyuan; CHAO Yexuan; YU Yuanshan; WENG Shaoquan; BU Zhibin; WEN Jing

doi:10.13982/j.mfst.1673-9078.2025.8.0474

Abstract：High-purity litchi γ-aminobutyric acid(GABA)was prepared via separation and refinement through sequential alcohol precipitation,resin column chromatography,and crystallization.Through a static adsorption experiment,the 732 cation exchange resin was screened from nine different types of resins,where its adsorption and desorption rates reached 81.56%and 88.26%,respectively.Evaluation of the static adsorption kinetics indicated that adsorption on the resin was primarily controlled by liquid-film diffusion,and was also influenced by the combined effects of multiple diffusion processes,such as intraparticle diffusion and adsorption-desorption on the internal surfaces of the particles.A dynamic elution experiment revealed that the highest raw material utilization rate was achieved at a sample loading of 8.25 mg/g.By taking the purification efficiency and cost into comprehensive consideration,the optimal elution conditions were determined as follows:sample concentration:1.0 mg/mL,sample loading flow rate:1.0 mL/min,sample pH value:4,eluent concentration:1.5 mol/L,elution flow rate:1.0 mL/min.Under these optimized conditions,the purity and yield of the obtained litchi GABA were 77.40%and 92.05%,respectively.By crystallization from the purified sample solution,the purity increased to 95.35%,and the structure of the obtained crystal was identified as GABA through nuclear magnetic resonance analysis.In conclusion,the present study demonstrated that a combination of alcohol precipitation,ion exchange column chromatography,and crystallization processes enabled the recovery of GABA from litchi at a purity of>95%.The results of this study can serve as a valuable technical reference for the development and utilization of litchi GABA.