Optimization of Extraction Process and Component Analysis of Oleoresin from Smoked Amomum tsaoko by Response Surface Methodology

In order to obtain the best extraction process of smoked Amomum tsaoko(SDAT) oleoresin, the extraction solvent, extraction temperature, solid-liquid ratio, extraction time and particle size were regarded as the influence factors. On the basis of single factor experiment, the eexperimental design of three factors and three levels was used by Box-Benhnken central composite method, according to the extraction rate of SDAT oleoresin as the response value, and the extraction conditions were further optimized by response surface methodology(RSM). The results showed that the optimum process conditions of SDAT oleoresin was as follows: Anhydrous methanol as solvent, extraction temperature was 75 ℃, solid-liquidratio was 1:20(g/mL), extraction time was 7 h and particle size was 80 mesh. The regression equation predicted that the theoretical extraction rate of SDAT could reach 9.57%, the average extraction rate of the three validation experiments was 9.48%, and the predicted value was close to the actual result. And 58 compounds were identified by GC-TOF-MS, including alcohols(31.59%), aldehydes(21.13%), alkenes(1.23%), ketones(1.56%), esters(2.38%) and phenols(0.79%), 1,8-eucalyptol(9.28%), α-terpineol(3.55%), gera-niol(8.4%), trans citral(5.78%), 2-methyl-3-ph-enylpropanal(6.33%), etc. Through the determination of the best process of SDAT oleoresin, the detected components are mainly concentrated in alcohols and aldehydes, which provides a theoretical basis for the nutritional components and biological activity of grass fruit oleoresin in the later stage.