CENTRAL COMPOSITE DESIGN FOR OPTIMIZING EXTRACTION OF EGCG FROM GREEN TEA LEAF (CAMELLIA SINENSIS L.)

Objective: This study was intended to optimize the extraction condition using central composite design.Methods: Central composite cesign with three independent variables, namely water temperature, brewing time, and brewing number were used to obtain the optimum extraction condition. Two dependent variables, namely yield of extraction and epigallocatechingallate level were used as a response parameter. Epigallocatechin gallate level was determined by using high-performance liquid chromatography method.Results: Extraction yield was varied from 0.30 g to 0.72 g. All variables, namely water temperature, brewing time, and brewing number were able to increase the extraction yield. Epigallocatechingallate level was varied from 190.23 mg/g to 301.74 mg/g. Water temperature, brewing time, and both interaction were able to increase the epigallocatechin gallate level in green tea extract.Conclusion: Optimum extraction condition was shown using hot water at a temperature of 95 °C for 20 min and two-times infusions. The condition obtained extraction yield and epigallocatechingallate of 0.70 g and 286.87 mg/g dry weight, respectively.

Studied on the extraction, response surface analysis and antioxidant activity of flavonoids in the Momordia cochinchinensis seeds

This text was mainly studied the extraction flavonoids technology from Momordia cochinchinensis seeds. The optimum extraction condition was as follows: when the ratio of liquid to solid was 20:1, the ethanol concentration was 90% and the extraction time was 2h. Under this condition, the actual average yield of flavonoids could reach 0.363%.

Investigation on the Extraction of Aluminum and Iron from Fly Ash by Sodium Carbonate Fusion Method

In recent years, utilization of fly ash has gained much attention in public and industry, which will help reduce the environmental burden and enhance economic benefit. In the utilizations of fly ash, the most high value-added applications is extraction of metal elements from fly ash. In this paper, the aluminum and iron extraction was investigated by orthogonal experiments. The results show that the optimum extraction condition was reaction temperature 800 °C, reaction time 3 h, the mass ratio of fly ash to Na2CO3 was 1:1.5.

Optimization of Extraction Conditions of Essential Oil from Latifolia miq Roots and Stems with Supercritical CO2 Fluid

Studying on the extraction process of essential oil from Latifolia Miq roots and stems by Supercritical CO2 extraction. The effects on extracting ratio were investigated by using single factor test, adding content of grinding fineness of raw materials,extracting temperature, extracting pressure and extracting time. The optimum extraction condition was determined by orthogonal test. The results showed that the optimum condition of the extraction was as follows: grinding fineness 90 mesh, extracting temperature 45 °C, extracting pressure 20 MPa and extracting time 2.5 h.

Extraction of Polyethylene Residue Components in Soil

The extraction of polyethylene residue components in soil was presented in this work, where polyethylene (PE) powder (Mw=5598) was taken as a simulated polyethylene residue, and decalin was as an excellent solvent. The effects of times of reflux extraction, total extraction time and soil type on the extraction ratio were investigated, aimed at finding out the optimum extraction condition. Results show that the optimum extraction ratio achieves up to 90 % (w/w) at 100 after extraction for 20 mins thrice. Meanwhile, the times of reflux extraction has the most significant influence on extraction ratio, followed by the total extraction time. However, soil type has little influence. The FTIR spectra illustrates that the structure of PE is not destroyed during the extraction. However, the molecular weight and molecular weight distribution test show the average molecular weight of PE decreases after the extraction, which is possibly caused by the degradation of PE.

Isolation and Characterization of Rice Prolamin

Rice prolamin, constituting 10, 13 and 16 kDa polypeptides, is indigestible and may work as a kind of ‘resistant protein’. To investigate the effective method for isolation of prolamin, in this study, prolamin fractions were extracted from defatted rice flour by 70% ethanol, 55% and 60% n-propanol, 55%, 60% and 100% ethylene glycol, and 60% isopropanol, respectively. The isolated prolamin fractions were compared and characterized by yield, efficiency of extraction and SDS-PAGE patterns. Our results indicated that the optimum extraction condition for isolation of prolamin was 55% n-propanol, with 13 kDa and 16 kDa as the dominant fractions in prolamin.