Separation of Oleoresin from Ginger Rhizome Powder Using Green Processing Technologies

Ginger oleoresin is an important condiment in food and pharmaceutical industries because of its antioxidant and polyphenolic compounds. The effects of various extraction methods on yield parameters were presented in this article. The ultrasound treatment showed its potential to increase oleoresin extraction rate. The ultrasound‐assisted supercritical carbon dioxide extraction was found to be the best method of extraction with the highest oleoresin yield of 8.15 ± 0.06% at 35°C temperature and 25 MPa pressure. The supercritical carbon dioxide extraction had 6.87% oleoresin yield at 25 MPa pressure, 40°C and 15 g/min CO₂flow rate. The signal‐to‐noise ratio showed that pressure and temperature had significant effect on the oleoresin yield, but their effect on flow rate was not significant. The ultrasound‐assisted solvent extraction was 1.75 times faster than simple soxhlet extraction. PRACTICAL APPLICATIONS: Supercritical carbon dioxide extraction is an environment‐friendly technology that separates pure compound from natural resource. Limitations of the solvent extraction method and steam distillation, such as residual organic solvent in product and degradation of thermally liable compounds, respectively, are major factors toward supercritical carbon dioxide extraction method gaining much attention in the food, cosmetic and pharmaceutical sectors. Ginger consists of specific oleoresin because of the presence of phenolic compounds. It has significant use in some foods and medicines as well. Hence, the optimization of the process to separate this oleoresin is an uphill task because of lack of literature. The orthogonal array design is a tool to reduce the number of experiments, and can become a useful tool in optimizing the experiment. This reduces the time of the experimentation, the cost on research, while obtaining better results. In this regard, the study was conducted to extract ginger oleoresin using supercritical carbon dioxide and orthogonal array design.