Optimization of Eleutherine palmifolia (L.) merr enfleurage extraction using response surface methodology for flavonoid obtaining as a bioactive of edible film

The important content of bioactive compounds for edible films is flavonoids. Most flavonoid extraction is done through maceration, which requires the expensive solvents and a long processing time. The modified enfleurage method in this research outperformed maceration, which had been proven to extract flavonoids from Eleutherine palmifolia (L.) Merr or Dayak onions with optimal results. The enfleurage method involved mixing Dayak onion powder with white butter in a chassis, followed by dissolution, filtration, and vacuum evaporation. Enfleurage optimization of Dayak onions was carried out using the Response Surface Methodology (RSM), which utilized the Central Composite Design (CCD) with 2 process parameters, 5 code levels, and 5 center points. The process parameters are the ratio of fat to Dayak onions, and the enfleurage time. The optimization results showed that there was a significant effect of both process parameters on the response variable, and its effect followed a second-order polynomial. The optimum process conditions for flavonoids were at a ratio of fat to Dayak onions of 3.39:1 for 0.79 days, the results were 174.70 mg QE/g sample. Under optimum conditions, an antioxidant activity value of 13.34 ppm (very strong) and a total phenolic content of 142.92 mg GAE/g sample were also obtained. The presence of flavonoids and other bioactive compounds in the extract was proven through GC-MS, FTIR, and qualitative analysis. The extract produced is suitable for making edible films because it has been proven to increase physical and mechanical properties, and extend the shelf life of edible films for 3.5 months.