RSM- and ANN-Based Optimization of Bioactive Anthocyanin and Phenolic Compound Recovery from Rosa damascena Flowers...

The present study investigated the use of natural deep eutectic solvents (NaDESs) combined with ultrasound-assisted extraction (UAE) for the efficient recovery of anthocyanins and antioxidant phenolics from Damask rose (DR). A wide range of environmentally friendly solvents was screened, and choline chloride-propylene glycol (ChCl-PG) was identified as the most effective extraction medium. The extraction conditions were optimized using response surface methodology (RSM) and artificial neural network (ANN) models to maximize anthocyanin and phenolic contents, as well as antioxidant activity. Under the optimal parameters, the DR extracts exhibited relatively high levels of bioactive compounds, including total anthocyanin content of 5.2-5.3 mg cyanidin-3-glucoside equivalents g^-1 sample, total phenolic content of 63.4-64.2 mg gallic acid equivalents g^-1 sample, along with substantial antioxidant potential (DPPH: 68.2-68.8% inhibition, FRAP: 581.6-591.9 μmol Trolox equivalents g^-1 sample). Chromatographic analysis of the optimum extract revealed cyanidin as the predominant anthocyanidin in DR, and its stability was further evaluated, revealing improved preservation under dark conditions at lower temperatures over a 15-day storage period. Moreover, the IC₅₀ values confirmed antimicrobial effects against the tested foodborne pathogens. Furthermore, the inhibitory effect of the DR extract remained stable against S. aureus and S. cerevisiae throughout the storage period. Overall, the findings demonstrate that NaDES-UAE is a promising and sustainable approach for obtaining anthocyanin-rich DR extracts with antioxidant and antimicrobial potential.