Optimization of experimental conditions for bioactive compounds recovery from raspberry fruits (Rubus idaeus L.) by using combinations of ultrasound-assisted extraction and deep eutectic solvents

Raspberry fruits (Rubus idaeus L.) have been reported to contain phenolic compounds, of which anthocyanins are the most abundant. A novel procedure of ultrasound-assisted extraction (UAE) using deep eutectic solvent (DES) for efficient extraction phenolic compounds and anthocyanins from raspberries is considered. Namely, the green approach for optimization by response surface methodology (RSM) based on Box-Behnken Design (BBD) was proposed in this study. Three carboxylic acid-based DES, like acetic acid/glucose (DESAAGLU), formic acid/glucose (DESFAGLU), and lactic acid/maltose (DESLAMA), were tested for their efficiency in the recovery of phenolic compounds and anthocyanins from raspberries. The optimum extraction parameters were obtained; extraction time of 60 min, a solvent volume of 35 mL, and added water on DES of 30 mL (v/v). The results of this study indicated that optimizing extraction conditions are critical for quantifying phenolic compounds and anthocyanins. The present model can contribute to finding a cheap way of delivering natural bioactive compounds in the food, cosmetic, and pharmaceutical industriesas well as a natural food colorant in dietary applications with potential health benefits.