Author:

Keywords:

Science & Technology, Life Sciences & Biomedicine, Food Science & Technology, UAE, mass-volume ratio, solvent composition, bioactive compounds, PHENOLIC-COMPOUNDS, ANTIOXIDANT ACTIVITY, BIOACTIVE COMPOUNDS, FISH-OIL, FOOD, PHLORHIZIN, PHLORETIN, MICROWAVE, OPTIMIZATION, LEAVES, mass–volume ratio, 0908 Food Sciences, 3006 Food sciences, 3106 Industrial biotechnology

Abstract:

This study focused on the extraction of polyphenols from applewood using ultrasonic-assisted extraction (UAE). First, the influence of solvent composition and mass–volume (m:v) ratio on the extraction yield was studied at a lab scale (200 mL). Overall, a ratio of 1:33 (m:v) resulted in a higher yield of polyphenols. Furthermore, both a higher yield of polyphenols and higher antioxidant capacity were detected in the extracts produced in the presence of a 30 v/v % ethanol mixture compared to pure water; a further increase in ethanol did not improve the extraction yield. Second, under the optimal conditions (30 v/v % ethanol–water; 1:33 and 1:20 (m:v)), the UAE technique was applied at a pilot scale (100 L). At 1:33 (m:v), the polyphenol yield was lower at the pilot scale compared to the lab scale; by contrast, at 1:20 (m:v), production at the pilot scale resulted in a higher yield compared to the lab scale. To identify and quantify individual polyphenols, HPLC-PDA analyses were performed. Phloridzin appears to be the major identified compound. Finally, the UAE process was compared to a conventional solid–liquid extraction technique, showing that a significantly higher yield could be obtained with UAE.