Optimization of ultrasonic extraction for enhanced polyphenol profile and antioxidant capacity in mango seeds: A comparative study with thermal extraction

Abstract

The mango seed (MS) is a by-product with a high content of bioactive compounds and antioxidant capacity (AOX). Ultrasound-assisted extraction (UAE) has been recognized as an efficient technology for the extraction of bioactive compounds in plant materials. Nonetheless, it is essential to optimize the process conditions and compared with conventional technologies. The objective of this study was to compare the profile of bioactive compounds and AOX in an optimized ultrasound extract with a thermal extract. The optimized parameters for UAE included exposure to light, 1 s ultrasound pulse, 8 min extraction, 40 % amplitude, 60 °C extraction temperature, 20 % (v/v) ethanol, 35:1 (v/w) liquid-to-solid, and 850 µm particle size and showed gallic acid content of 1.97 mg/g MS. The thermal extract had a higher total soluble phenol content, mainly composed of gallates and gallotannins. Nevertheless, specific compounds, such as maclurin galloyl glucoside and quercetin xyloside, were uniquely identified in the UAE-optimized extract. DPPH and ABTS values were higher in the thermal extract. The half-maximal inhibitory concentration for the thermal treatment was 15.93 mg, while for UAE, it was 19.77 mg GAE/mL. Both thermal and ultrasound mango seed extracts exhibit significant potential as functional ingredients due to their high content of polyphenols and AOX.

Keywords

• Mango seed
• Ultrasound-assisted extraction
• Thermal extraction
• Bioactive compounds
• Antioxidant capacity