Advanced characterization of polyphenols from Myrciaria jaboticaba peel and lipid protection in in vitro gastrointestinal digestion

Ultrasound-assisted and solvent extractions resulted in similar levels of hydrolyzable tannins (10.3-6.0 mg/g), anthocyanins (7.8-10.2 mg/g) and flavonols (0.24-0.32 mg/g) for dried Myrciaria jaboticaba peel (DJP). Ultrasound was efficient for the extraction of poorly soluble hydrolyzable tannins but affected the stability of anthocyanins and flavonols. UPLC-DAD-MSn allowed the identification of 44 hydrolyzable tannins as single and mixed hexosides bearing galloyl, HHDP and tergalloyl units. Twelve mixed HHDP-galloylgluconic acids and tergalloylated hexosides were newly discovered in this work. Acid hydrolysis of both ultrasonic extract and DJP yielded five major compounds, i.e. gallic acid, ellagic acid, gallic acid-C-hexoside, valoneic acid dilactone and sanguisorbic acid dilactone and pointed to higher contents in hydrolyzable tannins than by summing individual polyphenols after UPLC. Last, cyanidin-3-O-glucoside and hydrolyzable tannins from the ultrasonic extract inhibited lipid peroxidation of a Western type meal in in vitro digestion, suggesting a health benefit for these jabuticaba polyphenols.

Automated summary

Ultrasound-assisted and solvent extractions showed similar efficiency in extracting hydrolyzable tannins, anthocyanins, and flavonols from Myrciaria jaboticaba peel. UPLC-DAD-MSn identified 44 hydrolyzable tannins and discovered new compounds, with acid hydrolysis revealing higher contents of hydrolyzable tannins than individual polyphenols. Furthermore, cyanidin-3-O-glucoside and hydrolyzable tannins from the ultrasonic extract exhibited potential health benefits by inhibiting lipid peroxidation in vitro digestion.