Quantification of Bioactive Compounds by HPLC-ESI-MS/MS and Evaluation of Antioxidant and Enzyme Inhibitory Activities of Acorn Flour Extracts

This study provides the first comprehensive evaluation of the bioactive potential of acorn flour extracts (Quercus robur, Fagaceae) prepared at different temperatures (20, 60, 80 and 100 °C), focusing on polyphenolic content, antioxidant properties and enzyme inhibitory activities. Through HPLC-ESI-MS/MS analysis, 36 bioactive compounds were identified, with the extract at 60 °C showing the highest concentrations of key polyphenols, notably gallic acid (210,008.9 mg·kg−1) and ellagic acid (45,469.6 mg·kg−1). This extract also exhibited a high antioxidant activity and significant inhibition of glucosidase and acetylcholinesterase, suggesting potential benefits for diabetes management and neuroprotection. The results indicate that extraction temperature affects bioactivity, with the 60 °C extract standing out as a promising candidate for nutraceutical, pharmaceutical, and cosmeceutical applications due to its rich polyphenol profile and potent biological properties.