o-Quinone trapping by flavonols

Area of Science:

• Food Chemistry
• Organic Chemistry
• Biochemistry

Background:

• o-Quinones are reactive carbonyls found in foods.
• Flavonols are natural compounds with potential antioxidant properties.
• Understanding flavonol-quinone interactions is crucial for food safety and quality.

Purpose of the Study:

• To investigate the reaction between flavonols (quercetin, kaempferol, morin) and catechol-derived o-quinones.
• To determine the ability of flavonols to trap and remove reactive carbonyls in food systems.
• To characterize the reaction products and identify factors influencing their formation.

Main Methods:

• Reaction of selected flavonols with catechol and 4-methylcatechol.
• Isolation and structural elucidation of reaction products using NMR and Mass Spectrometry.
• Quantification of adducts and dimers in laboratory and commercially fried onions using LC-MS/MS.

Main Results:

• Flavonols reacted with o-quinones, forming adducts via C2 addition, leading to C-ring opening.
• Flavonol dimerization occurred when an o-diphenol group was present.
• Adduct and dimer formation in fried onions depended on heating, pH, and antioxidants.

Conclusions:

• Flavonols effectively trap o-quinones, contributing to the reduction of reactive carbonyls in food.
• The reaction pathway involves C-ring opening and potential dimerization.
• Reaction conditions significantly impact the extent of adduct and dimer formation in processed foods.