EFFECT OF STORAGE AND DOMESTIC PROCESSING ON THE CONTENT AND COMPOSITION OF FLAVONOL GLUCOSIDES IN ONION (ALLIUM-CEPA)

The stability of the major flavonol glucosides, quercetin 3,4'-O-diglu coside (QDG) and quercetin 4'-O-monoglucoside (QMG), was studied in tw o varieties of onion (Red Baron and Crossbow) that were cured and stor ed for 6 months under normal commercial conditons and analyzed at; reg ular intervals. Onions were also cooked by boiling in water and by fry ing in oil under normal domestic conditions. Apart from a 50% loss of quercetin 4'-O-monoglucoside during the initial drying process, little change in content and composition was observed over 6 months of stora ge. Neither boiling nor frying resulted in interconversion of the quer cetin conjugates or production of free quercetin, although a 25% loss overall was recorded for each process.