Flavonoids and other phenolics in herbs commonly used in Norwegian commercial kitchens

Significant quantities of several important herbs are processed and consumed from Norwegian commercial kitchens annually although surprisingly the contents of polyphenols have been scarcely characterized. We here report on the qualitative and quantitative content of polyphenolic compounds from ten of the most utilized herbs. From parsley (Petroselinum crispum) var. Darki, isorhamnetin 3-(6″-malonylglucoside)-7-glucoside (2) and diosmetin 7-(2″-apiosyl-6″-malonylglucoside) (8) are reported for the first time, in addition to seven known flavonoids, some of which are reported for the first time from this plant species. Oregano, rosemary and thyme contained the highest amounts of total phenolics with maximum levels of 23.8, 24.2 and 23.4 mg GAE g^-1 dry matter, respectively. Fresh herbs contained significantly higher quantities of phenolics than processed, dried herbs. Parsley, coriander, dill and thyme were the richest sources of flavonoids among the investigated herbs.