In recent years, quercetin has become one of the best-known flavonoids in the world of dietary supplements. Found naturally in numerous plant-based foods, it is a substance that continues to attract interest due to its botanical origin and the role it plays within the plant kingdom.
But what do we really know about quercetin?
Behind this name lies a story of biodiversity, plant extracts and formulation choices.
1. Quercetin is a substance produced naturally by plants
Quercetin belongs to the flavonoid family, a very broad group of phytochemicals naturally produced by plants.
These natural organic substances are present in numerous species, where they contribute to the plant’s strategies for adapting to the external environment.
2. The name quercetin derives from the oak
An interesting fact concerns the very origin of its name.
The term ‘quercetin’ derives from the Latin *Quercus*, meaning oak. The compound was in fact first identified whilst studying certain species belonging to this botanical genus.
Today we know that quercetin is not only found in oaks, but in numerous plant species belonging to different botanical families.
Its distribution throughout the plant kingdom is, in fact, very widespread: it is found in fruit, vegetables, leaves, seeds and other parts of the plant.
3. The amount of quercetin in foods can vary considerably
Quercetin is naturally present in many foods that form part of our traditional diet.
The main sources include: capers, onions (especially red ones), apples, red grapes, citrus fruits, berries, broccoli, celery, radicchio and green tea.
Among commonly consumed foods, capers are considered one of the naturally richest sources of quercetin.
However, the content of this flavonoid is not fixed: it can vary depending on the plant species, variety, growing conditions, exposure to light, degree of ripeness, and methods of storage and preparation.
This variability is a characteristic of many compounds found in plant-based foods.
4. Quercetin is concentrated mainly in the outer parts of the plant
Many natural organic compounds produced by plants are found in greater quantities in the parts most exposed to the environment, such as skins and leaves.
This is because these areas form the interface between the plant and the outside world. For this reason, whenever possible and in accordance with good food safety practices, choosing whole vegetables can help to enhance the overall nutritional profile of food.
A varied and balanced diet, rich in fruit and vegetables, naturally provides numerous compounds characteristic of the plant world, including flavonoids such as quercetin.
5. In supplements, quercetin is obtained from selected plant extracts
The presence of quercetin in food represents its most natural link to our diet, but in food supplements it is used via a different route.
Quercetin intended for use in supplements is generally obtained from selected plant-based raw materials that undergo extraction and standardisation processes.
This makes it possible to produce formulations in which the amount of quercetin is defined and clearly stated on the label.
The difference between diet and supplementation does not lie in the nature of the molecule, but in the way it is consumed: food naturally provides a variety of plant-based substances, whilst a supplement allows for the intake of a precise amount of a specific ingredient.
6. The botanical source of quercetin may vary: Dimorphandra mollis and Sophora japonica
A little-known fact concerns the botanical origin of the quercetin used in supplements.
The quercetin molecule is the same, but the plant from which it is obtained may differ.
Among the best-known plant sources is Sophora japonica, now botanically classified as Styphnolobium japonicum, a species belonging to the Fabaceae family traditionally used as a plant-based raw material rich in flavonoids, including rutin and quercetin.
Another plant source used to obtain quercetin is Dimorphandra mollis, a plant native to Brazil which also belongs to the Fabaceae family.
The distinctive feature of Dimorphandra mollis lies in its natural quercetin content, found mainly in the fruits, which can be used as a source for extracts intended for the formulation of food supplements.
The choice of plant species is therefore a key factor in the development of a supplement: it is not just a question of which ingredient is used, but also of its botanical origin and the process involved in turning the plant into an extract.
In the case of the Erbamea Quercetin supplement, the formulation uses quercetin derived from Dimorphandra mollis and provides 200 mg of quercetin in each vegetable capsule.
Quercetin: from natural source to high-quality supplement
Quercetin is a flavonoid found naturally in numerous plant-based foods.
The journey from plant to supplement involves botanical selection, extraction and standardisation – factors that help to define the characteristics of a formulation.
A varied and balanced diet remains the foundation for naturally obtaining a wide range of plant compounds. Dietary supplements can be a practical choice for those wishing to incorporate a specific intake of selected ingredients into their daily routine.
For this reason, when choosing a quercetin supplement, it is important to consider not only the name of the ingredient, but also the quality of the raw material, the transparency of the formulation and the characteristics that make each product unique.
Dr Andrea Cima – Pharmacist and R&D Specialist – Erbamea
