You can see polyphenols in these beautiful black barley grains. These dark grains are packed with anthocyanins – coloured water-soluble pigments – and are one of the phytochemicals referred to as polyphenols. These are naturally occurring compounds that are what give plants their colours and help to protect them from various stresses that they might face in nature, such as high levels of sunlight. Many research studies suggest that consuming these plant phytochemicals, including polyphenols, are good for you as they are antioxidants.
Types of polyphenols
Polyphenols are divided into four different categories based on the presence of a number of phenolic groups and structural elements and in grains that contain complex polyphenols, they are predominantly found in the outer layers of the plants, which is why milling the wholegrain is important. There are actually 4 different categories of polyphenols in food:
- Flavonoids: these have a potential effect on radical scavenging and inflammatory reactions. They are predominantly found in fruits, vegetables, legumes, red wine, and green tea. They are further divided into a number of subgroups namely, flavones, flavonols, flavanones, isoflavones, anthocyanidins, chalcones, and catechins.
- Stilbenes: found in grapes, red wine, and peanuts. Resveratrol is the most well-known compound among the group.
- Lignans: found in seeds like flax, linseed, grains, fruits, legumes, cereals, algae, and certain vegetables.
- Phenolic acids: found in kiwis, plums, apples, coffee, tea, cinnamon, blueberries, and cherries and have two subgroups, namely hydroxybenzoic acids, and hydroxycinnamic acids.