[Chemistry Class Notes] on Anthocyanins Pdf for Exam

Anthocyanin Definition

Anthocyanins are also known as Anthocyanins. These are water-soluble pigments present in plants, especially in fruits and vegetables. The red, blue, purple, pigments in fruits, vegetables and tubers are due to Anthocyanins. These pigments belonging to the phenol group are in glycosylated forms. When it comes to anthocyanin meaning, the word ‘Anthocyanins’ came from the combination of ‘Anthos’ and ‘Kyanous’. The former implies flowers whereas the latter signifies dark blue colour.   

Most of the red, blue, purple flowers contain Anthocyanins. For example, red hibiscus, red roses, pink blossom, blue rosemary, blue chicory, purple sage, purple mint, lavender are edible. Some of these are commonly used as food, colourants and as folk medicine too.

What Is Anthocyanin?

Anthocyanin is a sub-division of phenolic phytochemicals. It is mostly found in the fruits and flowers, particularly their epidermal tissues’ vacuolar sap. Since Anthocyanin is available as a glycoside, you can call it as a glycone. They are a subclass of flavonoids. Thus, they are polyphenols which give the unique colour of the plants or parts of the plants. Apart from normal anthocyanins, Acylated Anthocyanins are also present in plants.   

Properties of Anthocyanins

They are responsible for the red, blue or purple colours of vegetable petals, cereals like eggplants, onions, black rice, berries. Along with carotenoids, the autumn leaf colour is partially dependent on the presence of anthocyanins.

Based on their anthocyanin chemistry, they can be classified into two groups, flavonoids and phenolics. These plant pigments are soluble in water.

It has been used as an appetite stimulant, choleric agent and to prevent other diseases as well. Since this is a bioactive component, the bioavailability is the crucial factor for maintaining good health and healing several illnesses.

Source of Anthocyanins

The fruits, vegetables, grains containing anthocyanins are delicious as well as nutritious. Some of the foods that contain Anthocyanins in high amounts are blackberries, purple asparagus, concord grapes, pomegranates, eggplant, raspberries, purple corn, red cabbage, black rice. Still, Anthocyanins are present in fruits and vegetables; they are available in compound forms, not independently. And it is found that the effects are much better when they are consumed in combination with other compounds rather than in isolation. More research is still required to explore different aspects of Anthocyanins.

Uses of Anthocyanins

Anthocyanins have a vast area of applications.

• The red, blue or purple pigments extracted from the plants are widely used as dye or food colourant. For instance, Anthocyanin extracted from grape skin is heavily used for adding attractive colours to fruit jams, beverages, or confectionaries.

• Several anthocyanin-rich flowers and fruits are used as medicines for treating different ailments. They possess various properties like anti-microbial, anti-cancer, anti-inflammatory, anti-diabetic, as well as anti-obesity. They are also highly effective for the prevention of cardiovascular disease (CVDs). Hence Anthocyanins are potential pharmaceutical ingredients having great medicinal values.

• Since people are now concerned about the toxic effects of synthetic food pigment, the demand for plant-based colourants like Anthocyanins is increasing rapidly in the food industry.  

The Basic Anthocyanin Structure and Anthocyanin Formula

(Image to be added soon)

This picture depicts the structure of anthocyanins. 

The structure of anthocyanin has come from flavylium ion and its basic formula is C15H11O+..  

Therapeutic Effects

Anthocyanins are known for their therapeutic effects in different diseases.

Anticancer: Anthocyanins have been studied extensively for treating cancer as well as antiangiogenesis. Antiangiogenesis is a method that stops new blood cell formation that sends oxygen to the tumour cells. It helps in developing cancerous cells. The study for particularly these diseases is based on models of animals along with in-vitro and cell structure. 

Anti-diabetic: Anthocyanins are widely used for treating diabetes as in many research, it is seen that anthocyanin-rich Cornus fruits work fantastic in diabetes treatment. For this reason, consumption of Cornus fruits has been prescribed in traditional diabetes treatment in China since ancient times. In studies, noticeable improvement has been seen due to the consumption of anthocyanin-rich fruits for eight weeks at one go.

Anti-obesity: Anthocyanins have potential to fight against obesity. According to a study, the inclusion of purple corn in a regular diet for 12 weeks helps to reduce body weight as well as the weight of white and brown adipose tissues also decreases.