Hibiscus sabdariffa, is an annual herb or perennial shrub of Malvaceae, growing in tropical and subtropical regions. Hibiscus sabdariffa originated in West Africa and India, distributed in tropical and subtropical areas. It is said that it originated in India, introduced into Britain in 1596. It was used as a condiment in the 18th century. Later, some people introduced this varieties from Hawaii and the Philippines and successfully planted in Taiwan and continued to propagate. Nowadays Hibiscus sabdariffa extract is distributed in Guangdong, Guangxi, Fujian and Yunnan in China and widely produced. It has dual properties of edible and medicinal and plays an important role in today's domestic and international markets.

What are polyphenols

Vegetable tannins, also known as plant polyphenols, are a kind of polyphenol compounds widely existing in plants. The content of plant tannins is only inferior to cellulose, hemicellulose and lignin in vascular plants. It is widely distributed in the skin, root, leaf and fruit of plants, with the content up to 20%. Plant tannin is a secondary metabolite of plants, which belongs to natural organic compounds. Polyphenols are compounds found in plant foods and have potential health promoting effects. It is found in some common plant foods, such as cocoa beans, popcorn, tea, soybeans, red wine, vegetables and fruits.

Effect of polyphenols:

Oxidative damage is an important cause of many chronic diseases, such as cardiovascular disease, cancer and aging. The antioxidant function of polyphenols can prevent these chronic diseases. Polyphenols in chocolate are powerful antioxidants, it can inhibit LD sterol oxidation. LD cholesterol, namely "bad cholesterol" is the "impurity" in blood, it can cause arteriosclerosis, coronary heart disease and myocardial infarction and other diseases. Polyphenols can also prolong the working time of other antioxidants in human body, such as vitamin E and vitamin C, promote vasodilation, reduce inflammatory reaction and blood clot formation, so as to prevent cardiovascular disease.

In addition to antioxidant effect of polyphenols in Hibiscus sabdariffa extract, researchers found that the intake of polyphenols while eating high-fat food can reduce the threat of high-fat food to human health. Although polyphenols are widely distributed in plant-based foods, their content and structure vary greatly in different foods. Moreover, the content of polyphenols in plants is affected by many factors, such as maturity, variety, processing and storage conditions.