June 14, 2012
Drinks Containing Hibiscus Are The Highest In Antioxidants
The tea made from hibiscus flowers is known by many names in many countries around the world and is served both hot and cold. The beverage is well known for its color, tanginess and flavor. A new study conducted in Portugal found that drinks containing hibiscus exhibited higher antioxidant activity than other beverages.
It is known as bissap in West Africa, karkade in Egypt and Sudan, flor de Jamaica in Mexico, gudhal in India and gongura in Brazil. Some refer to it as roselle, a common name for the hibiscus flower.
Rita Alves and others at the Universidade do Porto analyzed 19 different drinks on the Portuguese market.
The results were published in the Food Science and Technology Journal.
Hibiscus tea is popular as a natural diuretic; it contains vitamin C and minerals, and is used traditionally as a mild medicine.
A study in
Food Research Journal showed that anthocyanins are a major source of antioxidant capacity in Hibiscus extract.
A 2008 USDA study shows consuming hibiscus tea lowers blood pressure in a group of prehypertensive and mildly hypertensive adults. Three cups of tea daily resulted in an average drop of 8.1 points in their systolic blood pressure, compared to a 1.3 point drop in the volunteers who drank the placebo beverage. Study participants with higher blood pressure readings (129 or above) had a greater response to hibiscus tea: their systolic blood pressure went down by 13.2 points. These data support the idea that drinking hibiscus tea in an amount readily incorporated into the diet may play a role in controlling blood pressure, although more research is required.
Alvez et al. compared samples for total phelonics, total flavonoids and ascorbic acid content to determine the level of antioxidant activity.
"Nowadays, new emerging products claiming antioxidant properties are becoming more frequent. However, information about this topic in their labels is usually scarce."
"In general, beverages containing green tea and hibiscus showed higher phenolic contents and antioxidant activities than those without these ingredients," said the study.
Tea Based Products
The researchers analysed two distinct categories: tea-based products and juices.
They found that a tea formulation containing aromas, hibiscus and pineapple had the highest antioxidant activity of all beverages analysed.
This recipe was the highest in phelonics and showed the strongest DPPH scavenging activity.
A borututu roots infusion was found to have the lowest antioxidant activity of the teas.
"Although borututu roots were described in the label as a phelonics-rich product, the recommended sample/volume ratio for the infusion preparation was very low," said the study.
In juices, a mixture of pomegranate juice, grape juice and carrot concentrated juice, which also contained hibiscus and green tea extract, was found to display the highest antioxidant.
Blackberry and Raspberry-based juices were seen to show among the lowest activity.
The samples used in the study were selected at random from supermarkets and herbalist shops in Portugal, with a preference for those claiming antioxidant properties. Brands of the selected products were not revealed.
Citation: Costa, A. S. G., et al., 'Teas, dietary supplements and fruit juices: A comparative study regarding antioxidant activity and bioactive compounds', LWT - Food Science and Technology (2012), doi:10.1016/j.lwt.2012.02.030
John Summerly is nutritionist, herbologist, and homeopathic practitioner. He is a leader in the natural health community and consults athletes, executives and most of all parents of children on the benefits of complementary therapies for health and prevention.