RESEARCH PUTS ROOIBOS TO THE TEST

The Rooibos Council is investing over R2million in independent research this year in an ongoing programme to find out more about the properties, applications and cultivation of Rooibos.

Six product research grants, totalling R974 705, have recently been awarded to two existing research projects, plus four new projects. These latest grants are in addition to R1,2 million already allocated to cultivation research (plant improvement, integrated pest management and organic cultivation practices). Furthermore, rooibos research has been independently undertaken and is ongoing at international universities and research organisations as far afield as Sweden, the USA, Japan, and other countries.

Of the six latest South African research grants, two existing projects that have received funding examine the cancer-preventing properties of South African herbal teas (Prof. Wentzel Gelderblom of the Medical Research Council); and objective quality parameters for rooibos (Prof. Lizette Joubert of the Agricultural Research Council).

Four new research projects examine the influence of rooibos on stress (Dr Amanda Swart of Stellenbosch University); rooibos and exercise (Prof. Jeanine Marnewick of the Cape Peninsula University of Technology); the hygienic processing of rooibos (Prof. Pieter Gouws of the University of the Western Cape); and determining what exactly is in a cup of rooibos tea (Prof. Andrew Marston, University of the Free State.)

The six grants were approved after a rigorous process beginning in June 2009, when a call for expression of interest in rooibos research was issued to South African universities and science councils, as well as to all members of the Indigenous Plant Use Forum.

Researchers were invited to submit expressions of interest in three broad research areas: The chemistry, biochemistry and bioactivity of rooibos; the health promoting properties of rooibos and its potential to prevent and/or treat lifestyle diseases; and genetic improvement of the rooibos plant to optimise its cultivation, disease and drought resistance and biochemical composition.

Nine applications were finally reviewed by the SA Rooibos Council’s Product Research Committee and board of directors, plus a panel of three independent scientists.

“There is a need to gather reliable information on the kind of scientific evidence that is required to substantiate health claims (on product packaging, as well as in advertising, advertorials and editorial copy) in different countries – for example South Africa, the EU, countries in the Far East, USA, Canada and Australia,” said Product Research director Mientjie Mouton.

“Extensive anecdotal evidence also suggests that rooibos has other beneficial effects not yet fully verified or understood by science. Future research challenges for rooibos include exploring its anti-allergic properties and immune-boosting effects, better understanding the active compounds in rooibos and exactly how they achieve their anti-cancer and anti-ageing effects, the optimal use of rooibos as part of a healthy lifestyle, additional comparative studies with other herbal teas, plus more human studies.”

Researchers have already found that rooibos can prevent or slow down cancer and promote heart health (South Africa), may help to control diabetes and its complications (Slovak Republic), could contribute to hormone replacement therapy (Japan), and be used in the treatment of stomach cramps and diarrhoea (Pakistan, Canada and Germany).

The Rooibos Council was established in April 2005 as a non-profit company to promote the interests of the South African Rooibos industry locally and internationally. It serves as a representative platform for its members consisting of producers, processors, manufacturers, as well as local marketers and exporters.

Note to editors:
The research reviews listed below provide a comprehensive overview of recent research into the potential health benefits, production and quality aspects of rooibos and related products. Research abstracts are also available on the website www.sarooibos.co.za.

1.Joubert, E. & Schulz, H., 2006. Production and quality aspects of rooibos tea and related products. A review. Journal of Applied Botany and Food Quality 80, 138-144.
2.McKay, D.L., & Blumberg, J.B., 2007. A review of the bioactivity of South African herbal teas: Rooibos (Aspalathus linearis) and Honeybush (Cyclopia intermedia). Phytotherapy Research 21, 1-16.
3.Joubert, E., Gelderblom, W.C.A., Louw, A., De Beer, D., 2008. South African herbal teas: Aspalathus linearis, Cyclopia spp. and Athrixia phylicoides: A review. Journal of Ethnopharmacology, 119, 
376-412.
4. Joubert, E., Gelderblom, W.C.A., Louw, A., De Beer, D., 2008. Phenolic contribution of South African herbal teas to a healthy diet. Natural Product Communications 4, 1-18.

 

 

NEW FLAVOUR WHEEL DISCERNS INFUSED NUANCES OF ROOIBOS TEA

South African researchers have developed a flavour and mouthfeel wheel that provides 27 descriptive attributes for Rooibos tea as a tool to facilitate communication among producers, processors, grading experts, marketers, flavour houses, importers and consumers.


Many of us have taken a sip of tea and immediately been able to distinguish the taste as either good or bland, without being able to say why.  In order to go beyond simplistic distinctions and to properly discern the great many tastes and aromas that give rooibos tea its flavoured nuances, South African researchers have developed a flavour and mouthfeel wheel for the unique homegrown brew.

The novel wheel provides 27 descriptive attributes for rooibos – 20 flavour and seven taste and mouthfeel descriptors – and will be a practical tool to facilitate communication among rooibos producers, processors, grading experts, marketers, flavour houses, importers and consumers.

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The wheel is the work of a team including Ilona Koch, a Masters student at Stellenbosch University. Under the leadership of Professor Elizabeth Joubert of the Agricultural Research Council, (who designed the project proposal together with Stellenbosch University lecturer Ms Nina Muller), Koch and a team of researchers have spent over a year compiling data through numerous experiments with rooibos tea.

“This study was conducted to characterise and quantify the sensory attributes associated with rooibos flavour (taste and aroma) and mouth-feel to paint a more comprehensive picture of what is frequently referred to as ‘typical’ or ‘characteristic’ rooibos flavour,” said Koch.

The researchers studied 69 different rooibos samples originating from 64 different plantations in various production areas. These samples had been graded from A to D, representing the highest to the lowest tea quality respectively.

A strict protocol was followed when brewing the tea – 300g of boiling, deionised water was poured onto 5.8 g of dry tea leaves, which was infused for five minutes. The tea was strained and stored in a stainless steel thermos flask to keep the temperature constant, and 100 ml of tea was served to each taster in a white porcelain cup covered with a plastic lid to prevent evaporation and loss of volatiles. The tea cups were preheated in an oven set to 70°C, and kept in water baths with the temperature regulator set at 65°C throughout the sensory analysis session.

Nine judges took part in the study, selected on availability and interest. “Most of them had extensive experience with descriptive analysis of a wide range of products.  None of them, however, had previous experience with sensory analysis of rooibos,” said Koch.

During the first training stage the panellists were exposed to a number of rooibos samples to become familiar with the product and the evaluation protocol. During 22 one hour sessions, the 69 samples were analysed and compared to one another, and the panel generated aroma, taste and mouth-feel terminology.

Some 85 aroma and 38 taste and mouthfeel descriptors were generated at this stage, but this proved to be too large a field of data for the efficiency necessary to produce the wheel. The number of descriptors was subsequently reduced to eight aroma descriptors and nine taste and mouth-feel descriptors. A score card was developed which showed each of these 17 descriptors together with a 10cm unstructured line scale ranging from “none” to “prominent”.

After training was over, the panel used the score card to rate the intensity of the 17 attributes for each of the 69 samples during 40 sessions spread out over eight weeks.

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Through the research, it was uncovered that the positive sensory characteristics such as floral, woody, honey and sweet could be separated from the negative attributes such as green plant, hay-like, dusty and sour. In light of this, the descriptors were grouped according to the positive or negative impact on the quality of the sensory experience.

While the research delved into a number of experiments to deduce specific data including the effect of steam pasteurisation, the effect of particle size and the oxygen radical absorbance capacity of rooibos (ORAC), the flavour and mouthfeel wheel represents the attributes of unpasteurised rooibos infusions.

The wheel will be further updated and refined with samples from another season during the three-year project, which will run until March 2012.  It is being funded by the SA Rooibos Council and the Technology and Human Resources for Industry Programme (THRIP) that aims to boost South African industry by supporting research and technology development.

Now drinking tea will no longer be about whether it’s simply good or average, but a sensory experience akin to the tasting of wine where you will be able to indulge in the subtle tannins and fine distinctions in taste and aroma that rooibos infuses into each of its products.

Contacts:
Professor Elizabeth Joubert
Agricultural Research Council
Phone: +27 21 809 3444 – Fax: +27 21 809 3430
joubertl@arc.agric.za

 

 

Homegrown herb may provide hope for diabetics

4 August 2011

Rooibos, known for its many health benefits from reducing the risk of heart disease and strokes, to preventing cancer and boosting the immune system, may also be beneficial for managing diabetes.

A number of local and international studies have found encouraging evidence that rooibos could help to control diabetes and its complications.

A 2006 study in the Slovak Republic found that rooibos provides effective protection against oxidative stress in diabetic rats. The scientists recommended the use of rooibos for the prevention and therapy of diabetic vascular complications, especially in protecting eye membranes against peroxidation.

Last year a Japanese team found that aspalathin, the most active antioxidant in rooibos, helped improve the glucose uptake of muscle cells and consequently maintain normal blood sugar levels in mice with Type 2 diabetes. They also found that aspalathin stimulated pancreatic beta-cells to secret insulin and helped to improve impaired glucose tolerance in the animals.

Two South African researchers, Professor Elizabeth Joubert of the Agricultural Research Council and Dr Johan Louw of the Diabetes Recovery Platform at the Medical Research Council, are co-applicants for a worldwide patent to develop and produce an anti-diabetic extract of rooibos for the treatment of Type 2 diabetes.

These two local scientists are also leading a new three-year R1million, SA Rooibos Council-funded study – kicking off in 2011 – to determine whether rooibos can play a role in combating obesity.

Doctors believe that Type 2 diabetes and obesity are connected as many people who develop the disease are overweight or clinically obese.

“Numerous studies over the past few decades have helped us understand the complex and unique blend of antioxidants found in rooibos. These studies indicate that there may be more health benefits than we may have thought, which is why we are funding the additional research,” says Mientjie Mouton, Chair of the Product Research Committee of the South African Rooibos Council..

Aspalathin is unique to the plant species Aspalathus linearis. This fynbos plant thrives in the Western Cape’s Cedarberg region where it is commercially cultivated and wild-harvested for the production of rooibos tea. The SA Rooibos Council supports a number of local studies into rooibos’ health benefits. In addition to the obesity study it is funding several research projects into how rooibos can counter cancer and stress as well as the link between rooibos and exercise.

Research confirms rooibos is good for you

February 2011

‘Rooibos is good for you’, is a contention that’s been around for at least the past 40 years, but increasingly scientific research indicates that there’s more than a little substance to the claim.

The first evidence of people making tea with rooibos only occurs about 300 years ago. Wild plants were harvested using axes and the leaves were bruised with hammers before being left to ferment in heaps and then dried in the sun. It’s essentially the same process used today, although now the equipment is a little more sophisticated.

Rooibos became popular with the early Dutch settlers, not for its health but economic advantages. It was a cheap alternative to the expensive black tea that was imported from Europe.

Carl Thunberg, a botanist from Europe, was the first to document the rooibos plant and the tea brewed from it in 1772. After this, the scientific community doesn’t appear to have lavished much attention on the ‘mountain’ tea until the early 20th century.

That’s when Dr Le Frans Notier, a doctor and nature lover, began researching rooibos’ medicinal value and agricultural potential.

Rooibos of course is not a true tea, but a herb and the brew made from the dried leaves is a herbal infusion known as a tisane. The vibrant amber hue comes from the natural colorants that develop during the post-harvest fermentation or oxidation process and is brought about by natural enzymes in the plant.

Green or unfermented rooibos is lighter, with a milder taste. Both traditional and green rooibos are natural products and contain no colorants, additives or preservatives – although they can be stored for long periods without the taste or quality deteriorating. They have no kilojoules and contain no caffeine.

Scientific interest in rooibos remained muted until after 1968, when Mrs Annetjie Theron used rooibos to help soothe her allergic baby’s colic. She published a book called ‘Allergies: An Amazing Discovery’ and went on to launch a range of health and skin-care products with rooibos as the main ingredient.

Although Mrs Theron’s evidence was anecdotal rather than scientific, there’s little doubt that her claims stirred considerable interest in rooibos’ health benefits. Since then there’s been considerable research done in South Africa and abroad into how rooibos might help prevent or treat a variety of illnesses.

Rooibos contains a complex and unique blend of antioxidants, the most active of which – aspalathin – is found only in the plant species Aspalathus linearis. Antioxidants bind with free radicals, preventing them from damaging cells and causing cancer or oxidising with cholesterol to clog blood vessels resulting in heart attacks and strokes. Research over the past decade has proven the therapeutic ability of rooibos to fight cancer, protect the liver against disease, boost the immune system, relieve allergies and treat digestive disorders.

By investing in research in South Africa and keeping a close eye on studies done overseas, the South African Rooibos Council is able to provide scientific evidence to confirm the plant’s health benefits as well as police inaccurate or unsubstantiated claims.

Its research budget is R1 million a year and it is currently supporting studies at several local universities and science councils on how rooibos can counter cancer and oxidative stress as well as the link between rooibos and exercise. A project on rooibos and obesity has been approved for funding in 2011.

Scientists here and around the world continue to research rooibos to gain a better understanding of this unique herbal tea. Some are investigating the health benefits of rooibos and its potential to combat a range of diseases, while others are trying to understand how the bioactive components in rooibos work.

Recent and ongoing research:

International researchers found the antioxidants in rooibos are potent enough to measurably elevate the antioxidant levels in blood, boosting the body’s natural defences. The effect peaks an hour after drinking two cups of rooibos.
“That’s why we recommend drinking up to six cups of rooibos spaced throughout the day for a sustained health benefit,” says Professor Jeanine Marnewick from the Cape Peninsula University of Technology, who led a local study that showed the beneficial effect of drinking rooibos to promote heart health.
The benefits are the same whether the rooibos is drunk hot, as tea, or cold as iced tea. Six cups also provide the recommended daily hydration.
South African scientists from the Medical Research Council’s PROMEC Unit and the Oxidative Stress Research Centre at the Cape Peninsula University of Technology have found that rooibos could help prevent skin cancer. The implications are particularly relevant in South Africa which, with 20 000 reported cases annually and 700 deaths, has the second highest incidence of the disease in the world after Australia.
The CPUT study concluded that the polyphenolic-rich extracts from rooibos and honeybush have anti-tumour and photoprotective properties. This indicates potential for use in cosmeceuticals for sun protection and as part of a strategy for preventing non-melanoma skin cancers in humans.
The MRC team found that rooibos exacerbated cell death in UV exposed cells, which could play a role in cancer prevention. It also concluded that rooibos may prevent skin cancer by delaying the progression of abnormal cells, interfering with their growth and viability.
Researchers in Pakistan, Canada and Germany joined forces to explore the use of rooibos to treat gastrointestinal upsets, using an animal model. Their results explained the biochemistry of how the flavonoids and other active ingredients in rooibos achieve a calming effect on the digestive system. They concluded that it is justified to use rooibos for the treatment of gastrointestinal disorders such as gut spasms.
Two South African researchers, Professor Elizabeth Joubert and Dr Johan Louw, are co-applicants of a worldwide patent (filed in 2007) to develop and produce an anti-diabetic extract of rooibos, particularly for the treatment of Type 2 diabetes.
A Japanese study showed that rooibos could reduce inflammation in rats with colitis (open sores in the colon) via increased antioxidant activity and a consequent reduction in damage to DNA caused by oxidation.
Researchers in Japan showed that the active ingredients in a water-soluble fraction of rooibos restored immune function in immune-suppressed rats. These results hold significant potential for future research into the immune-boosting properties of rooibos that might benefit people living with HIV/Aids.
Researchers from the Slovak Republic have demonstrated the anti-ageing effect of rooibos in Japanese quails. The birds were given rooibos to drink and had ground rooibos added to their food. The hens on the rooibos diet laid more eggs and kept laying eggs as they were getting older, compared to the control group.

Protection of rooibos could boost economic growth

4 August 2014
The recent ruling to protect the rooibos trademark under Geographical Indicators (GI) framework of South Africa’s intellectual property (IP) laws is a major step in protecting South African products and promoting economic growth and competitiveness.

The reciprocal agreement between South Africa and the European Union sees South Africa’s rooibos and the EU’s feta cheese get GI protection and gives rooibos producers ownership and authority over the name.

Dawie de Villiers, chairman of the SA Rooibos Council says: “Obviously we’re delighted that this iconic South African product now enjoys international protection under a robust regulatory framework.

“Governments have an obligation to protect their nations’ assets and the Department of Trade and Industry’s (Dti) efforts in securing GI for rooibos could provide real impetus for other intrinsically local products, says De Villiers. “By rights, a GI for rooibos should be a fairly simple undertaking. It’s grown in a very specific and limited part of the Western Cape and nowhere else in the world.

“So an attempt, for example, by the French company Compagnie de Trucy to register rooibos as French was mischievous, to say the least.

We were delighted that the Trade and Industry Minister, Mr Rob Davies scrutinised the issue from all angles and then acted boldly.”

Gazetting a proposal to protect rooibos and names such as Rooibosch, Rooibostee, Rooitee and Red Bush under the Merchandise Marks Act now protects this globally unique product under domestic law. This enables the Dti to seek international protection usiWIPO (World Intellectual Property Organisation), explains De Villiers.

“This could help set a precedent for the protection of other products from a specific, localised area, such as tea and Karoo lamb.

GI’s are used to protect products specific to a region, which is why champagne may only be labelled as such if it comes from the Champagne area of France, and Darjeeling tea from a specific area of India, and Colombian Coffee from Colombia.

De Villiers adds: “Achieving this protection for rooibos was partly the result of eight years of intensive research, collation of fact and some intensive lobbying. The GI allows a number of important steps. From the perspective of growing the rooibos sector, quality control is crucial, as it enables us to ensure the authenticity of products containing rooibos tea blends. A minimum of 80% rooibos content is required for it to be described as an official rooibos product.”

Other crucial benefits include rooibos’ use as a powerful tool for promoting regional tourism and for protecting the biodiversity of the area, which is especially important considering the fynbos region’s fragile ecosystem.

All these benefits will in turn contribute to the socioeconomic development of the area and the livelihoods and dignity that sustainable development will yield.

It means, in short, that SA’s rooibos tea producer can take ownership of the rooibos name and that name may only be used on products they produce and which are endorsed by them, concludes De Villiers.