Fragrancy with flavour

Consumption of herbal teas is bucking the trend of declining tea sales. But the ability to make health claims for them are limited, reports Michelle Knott

Whether it's a broken marriage or a surprise encounter with long-lost offspring, crises in Soapland always seem to meet with the same response: 'I'll put the kettle on.' Unfortunately, real life is not living up to the TV image, according to Mintel. The company's research shows that sales of standard tea bags have declined by 16% and loose tea has dropped 9% in the past two years.

In fact, the total tea market in the UK has declined by 12% in five years, falling from £707m to just £623m in 2004. Competition from coffee is partly to blame, while younger people in particular are ditching tea in favour of soft drinks, bottled water and fruit juice.

But tea is relying on two consumer trends to help it fight back. First there is the booming demand for food and drink to support a healthier lifestyle. Tea is increasingly being marketed as high in antioxidants that may help prevent cancer, while consumers also consider naturally caffeine-free herbal and fruit teas to be a healthy option. The herbal and fruit tea sector enjoyed a 30% boost in sales from 2002 to 2004 to reach almost £64m.

The second front is the trend towards fine foods. This has fuelled an interest in finer quality tea, as well as tea with more exotic flavours. This has driven a rise in the speciality tea sector of 50% over the same period, bringing it to almost £104m.

Health brings wealth

Traditional black tea, green tea, white tea and oolong tea all come from the same plant, Camellia sinensis. The difference lies in the way the tea is processed and that starts with picking. Hand-picking ensures that only the youngest leaves are taken from the tips of the plant. This is known as a fine pluck. Mechanically harvested tea typically includes older leaves from lower down the plant.

"In the green leaf the antioxidants are in the form of catechins and these can occur at up to 26-30% on a dry weight basis for a fine plucked leaf. This can go down to 5% in coarse harvested tea. You want to pick just the tips," says Nigel Melican of Teacraft, which supplies processing equipment to the tea industry globally, as well as consultancy services through its sister company, Tea Technology Associates.

There are five catechins in tea and the ratio between them varies with the season and the tea variety. The most potent antioxidant is epigallocatechin gallate.

In the case of white tea, the time of year at which the tea is picked is important since only the very youngest leaves have the coating of fine white hairs that the tea derives its name from. Apart from that it's the degree of fermentation that determines whether you end up with green, oolong or black tea. "It's an enzymatic fermentation. You crush or break the cell substrates and there's a natural enzyme in the leaf that starts to oxidise them," says Melican.

Green tea is unfermented so the leaves are heated and dried immediately to destroy the enzyme and stop the process in its tracks. Oolong tea is partially fermented before the process is stopped and black tea is allowed to ferment fully before drying.

In green tea you should essentially end up with the catechins that were in the leaf to start with, minus a few percentage points. During fermentation to oolong or black tea, the catechins oxidise to theaflavins. "Theaflavins are what give tea a bright orange colour and a brisk, bright taste," says Melican.

Like catechins, theaflavins have also been shown to have antioxidant properties, so a good oolong or black tea still has health benefits, although theaflavins may be present at a lower concentration (as low as between 1 and 2% dry weight in some black teas). This is because the theaflavins can also polymerise to form thearubigens, which can account for between 10 and 20% of the dry weight of some black teas. These compounds are less well characterised and no health claims can be made about them. "I've not seen any work that shows that thearubigens have antioxidant properties," says Melican.

Any 'abuse' of the tea during processing can further erode the content of beneficial compounds. For example, tea is typically dried using dry heat or steam for 20 minutes. But Melican has carried out consultations for producers in some parts of the world which are using substandard equipment that forces them to dry the tea for 90 minutes.

In addition, tea will degrade over time. "The beneficial compounds aren't volatile, but they will carry on with their chemistry, so if you have tea that's been around a bit it's not so good," says Melican.

The urge to herbal

Age is also a critical factor in the quality of herbal teas, according to Keith Garden, md of Only Natural Products, which makes the Dr Stuart's range. "The volatility of the essential oils varies depending on the herb. For example, camomile is quite stable but peppermint is extremely volatile. This makes it wonderfully aromatic but it means that it can easily contaminate other stock during storage and quickly loses its flavour," he says.

"Our Skin Purify tea [which is a blend of red clover, nettles and lemon balm] is another one that must be packed almost as soon as it comes in. So we generally have to be very careful about stock rotation. Some companies keep their stock for ages and it can be up to two years old when it arrives. Ours is closer to 16 or 18 weeks."

The Dr Stuart's brand is positioned as a premium product and the company guards its reputation jealously. Garden believes that Only Natural Products is the only company in the market selling herbal tea to the German Pharmacopoeia 10th Edition (DAB 10) standard. This lays down strict criteria for the levels of contamination and levels of essential oils permitted in the herbs.

Garden also says it's been important for the company not to jump on the bandwagon every time a new herbal remedy hits the headlines: "We have to be sure things have long-term value so we tend to create products at the end of a trend. For example, we've just introduced Rooibos, even though it's been around for a while."

Going the niche, premium route seems to be paying off, with Dr Stuart's claiming 28% annual growth in supermarkets and even higher growth in independent health food shops. This is in spite of the fact that herbal tea is restricted in the health claims that can be made for it.

"Valerian is believed to help people sleep and echinacea is believed to boost immunity against colds, but we can't mention either of those things on the packaging or marketing materials," says Garden. "It's frustrating because we have to rely on consumers to understand the benefits they can hope to get from the products."

Get fruity

Whether it's black tea flavoured with lemon or bergamot oil, or a caffeine-free fruity number, the common problem that flavoured tea manufacturers face is flavour retention. A lot of the fruit flavourings are introduced as spray dried particles, which are so fine that a high proportion escapes from the bag before brewing. Volatile essential oils are also easy to lose during processing and storage since they will oxidise or evaporate from a flavoured tea.

According to Bristol-based Tastetech, encapsulation could be the answer to both problems. The company has already established its encapsulation technology and for the past 12 months has been looking at what it can do for the tea industry.

Its encapsulated fruit flavour granules are over 0.5mm in diameter, which makes them far less likely to escape from the tea bag before brewing. Tastetech is currently looking to take this up to as much as 1mm. "You wouldn't want them any bigger," says technical manager Gary Gray. "You need them fairly small to get good flavour release."

Gray also believes that encapsulation can help prevent volatile essential oils evaporating or oxidising and so extend shelf-life. "It's impossible to quantify yet, but we have good reason to believe that oxidation is reduced because everything is tied up. This should extend the shelf life of the final product."

Whether it's speciality, herbal or flavoured teas, it's the top-end products that stand the best chance of riding out the current slump in consumption on a rising tide of health-conscious, gourmet consumers.FM