It is undeniable that the British are unique in the world in their obsession with tea. This magical leaf from the East flourished in this exotic country in less than three centuries and completely transformed British food culture. While almost every corner of the world is being awakened by Starbucks coffee in the early morning, the British Isles are still clinging to their English breakfast. From early morning to late at night, many families across the country turn on the kettle and make tea.

Since tea washed up on British shores, this firm bitterness continues to inspire fondness | CREDIT: depositphotos

We Devonians are naturally deeply influenced by tea culture. We even innovated with afternoon tea, and this was the first time I learned that tea doesn’t just refer to a drink, it can also be an umbrella term for several meals. Devon Cream Tea, an afternoon tea made with warm scones, jam and clotted cream. Maybe this doesn’t sound very culinary, but among the crowds of people enjoying various afternoon teas, you’ll be instantly recognized as a classic Devonian.

A proper Devonian will confidently cover cream the scone first and then jam on the top | CREDIT: AlexG

Tea itself is an incredible gift of nature. Tea is rich in antioxidants, which are a bit like preventing the human body from rusting, thereby delaying cell aging. Drinking tea can also help you focus and reduce stress because tea also contains caffeine. Recent research suggests that polyphenols in tea may also play an important role in preventing cancer.

So many benefits may make you appreciate the tradition of English breakfast and continue to stick with it, however, if you look at a survey by The Tea Group, tea is currently being replaced by herbal teas and fruit teas. More than half (55%) said their favourite tea was herbal tea or a related product, while 45% chose English breakfast. What was the reason for breaking with tradition?

The end of the cuppa? Herbal and fruit teas have become more popular among Britons | CREDIT: thisNZlife

Since herbal tea is not produced from the Camellia sinensis plant (tea plant), it is not considered true tea. A more formal term is “tisanes.” Herbal tea itself is a general term for drinks produced by infusions of different herbs. The raw material is not limited to plant leaves, it can be plant roots, stems, fruits, flowers, seeds, bark or even the whole plant. An article in the Journal of Future Foods conducted a complete study of the active chemical ingredients of herbal tea.

Polyphenols

Polyphenols are mainly distributed in the fruits, leaves, roots and bark of plants. Flavonoids are the most studied polyphenols in this field. This is a large family of compounds. The well-known catechins (tea leaves), hesperetin (citrus fruits), anthocyanins (blueberries and other berries), quercetin (onions, tea leaves, apples), are all flavonoids. The benefits of polyphenols to the human body are reflected in their antioxidant properties. Polyphenol-rich beverages increase plasma antioxidant capacity and protect cellular components from oxidative damage, thus limiting the risk of various degenerative diseases.

Terpenes

Terpenes are widely distributed in plants. It gives different plants their aromatic properties and colour, such as the smell of cinnamon and the red colour of tomatoes. The main terpenes in herbal tea include oleanolic acid, ursolic acid, Akebia saponins, hollyrin, etc. In the past decade, numerous studies have shown that terpenes play an important role in treating various diseases. Terpenoids are antimicrobial in nature and disrupt the reproduction and development of microorganisms, such as antibacterial ability against foodborne microorganisms. The anti-cancer effect of terpenes has been widely reported. One study showed that citral (the essential oil component of lemon) has the effect of inhibiting the expression and metastasis of rectal cancer cells and inducing apoptosis of cancer cells, making it an effective source of anti-cancer agents.

Alkaloids

Alkaloids are nitrogen-containing compounds found primarily in the plant kingdom. The alkaloid content in plants is within a few percent, and depending on the plant, the greatest concentrations occur in leaves, fruits, seeds, roots or bark. Caffeine is one of the well-known alkaloids, which is essentially a stimulant of the central nervous system. Montanine is an alkaloid isolated from the plant Amaryllis. It has the effect of inhibiting acetylcholinesterase, so it plays an important role in controlling stress, anxiety and epilepsy. Physostigmine, derived from calabar beans, may improve cognitive performance in Alzheimer’s patients by inhibiting the BChE enzyme.

There are many kinds of herbal tea recipes, and raw materials from all over the world provide herbal tea with a very rich taste and medicinal effects. In general, the effects of most herbal teas involve antioxidant capabilities, antibacterial capabilities, anti-diabetic capabilities, anti-cancer capabilities, and any effects of the tea itself. Due to the increasing awareness of nutritious food consumption and health care, the growth trend of herbal tea market is obvious. The large consumption of herbal tea is a good reflection that health is widely valued by society, but on the other hand, the hundreds of millions of tons of tea residue produced every year are causing food waste and environmental problems.

At present, the most basic ways to deal with tea residues include landfilling, incineration or composting. However, the damage caused to the environment by tons of tea residues treated in this way cannot be underestimated. A report from India pointed out that most tea factories in India do not carry out proper treatment in accordance with relevant regulations, resulting in pollution of water, soil and air. The utilization rate of tea residue is very low. Some is purchased for animal feed, a smaller portion is used to extract caffeine, and the rest is disposed of entirely as waste.

Unfortunately, few people realize the potential and sustainable value of tea residues | CREDIT: iStockphoto

This greatly underestimates the potential and sustainable value of tea residues. In the context of today’s global food sustainable development being vigorously promoted, it is necessary to extract the economic value of tea residues. Effective chemical components still remain in the tea residue, such as polyphenols, amino acids, cellulose, lignin, tannins, etc. The secondary processing of tea residues can continue to create economic value without secondary planting or reclamation. Even if the nutrients from the waste are not used for drinking, the ingredients in the tea leaves can be extracted to make cosmetics or perfumes, and the cost will be greatly reduced.

Paper manufacturers will be delighted with the tea residues. A study in Turkey found that tea residues mixed with certain pulps in proportion can make paper strong enough while remaining economical. This essentially saves more trees from being cut down.

Due to the plant elements in the tea grounds, it can be processed into a high-quality fertilizer. A classic case is the use of polyphenols and nitrogen-containing alkaloids in tea residues, which can become an ideal growth substrate for mushrooms. Some experts suggest that tea residues can not only increase agricultural yields and provide farmers with economical natural fertilizers, but also reduce heavy metal toxicity in the soil.

The nutrients  found in tea residue make it an ideal fertilizer for garden plants | CREDIT: Unsplash

Energy management is a major goal in the circular economy. Tea residue as a biological waste can be converted into usable energy. Tea residues are pyrolyzed at high temperatures and produced through gasification to produce bio-oil and biochar. Charcoal can be converted into briquettes and bring efficient and cost-effective solid fuel to industry.

When you finish a cup of nutritious and comforting herbal tea, you look at the tea leaves that have soaked and adhered to the cup, and you start to frown and think about the best way to deal with them. You already understand that the tea leaves themselves still have valuable value. If you happen to have an iDigest installed at home, why not let iDigest do the rest of the work? iDigest was developed by Intellidigest, a company focused on global food sustainability currently leading the way in the recovery of nutrients and chemicals from food waste.

IntelliDigest has developed an automated bioreactor to break down waste into organic chemicals | CREDIT: IntelliDigest

Inspired by how humans eat and digest food, the machine uses artificial intelligence to break down collected food waste into small particles and then convert the waste into concentrated chemicals. These chemicals will be an important part of the circular economy. Taking herbal tea waste as an example, they can be used in paper making, composting, fuel manufacturing, adsorption, animal feed, etc. During the decomposition process, iDigest can also analyse the carbohydrate, fat and protein components of the waste and provide a report.

World Food Tracker provides detailed information about each meal and its nutritional content, which you can find and download on Google play | CREDIT: IntelliDigest

Thanks to its innovative programming, it can also connect to the World Food Tracker app, giving you insights into food waste. If you want to know how to make a cup of herbal tea, you can open World Food Tracker and search using the recipes it provides. The app automatically provides you with a shopping list and the nutritional content. Intellidigest has partnered with local food producers through the Plan To Save campaign to ensure food is produced sustainably. By sharing shopping lists with local farmers, this helps them prioritize sustainable food production to eliminate food waste.