**2.1 Jasmine scented tea**

Jasmine scented tea is mainly produced in the Guangxi, Fujian, Sichuan and Yunnan provinces of China. It is a reprocessed tea made by blending tea with jasmine flowers. When brewed and consumed, its aroma is strong, fresh and refreshing. Jasmine scented tea generally uses green tea as the tea base. The choice of tea base is an important factor in determining the quality of jasmine scented tea. The aroma and taste of jasmine scented tea can be improved by making jasmine scented tea with green tea scraps of different particle sizes [18]. Different drying methods lead to changes in the surface and microstructure of the tea base, which in turn affect the quality of the finished jasmine tea. The emergence of vacuum freeze-drying technology has resolved this issue and the moisture content and overall quality of tea base have reached controllable conditions. Therefore, the quality of jasmine tea after scenting is better than that prepared by hot air drying [19].

Jasmine scented tea has physiological effects as well as significant health care properties. Studies have shown that jasmine scented tea can help obese people to reduce lipid levels and lose weight [20, 21]. Improved living conditions have led to women focusing more on ageing and skin problems. The anti-ageing and anti-oxidant health effects of jasmine tea also play an important role in the health benefits of jasmine tea. The polyphenols and pigments in jasmine tea have anti-bacterial effects. Gargling with the water extract of jasmine scented tea can resolve oral problems, such as oral ulcers and swollen gums.

#### **Figure 1.** *Different types of scented tea. (a) Jasmine, (b) lily, (c) osmanthus, (d) rose, and (e) honeysuckle scented teas.*

### **2.2 Lily scented tea**

Lily scented tea is mainly produced in the Anhui, Jiangsu and Guangdong provinces. Lily scented tea is prepared by processing fresh lily and green tea together, which retains the original biological activity factor of lily and has the fragrance of green tea. In addition to its strong aroma, lily has edible and medicinal properties. After scenting is complete, the flowers are mixed with tea, dried and packaged together, which improves the quality of scented tea and enhances its edible and medicinal value. Current methods of lily scented tea preparation include the treatment of tea billet, maintenance of flowers and the triple scenting of flowers. Finally, high-quality lily and dried tea greens are mixed for drying. This method can control the water content of lily scented tea, improve the quality and taste of lily scented tea and improve its medicinal value [22]. During the traditional drying process of flowers and tea, secondary drying reduces the fragrance of flowers and affects the quality of scented tea, while processing technologies, such as microwave drying or the use of desiccants, can greatly reduce the loss of floral fragrance [23].

Lily scented tea has high nutritional and medicinal values. While it is often made into desserts, people in the Guangdong region prefer to use it to make a tea drink to relieve coughing and sputum production. Lily scented tea tastes sweet and has no irritating taste. It moistens the lungs to stop coughing, clears away heart-burn and calms the mind. Lily scented tea is nourishing and medicinal and can be consumed all year round. It contains a variety of alkaloids, which have a preventive effect on leukopenia, increases the red blood cell count in the blood and has therapeutic effects on cytopenia after chemotherapy and radiotherapy [24, 25]. Lily scented tea can also improve the immune system and has preventive effects on a variety of cancers. The 'Compendium of Materia Medica' states that lily scented tea is a high-quality tonic and has properties similar to those of ginseng in tea.

### **2.3 Rose scented tea**

Rose scented tea is mainly produced in the Guangdong and Fujian provinces in China. It is one of women's favourite scented teas and is also the most common scented tea. Brewed rose scented tea exudes a refreshing aroma and refreshes the consumer. The quality of the finished product of rose scented tea is related to the processing technology. The type of rose and tea base used during the process directly affects the quality of scented tea. During the scenting process, freeze-dried roses are selected and mixed with green tea for secondary scenting. Airtight conditions are maintained during the scenting process to ensure an appealing drinking taste and aroma. Nutrients are not lost during scenting, improving the medicinal value [26]. The tea needs to be dried after scenting. Microwave technology can preserve the fragrance of the scented tea to a great extent and resolve issues such as dull colour and loss of aroma of the scented tea due to high temperature and humidity during drying using the traditional process [27].

Rose scented tea is a precious medicinal material and traditional Chinese medicine often uses rose scented tea with other traditional Chinese medicines to produce different formulas. Using rose scented tea to make wine can reduce blood lipid levels, improve vitality and improve skin texture [28]. Rose essential oil refined from rose scented tea can promote the development of male hormones and sperm and promote blood circulation and metabolism. Rose scented tea is also a commonly used a gynaecological Chinese medicine and has a significant effects in the treatment

of gynaecological diseases [29]. Recent studies have shown that rose scented tea extract has anti-viral effects and has been used in the treatment of acquired immune deficiency syndrome and leukaemia and has achieved remarkable results.

## **2.4 Honeysuckle scented tea**

Honeysuckle is a type of vine that is widely used in the pharmaceutical, food and chemical industries [30–32]. Honeysuckle scented tea is prepared by combining fried green tea and fresh honeysuckle in a sealer, separating the green tea and honeysuckle with gauze and stacking them in multiple layers to fully mix the honeysuckle and tea. Finally, dried honeysuckle and green tea are mixed and packaged. This process gives the tea a strong aroma and medicinal properties.

Honeysuckle is commonly used as a precious Chinese medicine. It is used to reduce fever and toxins, free the channels and improve circulation and has broad-spectrum anti-bacterial and anti-viral effects. More than 70% of cold medicines and anti-inflammatory patented Chinese medicines contain honeysuckle, which is known as 'Chinese medicine antibiotics' and 'green antibiotics'. In addition to its medicinal properties, honeysuckle scented tea is used for beauty, weight loss and health care and has also been shown to protect and repair the body. Honeysuckle scented tea relieves heat stroke, sobers up individuals after consuming alcohol, clears the mind, relieves thirst, removes toxic substances from the body, lowers fat levels, reduces body weight, clears the skin, prevents ageing and increases longevity [33–35]. It can also lower blood pressure, lower serum cholesterol, increase coronary blood flow, prevent coronary heart disease and heart pain and inhibit the formation of cerebral thrombosis. Drinking honeysuckle scented tea can also improve the body's resistance to hypoxic free radicals, delay ageing, improve microcirculation, remove peroxidised fat deposits and promote metabolism.
