Youngmok Kim, Ph.D., is a senior research scientist at Synergy Flavors, where he conducts research on tea, tea beverages, tea ingredients and the health benefits of tea.
In the current national and global beverage market, there is a trend toward functional drinks. Consumers are moving away from soft drinks because they are becoming more aware than ever of the high amounts of sugar they contain, as well as sugar's negative health impacts. This growing health-related trend is putting tea in the forefront of consumers’ minds as they begin to look for healthier beverage alternatives, such as ready-to-drink (RTD) teas.
Why tea is hot — even when it’s served cold
Tea is a leader in the functional beverage segment, which is the hottest category in the global beverage market. It’s popular because it is enhanced with tea extracts that have natural health benefits, and is further strengthened with additional functional ingredients. Examples include energy drinks with tea extracts and tea beverages with added natural extracts, such as ginseng and guarana.
Tea extracts are becoming one of the most popular functional ingredients and are now viewed as essential ingredients for many types of functional beverages in these categories: health and wellness, such as vitamin water; energy and stimulation, including energy drinks; hydration, such as sports drinks; and weight management or weight-loss drinks. The active compounds that increase the positive benefits of tea extracts are polyphenolics and caffeine. The amount and stability of these compounds in tea extracts varies depending on the tea leaves’ growing conditions, harvest times, processing amounts and age.
How to create RTD tea
Water, tea, flavors, sweeteners, acids and preservatives are the main ingredients in RTD tea. When considering what type of water to use, most manufacturers choose filtered water because it doesn’t have any odors or minerals that could alter the taste or decrease the overall quality of the RTD tea.
Another factor to consider during the RTD tea-making process is how to add tea extracts or brewed tea to RTD tea bottles. There are three common methods, which include:
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The liquid tea extract method. For this process, tea is brewed at a facility and then concentrated before being added to the bottle, along with other ingredients, such as flavors and acids. This is a better way to keep the flavor of tea because the liquid tea extract usually does not need to go through high-heat processing, such as spray-drying for concentration. Using this method, better extractors capture the aromatics of the brewing process and put them back into the concentrate to create the final product.
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The powdered tea method. This process uses powdered tea that is first extracted and then spray-dried for a longer shelf life. These tea solids are then added to RTD tea with other ingredients. The downside to using powdered tea is that the tea’s beneficial compounds, such as catechins (the main antioxidants in tea) and natural tea aroma compounds are degraded during the spray-drying process, resulting in less good-for-you tea.
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The single-strength brewed tea method. The quality of this method is excellent; however, controlling variation can be difficult when different tank sizes or multiple bottler locations are required. In this method, single- strength tea is brewed on-site to be quickly incorporated into the finished bottled beverage. This tea is typically hot-filled with no preservatives and is usually not sweetened at all, or is minimally sweetened. This method allows for only a small amount of ascorbic acid or other organic acids to be added to improve the storage stability of the product while still keeping the original quality taste of the tea.
To improve flavor, taste and stability, acids are added during the RTD tea creation process. Citric acid is the most popular acid in beverage applications because it is easy to use and readily available; however, ascorbic acid is quickly taking over citric acid’s position because of its many advantages. Ascorbic acid can lower pH just like citric acid can, acts as an antioxidant and protects and keeps flavor stabilized. Another benefit is that ascorbic acid adds nutritional value to the drink, so a beverage can claim a certain percent of ascorbic acid (vitamin C) on the label.
One of the final steps in creating RTD tea is adding chemical preservatives to shelf-stable products to ensure its microbial stability during storage. The most common preservatives are potassium sorbate, sodium benzoate and EDTA (Ethylenediaminetetraacetic acid). They help prevent mold, yeast, bacteria and fungi growth that could cause decolorization, turbidity development and flavor changes. For potassium sorbate and sodium benzoate to be effective, the pH of the beverage is very important, so acids are added to adjust pH.
For RTD tea applications, the overall taste of a tea beverage can be enhanced by the addition of tea essence to replace the volatile aromatics that are lost during the brewing process. Without essence, tea beverages tend to lose the appealing top note flavor of fresh tea. Additional characterizing flavors can also be added to tea beverages. The most popular are lemon, peach and raspberry, followed by pomegranate, mint, mango, orange and berry. Recently, new flavors such as ginger, super fruits and coconut have started to gain in popularity.
The future of RTD tea
Clean label is a consumer-driven movement demanding a return to real food and transparency through authenticity. Clean food products contain natural, familiar and simple ingredients that are easy to recognize, understand and pronounce. The products include no artificial ingredients or synthetic chemicals. In Innova Market Insights' top 10 food and beverage trends for 2017, the most important and popular trend on the list is “clean supreme.”
Clean label teas are made with tea that delivers the maximum level of health benefits, and non-clean label teas are most often made with caramel color (to mimic real tea’s color), tannic acid (to mimic real tea’s bitterness and astringency) and tea flavor (to create a real tea experience overall). For consumers to get the full health benefits that they are looking for from tea, it is important for manufacturers to produce tea that is not only healthy but also clean.