Production of instant powder green tea enriched with herbal mixtures

Date

2023-4-27

Author

Çelik , Merve

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Black tea is the most consumed beverage in Türkiye following water. Due to the benefits of green tea for human health, the consumption of green tea is also gradually increasing. In addition to the diverse range of tea variations, it is also widely known that Türkiye has not yet generated a market for instant green powdered tea yet and that this product category has not yet been extensively developed. During tea production, significant amount of tea waste is generated. This waste is also called as the tea fiber, and fiber and is not utilized in the further blending and packaging processes. In this study, instant tea from tea waste fibers were produced. Instant tea was produced by “super grinding" to create a powder tea with high dispersibility. Within the scope of this study, tea was dried and blended with rockrose herbs to give functional properties to the instant teas. To obtain the instant powder teas, tea fibers were brewed after super grinding using 2 different approaches. Hot brewing was performed at 70 °C for 20 minutes and cold brewing was performed at 25 °C and 2 hours. Following the brewing, drying was performed on the filtrates obtained with brewing. Instant tea powder was produced by using 2 drying methods: freeze and spray drying. Unlike the freeze-drying method, the drying process was carried out by adding inulin to the solution during spray drying, thus increasing the amount of dry matter content. As physical characterization tests, moisture content, water activity, hygroscopicity, particle size, solubility, morphological and turbidity experiments were performed for the final products. Antioxidant activity, total phenolic substance, gallic acid, caffeine and L-theanine content were determined as the chemical characterization experiments. A detailed analysis of the epigallocatechin (EGC), epicatechin gallate (ECG), epicatechin (EC), and epigallocatechin gallate (EGCG) by HPLC was also carried out. In general, the physical properties are almost similar to the teas obtained by freeze & spray drying methods. In terms of chemical analysis, the antioxidant capacities were found to be higher in freeze dried samples. Scanning electron images showed that spray dried powders were spherical in shape indicating that inulin encapsulated the extracts.

Subject Keywords

Instant green tea, Waste tea fiber, Supergrinding, Rockrose

URI

https://hdl.handle.net/11511/103248

Collections

Graduate School of Natural and Applied Sciences, Thesis