Quality analysis and antioxidant activity of different types of tea powder

Ye et al. Food Production, Processing and Nutrition (2024) 6:36 https://doi.org/10.1186/s43014-023-00198-1 Food Production, Processing and Nutrition Open Access RESEARCH Quality analysis and antioxidant activity of different types of tea powder Yutong Ye1,2, Zeyi Ai1, Ronglin Li1, Yang Tian2 and Yiyang Yang1* Abstract As a natural product with health benefits, tea powder (TP) is widely used in food processing field. In order to explore sensory evaluation, quality components and antioxidant activities among different types of TP, matcha TP, Huangjinya green TP, oolong TP, black TP and Pu-erh TP were used as the research objects. Our results showed that total scores of sensory evaluation of unfermented TPs were higher than those of fermented TPs, whilst the colour of those unfermented TPs was more bright. Furthermore, taste attributes showed that sweetness was conducive to the formation of the taste of black TP, and aftertaste-bitterness was beneficial to matcha and Pu-erh TP. Umami was suggested as a vital contributing factor to the mellow taste of Huangjinya green TP, while sourness and bitterness were not propitious to form the taste quality of tea powder. The non-volatile quality components analysis revealed that tea powders with more fermentation usually contained fewer amino acids and catechins, but glutamate and gamma-aminobutyric acid were higher in black TP than in oolong TP. Theanine, glutamic acid and arginine were the main iconic components affecting the amino acid composition of different types of tea powder in our study. Meanwhile, the contents of ester catechins (ECG, EGC, EGCG) in black TP and Pu-erh TP were significantly lower than those in green TP and oolong TP. In addition, the free radical scavenging ability of unfermented TPs were stronger than that of fermented TPs. Therefore, to maximize the health benefits and sensory attributes of different types of TP, the use of unfermented tea powder is recommended. However, different manufacturing process of tea powder can enrich the taste of tea foods, thus giving people more choices. Keywords Tea powder, Different types, Quality components, Volatile components, Antioxidant activity *Correspondence: Yiyang Yang Full list of author information is available at the end of the article © The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. Ye et al. Food Production, Processing and Nutrition (2024) 6:36 Page 2 of 13 Graphical Abstract Background China, where the origin of tea (Camellia sinensis (L.) Kuntze), is the first country to discover and use tea in the world. With the long-term natural evolution and artificial selection, China now owns tremendous tea plant resources, including seed resources and cultivated varieties (Xu et al. 2017). The manufacturing process is among the most crucial factors affecting tea quality, and it substantially determines both the types and relevant chemical constituents of tea. According to their manufacturing process, tea is classified into six types, green tea, yellow tea, white tea, oolong tea, black tea and dark tea (Xu et al. 2017). Catechins and alkaloids are considered to be the major bioactive chemicals in all tea types. Therefore, tea exhibits numerous bioactivities, such as antioxidant, antimicrobial, anti-cancer, anti-inflammatory, and antihyperglycemic activity (Liu et al. 2017). Dried tea leaves are used not only for beverages but also as an additive to various kinds of food, especially in the form of ground powder. Tea powder is a new type of tea product developed on the basis of superfine crushing technology, which can crush tea leaves into powder with particle size below 1 μm ~ 10 μm and has the characteristics of micronization (Talib Hamzah et al. 2022). It is reported that superfine grinding of green tea could markedly increase the extraction of total polysaccharides, leading to an improvement of antioxidant activity against hydroxyl radicals (•OH) (Hu et al. 2012). Adding a certain amount of matcha in cake production, the fresh tea flavour can not only reduce the sweetness of the cake but also make the cake have certain healthcare functions (Wei et al. 2023). Fresh noodles with a distinct aroma of rice crust could be realised by adding large-leaf yellow tea powder (Wang et al. 2023). Nevertheless, previous studies on tea powder have mostly focused on optimizing its process as an additive, and have mostly focused on green tea powder. The knowledge of other tea types remains unclear, therefore, our study explores the sensory quality, non-volatile and volatile quality components, and antioxidant activity of different types of TP, which could provide necessary support for the food industry and essential information for consumers when choosing tea powder. Materials and methods Experimental materials Matcha TP, Huangjinya green TP, oolong TP, black TP, Pu-erh TP raw materials are from Jiangsu Xinpin Tea Industry Co., Ltd. The production date was from May 2020 to October 2020. Analysis of taste profile of tea infusions The taste profile of green tea infusion was measured by the Insent taste system (Sartorius BSA124S-electronic Ye et al. Food Production, Processing and Nutrition (2024) 6:36 balance Technology Inc.). The tea infusion was cooled to 25° C in the water bath for taste analysis according to the previous work (Xu et al. 2017). Sensory evaluation The tea sensory quality was assessed by 3 professional tea tasters from the Department of Tea Science at Jiangsu Academy of Agricultural Sciences, using the 100-score tea powder quality grading system according to the China National Standard (GB/T 8313–2018), in which appearance, liquor colour, aroma and taste accounts for 10%, 20%, 35% and 35%, respectively. 0.6 g tea powder of each sample was extracted with 150 mL freshly boiled distilled water for 3 min. Tea infusions were individually presented in white porcelain bowls. Panelists were instructed to smell and drink tea infusions and pause for 30 s between samples. Measurement of amino acid, tea polyphenols, catechins and other quality components The multiple reaction monitoring (MRM) mode was used to analyse the amino acids. The LC–MS/MS an (...truncated)