foods Article Using Sensory Wheels to Characterize Consumers’ Perception for Authentication of Taiwan Specialty Teas Tsung-Chen Su 1, Meei-Ju Yang 1, Hsuan-Han Huang 1, Chih-Chun Kuo 1 and Liang-Yü Chen 2,* 1 Tea Research and Extension Station (TRES), Yangmei, Taoyuan City 326011, Taiwan; [email protected] (T.-C.S.); [email protected] (M.-J.Y.); [email protected] (H.-H.H.); [email protected] (C.-C.K.) 2 Department of Biotechnology, Mingchuan University, Taoyuan City 333321, Taiwan * Correspondence: [email protected]; Tel.: +88-697-306-5741 Abstract: In the context of fair trade and protection of consumer rights, the aim of this study was to combat adulteration, counterfeiting, and fraud in the tea market, and rebuild the image of high-quality Taiwan teas. Experts at the Tea Research and Extension Station, Taiwan (TRES), are engaged in promotion of the systems of origin identification (AOC) and grading for authentication of Taiwan’s premium teas. From tea evaluation competitions (bottom-up quality campaign), the flavor descriptions and consumers’ perceptions were deconvoluted and characterized for the eight Taiwan specialty teas, namely, Bi-Luo-Chun, Wenshan Paochong, High-Mountain Oolong, Dongding Oolong, Tieh-Kuan-Yin, Red Oolong, Oriental Beauty, and Taiwan black tea. Then, according to the manufacturing processes, producing estates and flavor characters, the specialty teas were categorized into six sensory wheels. The flavor descriptors of the sensory wheels were also recognized in consumers’ feedback. In recent years, the performance of international trade in tea also demonstrates Citation: Su, T.-C.; Yang, M.-J.; that the policy guidelines for authentication of specialty teas are helpful to the production and Huang, H.-H.; Kuo, C.-C.; Chen, L.-Y. marketing. Furthermore, the development of sensory wheels of Taiwan’s specialty teas is the Using Sensory Wheels to cornerstone to the establishment of the Taiwan-tea assortment and grading system (TAGs) for Characterize Consumers’ Perception communication with the new generation consumers, enthusiasts, sellers, and producers. for Authentication of Taiwan Specialty Teas. Foods 2021, 10, 836. Keywords: tea competitions; sensory evaluation; labeling; flavor profiling; aroma attribute; traceability https://doi.org/10.3390/ foods10040836 Academic Editor: Bohdan Luhovyy 1. Introduction Received: 16 February 2021 Tea is the most popular beverage in the world after water, and the tea leaf (from Accepted: 9 April 2021 Camellia sinensis) is also one of the main agricultural commodities in international trade [1]. Published: 12 April 2021 Taiwan produces many famous tea beverages, due to its unique geographical and climatic environment for tea production, and is influenced by neighboring producers (mainland Publisher’s Note: MDPI stays neutral China, Japan, Korea, Vietnam) within the East Asian tea culture sphere [2,3]. For hundreds with regard to jurisdictional claims in of years, the development of tea-related industries has played an important role in Taiwan’s published maps and institutional affil- economic and social growth. Today’s tea consumer market has expanded to include iations. merchandise tea, premium tea, bottled tea, and ready-to-drink tea [4]. However, the diversification of culture and international economic activities have caused changes in eating habits that have impacted the industrial supply chain of tea leaves in Taiwan [5]. The topic of tea culture research has attracted new attention. Copyright: © 2021 by the authors. Specialty tea consists of whole-leaf or partial loose-leaf tea, in contrast to commodity Licensee MDPI, Basel, Switzerland. tea, which is cut and blended for industrial extraction or used in tea bags in stores. As part This article is an open access article of the global trend towards healthy eating, tea consumption is related to the phytochemicals distributed under the terms and in various tea infusions for tastes and physiological activities, which may provide some conditions of the Creative Commons health benefits for chronic diseases (such as cardiovascular disease and cancer) [6]. Specialty Attribution (CC BY) license (https:// tea is usually expensive, and highly popular due to its unique flavor, excellent qualities, creativecommons.org/licenses/by/ and small supply from tea estates. According to the popularity of the market items, the 4.0/). Foods 2021, 10, 836. https://doi.org/10.3390/foods10040836 https://www.mdpi.com/journal/foods Foods 2021, 10, 836 2 of 17 Foods 2021, 10, x FOR PEER REVIEW 2 of 18 items,distinct the manufacturing distinct manufacturing processes of processes eight Taiwan of eight specialty Taiwan teas specialty are demonstrated teas are indemon- detail stratedand partitioned in detail intoand partitioned the different into flavor the categoriesdifferent flavor in Figure categories1. in Figure 1. Figure 1. The manufacturing processes and flavorflavor categories of eighteight specialty teas in Taiwan. The flavorsflavors of DongdingDongding Oolong, Tieh-Kuan-Yin, andand RedRed OolongOolong areare assignedassigned toto the flavorflavor category of heavy roast ball-type Oolong tea (HRBOT). Since 1991, the import quantity of Taiwan’s tea has rapidly surpassed the export quantity, as shown in Figure 2. Due to changes in industrial structure, decreased land Foods 2021, 10, 836 3 of 17 Foods 2021, 10, x FOR PEER REVIEW 3 of 18 Since 1991, the import quantity of Taiwan’s tea has rapidly surpassed the export quantity, as shown in Figure2. Due to changes in industrial structure, decreased land resources, and rising labor costs, Taiwan has also transformed from a tea exporter to a tea resources, and rising labor costs, Taiwan has also transformed from a tea exporter to a tea importer to meet domestic consumer demand. The development of the tea industry also importer to meet domestic consumer demand. The development of the tea industry also emphasizes environmental and sustainable responsibility, and authentication of health, emphasizes environmental and sustainable responsibility, and authentication of health, natural, local, and traditional characteristics [7]. Thus, Taiwan’s tea industries have con- natural, local, and traditional characteristics [7]. Thus, Taiwan’s tea industries have con- ceived the creation of a high-value, high-quality economic ecology and industrial routes ceived the creation of a high-value, high-quality economic ecology and industrial routes guided by government policies, such as traceability and grading systems in agricultural guided by government policies, such as traceability and grading systems in agricultural products [8]. products [8]. Figure 2. ComparisonFigure 2. Comparison of import and of import export and trade export quantities trade ofquanti Taiwan’sties of tea-related Taiwan’s productstea-related in products the periods in 1989~1993 and 2015~2019.the The periods import 1989~1993 and export and data 2015~2019. were sourced The import from the and agricultural export data statistics were sourced website from (accessed the agricul- on 15 August 2020) of the Counciltural of statistics Agriculture website in Taiwan. (accessed on 15 August 2020) of the Council of Agriculture in Taiwan. Food authenticationFood authenticationis the process of is theveri processfying compliance of verifying with compliance a food label with instruc- a food label instruction. tion. Whether fromWhether a business from a perspective business perspective or a legal or perspective, a legal perspective, food authentication food authentication has has aroused aroused significantsignificant interest. interest. Labeling Labeling and ingredient and ingredient regulations regulations may vary may by varycountry by countryor or region region for food forsafety food issues safety or issuesprevention or prevention of criminal of activities criminal [9]. activities Many beverages, [9]. Many such beverages, such as as wine, coffee,wine, and beer, coffee, are and labeled beer, arebased labeled on the based biological on the materials biological [10] materials and the [10 pro-] and the protected tected designationdesignation of origin of and origin processing and processing methods methods [11]. However, [11]. However, the genetic the genetic bioinfor- bioinformation of mation of freshfresh tea leaves tea leaves has been has beendestroyed destroyed and is and difficult is difficult to identify to identify after after undergoing undergoing processing processing withwith physical physical stress, stress, high high temper temperatureature drying, drying, and and extraction extraction with with hot hotwater. water. Numerous technologicalNumerous approaches technological have approaches also been haveutilized also to been profile utilized the character- to profile the characteris- istic fingerprinttic of fingerprintbeverages with of beverages physical or with chemical physical data or [12,13]. chemical However, data [12 ,it13 is]. difficult However, it is difficult to connect theseto auxiliary connect theseverification auxiliary methods verification with consum methodsers’ with impressions consumers’ of impressionstea and of tea and use them for authenticationuse them for in authentication tea trade. The in Tea tea Research trade. The and Tea Extension Research Station, and Extension Taiwan Station, Taiwan (TRES) and industrial(TRES) experts and industrial proposed experts the st proposedrategic framework the strategic of “Image framework Shaping of “Image of the Shaping of the International BrandInternational of Taiwan Brand Tea and of Taiwan