Characterization of Volatile Compounds and Sensory Analysis of Jasmine Scented Black Tea Produced by Different Scenting Processes

Abstract

Jasmine scented black tea is widely popular in China and the scenting process is the most crucial issue affecting its aroma quality. This study aimed to analyze the influence of different processes on aroma quality and the specific contribution of volatiles to aroma quality. To achieve it, the headspace solid‐phase microextraction method combined with gas‐chromatography mass‐spectrometry was used to identify and quantify the volatile compounds, and further collected the characteristics according to odor activity values or contents. The quantitative descriptive analysis (QDA) and traditional sensory analysis (TSA) were used to evaluate its aroma quality and the correlation analysis between QDA and characteristic aroma compounds was carry out to analyze the specific contribution of characteristics to sensory quality. The GC/MS results showed that 130 aroma components and 20 characteristics were identified in 6 tea samples and more new volatile components appeared and less original volatile components disappeared in traditional scenting process (TSP) compared with continuous scenting process (CSP). The QDA and TSA results showed that TSP samples had better “overall” and “jasmine” than CSP samples. The correlation analysis between QDA and characteristics showed that nerolidol and methylbenzoate were related to “overall,” linalool and methyl anthranilate to “jasmine,” and decanal and benzeneacetaldehyde to “sweet floral,” “roasted,” and “fermented.” This study suggested that TSP is a favorable scenting process for black tea, and QDA is an objective and digital sensory evaluation method for jasmine scented black tea. Practical Application Compare the effect of scenting technology on the aroma quality of jasmine scented black tea based on sensory analysis and chemical analysis, and suggested a favorable scenting process for processing jasmine scented black tea with better qualities. Explore the correlation between aroma composition and specific aroma properties to provide some useful information about guiding the scenting process to acquire a product with target aroma qualities. And the application of QDA for evaluation of jasmine scented black tea was better for consumers to understand the quality attributes of product.

Comparison of Volatiles in Different Jasmine Tea Grade Samples Using Electronic Nose and Automatic Thermal Desorption-Gas Chromatography-Mass Spectrometry Followed by Multivariate Statistical Analysis

“…Linalool, imparts a floral, fruity, and woody odor in jasmine tea, and benzyl alcohol provides a sweet, roasted, mild, fruity and citrus-like aroma, were contained in both the tea dhool and jasmine flowers [4,27,31]. Here, the relative content of 3-hexen-1-ol in alcohols was lower than both linalool and benzyl alcohol.…”

“…These four volatile compounds are found in green tea, and existing studies show that cyclopentanone, (Z)-Linalool oxide and (E)-Linalool oxide are negatively correlated with the grade of green tea [16,32]. It also was reported that phenyl ethyl alcohol, α-Terpineol, and geraniol were all derived from jasmine flowers, having floral or sweet odor [3,4,33]. MS,RI Eugenol 0.12 ± 0.00b 0.25 ± 0.04a 0.11 ± 0.02b 0.10 ± 0.03b 0.05 ± 0.02b 0.06 ± 0.02b a-d Means ± SD followed by the same letter, within a row, are not significantly different (p > 0.05); e 1G, 2G, 3G, 4G, 5G, and 6G represent the standard sample for the grade of jasmine tea from high rank to low rank; f MI, method of identification; N.D., peak intensity lower than triple signal-to-noise.…”

“…Shown in Table 1, the volatile compounds were identified by matching their mass spectra fragmentation patterns, retention index with those stored mass spectra libraries (NIST 11.L and Wiley 7), and combining them with existing works of literature [3,4,[26][27][28]. The relative content of identified compounds was obtained by comparing them with the peak area of internal standards ( Table 2).…”

“…There were thirteen kinds of identified alcohol in the jasmine tea grade samples. Among these identified alcohols, linalool and benzyl alcohol, which are abundant in jasmine flowers [4,27,30], accounted for 52.32% and 30.91% of the total content of alcohol, respectively.…”

“…Moreover, the health effect of tea also has been widely confirmed [2]. Both of these concepts make jasmine tea a popular tea worldwide [3,4]. Traditionally, the processing of jasmine tea, includes the following seven steps (shown in Figure S1) of tea dhool preprocessing, fresh flowers maintenance, tea and flower combination, scenting, flower removal, drying, and packing [5].…”