## 1 Introduction  
Black tea, renowned globally for its distinct, diverse, and rich aroma, is the most widely produced and consumed tea type worldwide [1]. The aroma of black tea is characterized by sweet, floral, honey, and caramel-like notes [2, 3]. Aroma performance is constituted by the mixture of multiple volatile flavor compounds (VFCs) [4, 5], making the study of VFCs a focal point in tea research. To date, over 600 aroma components have been identified in black tea, primarily consisting of aldehydes, alcohols, esters, alkanes, and ketones [6]. Among these, geraniol (rose floral), trans-\(\beta\)-ionone (floral), methyl salicylate (floral), (Z/E)-linalool oxides (floral), linalool (sweet floral), phenylacetaldehyde (honey),and \(\beta\)-damascenone (sweet, honey-like) amongst others are recognized as the predominant aroma-active compounds [7,8], which are primarily generated during tea processing.  
The processing of black tea involves several stages: withering, rolling/rolling and cutting, fermentation, and drying. Withering, the initial step, plays a crucial role in shaping the overall aroma quality of black tea [9,10]. Appropriate withering techniques can promote the favorable transformation of volatile aroma compounds in fresh tea leaves, thereby enhancing the tea's aroma quality [11]. With continuous innovation in withering technology, many black-tea-producing regions in China have incorporated shaking into the withering process to enrich flavor, resulting in what is known as shaken black tea (SBT) [12]. Shaking involves rotating withered leaves using a water sieve or shaker machine. Studies have shown that shaking facilitates friction-induced damage along the leaf edges, stimulating enzyme activities such as oxidase, hydrolase, and reactive oxygen species metabolism enzymes [13], thereby promoting the synthesis of floral compounds like indole, methyl jasmonate, and \(\beta\)-ionone, and significantly enhancing the floral flavor of black tea [14,15].  
Additionally, previous research demonstrated that yellow, orange, and red-light withering can significantly improve the aroma and taste quality of black tea, with yellow light particularly effective in increasing the content of VFCs such as linalool and geraniol [16]. Numerous studies also highlighted the role of light quality in tea spreading and withering processes. For instance, yellow light combined with low-temperature treatment markedly enhanced the synthesis and accumulation of methyl salicate and indole during green tea spreading [17], while red-light withering primarily influenced the accumulation of terpene volatile components in the later stages of black tea withering by upregulating key synthase gene expression [18]. Furthermore, warm-air withering is commonly used in black tea production to accelerate water loss and shorten withering time [19], though there is limited research on the effects of high-temperature withering on black tea aroma components.  
While existing research has primarily focused on the impact of individual technologies on black tea quality, there is a lack of systematic investigation into the combined effects of multiple withering technologies, particularly on aroma quality. The influence of different combinations of yellow light, high temperature, and shaking on the metabolism of volatile compounds in black tea remains unclear. Therefore, this study explores the effects of different shaking combinations of yellow-light or high-temperature withering on the volatile aroma compounds of black tea, aiming to provide theoretical and practical insights for the application of various withering techniques in black tea production and to lay the groundwork for optimizing processing technologies for high-quality black tea.