Investigation of the Microbiota, Volatile Flavour Compounds and Sensory Quality of Tea and Coffee Flower Rice Wine After Fermentation Process Optimisation

ABSTRACT To develop a new‐type of rice wine, tea flowers and coffee flowers were added due to their unique flavour, and the fermentation parameters were optimised. Meanwhile, the microbiota and volatile flavour compounds (VFCs) in tea and coffee flower rice wine (TCFRW) were investigated. The results showed that the optimised TCFRW exhibited a buff, transparent colour, rich and harmonious aroma, and mellow and refreshing taste by the sensory evaluation when 1.1% tea flowers and 0.7% coffee flowers were added, respectively, and fermented at 25.4°C for 3.3 d. Meanwhile, Pediococcus (the relative abundance was 62.6%) and Lactobacillus (18.7%) were the dominant bacteria at the genus in TCFRW, while Rhizopus and Saccharomyces were the main fungi, accounting for 68.2% and 11.3% respectively. Furthermore, 798 VFCs belonging to 13 classes were successfully detected and identified in TCFRW, including 217 esters, 158 terpenes, 93 heterocyclic compounds and 84 ketones, while coffee flowers are rich in terpenes, providing the wine with a violet almond aroma, while tea flowers mainly contribute phenylethanol linalool floral fragrance. The synergistic fermentation of the two with glutinous rice can significantly enhance the floral OAV of TCFRW. To sum up, this study will provide a theoretical basis and practical guidance for the development and quality control of novel products of rice wine and enhancing the value‐added potential of tea flowers and coffee flowers.