Changes on Physical, Chemical and Sensory Properties of Compressed White Tea Cakes During Processing

To decipher the quality in relation to processing of compressed white tea cakes, the physical and chemical changes of the tea leaves at key stages in varied processes were monitored. Four treatments, including steaming (ZQ), moisturizing (SM), pressing (YS) and prolonged drying after compressing (YB), in the making of the product were applied for evaluation. All treatments exerted significant effects on the compactness of the cakes with a 100%-150% increase on the bulk density. Among the treatments, ZQ also significantly affected the leaf color, amino acid content and green note reduction; SM stimulated protein hydrolysis as well as amino acid and thearubigins accumulations; YS lowered the polyphenol content, and increased the concentration and freshness of the brewed tea; and, YB encouraged formation of the characteristic aroma and taste of the white tea cakes with increased water extracts and polyphenols as well as heightened conversion of green/earthy to fragrant/elegant note for the brewed tea.