Quality analysis of Hawk-black-tea made from Machilus rehderi and Lindera glauca

【Objective】 The research aimed to provide a theoretical basis for the development of local Hawk tea industry in Guizhou by evaluating the quality of Machilus rehderi and Lindera glauca Hawk-black-tea.【Method】 According to the traditional black tea process, the Hawk-black-tea was made from fresh leaves of M. rehderi and L. glauca as the research materials. Then sensory evaluation, determination of biochemical components and related analysis of two kinds of Hawk-black-tea were carried out, and their volatile substances were detected by gas chromatography-mass spectrometry.【Result】 The L. glauca Hawk-black-tea had a curly shape, a long and high aroma, and a mellow taste, the total score of L. glauca Hawk-black-tea was 90.08; the M. rehderi Hawk-black-tea had a tight shape, a long-lasting aroma, and a fresh, sweet, and mellow taste, the total score of M. rehderi Hawk-black-tea was 89.84. The contents of tea polyphenols, protein and theaflavin in L. glauca Hawk-black-tea were 62.3%, 37.5% and 11.1% significantly higher than those in M rehderi Hawk-black-tea respectively(P<0.05, the same below). The content of flavonoids in M. rehderi Hawk-black-tea was 29.3% significantly higher than that in L. glauca Hawk-black-tea. Seventeen kinds of amino acid components were detected in both kinds of Hawk-black-tea. The total content of amino acid components in L. glauca Hawk-black-tea was 5.4% higher than that in M. rehderi Hawk-black-tea. Aspartic acid, glutamic acid, lysine and leucine contents were the higher components in the two kinds of Hawk-black-tea. The water extract and theaxanthin of L. glauca Hawk-black-tea was signi-ficantly positively correlated, and there was significant negative correlation between the water extract and total flavonoids, soluble sugar, protein and crude fat. The water extract of M. rehderi Hawk-black-tea was significantly positively correlated with protein, and negatively correlated with total flavonoids, theaflavins, crude fat and ash. A total of 15 volatile compounds were detected in L. glauca Hawk-black-tea by gas chromatography-mass spectrometry, including eight terpene hydrocarbons, two alcohols, one aldehyde, two esters, and two other compounds. Fourteen volatile compounds were detected in M. rehderi Hawk-black-tea by gas chromatography-mass spectrometry, including five terpene hydrocarbons, one alcohol, four aldehydes, one ester, and three other compounds.The highest volatile compounds in two kinds of Hawk-blacktea were terpenes.【Conclusion】 Through the determination of sensory evaluation results, biochemical components and volatile substances, the fresh leaves of L. glauca and M. rehderi are suitable for making Hawk-black-tea, with good quality and different characteristics.