Abstract: In order to explore the effect of fermented loose tea technology with Eurotium cristatum LJSC.2005 on the quality of primary dark tea, the major part of Hunan Fu tea, the sensory evaluation, biochemical composition analysis and head-space solid-phase micro-extraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) technologies were used to analyze its effect on the primary dark teas made from six main tea cultivars in Hunan Province. The sensory evaluation results show that, compared with the primary dark tea, the loose tea sample after fermentation had golden flowers, deeper color, more flat and tight strips and deeper tea soup color. Its taste changed from astringency to mellow and its aroma changed from the flowery and fruity aroma of sun-dried dark tea and the smoky pine aroma of the seven-star stove to the strong and pure fungus aroma. Biochemical component analysis shows that the contents of taste components such as flavonoids, tea polyphenols, free amino acids, catechins and quercetin in fermented loose tea were generally lower than that of primary dark tea, and the soluble sugar and myricetin show a downward trend. HS-SPME/GC-MS analysis shows that there were a total of 71 aroma components in the tea samples, including 14 hydrocarbons, 16 alcohols, 10 aldehydes, 10 ketones, 6 esters, 4 phenols, 1 lactone, 6 nitrogen compounds and 4 oxygen compounds. Styrene and geraniol isobutyrate were the common aroma components of the primary dark tea. (E)-linalool 3,7-oxide, isophytol and acetophenone were the common aroma components of the fermented loose tea. Compared with the aroma components of primary dark tea, 16 components such as methyl salicylate, (E)-oxidized linalool (furan), (E)-linalool 3,7- oxide, β-ionone and geraniol isobutyrate were the characteristic aroma components of the loose tea fermented by Eurotium cristatum LJSC.2005.

Key words: Eurotium cristatum LJSC.2005, primary dark tea, fermented loose tea, Fu tea