| For considering the low utilization and economic benefit of summer and autumn tea leaves and the tradition of production and consumption of acid tea in minorities, the technology of acid tea fermentation was studied. The effects of different factors on the quality formation of acid tea were studied, the fermentation process technology of acid tea was optimized, the dynamic of acid tea’s quality formation was analyzed, the health quality of acid tea was tested, and the quality standard of acid tea was established, and five different flavors products of acid tea were produced preliminary. These provided technical and theoretical basis for development and production of acid tea, created a new way of the development and utilization of fresh summer and autumn tea leaves, enriched the kinds of biological tea products and improve the value of tea products to meet the demand for people’s health.The results were as follows:1 Effects of Different Materials Treatments on the Quality of Acid TeaAccording to the sensory quality and the chemical quality of acid tea fermented by the materials of different tenderness, different de-enzyming methods, different water loss rate, different rolling time, the results showed that a bud with a leaf or two leaves, blanching fixing,25% of water loss rate and 10 min of rolling time were more benefit to form the unique quality of acid tea.2 Effects of Different Fermentation Conditions on the Quality of Acid TeaAccording to the sensory quality and the chemical quality of acid tea fermented by the conditions of different salt concentrations, different fermentation temperature and different fermentation time, the results showed that 4% of salt concentration,25℃of fermentation temperature and 7d of fermentation time a bud with a leaf or two leaves, blanching fixing,25% of water loss rate and 10min of rolling time were more benefit to form the unique quality of acid tea.3 Optimization of the Fermentation Technology of Acid TeaBased on the results of single factor experiments, the orthogonal experiment (L9 (34)) was conducted to optimize the fermentation conditions of salt concentrations (2%, 4%,6%), fermentation temperatures (room temperature,30℃,37℃) and fermentation times (5 d,7 d,9 d) through analyzing the quality of acid tea. The results showed that the optimum fermentation conditions of acid tea were 2% of salt concentration, room temperature of fermentation temperature and 7 d of fermentation time. 4 Analysis of the Dynamic of Quality Formation of Acid TeaThrough the dynamic analysis of the quality formation of acid tea, pH values, tea polyphenols, amino acids, soluble sugar, caffeine and water extracts of acid tea were showing an overall downward trend in the fermentation process, and up to stationary state in the end. According to the results of sensory evaluation, the score of acid tea was the highest in seventh day of fermentation time, and 7 d of fermentation time was favourable to the quality formation of acid tea.5 Effects of Different Fermentation Methods on the Quality of Acid TeaThe main quality components and sanitary indexes of acid teas fermented by natural fermentation and inoculated fermentation under the optimum parameters of fermentation technology, were compared, and the unfermented tea samples was as a control. The organoleptic quality of natural fermentation was better than that of inoculated fermentation, the content of amino acids, flavonoids, theaflavin, theabrownins and water extracts of acid tea fermented by natural fermentation was rather higher than those of acid tea fermented by inoculated fermentation.The aroma components in acid tea were extracted by headspace solid-phase micro-extraction (HS-SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS), and 44 kinds of aroma components were detected. The aromatic components in acid tea were mainly alcohols, aldehyde and alkene. The total content of aroma components in acid tea reduced after fermentation, the content of acid tea fermented by natural fermentation slightly higher than that of acid tea fermented by inoculated fermentation.6 Sanitary Indexes and Quality Standards of Acid TeaAmong the health indicators of acid tea, except that the content of aluminum (218 mg/kg) was slightly higher, the contents of copper, lead, arsenic, fluoride and nitrite were 5.32 mg/kg,2.55 mg/kg,0.17mg/kg,113.59 mg/kg and 0.32 mg/kg, respectively, and low to the relevant limits. E. coli was low to 30 MPN/100g, and the pathogenic bacteria (Salmonella, Shigella, Staphylococcus aureus and Hemolytic streptococcus) were not detected.According to the pickles standard (GB 2714-2003), the limit of chromium, cadmium, mercury, arsenic and fluoride in tea (NY 659-2003), the limit of food contaminations (GB 2762-2005), and other relevant limits, the quality standards of acid tea were proposed: copper (Cu)≤60 mg/kg, arsenic (As)≤0.2 mg/kg, lead (Pb)≤3 mg/kg, fluoride (F-)≤200 mg/kg, nitrite (NaNO2)≤4 mg/kg, E. coli≤90 MPN/100g (bulk) and≤30 MPN/100g (bags), and pathogenic bacteria(Salmonella, Shigella, Staphylococcus aureus and Hemolytic streptococcus) could not be detected.7 Five Different Flavors Products of Acid Tea were Produced PreliminaryThe formulas of five different flavors products of acid tea were as follows:Original acid tea:20% sunflower oil,2% zanthoxylum,3% ginger and 3% garlic.Sweet acid tea:20% sunflower oil,2% zanthoxylum,3% ginger,3% garlic and 4% sugar.Spiced powder acid tea:20% sunflower oil,2% zanthoxylum,3% ginger,3% garlic and 0.1% five-spice powder.Pungency acid tea:20% sunflower oil,2% zanthoxylum,3% ginger,3% garlic and 5% capsicum powder.Lobster sauce acid tea:20% sunflower oil,2% zanthoxylum,3% ginger,3% garlic and 20%lobster sauce. |
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