Study On New Processing Technique Of Tengcha

Tengcha, a wild liane, belongs to Ampelopsis Michx of Vitaceae. Being of great value in medicine, the leaves had been usually processed into dry sample to brew and drink.The orthodox processing technique of Tengcha had lots of defects, considering this situation, through studying Tengcha in Laifeng county, Enshi municipality, a set of new processing technique was brought forward in this research. And through investigating the variation of biochemistry components during processing of new technique, the de-enzyming condition and shaping technics were optimized, the technical process and its parameter were confirmed, the mechanizing processing technique was carried into effect, the standard was drawn up. In addition, orthogonal design experiment and regression analysis were applied to the research of organoleptic evaluation. The following were all the results:Variations on the contents of main biochemistry components during processing of new technique were investigated. Results showed that contents of flavonoids, chlorophyll and soluble protein decreased, and that of amino acids, soluble sugar increased first and then decreased. The result of color analysis indicated that the values of a* of drying sample and liquor were all negative and that of b* were all positive, the green hue and lightness reduced, and the yellow hue raised during the processing.The processing material of Tengcha was studied for the first time. It was found that the influence of the materials in different parts on quality was significant. The bud and leaf characterized good suitability for processing and abundant nutrient substance; The utilization value of stalk was low because of less nutrient substance in it. The quality of Tengcha made from wild material was inferior with the color yellow, the aroma tender and the taste saline. On the contrary, the quality of Tengcha made from domestic material was superior, but the fertilizer ought to be used in reason during the management of planting. The picking of bud and leaf should be separate, the bud was used to process into slap-up product and the leaf into general product.Random design experiment was used to research the influence of de-enzyming temperature (100℃, 120℃, 140℃) and time (50s, 70s, 90s) on the quality of Tengcha. Results made clear that the contents of chlorophyll and amino acids increased first and then decreased, the flavonoids content reduced and the soluble sugar content raised with the de-enzyming temperature rising and time delaying. At high temperature for long time, the sample would get burnt. Oppositely the gramineous substance in the sample was not easy to get rid of at low temperature. According to the organoleptic evaluation and the variation of biochemistry components, it was regarded that the optimizing condition was: de-enzyming temperature 120℃and time 70s or de-enzyming temperature 140℃and time 50s.Two-pan quhao roasting machine was applied to the shaping procedure of Tengcha. Orthogonal design experiment was used to research the influence of shaping temperature (120℃, 150℃), leaf weight (8kg, 11kg) and water content (38%, 45%) on the quality of Tengcha. It was revealed that the influence of shaping temperature, leaf weight and water content on the quality of Tengcha were significant, in which the shaping temperature and water content were the main factors. The protein and polysaceharide tended to hydrolyze under high water content at high temperature, which made the contents of amino acids and soluble sugar increased. The high shaping temperature was not benefit to maintenance of active components and forming of green hue because it promoted the decomposition of flavonoids and chlorophyll. The influence of leaf weight on the appearance of Tengcha were also significant. The quality of tight and round appearance was not easy to be formed at fewer leaf weight. Considering comprehensive characteristics, optimization of the shaping condition was as follow: shaping temperature 120℃, leaf weight 11Kg and water content 38%.The effect of brewing time, temperature and the dosage on the quality of Tengcha were investigated for the first time. It was founded that high-quality liquor could be obtained under the conditions of brewing temperature 95℃, time 2.5 min and the dosage 3.5 g. The regression equation of total quality score of Tengeha upon the light-dark L^* (X₁), the red-green a^* (X₂), the yellow-blue b^* (X₃) was Y=361.18-4.63X₁+1.89X₂- 2.16X₃ (R²=0.6348, p＜0.01). The model was statistically significant and matched with actual problem. The liquor chromaticity was correlated significantly with the quality of Tengtea., which could be a useful monitoring means of the quality of Tengtea.Mechanizing technical process was carried into effect. The technics flow could be confirmed as: Fresh leaf—withering—de-enzyming(rotary continuous de-enzyming machine)—rolling(roller)—second drying(rotary continuous de-enzyming machine) shaping and drying(two-pan quhao roasting machine)—improving aroma(two-pan quhao roasting machine).The standard about quality and processing technique of Tengeha was drawn up. This standard which could provide guarantee for the steady quality of Tengeha was regulated strictly on quality of fresh leaf, processing technique, management of health, quality of dry sample, indexes of health, regulation of test, lab, management of store et al.