Study On Light Response And Physiological And Biochemical Quality By LED To Oolong Tea Withering

Oolong tea is a type of special tea with high aroma(flower and fruit aroma).Sun withering is the first process to formate a strong aroma,mellow taste and fine qualities of Oolong tea.The peak production of Oolong tea in spring,which often meet rainy and wet weather,leading to low stuffily aroma and thin smell quality without normal sun withering.In order to make up for sun withering in wet weather,the test is based on the superiority with high purity luminous of LED,taking rain leaves of South Fujian Oolong tea as research object,combining sun withering and interior withering,preliminary discussing the influence on light response change rule and characteristics,physiological and biochemical,aroma and quality with different spectral withering by LED.Test results are as follows:1、The test and evaluation on physical performance of LEDThe irradiation distance(100～500mm)between light luminous surface and receiving surface from the different spectral LED is larger,the uniformity of receiving surface is better.Through comprehensive testing,we can concluded that the best irradiation distance of different spectral by LED(emitting area is 200mm×200mm)is 200～300mm.2、Study on light physiological response under different light environment witheringWith sun withering and LED withering,excised leaf generated light response that the net photosynthetic rate is more than 0μmol·m-2·s-1.Present a trend that first increased and then decreased as a "∩ unimodal type",response time is short.Under interior withering,the net photosynthetic rate almost stable at-2.5μmol·m-2·s-1.The net photosynthetic rate of light withering is remarkable larger than interior withering.The leaf temperature of different light processing is 1～3 ℃ higher than interior withering.3、Study on the light response character of sun witheringThe change trend of stomatal conductance、transpiration rate and the net photo synthetic rate are similar in the process of sun withering.Comparison with interior withering,the stomatal conductance and transpiration rate of sun withering show that leaf stomata are stretched by the light induction,increased transpiration,promoted leaf dehydration and transformation of substances containing.4、The effect on light response character by monochromatic of LEDWith decrease of light wavelength,the net photosynthetic rate show the change with first decreased and then increased,red LED is maximum,blue LED take second place,yellow LED is minimal;With decrease of PAR,the net photosynthetic rate show the change with basically stable after rising first,the net photosynthetic rate has maximum when the PAR value reaches 600μmol·m-2·s-1,strong light inhibition of photosynthetic ability;Under the different withering temperature,With increase of temperature,the net photosynthetic rate has maximum when withering temperature reaches 30℃,high temperature can cause leaves turn red.5、The effect on light response character by combined of LEDUnder different proportion,the combined light(R:B = 1:1)makes green leaf reaction of net photosynthetic rate has a maximum;Under different PAR is decrease,the net photosynthetic rate present a change that first increased and then decreased slightly,the net photosynthetic rate has maximum when the PAR value reaches 600μmol·m-2·s-1;When continuous light irradiates green leaf for 30 minuter can show a better light response ability.6、The influence of Tieguanyin tea physical and chemical ingredients on different spectrum of LED witheringThe temperature of tea leaves raise rapidly which processed by the sunlight and combined LED,water loss rate are fast,and interior withering rate is slowest.The comprehensive conclusion is that sunlight and blue LED is beneficial for the accumulation of soluble contain materials of tea,especially promote the accumulation of water extract and amino acid content.The net photosynthetic rate are positively correlated with each biochemical components(R2=0.180)for withering leaves,and it showed a very good coordination and balance effect,Improvement of the same level of each containing material provides a good material basis for later conversion and synthesis.7、The influence of Tieguanyin tea aroma components on different spectrum of LED witheringIn the raw tea aroma components of Tieguanyin processed by different ways,the main fragrant substances are alpha olefin(flowers material)and nerolidol(fruity fragrance material).The raw tea aroma quality of sunlight is best,aroma quality of yellow and blue LED is better,the interior withering is the worst.The net photosynthetic rate is higher,the raw tea aroma quality(flower fragrance material)is better.8、The influence of Tieguanyin tea quality on different spectrum of LED witheringThe sensory score of raw tea quality of sunlight is best,blue LED is better,the interior withering is the worst.The blue LED can replace the sunlight to compensate for the lack of sunlight on the rainy day,and it can promote the assigned material to produce clear flower fragrance,increase raw tea sensory quality of Tieguanyin.