Study On The Effect Of Modeling And Quality Of South Fujian Oolong Tea With Wrapping-rolling And Extruding-rolling Processing

In order to investigate the effect of the modeling and quality of south fujian oloong teawith wrapping-rolling and extruding-rolling processing, this thesis studied a number ofindicators of processing leaves made by wrapping-rolling and extruding-rolling.Theseindicators include physical properties, mechanical properties, leaves microstructure, color,aroma, biochemical, the leaching rate of rehydration and sensory quality. This studies can findthe differences and similarities, the advantage and disadvantage between the wrapping-rollingand extruding-rolling; Initially revealed the wrapping-rolling and extruding-rolling processintrinsic effect and the external effect and its mechanism of action; Providing a scientific basisfor oolong tea modeling technology research which is efficient, high quality and saving. Thestudy achieved the following results:1.The effect of physical characteristics of south fujian oolong tea with wrapping-rollingand extruding-rollingIn first modeling stage，extruding-rolling`s average leaves temperature is lower thanwrapping-rolling. In second and third modeling phase, extruding-rolling average leavestemperature is higher than wrapping-rolling; In the modeling process, processing leavesmoisture content of a downward tendency, the differences in the moisture content of the twocrafts is not significant, after bake extruding-rolling loss much water than wrapping-rolling. Indensity modeling process, bulk density of extruding-rolling is higher than wrapping-rolling. Inthe modeling process, deformation degree and unrecoverable deformation degree ofprocessing leaves decreases with decreasing moisture content, and increases with increasingforce. Degree of deformation in the processing was in a “low-high-low” tendency, extruding-rolling higher than wrapping-rolling.2.The effect of wrapping-rolling and extruding-rolling on the mechanical properties ofsouth fujian oolong teaIn first modeling stage, the modulus of elasticity and stress of extruding-rolling leavesare higher than the modulus of elasticity and stress of wrapping-rolling leaves,extruding-rolling leaves tend to be "yield" phenomenon, strain significantly elevated, propercontrol of density pressure rub efforts, avoid flat bars and caking. In second modeling phaseof two molding process, elastic modulus, stress and strain of processing leaves of the twocrafts at a high level; Stress and strain of extruding-rolling are higher than wrapping-rolling.This is an important reason why high pressure can improve process efficiency. In secondmodeling phase, elastic modulus and stress of processing leaves are on the rise. Strain isdecreasing, brittleness is increasing.Stress and strain of extruding-rolling are higher thanwrapping-rolling still.3.The effect of wrapping-rolling and extruding-rolling on the microstructure of south fujian oolong teaIn the modeling process, tissue and cells of processing leaves gradually compact. Tissueand cells of extruding-rolling processing leaves are tight than tissue and cells ofwrapping-rolling processing leaves. Processing leaves of extruding-rolling have deep creases,and processing leaves of wrapping-rolling have low creases. In first modeling stage,processing leaves tissue of extruding-rolling damage seriously than processing leaves tissue ofwrapping-rolling. extruding-rolling tissue arrange more neat than wrapping-rolling tissue.4. The effect of wrapping-rolling and extruding-rolling on the color of south fujianoolong teaIn the modeling process, chlorophyll a, b and total chlorophyll overall tended toincrease.Chlorophyll content of processing leaves of wrapping-rolling is higher thanprocessing leaves of extruding-rolling.The difference between the two crafts is significant.This is due high leaves temperature in the second and the third phase. In the modeling process,color L tended to decline, and color a tended to increase. The color L and a of processingleaves of extruding-rolling are lower than processing leaves of wrapping-rolling and thedifference between the two crafts is highly significant. The color b of processing leaves ofwrapping-rolling is higher than processing leaves of extruding-rolling, and the differencebetween the two crafts is highly significant.5. The effect of wrapping-rolling and extruding-rolling on the aroma of south fujianoolong teaThe total aroma of primary tea made by extruding-rolling is higher than the primary teamade by wrapping-rolling and the types is lower than the primary tea made bywrapping-rolling. Wrapping-rolling craft retain more sweet density fragrant and floral andfruity ingredients like hexanoate-3-hexenyl acetate and neryl acetone and other fresh leavesfen alcohols, while extruding-rolling craft produce more ketones, esters density other carbonylcompounds.6. The effect of wrapping-rolling and extruding-rolling on the biochemical compositionof south fujian oolong teaIn the modeling process, water-soluble substances, polyphenols, amino acids, flavonoidsis decreasing. Water-soluble substances, amino acids and flavonoids is increase temporarilyafter bake. The water-soluble substances, amino acids and flavonoids of primary tea made byextruding-rolling is higher than primary tea made by wrapping-rolling, while polyphenols islower than primary tea made by wrapping-rolling. The catechin of primary tea made byextruding-rolling is higher than primary tea made by wrapping-rolling.wrapping-rollingprocess is more conducive to the retention of catechins.7. The effect of wrapping-rolling and extruding-rolling on the sensory quality, Inclusions leaching rate and rehydration of south fujian oolong teaPolyphenols and amino acid content of primary tea made by extruding-rolling is higherthan primary tea made by wrapping-rolling in make tea for three times, while caffeine andflavonoids content is lower than primary tea made by wrapping-rolling in make tea for threetimes. Water-soluble substances of primary tea made by extruding-rolling is not balancebetween three times. wrapping-rolling is more balance than extruding-rolling. The sensoryquality of primary tea made by wrapping-rolling is better than primary tea made byextruding-rolling. and the difference between the two crafts is significant. The rehydrationcapacity and rehydration speed of primary tea made by extruding-rolling are higher thanprimary tea made by wrapping-rolling and the difference between the two crafts is highlysignificant.8. The economy analysis of wrapping-rolling and extruding-rollingwrapping-rolling not only greatly improves the efficiency of modeling and reduces thelabor intensity, but also greatly reduces the cost of modeling. The cost of produce onekilogram primary tea by extruding-rolling is only about1/3of produce one kilogram primarytea by wrapping-rolling.