Studies On The Influence Of Blending And Baking Process On Quality Of Tanyang Congou Black Tea

Tanyang congou is one of the three major black teas in Fujian.Its unique quality and flavor is deeply favored by consumers.In this research,six kinds of fresh tea leaves from Tanyangcaicha,Fu'andabaicha Jinmuda n,Jinguanyin,Meizhan and Baiyaqilan were selected to make different styles of Panyong congou black tea using traditional techniques and floral type respectively,to explore the influence of process and variety on the quality of Tanyang congou black tea;in order to enrich the Tanyang congou category,design different blending stratgies of traditional and floral Tanyang congou,through sensory evaluation,biochemical analysis and aroma determination,study the effect of the blending process on the quality of Tanyang congou,to improve the quality of Tanyang congou black tea and determine the characteristic flavor;For the problem of short storage time and weak aroma of floral-type Tanyang congou,A Baking orthogonal test with different temperature times is used to study the effect of baking process on the quality of Tanyang congou black tea,in order to improve and fix the quality of Tanyang congou and prolong storage time.This paper studies the influence of blending and baking process on the quality of Tanyang congou with holding the promise of improving and fixing the quality of Tanyang congou,and varing the products of Tanyang congou and extending the storage time.Moreover,our study provides theoretical basis for the blending and baking processes of Tanyang congou,and lays the foundation for the new round of development of the Tanyang congou industry.The research results are as follows:1 The effect of different techniques on the quality of Tanyang congou black teaThe effects of different processes and varieties on the quality of Tanyang congou were investigated by sensory evaluation,biochemical determination and colour difference analysis with 12 different kinds of different processes of Tanyang congou.The experimental results showed that the traditional-type was characterized as strong and mellow taste,and orange-red and bright tea soup.These quality characteristics were corresponding to biochemical characteristics of higher content of water extracts,amino acids,tea polyphenols,caffeine and thearubigins than the floral-type,and the statistic difference was significant;the floral-type exhi bited mellow and refreshing taste,orange and bright colour,and lingering aroma.Besides,the contents of theaflavins and theabrownins were significantly higher than the traditional-type.The colour difference of tea soup showed that the traditional-type L*value was lower than that of the floral-type,and the mean value was 0.09,while the a*value and b*value were higher than the floral-type Tanyang congou,the difference was 0.34 and 0.57 respectively.Combined with sensory evaluation,it showed that the traditional Tanyang congou's tea soup's colour is rich in red,taste strong and mellow,smell sweet and mellow,and the floral-type tea soup was brighter than orange and yellow,with a pleasant taste and high aroma with significant floral and fruity.2 The effect of different varieties on the quality of Tanyang congou black teaFuandabaicha and Tanyangcaicha are traditional varieties in the Tanyang region.Tanyang congou processed by both techniques shows that the taste of tea is mellow,sweet and lasting.The traditional Fuandabaicha tastes mellow and sweet,has sweet after taste,soup colour orange red bright and clear,sweet and rich lasting;amino acids(4.17%),tea polyphenols(14.12%),caffeine(4.80%),theaflavins(0.44%),and thearubigins(7.79%)Significantly higher than other varieties.The varieties(Jinmuadan,Jinguanyin,etc.)with high aroma are processed into Tanyang congou which exhited lasting and fragrant floral and fruity scent,mellow and refreshing taste with floral aroma,but lower strength;the golden peony tastes mellower and sweeter with floral and fruity flavor,and the soup is orange and bright.The aroma has a unique peachy scent and which is long and fragrant;The contents of tea polyphenols(10.89%),caffeine(4.43%)and theaflavins(0.40%)are also higher than those of other varieties.3 The quality characteristics of different blending stratgies and the influence on the quality of Tanyang congouIn order to improve the traditional Tanyang congou aroma and improve the flavor of the flower and fruit flavor,and to determine its characteristic flavor,design two different combinations of the stratgies,one is single type blending stratgies used traditional process of Tanyangcaicha and Fuandabaicha as the basal tea,and the high-fragrance varieties for adjust tea.The other is single type and composite type blending scheme which used floral process of high-fragrance varieties as the basal tea,and the Tanyangcaicha and Fuandabaicha for adjust tea.Screening through sensory evaluation,the experimental results showed that among the different blending schemes,P6,P7,P9,P12,P17 and P20 were selected;P6 peach scent is sweeter and thicker,and the taste is mellower and floral,and the degree of blending is high;P7 sweet floral fragrance is long lasting,and the taste is rich and sweet with floral fragrance;P9 peach scent is rich and long-lasting,with a mellow taste and rich peachy aroma;P12 clear floral fragrance with frankincense,tastes sweet and fragrant;P17 peach with floral notes,mellow and smooth;P20 has a sweet floral scent and is mellow and smooth.Among thecorresponding biochemical components,P7 water extract(36.76%),amino acid(4.26%),tea polyphenol(14.33%),caffeine(4.81%)and theaflavin(0.48%)were significantly higher than other teas.Similarly,the content of P6 safflower(8.97%)was significantly higher than that of other tea samples,and the content of P9 flavonoids(13.72 mg/g)was the highest value among the six samples.Compared with the corresponding basal tea,the sensory quality of each sample was improved.Among them,the traditional blending scheme improves the single flavor of the raw tea and enhances the rich purity of the aroma.The floral blending method of Tanyang congou improve the mellow taste of tea,increased the level and richness of the aroma.Applying it to actual production has a certain effect on improving the market competitiveness of Tanyang congou.4 Different aromas of Tanyang congou with different blending processesThe aroma determination was carried out by GC-MS using 6 kinds of Tanyang congou blending tea as materials,to analyze the differences of aroma components caused by different processes.The results showed that the traditional Tanyang congou had a high content of geraniol,linalool,methyl salicylate,and ?-juresene and D-limonene.Besides,the concetrention of geraniol and linalool,the nerolidol,benzyl alcohol,benzaldehyde,?-ionone,jasmone,acetate ester,?-myrcene,basilene and?-farnesene is also relatively high.D-limonene in the olefinic substance has the highest content in the floral single-matching sample,which is nearly 40%,but only about 10%in the floral-type compounding sample.And the principal component analysis showed that the contribution of this substance in the aroma of Tanyang congou was low and had little effect on the aroma.5 Aroma characteristics and composition of three characteristic scented Tanyang congouThrough the combination of blending and production,it was determined that the three main characteristic types of Tanyang congou black tea products are:peach-flavored,refresh-flavored type and sweet-flavored type.The aroma of the peach-flavored Tanyang congou is mainly sweet peach,with floral aroma and rich aroma;it mainly contains aroma substances with sweet fruit aroma,such as nerolidol,nerol,acetate ester,dihydro anemone,?-myrcene,etc.,and the relative content of geraniol is slightly lower.The aroma characteristic of the refresh-flavored Tanyang congou is refreshing floral with sweet or milk flavour,high aroma and purity;among them,aroma substances,such as linalool,trans-2-hexenal,methylheptenone and ?-farnesene,are refreshing and fresh floral fragrance which are relatively abundant.The sweet floral fragrance of Tanyang congou is mainly characterized by sweet and fragrant flowers and fruit aromas,and its aroma is more intense and persistent.It has more aroma substances with a sweeter floral aroma,such as geraniol,phenylethyl alcohol,?-ionone,?-myrcene,?-caryophyllen and other aroma components.Principal component analysis shows that the highest contribution rate of aroma in Tanyang congou is the aldehydes,esters and ketones,and the contribution of aromas such as yttrium,a-famesene and nerolidol is also large.Followed by most of the alcohols and some of the olefinic substances,such as linalool,geraniol,?-juresene and so on.The content of hydrocarbons and some esters alkenes such as jasmonide,?-caryophyllene,a-elemene and so on are at the middle level.The content of some alkenes and hetero-oxygen compounds,such as 2-ethylfuran,?-myrcene,D-limonene and y-elemene were the lowest.6 Analysis of Quality Storage Changes of Tanyang congou in Different Baking ProcessesIn order to reduce the problem of fast change of floral Tanyang congou quality and short storage time,this test uses the floral type P9,P12 and P17 as materials to match the sample,using different time(1h,1.5h,2h),different temperatures(80 ?,90 ?,100 ?)for orthogonal experiments.The results show that during the three-month storage process,HB2,HB3 and HB6 reduced the taste of the fire,and the flower and fruit fragrance remained intact.The freshness and mellow in the taste of the tea soup were stable,the quality remained good and the quality of the control sample was also greatly improved.Biochemical analysis showed that the water extract of HB2 after storage for three months(35.02%),tea polyphenols(11.70%),caffeine(4.73%),flavonoids(15.68 mg/g),theaflavins(0.42%)and the content of thearin(8.46%)was significantly higher than other samples.The aroma analysis showed that the content of HB2 geraniol(14.07%)was lower than that of CK1(18.13%),but the content of linalool(7.83%)was higher,and had more fruity substances such as benzaldehyde,n-hexanal,and methylheptenone,and baking aromas such as 2-ethylfuran and tea pyrrole.Therefore,the comprehensive sensory evaluation and biochemical analysis,baking time 1h,temperature 90 ? treatment HB2 is the best baking conditions for the Tanyang congou quality improvement and aroma fixation.The quality of the unbaked control changed greatly during storage.CK1 showed a water stuffy smell and a coarse taste after storage for three months.CK2 had a reduced floral aroma and a strong green leaf volatiles in both aroma and soup.The smell of peach in CK3 disappeared and turned into a floral aroma,what's more the mellow of the tea soup also decreased.The control group was seriously green leaf volatiles during the process of storage,and excellent quality characteristics also gradually disappeared with the storage time,and it transformed into green or stale taste.It indicated that the baking process which can improve the quality of tea and has a good effect on the storage time of tea plays an important role in the quality of tea,It is of great significance to the transportation,storage and sales links of Tanyang congou.