Thermo Fisher's Solution: Establishing a method for identifying Pu'er tea and white wine with ultra-high resolution MS

Tea + alcohol, ultra high resolution MS to help you technology New Year

At the end of the year, at the beginning of the year, it is a traditional festival, and it is indispensable to visit relatives and friends. Pushing the cup for a staggered time, the time rotation has gone through another year. After the "tea" and "wine", after the narration of the feelings, do you understand the origin of the wine and tea culture? Next, listen to Xiaobian for your sake...

As the origin of tea, domestic tea varieties can be described as colorful, competing for beauty, as many as hundreds. There are several versions of the title of " Top Ten Famous Teas " . Such as West Lake Longjing, Biluochun, Xinyang Maojian, Wuyi Rock Tea, Fujian Tieguanyin is a treasure. As one of the best, “ Pu'er Tea ” has been sought after by people from all walks of life for its high-quality raw materials, unique craftsmanship and natural post-fermentation. It is known as “ an antique that can be drunk ” .

When you first contacted Pu'er, did you remember what four big tea factories and six major tea mountains in your heart? Speaking of " old class " , " Mint Pond " , " Xigui " , " Iceland " , for tea lovers, it is sure to be a treasure. Yes, it is " Iceland " ! However, this " Iceland " is not the island country on the other side of the North Atlantic, but the Icelandic village in Yunnan. Pu'er tea is inseparable from the hills, and the price of a good mountain is also surprisingly expensive. In recent years, the momentum of Icelandic ancient tree tea has exceeded the old class, and the price remains high. In the 2018 spring tea price list issued by the Kunming Tea Industry Association , Iceland's Laozhai ancient tree hair tea is nearly 40,000 yuan a kilogram , which has become the " new era " Wang Xietang former Yan.

To be honest, the difference between Pu'er tea and tea is objective because of the different tea hills, storage years and craftsmanship, and the flavor is different. In the market, Pu'er tea can be seen everywhere, and the prices vary widely. Even the little friends who don't understand Pu'er tea know that the price determines the quality.

Still anxious to tell the quality of Pu'er?

The identification of the origin and quality of Pu'er tea relies mostly on professionals. We all have to rely on drinking and research. However, the goose, "The heart is not quiet, then the tea has no product. " If it is a taste of the heart , it falls into the ranks of violent things.

The laboratory of Associate Professor Li Wei of China Agricultural University has carried out the scientific sublimation of this tasting technology. Combined with the representative of Q Exactive and the most popular omics technology of ultra high resolution mass spectrometry , a set of identification methods for the origin and year of Pu'er tea has been established. Solve the deepest problems from the material basis. Abandoning the subjective judgment caused by " heart is not quiet " , it provides a strong technical guarantee for the identification and traceability of Pu'er tea. Research results published in the well-known industry journal Food Chemistry ^[1], interested partners can first download a small study.

“ Chen Yue Yue ” is the most attractive place for Pu'er tea, and the year naturally becomes an important factor in the quality of Pu'er tea. Teacher Li Wei was very fortunate to have obtained a sample of rare Icelandic ancient Pu'er tea, which was produced from 2006 to 2015. The characteristics of this sample coincided with the identification of the Pu'er tea year. The relevant personnel took a hit and analyzed the teas of these 10 years by means of ultra-high resolution mass spectrometry Q-Exactive . The results showed that the metabolite spectrum in Pu'er tea soup changed slowly with different aging time . In the first 3-4 years of preservation , 5-9 years, 10-12 years, there were three significant time points - regional changes, and the metabolite spectrum after 10 years of storage showed a steady state. This coincides with the traditional view that Pu'er tea will improve its quality over time.

Metabolic spectrum of Icelandic ancient Pu'er tea in different years

Icelandic ancient tree Pu'er tea composition - time trend

In order to verify the relationship between the origin of Pu'er tea and its flavor, and to unveil the mystery of the " Four Big Tea Plants and the Six Tea Mountaines " , Li Wei's laboratory conducted a more in-depth study. The experiment analyzed 12 samples of the main tea mountain , which were from Pu'er, the main producing areas of Pu'er tea, Linyi and Xishuangbanna. Through hierarchical clustering technology, it is found that there is a close relationship between the origin of Pu'er tea and its metabolic spectrum . Pu'er tea produced by Jingmai Mountain, Man Brick and Song Dynasty can be classified into one category; Pu'er tea produced in Yiwu and Jinggu areas can be classified into one category; Yuleshan, Litchi, Geden, Yibanghe Brown's Pu'er tea can be classified into one category, and He Kai is far from the distance, and the Pu'er tea produced is unique.

Further research found that even Pu'er tea produced by Chashan from the same area has a large difference. The five Pu'er teas from the four famous tea hills (Xin Song, He Kai, Brown, Nanxun) in Xihaibanna, Bohai County , have a certain correlation between the distribution on the PCA score map and the geographical location of Chashan.

This study is of great significance. The Q Exactive ultra-high resolution mass spectrometer is used for the quality identification and traceability of Pu'er tea. The quiz technology in life is quantified. On the one hand, the necessity of Pu'er tea aging is verified. The scientific research results have established mass spectrometry characteristics for the ancient Pu'er tea, which provides favorable experimental evidence for the improvement of Pu'er tea quality standards and promotes the healthy development of the Pu'er tea market .

I have a story, do you have any wine?

After telling the story of tea, let’s talk about wine, I have a story, do you have wine?

The wine culture has a long history in our country. According to legend, the wine was invented and manufactured by Dukang. The heroes of Chinese historical dynasties have a deep relationship with wine. Open the Tang poetry and Song poetry, you can find that wine is a frequent visitor in poetry, and you must have no less reciting. At the end of the Eastern Han Dynasty, Cao Cao had a sigh of " singing wine as a song, life geometry " ; poetry Li Bai loves wine, " life is full of joy, no gold makes the sky go to the moon " , " toasting the moon, the shadow into three " , leaving a lot of famous wine-related sentences; Su Shi, the representative of the Song Dynasty's heroic poet, has the mind of "When is the moon, the wine asks the sky " ...

In the New Year, the values ​​are old and new, and the mood of the New Year and the hilarious joy make the traditional Spring Festival and wine more suitable. Because wine can not only help, but also the lubricant of emotions, open the omnipotent key of the topic. Drinking at the wine table must be chatting, what topic? Today Xiaobian provides a little material for the audience. As we all know, liquor has a distinction between flavor, sauce, and fragrance. What is the cause of the difference in flavor?

In the laboratory where Xiaobian was located, a study was conducted in the early days to collect white wine samples of three flavors: Luzhou, Sauce and Fragrance. Each fragrance contains multiple samples of different brands and different quality levels. The results showed that in the two analysis groups, the white spirits of the three flavors of Luzhou-flavor, fragrant and sauce- flavored were clearly separated, and the different grades of different brands could be clearly distinguished . The metabolic profile of the Luzhou-flavor type is between the fragrance type and the sauce type, and the difference between the aroma and the fragrance is smaller than that of the sauce type.

Relative content of compound S1 in three scent samples in different brand groups

Further research found that the difference in the three white wine flavors was mainly composed of five marker components, including ethyl hexanoate. Related research shows that the fragrant component of Luzhou-flavor liquor is ethyl hexanoate. Through the established analytical model, another typical Luzhou-flavor liquor sample (沱牌曲酒, 50° ) was verified and analyzed. The results showed that the test sample could be well aggregated with the Luzhou-flavor sample, verifying the selected 5 The ability of the markers to identify three kinds of fragrant liquors.

It turns out that in the white wine we often drink, alcohol and water account for 98~99% , and the remaining traces account for 1-2% . At present, liquor production is dominated by fermented brewing, and the factors affecting the whole fermentation process are numerous. The quality of the wine produced in each production batch is inconsistent. In order to unify the various trace components inherent in the product and the appropriate ratio between them , it is necessary to blend . After the finished product after blending liquor, having a chemical composition which is fixed, and the fixed relationship between the ratio of these components to form respective different flavor and taste ^[2].

1. This part of Pu'er tea is part of the work of Li Wei, a member of China Agricultural University. For more information, please see: Food Chemistry, 2018, 271–278, Mass spectrometry-based metabolomics and chemometric analysis of Pu-erh teas of various origins

2. Cheng Mingchuan, Li Chen, Lu Chen, Jiang Wei, The application of high-resolution mass spectrometry based on the analysis of white wine flavor.

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