A Scientific Approach to the Bio-functional Factors of Baijiu (Chinese Liquor)

WUXI, China, Oct. 16, 2013 /PRNewswire/ -- In September 2013, "Liquor-making Science & Technology", one of the most famous core periodicals in the liquor-making industry, published its latest authoritative academic report "A Scientific Approach to Bio-functional Factors of Baijiu (Chinese Liquor)". In the report, it elaborates on the special bio-functional factors and their functions within Chinese Liquor, and compares Chinese liquor with wine. The data indicates that there are more health functional components in Chinese liquor than in wine:

By Yan Xu, Wenlai Fan, Xiangyang Ge

1. Centre for Brewing Science & Enzyme Technology Research, Brewing Microbiology and Applied Enzymology Lab
   
2. State Key Laboratory of Food Science & Technology, Key Laboratory of Industrial Biotechnology, Ministry of Education
   
3. Synergetic Innovation Center of Food Safety and Nutrition, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122)

The liquor industry is a traditional industry with several thousand years of history. A significant difference between Chinese liquor-making and Western brewing is the solid fermentation, which further explores the Chinese liquor function essence, forming 12 kinds of liquor flavor types approved by the liquor industry. However, our knowledge on the health function of the Chinese liquor still lags behind new developments in the industry and consumers, and our understanding is just the beginning of the scientific journey to the healthy function of Chinese liquor, which is also a great puzzle still in the world.

In view of this, the research team summarized and sorted some special functional components of Chinese liquor based on our research in the "Chinese liquor 169 plans" and a large amount of literature combined with the research results of trace elements, so as to promote the scientific understanding and exploration of active functional components in Chinese liquor.

1. Chinese liquor and its functional ingredients

"Liquor is a profound art", as one of the six distilling liquors in the world, nearly 98% of liquor is water and alcohol, with only 2% being the ingredients that create the aroma and decide the style, taste and characteristic of the liquor. By traditional perception, it is easy for us to link Chinese liquor with high consumption of food, harmful affects on health and drinking related social problems while ignoring its active functional components which are good for our health. They also can reduce the harm of alcohol, therefore, liquor composition (healthy ingredients or active ingredients) requires more understanding and awareness.

Objectively, the functional component of liquor refers to a series of factors or physiological active substances which can alleviate alcohol damage, fully display the body's defense function, regulate circadian rhythms, prevent disease and promote rehabilitation [1].

2. Special functional characteristics of Chinese liquor

The unique flavor substances of international distilled spirits such as brandy, whiskey, rum, and vodka, mainly come from the subsequent store and leaching process via immersion extraction from plant materials and storage containers. Foreign liquor function research focused on the experience and concept of the limited number of functional components in plant material from the container.

Compared with liquor from other countries, the traditional Chinese liquor brewing process differs in that it revolves around collected pits, mixed grain, a multidimensional microbial environment, solid-state fermentation, solid distillation and a series of strategies for achieving harmony and full body, which is also achieved by the natural and scientific brewing system. The flavor substances in Chinese liquor come from its complex material system (herbs), microbial natural fermentation metabolic system (main source), and the late storage system, which obtains a harmonious liquor body with rich composition.

3. The personalized special functional ingredient of Chinese liquor

It is the quintessence of China, the diversity and the complexity of its craft formed the richness of Chinese liquor flavor types. It can produce clear wine by steamed stubble and solid state fermentation.

3.1 Dongjiu type liquor

Dongjiu type liquors represented by Dongjiu, adopt special pit mud and a special solid state distillation process, with more than 130 kinds of Chinese herbs that have been grown in the Yunnan-Guizhou Plateau for years.

As a newly discovered compound in Chinese liquor research, terpene compounds, which its types and content in Dongjiu are the most significant, possess anti-cancer, antiviral activity and anti-inflammatory functions. These compounds are rarely detected in other liquor, leading to speculation that it mainly comes from the process of koji making adding Chinese herbal medicine and its fermentation products.

The terpene material in the finished Dongjiu liquor is 3400 - 3600 micrograms/L, ranking at the forefront of Chinese liquor, Among them, terpene olefins content is 1400 - 1500 micrograms/L accounting for about 44% of the total. Terpene oxide content is 1900 - 2200 micrograms/L, accounting for about 55% of the total [2], which mainly includes terpenes, terpene oxide, terpene alcohols, terpene ketone, terpene aldehydes and terpene ester compounds. Domestic and foreign research shows that the total content of terpene compounds in wine is less than 1000 micrograms/L. Dongjiu is significantly higher than wine for the healthy function of terpene compounds, which is less than the flavor spices limited to the standards set by the association of producers in the United States, and conforms to food safety legislation.

3.2 Luzhou-flavor liquor

Luzhou-flavor liquor is a well-balanced liquor that boasts an aromatic flavor and refreshing aftertaste, etc., which is common in the Chinese liquor market. In recent years, studies have found that Luzhou-flavor liquor contains rich functional components, such as the furan compounds discovered in Luzhou-flavor liquor in China. The foreign studies indicated that furan compounds are credited with antioxidant and anticancer activities.

Koga et al. researched the oxidation resistance of 4 - hydroxy - 2, 5 - dimethyl - 3 (2 h) - furan ketone (HDMF) and 4 - hydroxy - 2 (or 5) - (or 2) ethyl - 5 - methyl - 3 (2 h) - furan ketone (HEMF). They found these two compounds can inhibit the effect of hydrogen peroxide.

3.3 Maotai-flavor liquor

Maotai-flavor liquor production adopts high temperature starter-making, high-temperature stacking and a high temperature distillation process, which gives the liquor its complex and unique flavor composition system and function.

Research results showed that the types and content of pyrazine compounds in Maotai-flavor liquor were the highest at about 3000 - 6000 micrograms/L. It was closely followed by Luzhou, with a range of 500 - 1500 micrograms/L, and the total individual pyrazine compounds of Luzhou-flavor liquor also being able to reach the level of Maotai-flavor liquor. Qing scent liquor contains the fewest pyrazine compounds. W. L. Fan compared and analyzed different concentrations of pyrazine compounds in liquor samples [3].

3.4 The comparisons of the functional components between traditional Chinese liquor and wine

For many years, wine has been referred to as "the cleanest, most healthy beverage", helping further its popularity among consumers worldwide. It is widely believed that wine has positive health functions, but little is known about the related functions of traditional Chinese liquor. In order to verify the health functions of traditional Chinese liquor, comparisons of the three functional components were made between traditional Chinese liquor and wine (Table 1).

According to the data in Table 1, terpene and pyrazine compound content in Chinese liquor is much higher than wine, but polyphones content in wine is higher.

This is mainly due to the Daqu used in the Chinese traditional liquor which involves a natural strain, brewing and distilling process. Nevertheless, wine is fermented from grapes, and the differences come from the ingredients. On the other hand, the flavor substance in traditional Chinese liquor is selected and purified in the distillation process, which also indicates that traditional Chinese liquor  is cleaner and possibly healthier.

4. The explored ways of the functional components in Chinese liquor

With the development of our society and economy, people are becoming ever more health-conscious. Meanwhile, the development of modern science and technology will gradually unveil the positive functions of Chinese liquor. More healthy ingredients will be discovered in Chinese liquor, and the health function mechanisms of the functional components in Chinese liquor will become more widely recognized. This will not only make consumers around the world better understand Chinese liquor, but also promote the scientific and sustainable development of Chinese liquor while also speeding up the international development of the Chinese liquor industry!

References:

[1]. W. L. Fan, Y. Xu. Review of functional factors and quality safety factors of Baijiu (Chinese Liquor) [J]. Liquor Making Science & Technology, 2012, 213 (3), 17-22.

[2]. G.Y. Hu, W. L. Fan, Y. Xu, et al. Research on Terpenoids in Dongjiu [J]. Liquor Making Science & Technology, 2011 (7):29-33.

[3]. W. L. Fan, Y. Xu* and Y. H. Zhang Characterization of pyrazines in some Chinese liquors and their approximate concentrations [J]. Journal of Agricultural and Food Chemistry 2007, 55 (24): 9956-9962. 

SOURCE Jiangnan University