CC BY
0FERMENTED PRODUCTS OF MONGOLIAN NATIONAL MILK PRODUCTS
B. OYUNCHIMEG, O. OYUNSUREN
MNUMS, Darkhan
■ Abstract. Fermented dairy products constitute one of the most important functional food and is a vital component of the human diet in Mongolia. The important Mongolian traditional dairy products that have commercial significance are tarag, hoormog and airag which prepared from cow, goats, sheep, yaks, camel and horses milk. Each of these products has its unique flavour, texture and appearance. The objective of this review was to document traditional technology used and information on the microbiology of the products, and to identify various constraints to the development and commercialization offermented milk products.
Key words: airag, hoormog, tarag, fermentation, culture
Introduction
Fermented products are integral part of Mongolian heritage and have great social, religious, cultural, medicinal and economic importance and have been developed over a long period. There is evidence that fermented milk products have been produced since around 2000 BC in Asian steppes / 3/. Herodotus in the fifth century B.C. described how the Scythians made airag /kumiss/ from raw mare"s milk. Marko Polo, the First European traveler to the Far East in the thirteenth century mentioned fermented milk as a favorite drink of the Mongols/12/. The earliest reliable Mongolian source about fermented products appears in the famous literature of thirteenth century " Secret history of Mongols".
There is a wide variety of fermented products on the Mongolian land as a consequence of variations in the raw materials, methods which come from the habits and customs of the different regions of country. Milk from six species of domesticated mammals / cow, sheep, goat, horse, camel and yak/ has been used to make traditional fermented milk products in Mongolia.
The most common fermented milk product of Mongolia is airag that traditionally made from mares' milk. The drink remains important to the people of the Central Asian steppes, including the Bashkirs, Kazakhs, Kyrgyz, Mongols, Yakuts and Uzbeks. Another kind of sour milk is tarag which prepared from cow, goat and sheep milk. A third indigenous dairy product is khoormog, which is prepared from camel milk. In making fermented milk many different milks (sheep, cow, camel, mare, yak, khainag, goat), methods (low or high heat, fermentation times, agitation), materials (pots, bowls, skins or native wood/plant containers) and fermenting microorganisms (raw milk, a previously used culture, a pure culture, a fermenting vessel, or plants) are used.
Fermented products have probiotic effects as it contain sufficient levels of certain live and active cultures, which can help to improve bacterial microflora of the intestinal tract, it also help to preserve the precious nutrients of milk. Therefore use of fermented products for medicinal purposes has been practiced for several centuries in Mongolia. Technology of making traditional fermented products has been refined all the way down today and is the most suitable and perfect method in the animal husbandry conditions. But we are facing today the issue of making a technological solution of transferring these traditional methods into the production method.
Results and Discussion
In Mongolia the rural population still produce fermented milk by traditional methods and the art of making airag, tarag and khoormog will handed down from one generation to the next.
Airag. The mare's milk is filtered through a cloth, and poured into a large open leather sack with ready to drink airag. Within this container, it gets stirred with a wooden masher, in order to introduce air, and especially oxygen. The stirring then needs to be repeated regularly over one or two days. The added oxygen helps the fermentation process by a combination of lactic acid bacteria and yeast. Three types of airag are made: weak / acidity 70-90 0T, ethanol content 0,8-0,1%/, medium / acidity ~100 0T, ethanol 1,2-1,8%/, strong/ acidity ~ 120 0T, ethanol 1,8-2,5%/. The major products
ОФ "Международный научно-исследовательский центр "Endless Light in Science"
of fermentation are lactic acid, ethanol, and carbon dioxide. Airag is rich in C vitamin and essential fatty acids. Therefore, it is regarded as a dietetic product, and it is also used in the treatment of tuberculosis and gastrointestinal disorders.
Tarag. Cows, goats or sheep's milk are boiled and cream layer formed and removed then. Remaining milk is inoculated with indigenous starter culture and incubated for 5-6 h. Incubation is taken in wooden or metal vessel. Tarag is very similar to yogurt from Balkan land by sensor data, microbial flora and technology.
Khoormog. This product is prepared by first souring it in a skin bag or wooden vessel, normally with a capacity of 30 kg. Previously soured milk is added to the fresh milk. It is well mixed and each day, for 2-3 days, fresh milk is added to the mixture. Eventually the end product must have 3 to 5 times the original volume of "khoormog" that was initially added. The texture of khoormog formed during fermentation are tiny corpuscular characters and easily soluble, therefore, it is very digestible. Also, khoormog contains enormous amounts of amino acids such as glutamine, asparaginic acid, praline, leicine, lysine, methionine ets. Generally khoormog is rich in vitamins C,A,D as well as, all kinds of vitamin B are available /. Traditionally, the camel fermented milk is effective for reducing clubbing and are used for digestive organ ailments. Also, in combination with various herbs it was used for medicinal purposes.
Average Physical-Chemical Composition of Mongolian Traditional Fermented Products
Airag Tarag Khoormog
%Total solids _*_ _*_ 15,36
%Protein 2,7 2.8 2,93
%Fat 2,2 2.5 4,9
% carbohydrates 3,4 3.3 3,3
% ash _*_ _*_ 0,82
C vitamin mg/kg 68,0 70 _*_
Acidity T0 >98 >130 >80
% Alcohol 1,6 0.5 < 2
Data in tables are average results only. In fact, a high level of variability for all the parameters was seen among samples of the same product. This heterogeneity is a consequence of the lack of standard procedures for preparation of these products. Microbiological analysis of the different traditional fermented dairy products have been investigated /1-9/ for their micriobal flora identification. It showed that an important proportion of their microflora was represented by lactic acid bacteria.
A airag and khoormog are mixed fermented products including lactic and alcoholic fermentation. The research results showed that in the microflora of airag and khoormog, lactic bacteria and yeast dominate. The ability of lactic bacteria is to produce lactic acid.
Lactic bacteria plays a vital role in the fermentation of traditional products. They are non motile, do not form spores catalyse negative, are Gram positive, do not form a pigment, do not change nitrates into nitrites. However, some authors have described strains which on some properties differ from typical. They are mobile, change nitrates into nitrites, form spores, and are catalyse positive/ 10 /. Lactic bacteria from traditional fermented products presents a high resistance to adverse conditions of external environment in comparison to typically lactic bacteria. They growth in presence of medium including gall, NaCl and phenol and well develop at high temperature. Those properties can increase the spectrum of utilization of fermented products and are caused probably on climatic features of Mongolia.
The alcoholic fermentation yeasts such as Saccharomyces lactis, Saccharomyces cartiloginosus andlactobacilli, lactococci such as L. delbrueckii subspecies bulgaricus, Lactococcus lactis ssp.lastis, and Lactococcus lactis ssp.cremoris formed majority groups of the microflora of
ОФ "Международный научно-исследовательский центр "Endless Light in Science"
fermented mare"s milk or airag, prepared by Mongolian traditional technology. Generic and species composition of microorganisms in the starter culture of airag is the same in the different geographic regions of Mongolia, however their quantitative were significantly different among the natural zones. In the Gobi desert bacteria and yeast ratio was 2:1, in the steppe 1:1,5; and in Forest steppe region it was 1:2.
In the winter, the yeast content made up the majority of airag. In the spring and fall the yeast and bacteria ration is almost equal. In the summer, the amount of lactis acid bacteria increased in the product.
The new method of preparation of the airag at industrial level was formulated /2/. Main steps of technology based on continuously repeated biotechnological process of Lactic bacteria cultivation and acidity regeneration process within fermented mare's milk.
The microflora of khoormog was dominated by four bacterial species Streptococcus thermophilus, Lb.casei, L. delbrueckii subspecies bulgaricus and lactobacillus lactis and two yeasts, Candida krusei and Saccharomyces sp. Although the relative proportions of these organisms changed, all persisted in detectable numbers throughout fermentation. The principal species present during fermentation were L. delbrueckii subspecies bulgaricus and Streptococcus thermophilus and Lb.casei, the other organisms comprising a comparatively small proportion of the population. The yeasts isolates showed limited carbohydrate-assimilating capabilities, but played a role in flavor development and proteolysis /7/.
Lactic streptococci and lactobacilli were predominant in tarag. Analysis showed that traditionally fermented cows milk or tarag is characterized by a protosymbiosis between L. delbrueckii subspecies bulgaricus and Streptococcus thermophilus. /1,4/. Preparation method of ' tarag' in industry level was formulated and received the patent by L.Damdinsuren /1/. This method based on bacterial continuous cultivation, managing by temperature and acidity level. The such yeasts as a Saccharomyces, Torulopsis, Mycoderma formed minority groups, these population may not be essential microorganisms in fermented milk or tarag and the level of samples"s pH cannot favorise their growth. The presense of yeasts may be influenced by the age of tarag as well as the containers and processing methods used .
CONCLUSIONS
1. It is, therefore, important that the microbiology and biochemistry of these products, as well as their technologies be studied and documented in order to preserve them for future generations.
2. Studies on traditional fermented milk from Mongolia showed that lactic acid bacteria are the dominant microbial flora. Lactic streptococci and lactobacilli were predominant in tarag, while yeasts were found in airag and khoormog at almost the same average levels. The principal species found in tarag were Streptococcus thermophilus, and L. delbrueckii subspecies bulgaricus while Saccharomyces sp were found in airag and khoormog. From each product isolates from the predominant lactic flora were identified using biochemical tests.
3. Identifies species from airag, tarag and khoormog can be use as startes for small scale dairy industries. Owing to the nature of traditional Mongolian fermented products (fresh fermented products), the major criterion considered for selection of indigenous lactic starters will their acid production ability at different incubation temperatures. We are currently determining the amounts of some B vitamins and of aroma and flavour compounds in traditionally fermented milk. The further studies will be focus to the develop a starter culture in industry level.
4. In Mongolia the rural population still produce fermented milk by traditional methods and the art of making airag, tarag and khoormog will handed down from one generation to the next. Research into the processing technologies of these products is still in its infancy.
REFERENCE
1. Damdinsuren L., "Scientific basis on production of the Mongolian traditional products. Sc.D. dissertation. MAS. 2002
2. Damdinsuren L., "Scientific basis on biotechnological applications for Mongolian dairy production" Int.Sc.Symposium. "Nomadic cultural tradition-dairy products" UB., 2002
3. Indra R., Mongolian traditional dairy products. Monograph.
4. Tsoodol D., Monkhtyua P. "Characteristics of starter culture of the Mongolian fermented milk 'tarag" Scientific symposium. UB. 1974
5. Sukhbaatar R., " Investigation of micriobal flora of the airag". Research report. UB. 1976-1980.
6. Baldorj R., Biochemical and microbiological study of the airag" Ph.D. dissertation. UB. 1970
7. Batsukh Ts., Scientific basis on production of the functional dairy from camel milk" . Sc.D dissertation. MAS. 2005
8. 8. Ouynchimeg B., " Microbiological and technological study of the indigenous culture of tarag". Ph.D. dissertation. UB. 2007
9. Baldorj R., Tumenjargal D., Batjargal B., Biochemical and microbiological study of fermented mare"s milk prepared by traditional Mongolian technology. International Scientific Symposium. 2003.
10. Shigaeva M., Ospanova M., Microflore des produits laitiers fermentes traditionnels. Publ. Nauka, Alma Ata,1983
11. Batsukh Ts., Mongolian heritage of food consumption. Monograph. 2007
