Products made from camel's milk by Mongolian nomads

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1 Milk Science Vol. 55, No Original Report Products made from camel's milk by Mongolian nomads Satomi Ishii 1 and Kunihiko Samejima 1 ( 1 Graduate school of Agricultural Science, Rakuno Gakuen University, Ebetu Midorimati Bunkyoudai Ebetu, Hokkaido Abstract Mongolian nomads raise sheep, goats, cattle, horses and camels, and milk from these domestic animals is used to make various dairy products. Camels are raised in only a few areas of Mongolia, and there have been few reports on camel's milk and products made from camel's milk by nomads in Mongolia. We therefore carried out a survey on camel's milk and camel milk products in Mongolia. Analysis of camel's milk and cheese (Mongolian nomad called aaruul) made from camels' milk showed that the fat content of camel's milk is higher than that of milk from cows raised by Mongolian nomads. Milk from cows, sheep and goats is used for manufacturing dairy products after fat has been removed from the milk, but products are made from camel's milk without removal of the fat. Aaruul produced from camel's milk was found to have less water content and higher contents of protein, fat and calcium. An alcoholic beverage is also made by fermenting camel's milk. Raw wild plants are sometimes added to camel's milk during the process for producing aaruul. Aaruul made from camel's milk is very hard, but it was found that aaruul made from camel's milk was crushed more quickly by application of pressure of a tensile tester than was aaruul made from cow's milk. The dišerence in stress strain curve between camel's aaruul and cow's one is dependent on the content of fat. 1. Introduction Mongolian nomads raise all of the animals that are raised in nomadic regions throughout the world (sheep, goats, cattle, horses and camels) and make variousproductsfromtheirmilk. Dairy products are made after removal of the fat from milk. The dairy products are dried under the sun and stored for use in winter. The products are not matured like cheese in Western countries. There have been many reports on manufacturing processes of dairy products made by Mongolian nomads 2~8), but there have been some reports on camel's milk and products made from camel's milk 9~13). This is because camels are raised in restricted desert areas in Mongolia such as the Dont Gobi area. The Dont Gobi area is located in the southern part of Mongolia, and all of the ˆve Corresponding author (fax : , ishii@ rakuno.ac.jp) domestic animals are raised in this area. Since it is believed in ethnology that old customs remain in peripheral regions, we decided to carry out a study on camel's milk and camel milk products in the Dont Gobi area because of the possibility that traditional methods are still used for manufacturing dairy products in this part of Mongolia. 2. Materials and Methods 2.1 Study sites and samples A survey was carried out at Mandaruobou in the Dont Gobi area, about 550 kilometers south of Ulaanbaatar, in August A survey on camels and use of camel's milk was also carried out at Bayannunnjur in the desert belt of the Tuvo area, about 200 kilometers south of Ulaanbaatar, in August Samples of camel, cow, horse, sheep and goat milk as well as samples of aaruul made from defatted cow's milk and from camel's milk and samples of airag, an alcoholic beverage made

2 from camel's milk, were brought back to Japan and analyzed. 2.2 Analysis of samples The samples were stored at 5 C and brought back to Japan. All of the samples were analyzed by conventional methods 14). Contents of aaruul were determined by the Inductively Coupled Plasma Atomic Emission Spectrometry ( YAMATO SPS7800) 15). The alcohol content of airag was determined by GC (HITACHI G3000) equipped with a PEG6000 support column, and the lactic acid content of airag was measured by an Automatic Acidity Titrator (MITUBHI GT 05). ThepHof airag was also measured. The fracturability of aaruul was determined by using a Tensile Tester (INSTRON MINI55). 第 巻 3.2 Milking of camels and composition of camel's milk The camels are milked twice a day, in the morning and evening. About two liters of milk is obtained from one camel per day in August. As with horses, milking is started after the calves are allowed to suckle. Two people are involved in the milking, one to manage the calves and one to milk the camels. Milking is performed by women with theuseofawoodenbucket. Table 1 shows the results of compositional analysis of milk obtained from domestic animals in Mongolia. The protein and lipid contents of camel's milk (5.6 and 7.5, respectively) were found to be higher than those of milk from other domestic animals. It has also been reported that camel's milk is rich in vitamin A and vitamin B 20). 2.3 Viable bacterial cell number in airag and isolation of bacteria from airag Isolation and identiˆcation of bacteria in airag were carried out. The number of viable cells of lactic acid bacteria was counted on plate-count agar with MRS medium (Diˆco Co) andwithbcp medium (Nissui Co) after incubation for 72 hours at 32 C, and the number of viable yeast cells was counted on PDA medium (Eiken Co) after incubation for 72 hours at 28 C. Lactic acid bacteria and yeast were isolated 16,17) and identiˆed by Utimura and Okada method 18) and Iizuka and Goto method 19), respectively. 3. Results and Discussion 3.1 Camels in Mongolia There are two species of camels: dromedaries, which have one hump, and Bactrian camels, which have two humps. Camels in the Arabian Peninsula and Africa area are all dromedaries 12), whereas camels in Mongolia are Bactrian camels. Camels were the most abundant domestic animals in the survey sites. All camels have a three compartmented stomach, a structure that enables them to regurgitate and rechew ingested forage. They have strong resistance to cold and live for about 20 years. Camels are used not only as a means of transportation but also as a source of milk, fur hides and meat 20). 3.3 Processing of camel's milk Nomads in Mongolia do not drink milk from camels or milk obtained from any other domestic animals. Cheese is made from milk obtained from sheep, goats and cows after removing the fat from milk. However, it was found that none of the nomads in the survey sites removed the fat from camel's milk before using the milk for processing. Camel's milk including the fat content is strongly fermented by bacteria. The strongly fermented milk is then boiled, and a strongly acidic cheese (aaruul) is made from the solidiˆed product. Cheese that is made in many parts of Mongolia from weakly fermented camel's milk was not produced by nomads in either the Dont Gobi area or Bayannunnjur. Nomads in the survey sites said Table 1 Chemical analysis of animals milk. Water Solid Protein Fat Insolubled Nitorogen Ash Camel Goat 2) Goat Sheep 3) Cow 4) Cow Horse 5) , 2), 3), 4), 5) ; Mongolian nomad's animals ; This mark was value indicated the things of Standard Tables of Food Composition in Japan Fifth revised edition

3 第 号 that they preferred aaruul. The fact that aaruul is the most popular cheese produced by Mongolia nomads suggests that the production of aaruul by nomads has a long history. Raw wild plants are sometimes added to aaruul, and cheese containing wild plants that had been molded into donut shapes was seen to hang outside for drying in the survey sites. 3.4 Composition of aaruul Results of compositional analysis of aaruul are shown in Table 2. The fat and protein contents of aaruul made from camel's milk were found to be higher than those of aaruul made from cow's milk after removal of fat. The fat contents of aaruul made from camel's milk in the Dont Gobi area and in Tuvo Prefecture were 36.3 and 37.8, respectively, and the protein contents of aaruul made from camel's milk in the Dont Gobi area and in Tuvo Prefecture were 31.5 and 34.8, respectively. Raw wild plants are sometimes added to aaruul for health reasons and aaruul containing wild plants can be preserved for a longer time. Aaruul containing wild plants was found to have a high ash content (36.7 ). The mineral compositions of aaruul made from camel's milk and aaruul made from cow's milk after removal of fat are shown in Table 3. The sodium content of aaruul made from camel's milk (542 mg/100 g) was much higher than that of aaruul made from cow's milk (83 mg/ 100 g), and the calcium content of aaruul made from camel's milk (470 mg/100 g) was also higher than that of aaruul made from cow's milk (295 mg/ 100 g). These high concentrations of sodium and calcium in aaruul made from camel's milk are derived from the soil via ingestion of grass. 3.5 Physical properties of aaruul Aaruul is hardened by drying under the sun. The physical properties of samples of aaruul made from camel's milk and aaruul made from cow's milk without fat that were produced at the same time in 2004 were investigated using a Tensile Tester. As shown in Figure 1, aaruul made from camel's milk was crushed more quickly than aaruul made from cow's milk when a pressure was applied from above. The reason for the brittleness of aaruul made from camel's milk is thought to be the high fat content. Table 2 Chemical composition of fermented dairy products. Water Protein Fat Ash Camel's aaruul (in wild plants) Camel's aaruul 2) Camel's aarrul 3) Cow's aaruul 4) Cow's aaruul 5) ; This sample was brought from Donto Gobi area in ) ; This sample was brought from Donto Gobi area in ) ; This sample was brought from Tuvo area in ) and 5) ; These sample were brought from ubruhanngai area in 2002 Fig. 1 Stress strain curve for aaruul Table 3 Mineral analysis of dairy products. Na Ca P Fe K Mg Zn Cu Camel's aaruul Cow's aaruul 2) Gouda Cheese ; This sample was brought from Tuvo area in ) ; This sample was brought from Ubruhangai area in 2002 ; This mark was value indicated the things of Standard Tables of Food Composition in Japan Fifth revised edition

4 3.6 Processing of milk by nomads Nomads in Mongolia make various dairy products after removing the fat from milk, and the fat removed from milk is consumed as a source of energy. Mongolians living in the Inner Mongolia region of China use various methods for extracting fat from milk 2. Fat is extracted from all milk because of the small herd numbers. However, as the authors found in a previous survey in Mongolia, nomads with large herds often simplify the fat extraction process or use the milk for processing without extracting the fat because of the large quantity of milk. Fat is not extracted from camel's milk in Mongolia. This is thought to be due to the large quantity of milk obtained from the large herd numbers of camels raised by nomads in Mongolia. Extraction of fat from milk therefore depends on the types and numbers of livestock raised by Mongolian nomads. 3.7 Properties airag made from camel's milk Mongolian nomads also make fermented products from milk. Each nomad household has several containers for milk fermentation. Strongly fermented milk is used to make aaruul. Further stirring and fermentation results in production of alcohol by lactose fermenting yeast, and this product is consumed as an alcoholic beverage (airag). Analysis of samples brought back to Japan showed that airag made from camel's milk had a lactic acid content of 1.5, alcohol content of 2.2 and ph of 4.2. The results of compositional analysis are shown in Table 4. Both the protein content and fat content of airag made from camel's milk were higher than those of airag made from cow's milk.the viable lactic acid bacteria cell and yeast cell counts in airag were /ml and /ml, respectively. Several Lactobacillus strains and several Lactococcus strains were isolated from airag samples. The yeast isolated was Kluyveromyces marxianus var. lactis. Isolation of these microorganisms from various Mongolian dairy products has been reported 22,23). Many strains of bacteria and yeasts are used in the fermentation process for production of airag from camel's milk, and the various types and large quantities of organic acids produced are thought to contribute to the taste of the product. A slightly yellowish distilled Table 4 Chemical analysis of Airag. Water Protein Fat 第 巻 Ash Camel's airag Cow's airag 2) ; This sample was brought from Gobi area in ) ; This sample was brought from Ubruhangai area in 2002 liquor is obtained by distilling the unreˆned fermented camel's milk in a homemade still. The alcohol content of the distilled liquor is 8. The distilled liquor is kept in a cool place and served to guests. Acknowledgments We are also grateful to professor Nakamura K. for performing the Tensile Tester system. Reference Kurmann,J.A.,Rasic,J.L.J.,Kriger,M.V.,and Nostrand, R.: An international inventory of fermented milk, cream, buttermilk, whey, and related products. Encyclopedia of fermented fresh milk products. Elsevier, New York, pp (1992) 2) Konagaya,Y.:WorldoflifeinMongoliansteppe.Asahi Newspaper press, Tokyo, pp (1996) 3) Ishige, N.: Mongolian white dairy products. Tikuma Sinnpousya, Tokyo, pp (1997) 4) Takahashi, F.: The livestock farming and the utilizaition of milk in Mongolia (part Nature and livestock farming. Milk Science., 49,89 98 (2000) 5) Takahashi, F.: The livestock farming and the utilizaition of milk in Mongolia (part 2) The traditional milk products. Milk Science., 49, (2000) 6) Ishii, S., Samejima, K.: Dietary Survey on the diet of Mongolian Nomads. J. Jpn. Food Nutri Society., 50, (1999) 7) Ishii, S.: Some microbiological ˆndings on milk spirits in Mongolian nomads and their functions. Brewing Society of Japan., 97, (2002) 8) Adachi, S.: Civil history of dairy technology developments in the world with special reference to Asia. Tohoku Univesity press, Sendai, pp (2002) 9) Nakae, T.: Fuether Studies on chemical and biochemical properties of Mongolian milk an milk production ˆ- nal report on Mongolian Studies. Okayama Univesity,

5 第 号 Okayama, pp (1977) 10) JennessnR.,SloanR.E.:Thecompositionofmilksof various species: A Review. Dairy Sci. Abstr., 32, (1970) 1 Abu, I. H. L.: Composotion of camel milk. Milchwissenschaft., 42, (1987) 12) Wangoh, J. Z. F., Puhan, Z.: Composition of milk from three Camel (Camelus dromedaries) breeds in Kenya during Lactation. Milchwissenschaft., 53, (1998) 13) Muctar, A., Mohamad, M. L. R., and Mohamad, A. M.: Hard cheese making from camel milk. Milchwissenschaft., 45, (1990) 14) Japan Food Semiconductor Equipment and Materials International.: Food chemical composition. Korin, Tokyo, pp. 4 6, 94, 136, 151 (1979) 15) Pharmaceutical Society of Japan editing hygiene.: docimasy explanatory note Kanehara-syuppann, Tokyo, pp (2000) 16) Kander,O.,Wess,N.:GenusLactobacillus Beijeerink 1901.: Bergey's Manual of Systematic Bacteriology Vol. 2, Williams & Wilkins, Baltimore, pp (1986) 17) Lachance, M. A.: Kluyveromyces van der Walt e- mend. Van der Walt.: The Yeasts, a taxonomic study. (Kurtzman, C. P., Fell, J.). Elsevier, Amsterdam, pp (2000) 18) Utimura, T., Okada, S.: A lactic acid bacterium experiment manual. Asakura-syotenn, Tokyo, pp.1 68 (1992) 19) Iizuka,H.,Goto,S.:Aclassiˆcationandidentiˆcation of yeasts. Gakkai-syuppan-center., Tokyo, pp (1980) 20) Suzuki, Y.: Urxli n tämää winxihu. JICAHand Book, Ulaanbaatar, pp (2004) 2 Konagaya, Y.: Milk eating people. Iwanami-syoten, Tokyo, pp (200 22) Ishii, S., Kikuchi, M., and Takao, S.: Isolation and Identiˆcation of Lactic acid bacteria and Yeasts from chigo in Inner Mongolia, China. J. Animal Sci., 68, (1997) 23) Shuangquan, Burentegusi, and Miyamoto, T.: Micro ora in traditional fermented camel's milk from Inner Mongolia, China. Milchwissenschaft., 59, (2004)

6 第 巻 モンゴル遊牧民がラクダ乳からつくる乳製品 石井智美 鮫島邦彦 ( 酪農学園大学酪農学部食品科学科 ) モンゴル遊牧民はヒツジ, ヤギ, ウシ, ウマ, ラクダの乳を様々に加工してきた ゴビ地方のラクダはフタコブラクダで, 搾乳の中心家畜であるが, 飼育地域が限られ, モンゴル遊牧民のラクダ乳利用に関する報告はまだ少ない 筆者らは, モンゴル国のラクダ乳の成分, ラクダ乳からつくられたチーズ aaruul の一般成分分析, 微量成分分析を行った その結果, ラクダ乳はウシ乳より, 脂肪含有量が高かった ラクダ乳 aaruul は脱脂したモンゴルのウシ乳 aaruul に比べ, 蛋白質, 脂肪, カルシウム含有量が高かった ラクダ乳 aaruul に健康に良いと生の野草を加えることも行われていた そしてモンゴルのヒツジ, ウシ乳の加工で行われる脱脂がラクダ乳では行われていなかった Aaruul の硬さを Tensile Tester で測定した結果, 脱脂したウシ乳 aaruul より早い時間で崩れた aaruul の硬さには乳脂肪含有量が関与しているのではないかと考えた ラクダ乳酒中から乳酸菌は複数種の Lactobacillus 属と Lactococcus 属菌株, 酵母は Kluveromyces marxianus var. lactis を分離した