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Научни трудове на Съюза на учените в България-Пловдив. Серия В. Техника и технологии, естествен ии хуманитарни науки, том XVI., Съюз на учените сесия "Международна конференция на младите учени" 13-15 юни 2013. Scientific research of the Union of Scientists in Bulgaria-Plovdiv, series C. Natural Sciences and Humanities, Vol. XVI, ISSN 1311-9192, Union of Scientists, International Conference of Young Scientists, 13 - 15 June 2013, Plovdiv.
NUTRITIONAL AND CHEMICAL PROPERTIES AS A COMPARATIVE INDICATORS OF THE QUALITY OF COW MILK AND SOYBEAN
MILK
Dolevska Sandra, Vesna Karapetkovska Hristova, Petrovska Emilija, Krstanovski Aleksandar,Steve Veleska Mentor: prof. Dr.Stefce K. Presilski University "St. Kliment Ohridski'' Faculty of biotechnical sciences - Bitola, Republic of Macedonia
Abstract
The cow milk is a biological liquid, product of the milk gland, with yellow-white color and specific taste and smell. Soybean milk is a beverage produced from vegetable soybeans (soybean integrated whole grain either soy flour). Comparing the nutritional and chemical properties of these two types of milk, such as total dry material, water, total fat, protein, minerals (calcium, iron and phosphorus), lactose, pH, acidity and calorific value contained in one cup (245 g), the world's researchers come to the conclusion that, soybean milk is a rich herbal protein drink while cow's milk is also a rich source of nutrients.
The cow milk contains twice as much fat and ten times more fatty acids compared with the soybean milk.
The cow milk contains larger quantities of mineral substances (except Fe), and thus contains about three hundred times more Ca and approximately two times more P in terms of soybean milk, but soy milk contains more Fe (ten times) magnesium, copper (20 times) and manganese (42 times more) than this is contained in cow's milk. Both types of milk contain nearly identical amounts of protein and water, soybean milk contains fiber, while cow milk do not contain fiber at all. Although the choice of milk consumption is a personal decision within general health purposes - taking into account nutritional and chemical properties of these two types of milk, soybean milk is a better choice because it is characterized by low energy value, a lower percentage of carbohydrates, fats and fatty acids and is important for people who are allergic to cow's milk protein and lactose intolerant, but is still subjected to further scientific research investigations in general.
Key words: cow milk, soy milk, nutritional properties, comparison
Introduction
"Milk is the most perfect natural food" (Hippocrates 400 b.c.)
The importance of milk was perceived primary by our ancestors while their successors have
scientifically proven the importance of milk as a food, and in everyday practice they confirmed the importance of the value of the milk because it contains the necessary nutritive and protective substances, acting positively on the immune system and health.
Definition of the Milk: Milk is a biological fluid with very complex chemical composition (containing over 90 completely different components, with yellowish-white color and specific taste and smell..Milk is secreted by glands of females mammals specific time after birth (partus). Also milk can be considered as a suspension or emulsion of milk fat in water, found in dissolved solids (such as lactose and soluble minerals in the form of salts) as well as materials in the form of colloid (such as proteins).
Cow's milk production according to the latest data from the world literature, is considered up to 730 million liters per year. As because the percentage (%) of cow milk production worldwide is quite large, a general term MILK id being accepted fr this kind of milk, without having to specify the type of animal from which it comes. The composition of cow's milk is variable and dependent on a number of factors (health condition of milking cows, order and stage of lactation, method and type of feeding, type of milking (hand or machine), while the number of milking, individual characteristics, cow age, body mass, mobility, etc.)
Durability of processed cow milk is about 30 days depending on the method of storage and temperature. : Chemical composition of cow's milk in a glass of water 214,69 (gr), dry matter 12,9 (gr), ash 1,75 (gr), pH 6,9 (gr), acidity 0,21 (mgr) and soy milk in a cup is: water 228,51 (gr), dry matter 10,4 (gr), ash 0,66 (gr), pH 6,74 (gr), acidity 0,24 (mgr) (World Academy of Science, Engineering and Technology, 33 2009).
Colostrum is the first milk secretion which secretes immediately after giving birth, and a thick yellowish liquid. There are good physiological role in infant (greater amount of immune-active substances, vitamins and minerals), thus protecting against infections and allergies, cleans meconium, helps prevent jaundice, helps maturation of intestinal intolerance and prevents, reduces the severity of some infections such as diarrhea and measles. Laboratory studies show that colostrum also successfully protect the body from a number of the following bacterial species: Bacillus cereus, Salamonella enteritidis, Camplyobacter jejuni, Staphylococcus epidermidis, Escherichia coli 0127: H7, Streptococcus pyogenes, Helicobacter pylori, Listeria monocytogenes and similar.
Table no. 1: Representation in percents of the main components included in the composition of milk (Tratnik, 1998)
Components of Milk %
Water 86 - 89 %
Dry matter 11 - 14 %
Milk fat 3,2 - 5, 5 %
Proteins 2,6 - 4,2 %
Lactose 4,6 - 4,9 %
Minerals 0,6 - 0,8 %
Soy milk represent healthy and nutritious beverage, high quality protein source alternative to cow milk's protein and contain vitamins and minerals, protein, unsaturated fatty acids (50 - 60% more than cow's milk), but contains no cholesterol and even milk sugar, lactose, which causes
allergic reactions. It is produced from selected soy beans with bright color, rich in Q - 3 fatty acids, with all their quantity extracted in soybean milk.
Soy milk is naturally sweet, slightly sweet taste and pleasant smell, also does not contain any irritating ingredients, is easily digestible and can be consumed by infants and children. It is also being recommended for people who have cardiovascular disease, high blood pressure, arteriosclerosis, high amounts of cholesterol in the blood, and for people who are intolerant of lactose. However soybean milk is not recommended for children who are born prematurely, and for children with impaired renal function or who are intolerant of soy protein.
Table no. 2: Amino - acid composition of soy protein in various soy products (mg / 100 g protein), (Presilski., 2006.)
amino acids soya beans soy flour soy concentrate soy isolates soymilk tofu
Isoleucine 35 46 48 49 46 48
Leucine 79 78 79 82 79 83
Lysine 62 64 64 64 60 61
Methionine and cystine 21 26 28 26 16 14
Phenilalanine and tyrosine 87 88 89 92 80 83
Threonine 41 39 45 38 40 40
Tryptophan n/a 14 16 14 n/a n/a
Valine 37 46 50 50 48 49
Table 3: Nutritional composition of cow and soy milk (one cup) (World Academy of Science, Engineering and Technology, 2009 33
Fats (gr) Fatty acids (gr) Vegetable fibers (gr) Proteins (gr) Lactose (gr) Ca (mgr) Fe (mgr) P (mgr) Energy value (Kcal)
Soymilk 4,67 0,52 3,18 6,73 0 9,8 1,4 120,05 79
Cow milk 8,15 5,07 0 8,02 4,27 290,36 0,12 226,92 150
Results and discussion
The main difference between cow's milk and soybean milk is their different background, one is of animal origin, while the other is a product of the plant. Although we often encounter different ethical, hypothetical and questionable issues surrounding the selection and quality of the two types of milk, response that would arise would cover only nutritional differences between these types of milk.
Cow milk and all other animal food products is whole nutritios protein which fully satisfies consumers with the necessary amino acids (contains 8 grams of protein and 12 grams of carbohydrate) and thus as a rich source of nutrients, fully one glass of milk can meet 30%
of the daily value of calcium in the adult population and 50% of he needs of vitamin B12 and riboflavin (Clark, 2007). Often it is enriched with vitamin D in order to improve the resorption of calcium from milk. The milk sugar lactose in milk is an alimentary problem for some people who are intolerant of lactose (lack of the enzyme lactase), which causes intestinal bloating, gas and diarrhea occurrence.
Soybean milk is a great drink for the lactose tolerant people as for the vegetarians because one glass of soy milk contains 7 grams of protein, 4.5 grams carbohydrates 4.5 grams of fat and contains no cholesterol.
Although supplies the body with vitamins B, it is poor in vitamin B12 and calcium (Yazici et al., 1997). Both types of milk contain nearly identical amounts of protein and water, soybean milk contains fiber, while the cow milk do not contains it. In terms of mineral differences, soybean milk has a higher content of iron (10 times more), magnesium, copper (20 times) and manganese (42 times) in comparison with cow milk.
Conclusion
Milk is a complete food for human body which can fully satisfy all the necessary nutrients required for normal growth and development of the organism. Although the choice of milk consumption is a personal decision within general health purposes - taking into account nutritional and chemical properties of these two types of milk, soybean milk is a better choice because it is characterized by low energy value, a lower percentage of carbohydrates, fats and fatty acids and is important for people who are allergic to cow's milk protein and lactose intolerant, but is still subjected to further scientific research investigations in general.
References
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