STUDY OF PHYSICO-CHEMICAL PROPERTIES OF SOYBEAN MILK

ABSTRACT

The article presents the results of studying the physical and chemical properties of soybeans and milk obtained from them. When soy milk was extracted from soybeans in the traditional way and analyzed, it was found that its components are close to those of cow's milk. Cow's milk significantly differed from soy milk in terms of carbohydrate content.

АННОТАЦИЯ

В статье представлены результаты изучения физико-химических свойств соевых бобов и молока, полученного из них. Когда соевое молоко было извлечено из соевых бобов традиционным способом и проанализировано, было обнаружено, что его компоненты близки к компонентам коровьего молока. Коровье молоко существенно отличалось от соевого молока по содержанию углеводов.

Ключевые слова: соя, органолептический свойства, соевое молоко, цвет, запах, вкус, коровье молоко.

Keywords: soybean, sensory property, soy milk, color, smell, taste, cow milk.

Soybean is one of the grains with high protein content (35-40%) [1]. Soy protein is highly digestible, about 92 to 100%, and can be easily absorbed by the body[2]. Proteins provide many functional benefits to the food product (physico-chemical and organoleptic properties) and to the body when it is consumed [3]. Also, soy and its products are known to have high nutritional values and health benefits[4].

One of the most important constituents of soy is isoflavones, which range from 300 to 3000 μg/g [5]. Hsu et al[6] reported that isoflavones exhibit physiological activities such as inhibiting cancer cell proliferation, reducing cardiovascular disease, preventing osteoporosis, and alleviating hot flashes in menopausal women.

Soy contains a large amount of soluble carbohydrates. Soy has also been found to be a good source of several minerals essential for optimal health, including potassium, sodium, calcium, magnesium, sulfur, and phosphorus[7,8].

Soy milk is an aqueous extract of soybeans and has a milky appearance. Soy milk is traditionally made by soaking soybeans in water and grinding them together with the water. The obtained slurry product is heated to the boiling point for 15-20 minutes, then it is filtered and the insoluble residues (soybean okara) are removed. Soy milk was originally consumed in China. Soy milk is widely consumed mainly in China, Japan, Malaysia, Singapore and other Asian countries. In Western countries, the drink is slowly becoming popular. Soy milk has the same amount of protein as cow's milk, but it has very little saturated fat and absolutely no cholesterol. Unlike cow's milk, soy milk does not contain lactose. Therefore, soy milk is safe for lactose intolerant people [9].

Although some have argued that consumption of soy products has health benefits, particularly helping to lower triglycerides and low-density lipoprotein (commonly known as "bad" cholesterol), this connection is based on soy. has not been confirmed in ten years of research on protein consumption [10]. It is possible to replace animal proteins in the diet of babies with soy protein. However, it is not so easy to ensure that babies get enough minerals while drinking soy milk. Therefore, soy milk-based infant foods should be fortified with vitamins and minerals to ensure adequate absorption [11].

A number of recent scientific studies have explored the differences between cow's and soy milk[12,13]. Differences in their fat, protein, and sugar levels have been observed, and these differences may explain why people find soy milk easier to digest and less likely to develop intolerable symptoms.

Since the size of fats in soy milk is larger than in cow's milk, it is easier to digest. In addition, it has been found that the amount of trans fats in soy milk is significantly lower than that of cow's milk. Soy milk has a protein content similar to cow's milk, but contains less casein, known as alpha-s1-casein. Just like human milk, soy milk is lower in casein because of its higher soluble protein content than cow's and sheep's milk. This unique feature allows easy digestion of milk. Therefore, those who cannot consume casein can see a reduction in allergic symptoms when consuming soy milk[14].

The presence of an allergy to lactose is a special obstacle to the consumption of dairy products, which can cause a tendency to avoid it. Research shows that you don't need to give up milk altogether; people who are allergic to lactose can consume one or two servings of milk in divided doses with meals. The recommended daily intake of calcium can be achieved by consuming one or two servings of soy milk [15].

The aim of the research work is to obtain milk from soybeans and to study its physical and chemical properties.

Local soybeans grown in Norin district of Namangan region were used as raw material. The results of laboratory analyzed soybeans are presented in Table 1.

Table 1.

Quality indicators of soybeans

Physico-chemical parameters of soybean and products obtained from it were analyzed according to GOST 31388.

There are several methods and technologies for obtaining soy milk. Each method has its own characteristics and affects the chemical composition and organoleptic parameters of the obtained milk. All methods of obtaining milk include crushing, filtering, boiling and cooling processes, freezing, bleaching and treatment with reagents are used depending on the type of method. These processes serve to increase product quality and reduce time[9,10].

In order to obtain soy milk in the traditional way, first, 250 grams of local soybeans were soaked in warm water for 7 hours. Soybeans were placed in water at a temperature of 90-100°C and heat treated for 10 minutes. Then, the finished soybean mass was mixed with water in a ratio of 4:1 and ground using a blender. As a result, a porridge-like mass was formed. That is, protein substances in soybeans were extracted into water. Soy milk was squeezed out of the resulting mass using a special cloth bag. As a result, soy milk was created, which is very close to cow's milk in terms of composition and appearance. The quality of soy milk depends on the physico-chemical properties of soybean grain, grain processing conditions and the level of soybean protein extraction[16-18]. To determine the quality of soybean milk obtained in the experiment, its chemical composition and physicochemical properties were determined (Table 3).

Table 3.

Physico-chemical properties of soy milk

According to the specified indicators, it can be seen that the obtained soy milk is of high quality. From the data in Table 3, it can be seen that the chemical composition of soy milk is very close to that of cow's milk. In particular, the amount of protein in soy milk is 6.52%. Carbohydrate content was 2.83%, fat content was 2.5%, and ash content was 1.01%. Cow's milk is significantly different from soy milk in terms of its carbohydrate content.

In conclusion, it can be said that using soy milk instead of cow's milk into the food improves its organoleptic and physicochemical parameters. It increases the shelf life of food in particular. It also allows to reduce the cost of the product. This makes it possible to recommend the proposed recipe for wide use in the production of food products, such as margarine.

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