Introduction

Among food the major sources of polyunsaturated omega-3 (ω-3) fats are fish, especially of fatty varieties, seafood, wheat germ, dark green leafy vegetables, and vegetable oils such as linseed, soybean and walnuts. [1]

At the same time, adipose tissue of land animals, especially adipose tissue of mammals living in cold regions has the fatty acid composition of fat, wherein the polyunsaturated fatty acids (PUFA) presented in sufficient quantity [2].

Yakut horses all year round being on grazing, as well as wild animals, have developed effective system of protection from the cold due to the formation of sufficient amount of PUFA in adipose tissue.

Yakut horse’s fat, including young animals, differs from other animal’s fats by low melting point, high digestibility as determined by the high content of unsaturated fatty acids [3, 4, 5].

Within several years we have worked on the study of adipose tissue of Yakut horses, as one of the sources of raw fat, rich in polyunsaturated fatty acids ω-3 and ω-6 families [6].

Yakut horse has a high capacity for large deposits of fat reserves in the body. According to several authors, by the autumn 10.3-16.8% of horse carcass is fat, and internal fat deposition in mares of Yakut breed ranges from 6 to 11 kg. It is also noted that after the slaughter of 12-year old gelding only the inner content of the fat was 36 kg, and the output of the external fat was about 20% of the carcass weight [7].

The aims of research are an approbation of a low-temperature process for separating fat from fat-raw and study its composition.

Materials and methods

To investigate the fat it were sampled internal, abdominal, and subcutaneous fat of young animals and adults of Yakut horses.

Samples of fat were obtained during mass slaughter of horses at stable low temperature -20-30º C, in late October, early November.

Immediately after slaughter the fat raw materials were purified from dirt, bruising, blood clots and fringes of muscle tissue and frozen at -25-30 °C.

To separate the fat from the fat-raw we tested a low-temperature method.

The low temperature method for producing the fat has the following rational technological parameters: grinding fat at a temperature -10 – (-5) C° to a particle size of 3-4 mm, centrifugation at 3000 rev/min for 45 minutes followed by separation [8].

Determination of the composition of fatty acids carried out in the laboratory of All-Russian Research Institute of Meat Industry named after V.M. Gorbatov.

Allocation of lipids from the samples was performed by extraction with chloroform/methanol according to Folch. The purity of isolated lipids was checked by thin layer chromatography.

Determination of fatty acids composition was performed on a gas chromatograph HP 6890 firm “Hewlett Packard”.

Description of the methods set out in the Guidance on methods of quality control and food safety (ed. by I.M. Skurihin and V.A. Tutelyan. M.: “Brandes”, “Medicine”, 1998) – pp. 84 -93, and in the monograph: A.B. Lisitsyn, A.N. Ivankin, A.D. Nekludov. Practical methods of biotechnology. Analysis of components and micro impurities in meat and other food products. -M.: All-Russian Research Institute of Meat Industry, 2002. 402 p.

The results

As a result of studies, we obtained fat raw material with the following fatty acid composition (Table 1). The table shows the essential fatty acids which are present in the fat composition in the largest amount.

Table 1: Fatty acid composition of fat during low-temperature method, in %.

Table 1 shows that the fat composition of Yakut horse obtained by low-temperature method from the PUFA presented in sufficient quantities linoleic and γ-linolenic acids. Thus, of all the samples, the greatest amount of linoleic (7.52%) and γ-linolenic (13.63%) was observed in the fat composition isolated from the allocated internal fat-raw of Yakut young horses, and the least – a fat selected from the subcutaneous fat of Yakut horses: linoleic – 6.48% and linolenic – 9.005%.

For comparison we have taken similar data of fatty acid composition of fat raw of young Yakut horse (Table 2.).

Table 2: Fatty acid composition of fat raw of young Yakut horse, % [6]

Comparison of fat raw with indicators of the fat obtained by low-temperature method shows that fat obtained by low-temperature way saved their useful qualities, i.e. content of essential fatty acids – linoleic and γ-linolenic are not less than 6.6% and 9.005%, respectively.

We have found that 5-studied parts of Yakut horse’s carcasses have the highest content of PUFA the internal fat of horse. From table 2 it is observed the interesting regularity: α-linolenic (3.7%) and γ-linolenic (10.16%) fatty acids were found only in the internal fat composition, while linoleic acid (C18:2) evenly presented in composition of all the samples of fat.

When comparing the internal fat indicators obtained by low-temperature method, and fat-raw, it is seen that in the first case (Table 1) qualitative composition changed, i.e. the content of α-linolenic acid decreased, if the fat-raw was – 3.7%, in the fat obtained by low-temperature method was – 0.52%. This is because the α-linolenic acid (ω-3) is very unstable with respect to manufacturing processes. At the same time, an increase observed in γ-linolenic acid in fat, obtained by low-temperature method, if fat-raw was 10.16%, in the fat obtained by low-temperature method – 13.63%.

It is known that in the human diet much attention is paid to the ratio of ω-6/ω-3 of fatty acids. The study of the diet of ancient people in the Paleolithic era, and dietary habits of modern hunters, suggested that the diet of our ancestors it was approximately 1:1 [13]. Development of new technologies in crop and livestock production, widespread “fastfood” has led to a shift in the direction of this relation ω-6 of fatty acids. In a typical diet of modern man ratio ω-6/ω-3 is in the range of 10:1-25:1. The World Health Organization (WHO) recommends a proportion from 4:1 to 10:1, and should seek to increase the proportion of ω-3 fatty acids, as numerous clinical studies have confirmed the positive effect of increased intake of ω-3 fatty acids on human health, especially on the cardiovascular system [14].

According to the results of our research it was founded that the ratio of ω-6/ω-3 fatty acids of internal fat-raw of young Yakut horses is 6:1, which is ideally the recommended levels.

Thus, the internal fat of Yakut horse may serve as a highly valuable raw material for the production of food and preventive products for human use as a source of PUFA, as well as biologically active additives to food.

Fat obtained from the internal fat of Yakut horse by low-temperature method for physical, chemical, microbiological indicators, in terms of toxic elements, antibiotics and radio nuclides (Table 3) meets the requirements of safety [4].

Table 3: Microbiological indicators, toxic elements, antibiotics, pesticides, radionuclides fat Yakut horse

The obtained results lead to the conclusion that Yakut horse’s fat, particularly internal fat, can be used as a dietary product and as raw material for the creation of food supplements. We have defined the output of raw materials and products from one animal’s head.

It was found that between one head of a Yakut horse it is available from 3 to 6 kg of internal fat, depending on the age, breed and fatness. For analytical data 100 g of the internal fat contained 23 g of PUFA. Thus, from young animals can be obtained 2400-2700 g of fat and 690 g of PUFA and adult horse – 4800-5400 g of fat and 1380 respectively PUFA.

We received a patent of Russian Federation №2538367 C2 Russian Federation 11.20.2014 on the invention of “Concentrate of Yakut horse’s fat – raw material for food supplements”, registered in the State Register of Inventions of the Russian Federation [6].

Conclusions

1. The greatest amount of PUFA of the test samples – linoleic (7.52%) and γ-linolenic (13.63%) is set in the fat composition, isolated from young domestic Yakut horse’s fat.
2. There is a regularity as α-linolenic (3.7%) and γ-linolenic (10.16%) fatty acids found only in the internal fat, whereas linoleic acid (C18:2) is uniformly present in the composition of all the samples of fat.
3. The comparison of the internal fat obtained by low-temperature method and fat-raw revealed that in the first case, the qualitative composition changed, i.e. the content of α-linolenic acid decreased when in fat paddies it was 3.7%, in the fat obtained by low-temperature method it was 0.52%.
4. It was found that the ratio of ω-6/ω-3 fatty acids of internal fat of young Yakut horse is 6:1 that is according to the recommended standards.
5. Lipids obtained from internal fat of Yakut horse by a low-temperature method on the physical, chemical, microbiological indicators and indicators of toxic elements, antibiotics and radio nuclides meet safety requirements.
6. It was found that from 1 head of Yakut horse it is available from 3 to 6 kg of internal fat: from young horse – 2400-2700 g fat, 690 g of PUFA and the adult horse – 4800-5400 g fat, respectively 1380 g of PUFA.
7. It was received the patent for the invention of “Concentrate of Yakut horse’s fat – raw material for food supplements” registered in the State Register of Inventions of the Russian Federation on 20^th of November 2014.

Thus Yakut horse’s fat, particularly internal fat in the young animals, may be used as a dietary product and as raw material for the creation of food supplements

References

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