AP26196803 «Study of the quality and nutritional properties of new food products from non-traditional animal and plant sources».

- Based on an analysis of scientific literature, vegetable oils (sunflower, olive, and flaxseed oils) were selected for comparative study with animal fat — horse fat — taking into account differences in fatty acid composition and natural antioxidant content. Experimental studies were conducted on methods for extracting horse fat from raw material.

Using the traditional wet rendering method at a temperature of approximately 90 °C for 2 hours, the fat yield reached 88%. The microwave extraction method demonstrated higher efficiency: at a power of about 3 W/g and a processing time of 8–10 minutes, the fat yield reached 96–98%. Microwave extraction shortens the process duration and improves the quality of the extracted fat by reducing peroxide and acid values and decreasing residual moisture to 0.4%. Optimal parameters for microwave extraction were determined, allowing maximum fat yield with minimal signs of oxidation.

- The physicochemical characteristics of horse fat and vegetable oils were analyzed, including acid and peroxide values, refractive index, moisture content, and fatty acid composition. It was established that freshly obtained horse fat has low levels of hydrolytic and oxidative degradation: the acid value was 1.0 mg KOH/g, and the peroxide value was 2.8 mmol O₂/kg, meeting regulatory standards and indicating high fat quality. In comparison, the acid and peroxide values of vegetable oils were significantly lower (0.2–0.6 mg KOH/g and 1.5–3.0 mmol O₂/kg, respectively).

The refractive index of horse fat at 40 °C was 1.454, while for vegetable oils (sunflower and rapeseed) it was 1.466–1.468, reflecting differences in unsaturation levels. The moisture content of horse fat after extraction was approximately 0.3%, whereas refined vegetable oils had 0.05–0.1%, indicating a high degree of dehydration.

The fatty acid composition of horse fat consists of 38% saturated acids and 62% unsaturated acids, including approximately 39% oleic acid and 12% α-linolenic acid (ω-3). In terms of unsaturation, horse fat occupies an intermediate position between animal and vegetable fats, confirming its high biological value.

- The physicochemical properties of vegetable oils and horse fat were further investigated, including heat capacity, melting and crystallization curves, and rheological characteristics. The specific heat capacity of horse fat was approximately 1.9 kJ/(kg·K) at 20 °C in the solid state and about 2.1 kJ/(kg·K) at 40 °C in the molten state, comparable to liquid vegetable oils.

The heating curve showed an endothermic plateau in the 30–40 °C range, corresponding to phase transition and glyceride melting. Thermogravimetric analysis (TGA) indicated that the main melting peak of horse fat is around +37 °C, with complete melting occurring at 33–35 °C. The melting curve has a complex multi-step character due to the presence of glycerides of different compositions.

Rheological measurements showed that at 20 °C, horse fat is in a solid state (G' > G''), with a sharp decrease in structural strength in the 25–35 °C range. At 35 °C, the fat fully transitions to the liquid phase and exhibits Newtonian fluid properties with a dynamic viscosity of about 36 mPa·s. Compared to ruminant fats, horse fat has a lower melting temperature and greater plasticity, which is associated with a higher content of unsaturated fatty acids.

A comprehensive physicochemical analysis of vegetable oils and horse fat was conducted, including volatile components, glyceride composition, vitamin E content, and polyphenolic compounds.

According to GC–MS analysis, freshly obtained horse fat contains very low amounts of volatile substances (5–8 mg/kg), with the main compounds being trace aldehydes and ketones (hexanal ≈1.2 mg/kg, pentanal ≈0.5 mg/kg), and no secondary oxidation products, confirming the freshness and stability of the fat.

Analysis of lipid fractions showed a predominance of triacylglycerides (~96.5%), with minimal amounts of diacyl- and monoacylglycerides and free fatty acids, indicating high fat quality and low hydrolysis levels. The glyceride profile includes typical fractions rich in palmitic and oleic acids (POP, POO, PPO) and unique fractions containing linolenic acid (OLnP, OLnO), reflecting a high content of ω-3 acids.

The vitamin E (tocopherol) content in horse fat was low (<5 mg/kg, α-tocopherol ≈2 mg/kg), significantly lower than in vegetable oils, explaining the fat’s higher susceptibility to oxidation during storage. Polyphenolic compounds were not detected, consistent with its animal origin.

Despite low natural antioxidant protection, minimal initial peroxide and free acid content and storage in airtight cool conditions ensured the stability of horse fat. To extend shelf life, enriching the fat with plant antioxidants, such as vitamin E or extracts, is promising.

The obtained data allow a comprehensive characterization of the chemical stability, lipid structure, and antioxidant protection of horse fat and vegetable oils.