## 3 Results and Discussion  
### Physico-Chemical Properties of Sea Buckthorn  
The physico-chemical properties of sea buckthorn vary significantly due to growth in different areas as well as ecological and geographical conditions. According to the scientific research, the main physical and chemical parameters in 3 different samples of sea buckthorn fruits collected in the East Kazakhstan region were determined. The fleshiness of fruits was 85% on average, peel--8.73%, and seeds--6.27%. The total lipid content in the crude mass was 6.8% for flesh, 8.5% for peel, and 6.1% for seeds. The nutritive value of sea buckthorn fruits averaged 5.4 g of lipids, 5.7 g of carbohydrates, 2 g of dietary fiber, 2 g of organic acids, 0.7 g of ash, and 84.2 g of water. The energy value of sea buckthorn fruit was 76.2 kCal.  
Sea buckthorn is distinguished by its rich vitamin profile, which contributes to its nutritional and therapeutic significance [19]. Comparing the vitamin composition of sea buckthorn juice with the Recommended Daily Intake (RDI) reveals that sea buckthorn is exceptionally rich in vitamin C and vitamin B9 (folate) (Table 1). A 100 mL serving of sea buckthorn juice contains approximately 154 mg of vitamin C, which is about 171% of the RDI of 90 mg, thus exceeding the daily requirement for this vitamin. It also provides around 860 \(\upmu\)g (0.86 mg) of vitamin B9 per 100 mL, equating to 215% of the RDI of 400 \(\upmu\)g. However, the levels of other B vitamins are comparatively low: vitamin B1 at 0.033 mg (approximately 2.75% of its 1.2 mg RDI), vitamin B2 at 0.050 mg (3.85% of 1.3 mg RDI), vitamin B3 at 0.026 mg (0.16% of 16 mg RDI), and vitamin B6 at 0.076 mg (5.85% of 1.3 mg RDI) per 100 mL serving. Therefore, while sea buckthorn juice significantly surpasses the daily requirements for vitamin C and folate, it contributes minimally to the intake of other B vitamins. This composition indicates that sea buckthorn provides a substantial amount of essential vitamins, particularly vitamin C and several B vitamins, which are crucial for various metabolic processes and overall health maintenance [20,21]. The high levels of these vitamins make sea buckthorn a valuable ingredient for nutritional and functional food products.  
Sea buckthorn demonstrates a considerable antioxidant capacity and is rich in bioactive compounds. The antioxidant activity, assessed using the DPPH radical scavenging assay, was found to be 526 mg/g in methanol extracts and 363 mg/g in water extracts, indicating a higher efficacy of methanol in extracting antioxidant constituents. The total phenolic content (TPC) was measured at 117 mg/g in methanol extracts and 133 mg/g in water extracts, suggesting that water extracts may contain more phenolic compounds than methanol extracts (Table 2). Additionally, the \(\beta\)-carotene content was determined to be 48.9 mg per 100 g of sea buckthorn, highlighting its potential as a significant source of this provvitamin A carotenoid. These findings underscore the nutritional and functional value of sea buckthorn, making it a promising candidate for inclusion in health-promoting food products and nutraceutical applications.  
\begin{table}
\begin{tabular}{c c c} \hline
**Vitamin** & **Content, mg/L** &
\begin{tabular}{c} **Recommended Daily** \\ **Intake, mg/day**[22] \\ \end{tabular} \\ \hline B1 & 0.33 \(\pm\) 0.01 & 1.5 \\ B2 & 0.50 \(\pm\) 0.01 & 1.8 \\ B6 & 0.76 \(\pm\) 0.02 & 2.0 \\ C & 1540.54 \(\pm\) 30.11 & 90 \\ B3 & 0.26 \(\pm\) 0.00 & 20 \\ B9 & 8.60 \(\pm\) 0.13 & 0.4 \\ \hline \end{tabular}
\end{table}
Table 1: The vitamin content of sea buckthorn.