## 6 Nutritional and Health Properties  
A high content of PUFA--approximately 60%--characterizes apple seed oil. The composition of this oil contains the largest amount of linoleic acid (C 18:2, omega-6) in amounts ranging from 51% to 62%, followed by oleic acid (C 18:1, omega-9) from 28% to 38%, saturated acids from 7% to 9%, and erucic acid from 0.4% to 1.2% [11; 12; 14; 32; 37; 38; 39; 40; 41]. The content of \(\alpha\)-tocopherol (vitamin E) ranges from 50 to 60 mg per 100 g of oil [14; 25; 41; 42]. The physicochemical parameters of the oil are that the acid value is no more than 4.0 mgKOH/g and the peroxide value is below 15 mmol O\({}_{2}\)/g, which meets the requirements for cold-pressed oils [37; 41]. This oil contains natural antioxidants such as cocochromanols (tocopherols and tocotrienols) as well as carotenoids and phytosterols [14; 37]. This composition should be considered as health-beneficial because linoleic acid is one of the essential PUFAs that should be supplied through one's diet. Moreover, oleic acid has a protective effect on the circulatory system and is the main fatty acid in olive oil. The ratio of polyunsaturated to saturated fatty acids PUFA/SFA (P/S) in apple seed oil is approximately 7, similar to that in grapeseed oil (7.3) [27; 33]. Edible fats and oils with a P/S value \(\geq\) 2 are considered hypocholesterolemic [43]. Because of the high value of the P/S ratio, apple seed oil can be also considered hypocholesterolemomic. Increasing the P/S ratio in one's diet is recommended for the prevention of cardiovascular diseases [43]. Because of favorable fatty acid composition, rapeseed oil is recommended in a healthy diet and is often indicated as a nutritional reference point for other edible oils [44]. The P/S ratio for rapeseed oil is 7, as is the case for apple seed oil [45]. The high content of polyunsaturated fatty acids in apple seed oil suggests its susceptibility to oxidation. However, the high antioxidant potential of this oil has been demonstrated, which protects it against oxidation. It results from the high level of natural antioxidants in the oil, such as tocopherols, tocotrienols, phytosterols, carotenoids, and squalene [30; 46; 47; 48; 49; 50]. Animal studies indicate that the addition of apple seed oil to the diet of rats had a more beneficial metabolic effect on the body than rapeseed oil. It was shown in terms of the concentration of triacylglycer overlools and the atherogenic index of plasma, as well as the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in plasma [43]. Furthermore, apple seed oil has been shown to have antimicrobial activity, inhibiting the growth of bacteria, molds, and yeasts at a minimum inhibitory concentration (MIC) of 0.3 g/mL to 0.6 g/mL. [51]. Moreover, the cytotoxic effect of apple seed oil in vitro against specific cell lines has been described, demonstrating its potential as an anticancer agent [26; 41]. This effect is probably caused by high levels of natural antioxidants [11; 50]. Among these substances, the highest content was found for toochromanols, among which alpha- and beta-tocopherol predominated, at a level almost twice as high as in cold-pressed rapeseed oil [52]. Some authors indicate the presence of small amounts of erucic acid in apple seed oil [32]. Erucic acid in excess may be harmful to health, especially to the heart muscle. For this reason, the presence of erucic acid in edible oils in the EU cannot exceed 20 g/kg of oil [53]. Apple seed oil is safe in terms of the presence of erucic acid. The erucic acid content was found to be approximately 7 g/kg of oil (from 4 to 12 g/kg of oil) [32]. For comparison, the presence of erucic acid in rapeseed oil available on the market ranges from 0.17 to 9.68 g/kg of oil [54]. The limitation of apple seed use in nutrition is the presence of amygdala in them. When consumed significantly, amygdala is toxic to humans due to the cyanogenic degradation products it undergoes in the gastrointestinal tract [55; 56].