3.2. Fatty acid composition
Another important characteristic of the nutritional and functional quality of meat and meat products is the fatty acid composition. Generally, the composition of ground beef is about 18–20 g lipid/100 g total mass and its fatty acids content is divided into 46 g/100 g SFA, 51 g/100 g MUFA and 3 g/100 g PUFA (Valsta et al., 2005). Beef burger samples with 20 g lipid/100 g of total mass were used in our experiments, and total saturated, monounsaturated, polyunsaturated and trans-fatty acids (g/100 g) found in all tested samples are shown in Table 2. Since polyunsaturated fatty acids are oxidized rapidly, precautions must be taken during the irradiation treatment, such as maintaining a constant low temperature, a well established fat content, and minimizing the variation of the radiation dose applied since oxidative and nonoxidative changes can occur as consequences of these variations. Ionizing radiation causes radiolysis of water present in a great extent in meat, which generates free radicals such OH, hydrated electron and H. These compounds react with food constituents (Giroux & Lacroix, 1998) causing oxidation and loss of food quality. Merritt and Angelini (1978) reported that the amounts of radiolysis sub-products vary as a function of nutrient composition (e.g. fat content and fat composition) and also as a function of temperature during irradiation and the irradiation dose. Furthermore, additional biochemical changes may be related to irradiation effects as reported by Brito et al. (2002) who showed increase of trans-fatty acids and lipid oxidation as being one of the important factors that can be considered in the irradiation process.
3.2 องค์ประกอบกรดไขมันAnother important characteristic of the nutritional and functional quality of meat and meat products is the fatty acid composition. Generally, the composition of ground beef is about 18–20 g lipid/100 g total mass and its fatty acids content is divided into 46 g/100 g SFA, 51 g/100 g MUFA and 3 g/100 g PUFA (Valsta et al., 2005). Beef burger samples with 20 g lipid/100 g of total mass were used in our experiments, and total saturated, monounsaturated, polyunsaturated and trans-fatty acids (g/100 g) found in all tested samples are shown in Table 2. Since polyunsaturated fatty acids are oxidized rapidly, precautions must be taken during the irradiation treatment, such as maintaining a constant low temperature, a well established fat content, and minimizing the variation of the radiation dose applied since oxidative and nonoxidative changes can occur as consequences of these variations. Ionizing radiation causes radiolysis of water present in a great extent in meat, which generates free radicals such OH, hydrated electron and H. These compounds react with food constituents (Giroux & Lacroix, 1998) causing oxidation and loss of food quality. Merritt and Angelini (1978) reported that the amounts of radiolysis sub-products vary as a function of nutrient composition (e.g. fat content and fat composition) and also as a function of temperature during irradiation and the irradiation dose. Furthermore, additional biochemical changes may be related to irradiation effects as reported by Brito et al. (2002) who showed increase of trans-fatty acids and lipid oxidation as being one of the important factors that can be considered in the irradiation process.
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