On the other hand, in recent years, the food quality attracted the attention of consumers (Chen and Walker, 2005). Such characteristics can be found in a special group of foods called functional foods or extra special foods (Soccol, et al, 2010). By increasing the information of consumers on the public health and their attention to the role of food in their health, the consumption of functional foods, has received the public attention (Alhart, 2003; Roberfroid, …show more content…
Fatty acid composition not only affects physical properties, oxidative stability and sensory quality of dairy products but also positively influences humans’ health. Some health properties of fermented dairy products are due to the synthesis or release of bioactive substances including conjugated linoleic acid (CLA), exopolysaccharides (EPS), bioactive peptides, vitamins, gamma-aminobutyric acid (GABA) and oligosaccharides in the food matrix resulted from the metabolic activity of lactic acid bacteria (LAB), propionibacteria, yeasts and molds (Yadav et al., 2007; Ekinci et al., 2008). Therefore, recent clinical studies have focused on fatty acids with biological activity such as butyric acid, oleic acid, and CLA which may have key roles in the prevention of diseases. The CLA is a rare and unique compound compared to other anti-cancer compounds which despite its small amount in dairy products and ruminants meats, has wonderful effects including reduction of body fat accumulation, delaying the onset of type II diabetes, delaying the development of atherosclerosis, improving and preventing osteoporosis and improving the function of immune system. The fatty acid content of milk influenced by many factors, including, geography quality of agricultural activities, race, type and genetics and physiology of animals and also depends on milk processing