Functional foods comprise a variety of natural foods or foods that have been modified to have a functional influence on the health and well-being of consumers through elimination, addition, or modification of specific components by using technology or biotechnology (Diplock et al., 1999; Roberfroid, 2000). The term “Functional Food” was first introduced in Japan, in the early 1990s, as an alternative to conventional foods to prevent disease and reduce health care costs (Shimizu, 2003). One of the most important types of functional foods are functional dairy products, including low fat/ skim dairy products (Ozen et al, 2012), probiotic dairy products (Granato et al, 2010), dairy products fortified with vitamins/ minerals/ or omega-3 fatty acids, and low lactose/ lactose free milk (ADA, 2009). Probiotic products such as yoghurt and other fermented dairy products are considered as the first and most important functional food products by some authors (Azizpour et al, 2009). There are some strong evidences indicating that these products have health benefits such as improving the immune system, lowering cholesterol, treating alcoholic liver disease, improving lactose intolerance, preventing and controlling cancer especially colon cancer, lowering urinary tract infection, gastric ulcer, diarrhea and gastrointestinal diseases (Kirpich et al., 2008; Rampengan et al, 2010; Zhao et al, 2007). Over time, demands for functional foods have increased throughout the world (Martirosyan & Singh, 2015), probably due to increasing life expectancy and rising costs of health care (Siegrist et al, 2015). However, many people are not familiar with these products and even think that these foods are designed for certain diseases while consumption of functional foods can be beneficial for everyone (Hellyer et al, 2012). While functional foods market is growing constantly (Bigliardi & Galati, 2013), consumers’ acceptance is identified as an important and crucial factor affecting the chances of success in this market (Siro et al, 2008). According to several studies, acceptance of functional foods is influenced by various factors including those related to consumers such as awareness or knowledge about the concepts of functional foods and functional ingredients (Annunziata et al, 2016; Ares et al, 2008; Urala & Lähteenmäki, 2007; Vella et al, 2014), attitude towards these products (Peng et al, 2006; Rezai et al, 2017), the perceived healthiness of functional foods (Annunziata & Vecchio, 2011; Ares et al., 2008; Shan et al., 2017), past experience of illnesses (Maynard & Franklin, 2003; Verbeke, 2005), and the demographic and socioeconomic characteristic of consumers (Carrillo et al, 2013; Kraus et al, 2017; Urala & Lähteenmäki, 2007).