Sensory evaluation of hubbard JV chickens meat after propolis application in their diet.

Address(es): Doc. Ing. Peter Hascik, PhD., Slovak University of Agriculture in Nitra, Faculty of Biotechnology and Food Sciences, Department of Animal Products Evaluation and Processing, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic. *Corresponding author: peter.hascik@uniag.sk ABSTRACT Keywords: smell, taste, juiciness, tenderness, breast, thigh, muscle INTRODUCTION Poultry meat and poultry meat products are the essential part of human nutrition (Barroeta, 2007) and have an important role mainly in developed countries. In technological process of meat products, all components with effects beneficial to health are necessary to maintain. These components are water and major components as proteins and fats. Substantial portion in poultry meat consists of highly bio-available vitamins and mineral substances. Functional foods including meat products from poultry have to have almost identical or very similar sensory properties like traditional products. This depends on consumer and his point of view. Functional foods and cooked, baked, marinated or dry products from poultry meat have to be perceived as natural, tasty, safe and salubrious (Drewnowski and Gomez-Carneros, 2000; Anon, 2006). Food safety is an important aspect of food quality and efforts should be led to safety of new functional products from poultry meat (Burdock et al., 2006). The most consumers would be reluctant to accept new foods without proof of product safety into their diet (Niva, 2006). Meat quality may be affected already by manipulation of animal feeding (Kennedy et al., 2005; Assi and King, 2007) or post mortem manipulation of carcass body. Poultry meat and meat products are important source of proteins, but other components as fats have an important role in their composition, too. Nutrient content in meat products is between 40% and 50% (Ordo˜nez et al., 1999), and fat performs the primary role in sensory aspects as taste and juiciness of all meat products (Lucca and Tepper, 1994; Hughes et al., 1997; Cofrades et al., 2000). And each decrease of fat content may have a notable impact on meat products acceptability (Giese, 1996). New legislation, EU regulation and bans regarding the use of animal meal, classical antibiotic stimulators for growth and antimicrobial substances in feeds of animal including poultry lead to alternative application of new supplements and biotechnological products in science as well as in practice (Hascik et al., 2006, 2007; Bobko et al., 2009). In meat products, efforts are principally centred on modification of fat or fatty acids content (Grashorn, 2006), or on increasing of selenium content in poultry meat (Sevcikova et al., 2007) and variety of functional ingredients in meat through the fruit, cereals, crude fiber, plant proteins (Shaw, 2008), monounsaturated or polyunsaturated fatty acids (omega-3), vitamins, calcium, inulin and others (Farrell, 1995; Kennedy et al., 2005). Maintaining of appropriate technological, nutritional and sensorial properties in meat is one of the conditions for new component integration in animal nutrition, because different supplements can cause the deterioration of meat quality, mainly in term of sensory properties (Aleson-Carbonell et al., 2004; P´erez-Alvarez, 2006). In recent years, bee products (pollen, propolis or their extracts) are employed as alternative substitutes in nutrition of poultry including chicken broilers; and eventually, these bee products can have positive effects on health state, economic use of feed, nutritional as well as sensory product quality and can influence the economy of production in poultry industry (Kimoto et al., 1999; Mojto and Zaujec 2001; Prytzyk et al., 2003; Hascik et al., 2004, 2005ab, 2007; Wang et al., 2004; Shalmany and Shivazad, 2006; Seven et al., 2008). Sensorial aspects, which are measurable by human senses, are essential for consumer; and the aspects can influence the consumer purchase as well as food preference (Komiyama et al., 2008). According to Augustin and Fischer (1999), Brestenský (2002), Mojto and Zaujec (2003), Hascik et al. (2004), evaluated sensory properties are dependent on type of used feed mixture, content of intramuscular fat in meat, way of meat preparation, genetics and many others intra-vital and extra-vital factors. According Guardia et al. (2010), sensory analysis is a scientific discipline, which is useful to determine the objective and reproducible characteristics through the human senses. Sensory evaluation is most frequently performed after heat treatment. And five-point scale is used for each evaluated property, i. e. for smell, taste, juiciness and tenderness. Maximum of twenty points is for comprehensive assessment of meat quality. Nowadays, sensory analysis is uniquely included in the scientific methods despite the fact, that it is one of the oldest methods of food control; sensory analysis is a necessary part of obligatory assessment of food products quality (Neumann and Arnold, 1990; Pokorný, 1993). Many authors found that producers can more effectively identify, understand and respond to consumer preferences by the sensory analyses (Hashim et al., 1995; Owens and Sams, 1998; Liu et al., 2004; Fanatico et al., 2007; Saha et al., 2009). Moreover, sensory properties identification and consumer preferences are helpful for increasing the competitiveness in the market (Tabilo et al., 1999; Tan et al., 2001; Lawlor et al., 2003; Ponte et al., 2004; Young et al., 2004). The aim of this study was to examine the effect of propolis extract on sensory properties of meat. Propolis originated in Slovakia. We used 80% extract of propolis, which was added to feed mixtures for Hubbard JV chickens in different amounts. In this experiment, propolis extract was applied in the diet of Hubbard JV broiler chickens and we tested its influence on the sensory quality of breast and thigh muscles prepared by baking at 200 °C for 60 minutes, followed by final baking for 10-15 minutes. Five groups were created: one control (C) and four experimental (I, II, III, IV) groups. Each group consisted of 100 chickens. Fattening lasted 42 days. Chickens were fed by ad libitum system. The identical starter feed mixture were administered till the 21