THE EFFECT OF PLANT EXTRACTS ON LIPID OXIDATION AND OXYMYOGLOBIN OXIDATION IN BEEF MUSCLE MODEL SYSTEMS

摘要

IntroductionColour and lipid oxidation are important factors affecting the quality of fresh beef. The muscle pigment myoglobin is responsible for the colour of fresh beef. Lipid oxidation is a major quality deteriorative process in muscle foods resulting in a variety of breakdown products which produce off-odours and flavours. The processes of colour and lipid oxidation in beef are linked (O'Grady et al., 2001). In recent years, concerns regarding safety and toxicity of synthetic antioxidants prompted a surge of interest in the use of health promoting natural antioxidants derived from plant sources. The functional properties of many plant extracts have been investigated for their potential use as novel nutraceuticals. Nutraceuticals are believed to modulate the aetiology of many chronic diseases such as coronary heart disease, cancer and diabetes. Rosemary (Rosmarinus officinalis L.), oregano (Origanum vulgare L.) and sage (Salvia officinalis L.) are members of the Lamiaceae family and contain antioxidant compounds such as carnosol, carnosic acid and rosmarinic acid (Capecka et al., 2005). Compounds present in rosemary and sage possess anti-cancer (Cheung and Tai, 2007) and memory boosting properties, respectively. Extracts of oregano inhibited the growth of H. pylori a stomach ulcer inducing bacterium (Chun et al., 2005). Echinacea (Echinacea purpurea L.), a member of the Asteraceae family, contains compounds such as chlorogenic acid, cynarin, caffeic acid and cichoric acid. Echinacea has immuno-stimulatory and free radical scavenging properties (Facino et al., 1995). The aim of this study was to assess the influence of rosemary (R), oregano (O), sage (S) and echinacea (E) on oxymyoglobin and lipid oxidation in 25% M. longissimus dorsi (LD) in order to determine plant extract levels suitable for inclusion in beef and beef products.