PORK MEAT AS A FUNCTIONAL FOOD

PORK MEAT AS A FUNCTIONAL FOOD E. Bonos1, P. Florou-Paneri1*, E. Christaki1, I. Giannenas1, I. Skoufos2, A. Tsinas2, A. Tzora2, J. Peng3 1Laboratory ...
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PORK MEAT AS A FUNCTIONAL FOOD E. Bonos1, P. Florou-Paneri1*, E. Christaki1, I. Giannenas1, I. Skoufos2, A. Tsinas2, A. Tzora2, J. Peng3 1Laboratory

of Nutrition, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece 2Department of Animal Production, Technological Institute of Epirus, 47100 Arta, Greece. 3Laboratory of Animal Nutrition and Feed Science, Animal Nutrition and Feed Science Department, Huazhong Agricultural University, 430010 Wuhan, China. *Corresponding author: Panagiota Florou-Paneri, E-mail address: [email protected]

Technological Educational Institute of Epirus/ Faculty of Agriculture Technology

Introduction “A food can be regarded as functional if it is satisfactorily demonstrated to affect beneficially one or more target functions in the body, beyond adequate nutritional effects, in a way that is relevant to improved state of health and well-being and/or reduction of disease risk” “Functional foods” have become popular, despite the fact that this term has never been officially defined.

Functional foods “Functional foods” can include simple foods, technologically treated food products and/or their active components that can be used to prepare fortified foods, or can be consumed separately from foods as supplements The main ingredients used in functional foods include probiotics, prebiotics, synbiotics, vitamins, minerals, antioxidants, phytobiotics, proteins, peptides, amino acids, fatty acids (omega-3 FA, CLA). Functional pork meat and meat products can be produced with enhanced beneficial properties.

Pork meat and its role as functional food Chemical composition Pork meat offers excellent nutritive and dietetic properties. Its proximate composition demonstrates high protein content (19.1 – 23,4%) in lean tissue with high levels of essential amino acids.

Pork meat and mineral content Mineral content is constant at around 1.2–1.3 g/100 g meat Good source of Fe and Zn. Heme Fe in meat has the advantage of being more biologically available than the Fe in plant-based products. The Fe content in meat was found to be higher in local breeds reared extensively compared to the commercial breeds reared conventionally. Se and Zn are essential trace minerals due to their role in regulating various physiological functions. Fortification of pig diets with Se or Zn increased its content and lipid oxidative stability of pork muscle tissue Pork meat is characterized by low Na content

Pork meat and vitamin content Important source of bioavailable B vitamins and especially vitamin B12, however concentrations vary significantly not only among meats of different species but also among different carcass parts Folate is essential for normal cell growth and replication. Enriched meat with folate can yield a potentially functional product, since folate deficiency can lead to several health problems, most notably, neural tube defects in developing embryos. Vitamin E – very important role as antioxidant and immune enhancer. Like other meats, PM can be fortified with vitamin E through dietary supplementation. Vitamin E content in PM can be more than doubled by dietary supplements of 200 mg α- tocopheryl acetate/kg feed

Pork meat and FA composition The leanest cut of PM in the carcass is the loin, with an average lipid content of 1.8 g/100 g meat. Meat lipids usually contain saturated fatty acids (SFA) a part of which have atherogenic properties. However, meat cannot be described in general as being a highly saturated food, especially when compared to other products (e.g. certain dairy products). PM contains SFA in lower levels compared to some other meats and a main target is the SFA content of PM to be further reduced. For this reason, there is great interest in increasing PUFA, especially long chain n-3 PUFA, which have many known beneficial effects in PM and meat products.

Pork FA profile alteration The FA profile of PM can be modified by feeding and, partly by genetic selection or housing conditions (animals fed with grass – organic vs conventional breeding). Studies on genetic variation for long-chain PUFA metabolism that only partly depends on the carcass and muscle fat content, and this may allow selection for improved FA composition Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the most bioactive forms of n-3 fatty acids; these two functional food ingredients can be increased in PM through animal feeding.

Pork meat and CLA content Monogastrics are unable to synthesize conjugated linoleic acid (CLA), therefore the CLA present in their meat comes from the diet. CLA concentrations in monogastric animal meats can be increased, for example up to 130 fold in pig L. dorsi muscle, by supplementing diets with synthetic CLA. In addition, in pigs, dietary CLA supplements increased lean tissue deposition and decreased fat deposition in pigs. The rate of lean tissue deposition was maximized at a CLA inclusion level of 5.0 g/kg, whereas the depression in fat deposition was linear up to at least 10 g CLA/kg.

Pork meat and cholesterol content SFA increase low density lipoprotein (LDL) cholesterol levels in the plasma and thus increase cardiovascular (CVD) risk, while polyunsaturated fatty acids(PUFA) decrease LDL cholesterol levels. Feeding can influence PM cholesterol content. Considering the potential human health implications of cholesterol intake, this aspect is relevant and all feeding strategies must be directed to achieving the lowest cholesterol content. Feeding whole blue lupin seeds to pigs for 3 weeks exerted a marked hypocholesterolemic effect as the consequence of a marked decrease in the intestinal absorption of cholesterol, probably modulated by bile acid reabsorption and blue lupin phytosterols.

Pork meat lipid oxidation and antioxidants Meat with high PUFA content, shows an increased oxidative rate. The problem is even more serious when meat is minced, stored for long time, or cooked. The lipid oxidation rate can be effectively retarded using antioxidant vitamins, such as vitamins A, C and E. These antioxidant vitamins could be used in animal feeding or during meat processing (exogenous addition) for both human requirements and meat lipid stability

Herbs (aromatic plants) as antioxidants Herbs and spices (rosemary, sage, green tea, clove, cinnamon, rose petals) could be efficient food ingredients in improving the shelf life of (mainly processed) meats because they are potential sources of natural antioxidants, including flavonoids, tannins, phenolic acids, and phenolic diterpenes, while also promoting antiinflammatory, antimicrobial and anticancer activities. Other natural antioxidants extracted from plants, such as soybean, citrus peel, sesame seed, olives, carob pod, and grape skin could also be used for their equivalent or greater effect on lipid oxidation inhibition.

Other effects of aromatic plants In raw and cooked meat of several species and in meat products like sausages, patties and meatballs, some herbs and spices are added to improve flavor (rosemary extracts, sage, garlic), retard lipid oxidation-induced deterioration (rosemary extracts, green tea leaves, clove, garlic, sage, oregano), inhibit microorganism growth (clove, sage, oregano), and lower the risk of some diseases (green tea). In particular, oregano and sage EOs improved raw and minced pork and beef during a 12-day storage period. The effect was greater in cooked than in raw meat.

Seaweeds as feed supplements Recently, a significant reduction in lipid oxidation in Longissimus dorsi steaks from pigs fed with brown seaweeds compared to controls was found. Dietary seaweed reduced lipid oxidation to the greatest extent in liver tissue homogenates after iron-induced lipid oxidation in liver, heart, kidney and lung tissue homogenates over the 24 h storage period. There is great potential for the incorporation of marinederived bioactive antioxidant components into muscle foods via the animal's diet.

Conclusions Functional foods are a tool that can possibly be used in reducing public health costs. The consumption of PM in regular quantities could provide consumers with bioactive compounds because pig diet manipulation is very effective in increasing levels of PUFA, EPA, DHA, CLA, vitamin E, selenium etc. Also, lowering the n-6/n-3 ratio plays a key role in controlling CVD and other chronic diseases. Compared to meats of other animal species, pork lean meat has lower cholesterol contents, high levels of protein with essential AA, significant source of B vitamins. Dietary fortification with PUFA, long chain n-3 FA, vitamin E, Se, etc. meets the criteria required for PM to be considered as functional food

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Acknowledgements: This work is part of the project 12CHN91, of the Bilateral R&D Cooperation between Greece and China 2012-2014, funded by the Hellenic GSRT.