Food Chain 2004: Summaries of Session 1
Genomic Approach to Animal Breeding
Dr David MacHughFaculty of Agriculture, National University of Ireland, Dublin
Recent research findings have enabled scientists to discover and identify genes that are responsible for varying the physical features of livestock. Following identification, these genes can be manipulated and used to predict meat quality, tenderness, fat content, milk yield and disease resistance. This will help farmers and the food industry save money and supply better quality meat and livestock products to the consumer.
Dr David MacHugh, Faculty of Agriculture, National University of Ireland, Dublin, showed how gene technology can be exploited in livestock. In pigs and cattle, researchers identified genes that influence a wide range of characteristics such as growth, fat and muscle content. Manipulating these genes enhances or prevents the development of such commercial traits. For example, controlling the genes involved in milk production enhances the milk yield of cattle.
The physical characteristics of animals are influenced by both genetic and environmental factors. Although gene technology was originally developed for human research it has now moved on to livestock research. Applying current gene technology will allow animal breeders to select desirable traits that will result in the production of "designer" animals.
For years, animal breeding has been tailored using statistics and pedigree information. Future progress in animal research and gene technology will simplify and speed up traditional breeding programmes by increasing the accuracy of breed selection. This will result in a genetic improvement in farm animals that will lead to improved meat quality and livestock performance.
Producing livestock that comprise of more meat and less fat is of major commercial interest. Current dietary recommendations for the general public include consuming less fat in the diet. This has led to consumer demands for lean meat and low-fat meat products. Providing better quality meat and livestock products will promote healthier eating for the nation. So not only will designer livestock breeding benefit farmers and the food industry but the consumer too.
Genomic Approaches for Functional Food Cultures
Professor Dan O’ Sullivan, University of Minnesota, USA
Professor Daniel O’ Sullivan from the university of Minnesota discussed the exciting new technology that will separate probiotic fact from fiction. The technology is known as “genomics”, and it is about to revolutionise the global functional foods market.
The health benefits of probiotic bacteria are widely advertised but the lack of knowledge of how they work still evokes controversy. Several dis-believers have criticised probiotic research for depending more on mystique than science. Today, the tools exist to scrutinise the tiny worlds of the gut-friendly bugs, so scientists can tease out what is real from what is not. It is possible to dissect the bacteria and dismantle their genetic material.
According to Professor O’ Sullivan, understanding probiotic mechanisms is the greatest scientific challenge in probiotic research. Information hidden in the bacterial genes is the key to understanding how probiotics function in our bodies. Computer-assisted analysis can predict the functions of individual genes, compare them with genes from other bacteria and identify their evolutionary origins. Special DNA microchips are used to tell which genes are switched “on” or “off” depending on the conditions encountered by the bacteria as they pass through the digestive tract.
Probiotics have had nearly a century to prove themselves. Regulators are searching to define standards for many products marketed as probiotics. If research has been lacking in some areas, the gut feeling among experts is that genomics will provide the body of evidence needed to support probiotic health claims and reveal their true value. Gone are the days of fringe medicine and folk remedies; the future is bright for functional foods.
Cell Factories: Metabolic Engineering for Wholesome Foods
Dr Jeroen Hugenholtz, NIZO Food Research, the Netherlands
Dr Jeroen Hugenholtz, NIZO Food Research, the Netherlands, discussed the benefits of manipulating the genes of lactic acid bacteria in order to improve the quality, flavour and nutritional value of food. Using the methods presented, these bacteria can enhance the vitamin B content and flavour of fermented foods such as butter, yoghurt and fresh cheeses. The bacteria can also reduce the calorie content of food products by replacing sugars with low-calorie alternatives.
Certain bacterial strains are safe to use in the food industry and are known as food grade micro-organisms. Under normal fermentation conditions lactic acid bacteria produce lactic acid, however, using the new technology, these bacteria can be controlled to produce desirable products other than lactic acid.
Several food grade micro-organisms can be manipulated to produce large amounts of vitamins such as folate, riboflavin and vitamin B12. Fortifying raw food material in this way can help consumers reach their required daily intake of these nutrients.
Certain low-calorie compounds that taste like sugar can be used in fermented food products. Promoting the production of these low-calorie alternatives by the bacteria means that there are fewer calories in the resulting food products - good news for the calorie conscious. In addition, some lactic acid bacteria have been changed in such a way that they can actually enhance sweetness of fermented foods. Using such lactic acid bacteria, it is no longer necessary to add sugar to improve the taste of a fermented food product such as f.i. yoghurt.
More recent developments in this area of food research suggest that there are many more possibilities for applying this technology to food grade micro-organisms. This will lead to a whole range of novel food products offering various health benefits to the consumer.
