In the scope of this diploma thesis a further aspect concerning the reduction of methane gas in ruminants of a project funded by the European Commission, with the title Evaluating physiological and environmental consequences of using organic wastes after technological processing in diets for livestock and humans, short titel: SAFEWASTES, (Contract N° FOOD-CT-2005-513949), was investigated. This project was focused on the research and development of transforming waste from the food and herbal industries into high added-value products with a dietetic effect on animals and possibly on humans. It should contribute to replacing the use of antibiotics in animals after the ban to use antibiotics as growth promoters in the EU with regard to minimise the development of resistant strains of pathogenic micro-organisms. Besides many biological activities such as antioxidant, anti-inflammatory and anti-carcinogenic properties the plant extracts also showed a potential to reduce the production of methane in the gastrointestinal tract of livestock. One of the research studies which was realized during the SAFEWASTES project was the one of BECKER and VAN WIKSELAAR (2009). They investigated different pure secondary compounds and extracts of plant origin and their potential to decrease the methane production in ruminants. The two plant extracts, Mirtoselect and grape seed and the two pure substances, catechin and resveratrol showed the highest potential to do this (BECKER a. VAN WIKSELAAR, 2009). These four products were used in this diploma thesis for further investigations using HPLC analysis as experimental procedure.
First of all the samples of this diploma thesis were prepared with different extraction methods and afterwards HPLC analysis was performed. The best results were gained after the preparation of the samples with two extraction methods. One of these methods was the extraction of anthocyanins, described under point 2.2.2 and the other procedure was the extraction of procyanidins, outlined under point 2.2.3. The results which were gained by means of HPLC, were all pretty the same, regarding the four different plant additives. In all of the four different kind of samples a decrease of the ingredients was found comparing the samples with an incubation of six days (T=6) to the samples at the beginning of the incubation. This was also verified by a quantification of catechin and resveratrol.