Novel quality assurance concept for milk products: Characterization of heat resistant peptidases
- Publication Type
- Poster
- Authors
- Baur, C.; Krewinkel, M.; von Neubeck, M.; Wenning, M.; Kranz, B.; Fischer, L.
- Year of publication
- 2013
- Conference name
- GVC / Dechema Tagung: Effiziente Verfahren und Anlagen in der Bioverfahrenstechnik und Lebensmittelbiotechnologie
- Conference location
- Bad Wildungen
- Conference date
- 06.05. - 08.05.2013
<p></p> <p class="Haupttext" style="text-align: justify;"><span style="font-family: 'Arial','sans-serif'; mso-ansi-language: EN-US;">Psychrotrophic microorganisms which can be found in raw milk are able to grow at temperatures<span style="mso-bidi-font-style: italic;"> ≤7°C, although their optimal growth temperature may be higher, between 20 and 30 °C. As recognized in our studies the majority of these microorganisms found in raw milk belongs to the genus <i>Pseudomonas</i> and is possibly capable to secret heat resistant peptidases, which can withstand general UHT processes and remain active in the derived milk products. These peptidases can cause different types of spoilage like gelation or formation of bitter flavors before the expiry date is reached. Actually there is no quality assurance concept in the dairy industry to examine the presence of heat resistant peptidases in raw milk before manufacturing. The aim of this study is the development of a industrially suitable detection system of heat resistant peptidases and lipases in raw milk. In order to use the relevant heat resistant peptidases as references for the development of the detection system we identified and screened about 1100 microorganisms, which were isolated from original raw milk. The formation of extracellular peptidases was investigated in milk-medium at 6 and 30 °C. Further, the identified peptidase secreting microorganisms were cultivated and the peptidases were examined for their heat resistance. The most interesting heat resistant peptidases were characterized biochemically to develop the optimal assay conditions for the detection system.</span></span></p>