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Gewählte Master / Diploma Thesis:

Isabella Holzschuster (2017): DETECTION, IDENTIFICATION AND INHIBITION OF HEAT RESISTANT MOLDS IN FRUIT PREPARATIONS AND THEIR RAW MATERIALS.
Master / Diploma Thesis - Institut für Lebensmittelwissenschaften, BOKU-Universität für Bodenkultur, pp 67. UB BOKU obvsg

Data Source: ZID Abstracts
Abstract:
Heat-resistant molds have been a known problem for many years in the fruit processing food industry. According to the definition of HRM, these molds are able to survive temperatures of 75°C and above for a period of 30 minutes and longer. They are thus able to survive the conditions of pasteurization. Resistance to high temperatures is obtained by sexually formed ascospores. The most important representatives belong to the genera Byssochlamys, Neosartorya, Talaromyces and Eupenicillium. This master thesis includes an assessment of the three main components of fruit preparations (sugar, starch and fruit) regarding contamination by HRM. A screening of various starch samples showed rice and tapioca starch as a particularly susceptible source of HRM contamination. No HRM were detected during an environmental monitoring in a fruit-processing production plant. In order to examine various preservatives on their potential to inhibit the outgrowth of Byssochlamys nivea ascospores in malt extract broth, suspensions with high concentrations of ascospores (10*3 - 10*5 cfu/mL) were prepared in the laboratory. The cultivation of B. nivea in broth medium with 2% added sucrose and an incubation period of 25 to 30 days at 30°C proved to be suitable. The most successful method to produce ascospores from the heterothallic species B. spectabilis included the cultivation on Oatmeal Agar at 30°C. Inhibition tests in malt extract broth showed potassium sorbate (0.5 g/L, pH = 3.5), sodium benzoate (0.5 g/L, pH = 3.5), lactic acid (20 g/L, pH = 3.0), propionic acid (3.5 g/L, pH = 4.0), dehydracetic acid (1.8 g/L, pH = 4.0) and octanoic acid (0.5 g/L, pH = 4.0) to be effective against the outgrowth of heat-activated ascospores of B. nivea.

Beurteilende(r): Domig Konrad

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