Utjecaj ultrazvuka na tijek fermentacije mlijeka jogurtnom kulturom

master's thesis

• Title (english): Influence of ultrasound on a fermentation of milk yoghurt cultrue
• Author: Dolores Vicković
• Mentor: Rajka Božanić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology of Milk and Milk Products); Zagreb
• Defense date and country: 2014-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj ovog rada bio je ispitati utjecaj ultrazvuka visokog intenziteta na aktivaciju jogurtne kulture YC-380, tijek fermentacije mlijeka, udio proteina te fizikalna svojstva (električnu vodljivost, titracijsku kiselost, reološka svojstva, sinerezu) fermentiranog mlijeka nakon provedene fermentacije. Uzorci mlijeka tretirani su ultrazvukom ulazne snage od 270 W u trajanju od 8 ili 10 min te su potom inokulirani mikrobnom kulturom koja je bila prethodno aktivirana ultrazvukom (102 W / 75 s), odnosno kontrolnom, netretiranom kulturom. Dobiveni rezultati uspoređivani kontrolnim uzorkom proizvedenim na konvencionalan način (K). Osim toga, provedena je i senzorska analiza svih uzoraka kako bi se bolje interpretirale razlike između različito provedenih fermentacija. Inokulacija jogurtne kulture aktivirane ultrazvukom nije pokazala značajan utjecaj na skraćivanje trajanja procesa fermentacije mlijeka u odnosu na konvencionalnu fermentaciju.

Abstract (english)

The aim of this study was to investigate the effect of high intensity ultrasound on the activation of yoghurt culture YC-380, milk fermentation, protein content and physical properties (electrical conductivity, titratable acidity, rheological properties, syneresis) of a fermented milk after completion of fermentation. Milk samples were treated with ultrasound input power of 270 W for 8 or 10 minutes, and then were inoculated with a microbial culture that was previously activated by ultrasound (102 W / 75 s), or the control, untreated culture. The results were compared to a control sample produced by conventional means (K). In addition, sensor analysis of all the samples were made in order to better interpret differences between different spent fermentation. Inoculation of the yoghurt cultures activated by ultrasound showed no significant effect on shortening the duration of the milk fermentation compared to conventional fermentation.

• Keywords: ultrazvuk; fermentacija; fermetirano mlijeko
• Keywords (english): ultrasound; milk fermentation; fermented milk
• Language: croatian
• URN:NBN: urn:nbn:hr:159:851298
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-02 08:38:26