Utjecaj kemijskog sastava vina i ultrazvuka na inaktivaciju kvasca iz roda Brettanomyces

undergraduate thesis

• Title (english): The influence of wine chemical composition and ultrasound on the inactivation of Brettanomyces yeast
• Author: Mirta Prusac
• Mentor: Leo Gracin (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology and Analysis of Wine); Zagreb
• Defense date and country: 2017-07-17, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Kvasac iz roda Brettanomyces pripada među najznačajnije uzročnke kvarenja crnog vina. Ovaj kvasac ima sposobnost proizvodnje hlapivih fenola, 4-etilfenola i 4-etilgvajakola koji vinu daje prepoznatljivi “brett” miris što djeluje negativno na vino. U ovom radu ispitan je utjecaj različitog kemijskog sastava vina na inaktivaciju kvasca B. bruxellensis primjenom ultrazvuka visoke snage u kombinaciji sa povišenom temperaturom (termosonifikacija). Tretman je proveden u šaržnom sustavu izotermalno u trajanju od 1, 2 i 3 minute uz prethodno zagrijavanje uzorka na 43 °C. Inaktivacija kvasca B. bruxellensis praćena je nacjepljivanjem uzoraka vina na selektivne podloge gdje se pratio rast kolonija kvasca B. bruxellensis , a senzorske karakteristike vina određivane su pomoću Triangl testa. Utvrđeno je da je ultrazvuk visoke snage u kombinaciji s povišenom temperaturom uzrokuje inaktivaciju kvasca B. bruxellensis. Variranje pH vrijednosti vina nema utjecaja na inaktivaciju kvasca B. bruxellensis, dok dodatak šećera smanjuje inaktivaciju ovog kvasca.

Abstract (english)

Brettanomyces sp. yeast is considered a major spoilage yeast in red wine. It is harmful for wine because it produces volatile phenols (4-ethylphenol and 4-ethylguaiacol), compounds primarily responsible for Brett character in wine. In this study, influence of wine chemical composition and high power ultrasound in combination with high temperature (termosonification) on B. bruxellensis growth were examined. The treatment was conducted in a batch system for duration of 1, 2 and 3 minutes, while the samples were preheated at 43 °C. Inactivation of yeast B. bruxellensis was monitored by inoculation of wine samples on selective medium. Sensory characteristics of wine were determined using the Triangle test. Inactivation of B. bruxellensis growth was achieved using high power ultrasound in combination with high temperature (termosonification). The variation in the pH of wine has no effect on the inactivation of B. bruxellensis, while the addition of sugar reduces the inactivation of the yeast.

• Keywords: B. bruxellensis; kvarenje vina; termosonifikacija; ultrazvuk visoke snage
• Keywords (english): B. bruxellensis; wine spoilage; termosonification; high power ultrasound
• Language: croatian
• URN:NBN: urn:nbn:hr:159:405213
• Study programme: Title: Food Technology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-07-06 06:44:38