Utjecaj mliječno-kisele fermentacije na antimikrobnu i antioksidativnu aktivnost kiselog tijesta

master's thesis

• Title (english): Effect of lactic fermentation on antimicrobial and antioxidant capacity of wheat sourdough
• Author: Maja Kiš
• Mentor: Jasna Mrvčić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Fermentation and Yeast Technology); Zagreb
• Defense date and country: 2012-07-16, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Proučavan je utjecaj mliječno-kisele fermentacije s pomoću različitih bakterija mliječne kiseline na antimikrobnu i antioksidativnu aktivnost tijesta. Produkti fermentacije te fenolni spojevi određeni su pomoću HPLC-a te spektrofotometrijski. Antioksidativni kapacitet tijesta određen je DPPH i FRAP metodom, dok je antimikrobno djelovanje određeno mjerenjem zone inhibicije bakterija mliječne kiseline prema test mikroorganizmima, metodom s dvostrukim slojem agara i metodom difuzije. Rezultati su pokazali da bakterije L. buchueri i L. plantarum imaju najjače inhibitorno djelovanje prema plijesnima A. niger i Penicillium sp. Kiselo tijesto od integralnog brašna pokazalo je znatno veću antioksidativnu aktivnost od tijesta od crnog brašna (T- 1100) zbog prisutnosti oko četiri puta veće koncentracije fenolnih spojeva. Ferulinska, p – kumarinska, siringinska i vanilinska kiselina su najviše zastupljene. Tijekom fermentacije dolazi do povećanja koncentracije slobodnih fenolnih kiselina, posebice pri fermentaciji tijesta s pomoću bakterije L. brevis. S druge strane, L. sanfranciscensis tijekom fermentacije potroši slobodne fenolne kiseline što rezultira manjom antioksidativnom aktivnošću.

Abstract (english)

Effect of sourdough fermentation, by different starter culture (lactic acid bacteria), on antioxidant and antimicrobial activity of sourdough was determined and compared with spontaneous fermentation. Fermentation products and total phenols were determined by HPLC and spectrophotometrically. Antioxidant capacity of sourdough was determined with DPPH and FRAP methods, while the antimicrobial effect was conducted on test microorganisms with agar spot test method and agar well-diffusion method. L. buchueri and L. plantarum showed strong antifungal activity against A. niger and Penicillium sp. The antioxidant capacity of the whole-grain sourdough was significantly higher than the T-1100 flour sourdough due to four times higher phenolic acids concentration. Ferulic acid, p-coumaric acid, syringic acid and vannilic acid were identified. The content of free phenolic acids increased during the sourdough fermentation, particularly when L. brevis was used as a starter in sourdough. Free phenolic acids were metabolized during the fermentation by L. sanfranciscensis and that resulted in lower antioxidant capacity.

• Keywords: antioksidativna aktivnost; antimikrobna aktivnost; kiselo tijesto; bioaktivne komponente; bakterije mliječne kiseline.
• Keywords (english): Antioxidant activity; Antimicrobial activity; Sourdough; Bioactive compounds; Lactic acid bacteria
• Language: croatian
• URN:NBN: urn:nbn:hr:159:975443
• Study programme: Title: Bioprocess Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva (magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-09 11:16:58