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2. The impact of Saccharomyces and non-Saccharomyces yeasts on wine colour: a laboratory study of vinylphenolic pyranoanthocyanin formation and anthocyanin cell wall adsorptionBranka Mozetič Vodopivec, Dorota Korte, Irena Vovk, Alen Albreht, Lorena Butinar, Jelena Topič, 2020, izvirni znanstveni članek Ključne besede: Non-Saccharomyces yeast, Hydroxycinnamate decarboxylase activity, Sequential fermentation, Vinylphenolic pyranoanthocyanins, Anthocyanin adsorption
Objavljeno: 23.01.2020; Ogledov: 30; Prenosov: 0
 Polno besedilo (919,86 KB) |
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5. Occurence of biogenic amine - producing lactic acid bacteria in Refošk grape and wineJelena Topić Božič, Jan Reščič, Martina Bergant Marušič, Klemen Lisjak, Branka Mozetič Vodopivec, Lorena Butinar, 2019, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Lactic acid bacteria (LAB) are naturally present in grapes, musts and wines. During malolactic fermentation, besides the beneficial conversion of L-malic to L-lactic acid, LAB can form also other compounds like biogenic amines (BAs). BAs are formed through decarboxylation of corresponding amino acids, through the action of enzymes. Consumption of food containing BAs can lead to food poisoning such as histamine poisoning. Histamine, the most studied BA, is known to cause headaches, oedema, vomiting.
In the last years, BAs associated pathways have been described as strain dependent and not as species dependent. Because of the high variability of microorganisms to decarboxylase amino acids, the detection of bacteria that have the possibility to transform precursor amino acid into BAs is very important in order to estimate the risk of BAs accumulation in wines. Since in previous years during project AGROTUR I we detected the higher BA content in some wines, we decided to focus on the presence of BA-producing LAB in Refošk grapes and wines. Therefore, during AGROTUR II project LAB collection of autochthonous lactic acid bacteria was set-up by isolating LAB from Refošk grapes and wines, originated from the grape growing cross-border region Karst (Slovenia). Over 600 isolates were obtained using MRS medium with added cycloheximide and 2% tomato juice. In parallel, also selective enrichment was performed using MRS medium described above with additionally added 5% ethanol. BA-producing LAB were primarily detected in microtiter-plate format using the decarboxylase screening medium with added amino acids (histidine, lysine, ornithine or tyrosine), which enable us to identify histamine-, cadaverine-, ornithine and tyrosine-producing LAB. Selected representatives from each BA-producing LAB groups were further on confirmed with chromatographic analysis (HPLC) and molecular methods (multiplex PCR method). BA-producing LAB were in majority represented by thyramin-producers, thereafter followed cadaverine-producers, with putrescine and histamine producers being the least presented. This screening of the BA-producing LAB is also incorporated in our on-going accurate selection of LAB starters for potential production of Refošk wines.
Ključne besede: biogenic amines, lactic acid bacteria, refošk, grape, wine
Objavljeno: 22.01.2020; Ogledov: 27; Prenosov: 0
Polno besedilo (185,72 KB) |
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