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Determination of biogenic amine-forming potential of naturally occuring lactic acid bacteria (LAB) strains isolated from the grapes of Vitis vinifera cv. Refošk grape variety
Jelena Topić, Lorena Butinar, Martina Bergant Marušič, Dorota Korte, Branka Mozetič Vodopivec, 2020, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: Biogenic amines are naturally occurring compounds that have been reported in variety of food, such as fish, meat, cheese, vegetables, and wines. When biogenic amines are formed by microorganisms such as lactic acid bacteria (LAB) they may have adverse effect on human health. The most common biogenic amines found in foodstuff are histamine, tyramine, putrescine and cadaverine. LAB are used as starters in the production of several foods and beverages. In wines they are used in malolactic fermentation, where the conversion of malic acid to lactic acid occurs. The aim of this work was to determine biogenic amine-forming capacity of indigenous LAB strains isolated from grapes which were PCR positive and screening medium positive for biogenic amines. Three methods for the confirmation of LAB biogenic amine-forming potential were developed and compared: HPLC-DAD and TLC methods both using derivatization agent dansyl chloride and enzymatic method using horseradish peroxidase (HRP) and diamine oxidase (DAO) enzymes. The applicability of methods was tested on the three known biogenic amine-producing LAB strains: 0006, 9809, 9906 (IOEB, France). The limit of detection (LOD) of the methods was <1 mg/L for HPLC-DAD, 5 mg/L for TLC and 25 mg/L for enzymatic method. Although the LODs between the proposed methods differed, all of the three methods confirmed BA-forming potential of the three strains. Furthermore, the proposed methods were applied for the analysis of three indigenous strains: MKBT-282 (BA+), MKBT-307 (BA-) and MKBT-325 (BA+). The positive or negative BA-forming potential was confirmed with all of the three proposed methods.
Ključne besede: lactic acid bacteria, biogenic amines, histamine, grape
Objavljeno v RUNG: 10.07.2020; Ogledov: 2908; Prenosov: 0
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Implementation of high performance liquid chromatography coupled to thermal lens spectrometry (HPLC‑TLS) for quantification of pyranoanthocyanins during fermentation of Pinot Noir grapes
Jelena Topič Božič, Lorena Butinar, Natka Ćurko, Karin Kovačević Ganić, Branka Mozetič Vodopivec, Dorota Korte, Mladen Franko, 2020, izvirni znanstveni članek

Opis: In this work high performance liquid chromatography coupled to thermal lens spectrometry (HPLC-TLS) was applied for monitoring of vinylphenolic pyranoanthocyanins formation during the fermentation of Pinot Noir wines. Vinylphenolic pyranoanthocyanins are wine pigments, present in low concentrations, but very important for wine colour stability. Fermentation process was conducted with four different yeast strains, used as starters, either in sequential fermentation of non-Saccharomyces with S. cerevisiae yeast or as single fermentation with S. cerevisiae yeasts in order to test the applicability of developed method for monitoring of selected compounds in real wine fermentation experiments. The developed HPLC-TLS method showed higher sensitivity compared to HPLC coupled to diode array detection (DAD) technique for particular wine colour compounds. Obtained limits of detection (LODs), were 6- and 22-times lower in comparison to HPLC–DAD in gradient and isocratic elution mode, respectively, whereas limits of quantification (LOQs) 5 and 18-times lower. Lower LODs enabled earlier observation of vinylphenolic pyranoanthocyanins formation during fermentation (already at day 7) in the case of HPLC-TLS method in gradient mode, while by using HPLC–DAD in gradient elution mode the formation of vinylphenolic pyranoanthocyanins was noticed only after 12 days of fermentation.
Ključne besede: Thermal lens spectrometry (TLS), High performance liquid chromatography (HPLC), Pyranoanthocyanins, Wine, Yeasts
Objavljeno v RUNG: 18.06.2020; Ogledov: 3202; Prenosov: 0
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Yeasts and wine colour
Jelena Topić Božič, Olga Butinar-Čeh, Dorota Korte, Branka Mozetič Vodopivec, 2019, pregledni znanstveni članek

Ključne besede: yeast, Saccharomyces, non-Saccharomyces, wine colour, pyranoanthocyanins
Objavljeno v RUNG: 20.12.2019; Ogledov: 3893; Prenosov: 0
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