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Opis: Our investigation delves into the previously uncharted territory of cider composition from Norway. This study aimed to obtain an overview of the qualitative and quantitative compositions of general chemical parameters, polyphenols (individual and total expressed as gallic acids equivalents), selected esters, and selected C6-alcohols in ciders with the PDO label Cider from Hardanger. In total, 45 juice and cider samples from the fermentation process were collected from 10 cider producers in Hardanger in 2019, 2020, and 2021. Individual sugars, acids, ethanol, and 13 individual phenols were quantified using HPLC-UV/RI. Seven ethyl esters of fatty acids, four ethyl esters of branched fatty acids, ten acetate esters, two ethyl esters of hydroxycinnamic acids, and four C6-alcohols were quantified using HS-SPME-GC-MS. For samples of single cultivars (‘Aroma’, ‘Discovery’, ‘Gravenstein’, and ‘Summerred’), the sum of the measured individual polyphenols in the samples ranges, on average, from 79 to 289 mg L−1 (the lowest for ‘Summerred’ and highest for ‘Discovery’ and ‘Gravenstein’). Chlorogenic acid was the most abundant polyphenol in all samples. Ethyl butyrate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, ethyl isobutyrate, ethyl 2-methylbutyrate, isoamyl acetate, and hexanol were present at concentrations above the odour threshold and contributed to the fruity flavour of the Cider from Hardanger.
Ključne besede: cider, volatile aroma, esters, higher alcohols, polyphenols
Objavljeno v RUNG: 14.08.2024; Ogledov: 1477; Prenosov: 8
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Opis: Norwegian apple ciders have recently gained attention at the levels of international competitiveness. Accordingly, a comparative study on the chemical composition of selected Norwegian and French apple ciders was conducted to gain knowledge on what ubiquitous chemical parameters make the Norwegian ciders different from ciders from well-established producing regions. A total of 43 ciders, 24 Norwegian and 19 French, in the category of acidic dominant ciders, were included in the study. Ethanol, individual sugars and organic acids, pH, total phenols, aroma compounds including esters, C6-alcohols, volatile phenols and terpenoids, were analysed. Norwegian ciders showed higher contents in ethanol, malic and citric acids, whereas total phenols, pH, glucose, and fructose were higher in French counterparts. Regarding the aromatic profile, no significant differences were observed for C6-alcohols. In contrast, differences were more expressed in the case of esters and volatile phenols. Norwegian ciders were characterised by higher average concentration for all the groups of esters, with the most important differences measured for higher alcohol acetates. Norwegian ciders also displayed higher contents of 4-vinylphenol and 4-vinylguaiacol while French ciders contained substantially higher levels of 4-ethylphenol and 4-ethylguaiacol. These results are in mutual correlation with the empirical observation reporting Norwegian apple ciders as more acidic, alcoholic and with lighter body but fruitier profile. Whereas French ciders are often perceived with more structure and animalistic profile.
Ključne besede: alcohol, acidity, total phenols, aroma-compounds, apple cider
Objavljeno v RUNG: 25.03.2024; Ogledov: 2760; Prenosov: 8
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Opis: The presence of bioactive compounds in food and beverages of plant origin is mainly connected with higher nutritional value and better sensory properties. However, some of them can pose a threat to food product quality and human health. For example, excess biogenic amines (BAs) intake can cause different allergenic responses in individuals who have such intolerances. BAs have been intensively studied in recent years, especially in fermented foods like wine, meat, fish, and cheese. Among fermented beverages is apple cider still rather unexplored from this perspective. Especially since no such data exist for the Norwegian cider. Norwegian cider is becoming more and more popular in Norway in recent years among producers and consumers. Hardanger cider from Western Norway is very different from French, English, or Spanish ciders in terms of sensory characteristics, apple cultivars, and in the fermentation process. In Hardanger, the traditional cider is still produced by spontaneous fermentation of apple juice with naturally occurring yeasts that originate from the fruit or processing equipment surfaces. Lactic acid bacteria are known to be associated with BA formation. However, several studies reported about the BA-producing yeasts in winemaking. Due to the important role of natural yeasts in the production of Hardanger cider, we focused on the ability of BA formation by native yeasts. Thus, in our study, we followed the amounts of BAs in the Hardanger ciders during the fermentation process and characterize isolated yeasts if they have the ability to produce BAs under cidermaking conditions by performing a micro-fermentation experiment. From must/cider samples, taken during the fermentation process at 13 producers in the Hardanger region, we isolated 530 yeast isolates. Based on the sequencing of the D1/D2 domain of the 26S rDNA we identified 25 different yeast species. As expected, yeast diversity was higher at the beginning compared to the middle fermentation stage, when mostly different non-Saccharomyces yeast species prevailed, while at the end of fermentation mainly Saccharomyces species with high ethanol tolerance were present. BAs were analyzed with the HPLC-UV method. In all apple juice/cider samples 4 different BAs (putrescine, cadaverine, histamine, and tyramine) were detected and quantified with external calibration. On average in all cider samples from the producers total BA (summation of all BAs) concentration reached 9,45 mg/L, however in one case even 25 mg/L. Tyramine was the most abundant BA in all fermentation stages. 40 isolated yeast strains were further tested for BA formation in a small-scale experiment by fermenting apple juice. Results show that non-Saccharomyces yeasts mainly form histamine (1,68 mg/L) and tyramine (1,30 mg/L), while Saccharomyces yeasts putrescine (0,48 mg/L) and tyramine (3,53 mg/L). As a general conclusion, the occurrence and distribution of BA concentrations in the small-scale fermentation were lower (2,96 mg/L and 4,01 mg/L) and less variable than in the real ciders (average in final ciders 9,45 mg/L) and with tyramine being the most abundant BA in all samples analyzed.
Ključne besede: cider, yeast, biogenic amines, Hardanger, biodiversity
Objavljeno v RUNG: 23.06.2023; Ogledov: 2588; Prenosov: 9
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Ključne besede: HPLC-UV-RI, Cider, Wine, Must, Organic aacids, Ethanol, Glucose, Fructose.
Objavljeno v RUNG: 20.02.2023; Ogledov: 2244; Prenosov: 0
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Opis: V tem diplomskem delu smo obravnavali proces validacije dveh analiznih metod za določanje kakovosti vina. In sicer smo določali organske kisline kot so vinska kislina, jabolčna kislina, mlečna kislina, citronska kislina, ocetna kislina, in monosaharide glukozo in fruktozo. Analiza teh parametrov je pomembna pri nadzoru procesa pridelave vina kot tudi spremljanju kakovosti vina. V diplomski nalogi smo pregledali glavne metode za določanje kislin in sladkorjev v grozdju in vinu, v samem poskusu pa smo uporabili kromatografsko tehniko na osnovi tekočinske kromatografijo visoke ločljivosti v kombinaciji z detekcijo v ultravijoličnem (UV) za organske kisline in z detekcijo lomnega količnika (RID) za monosaharidne sladkorje. HPLC-UV/RID sistem omogoča enostavno pripravo vzorca na analizo (samo filtracija, mogoče redčitev, če je potrebna), hitro analizo in omogoča zadovoljive meje detekcije za potrebe določevanja omenjenih parametrov. Obe metodi smo opisali z različnimi parametri, kot je ponovljivost, linearnost, izkoristek v štirih različnih matriksih (dve beli vini, eno rdeče in eno jabolčno vino – cider), meja detekcije in meja kvantifikacije. Rezultate kvantifikacije skupnih sladkorjev in organskih kislin v vzorcih vin smo primerjali z rezultati akreditiranega laboratorija kjer je bilo to mogoče in ugotovili, da kvantifikacija z metodo standardnega dodatka omogoča primerljive rezultate z akreditiranim laboratorijem, predvsem za parameter skupni fermentirani sladkorji (glukoza in fruktoza). Vsebnost skupnih kislin določenih kromatografsko je bila nekoliko manjša od parametra skupne titrabilne kisline, kar je najverjetneje posledica manjšega števila posameznih kislin, ki smo jih vključili v ta parameter, pa tudi drugačne metode določanja kislin.
Ključne besede: vino, cider, HPLC, UV, RID, organske kisline, sladkorji, validacija
Objavljeno v RUNG: 02.08.2022; Ogledov: 3565; Prenosov: 77
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