Original title: Sledování chemických změn v mleté kávě skladované různými způsoby
Translated title: Monitoring of chemical changes in ground coffee stored in different ways
Authors: Lajtman, Roman ; Vítová, Eva (referee) ; Diviš, Pavel (advisor)
Document type: Master’s theses
Year: 2020
Language: slo
Publisher: Vysoké učení technické v Brně. Fakulta chemická
Abstract: [slo] [eng]
Táto diplomová práca sa zaoberá sledovaním chemických zmien v mletej káve skladovanej v rôznych obaloch, konkrétne stanovením vody, vlhkosti a aromatického profilu kávy v jednotlivých obaloch (plechovka, papierové vrecko, vrecko s polyetylénovou vložkou, obal z nízkohustotného polyetylénu s hliníkovou vložkou (LDPE+Al) a sklenená nádoba). Na začiatku experimentu bolo zistené, že obsah vody v káve bol 4,72 ± 0,10 % a obsah vlhkosti bol 9,47 ± 0,01 %. Na konci experimentu ako najvhodnejší obal, kde bol nameraný najnižší obsah vody, bola zvolená plechovka. Obsah vody bol stanovený na 6,51 ± 0,11 % a obsah vlhkosti bol 9,93 ± 0,01 %. Avšak rozdiely medzi ostatnými obalmi, okrem papierového vrecka, boli veľmi malé, a teda všeobecne je možné povedať, že plechovka, LDPE+Al obal, vrecko s PE vložkou a sklenená nádoba sú vhodné na skladovanie mletej kávy. Pri stanovení aromatického profilu v káve pomocou HS-SPME-GC-MS bolo identifikovaných celkom 44 aromatických látok. Najviac zastúpené skupiny látok boli furány a pyrazíny. Počas skladovania došlo k určitým stratám látok, a to kvôli 2 mechanizmom. Prvý je vyparovanie a druhý sú samotné oxidačné reakcie. Najviac aromatických látok sa vyparilo/degradovalo v papierovom obale, kde tento veľký úbytok súvisí s jeho bariérovými vlastnosťami. Ako najvhodnejší obal, pri ktorom došlo k najmenším úbytkom aromatických látok bola zvolená sklenená nádoba. This diploma thesis deals with the monitoring of chemical changes in ground coffee stored in various containers and then it deals with the determination of water, moisture and aromatic profile of coffee in individual containers, namely a can, a paper bag, a bag with a polyethylene liner, a bag from low density polyethylene with aluminium liner (LDPE + Al) and a glass container. At the beginning of the experiment it was found that the water content in the coffee was 4.72 ± 0.10 % and the moisture content was 9.47 ± 0.01 %. After the original sample was measured, the coffee was poured into 5 packages. At the end of the experiment, a can was chosen as the most suitable package where the lowest water content was measured. The water content was determined to be 6.51 ± 0.11 % and the moisture content was 9.93 ± 0.01 %. However, the differences between the other packages, apart from the paper bag, were very small, and thus in general it can be said that the can, the LDPE + Al package, the bag with the PE liner and the glass container are suitable for storing ground coffee. A total of 44 aromatics were identified when determining the aromatic profile in coffee by HS-SPME-GC-MS. The most represented groups of substances were furans and pyrazines. During storage, there was some loss of substances due to 2 mechanisms. The first of them is evaporation and the second one is the oxidation reactions themselves. Most aromatic substances have evaporated / degraded in paper packaging, where this large decrease is related to its barrier properties. A glass container was chosen as the most suitable packaging with the least loss of aromatic substances.
Keywords: aroma; determination of water; gas chromatography with mass detector (GC-MS); ground coffee; Karl-Fischer titration

Institution: Brno University of Technology (web)
Document availability information: Fulltext is available in the Brno University of Technology Digital Library.
Original record: http://hdl.handle.net/11012/195102

Permalink: http://www.nusl.cz/ntk/nusl-433547


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Universities and colleges > Public universities > Brno University of Technology
Academic theses (ETDs) > Master’s theses