Rosa damascena Mill roosi kroonlehtede mõju õunasiidri fermentatsioonile
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Kuupäev
2022
Kättesaadav alates
09.09.2022
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Roosi kroonlehtede kasutamisest toidus on tänapäeval palju räägitud ja seetõttu on
kasvanud huvi tuua toiduainetööstuse tootevalikusse Rosa damascena Mill
kroonlehtedest valmistatud roosiveega täiustatud õunasiider. Roosi kroonlehed muudab
kasulikuks nendes esinev eeterlik õli ning tänu sellele kasutatakse roosi kroonlehti näiteks
roosiõli ja roosivee valmistamiseks. Kuna roosisiider ei ole eriti levinud ja roosisiidriga
seonduvat teaduslikku informatsiooni on vähe, siis vajab selle tehnoloogia täiendavat
uurimist. Magistritöö eesmärk on uurida õuna- kui ka roosisiidri valmistamise
tehnoloogiat, roosi kroonlehtede kasutamise võimalusi siidri valmistamisel ning teha
kindlaks, kas roosivees leiduvad fenoolsed ühendid ja lisatud suhkur avaldavad mõju
siidri fermentatsiooniprotsessile.
Magistritöö katsete käigus valmistati erineva kontsentratsiooniga roosivett, õunamahla ja
suhkrut sisaldavad siidrid, mida kääritati 21 päeva. Kolme nädala pikkuse fermentatsiooni
jooksul määrati bakterite ja pärmseente arvukus, pH, suhkrusisaldus, happesus ning
antioksüdantsus, et hinnata roosivee mõju siidri fermentatsiooniprotsessile. Lisaks
analüüsiti roosivee proove, et saada teada, kas roosivesi sisaldab fenoolseid ühendeid.
Mikrobioloogiliste analüüside käigus selgus, et mikroorganismidele oli soodsaks
kasvukeskkonnaks nii tavaline õunasiider kui ka roosisiider. Pärmide ja bakterite arvukus
kasvas 21 päeva pikkuse fermentatsiooni jooksul (p < 0,05), aga arvukus ei sõltunud
lisatud roosivee kogusest. Lisatud suhkur pärssis mikroorganismide kasvu – mida suurem
oli suhkrusisaldus, seda madalam oli nii bakterite kui ka pärmseente arvukus. Keemilised
parameetrid nagu pH ja happesus sõltusid lisatud roosivee kogusest. Lisatud suhkruta
proovides kaasnes suhkrusisalduse kahanemisega keskmiselt ka pH kahanemine ja
happesuse suurenemine, lisasuhkruga proovides oli olukord vastupidine. Kuumtöödeldud
roosivesi sisaldas suuremas koguses fenoolseid ühendeid kui kuumtöötlemata roosivesi.
Suuremat DPPH radikaali neutraliseerimismõju täheldati siidri proovidel, mis sisaldasid
roosivett.
Recently much has been said about the use of rose petals in food and therefore there has been growing interest in bringing an apple cider made of rose water containing Rosa damascena Mill petals to the food industry's product range. Rose petals contain essential oils which have beneficial effect and thus it is possible to use rose petals for producing rose oil and rose water. As rose cider is not very common and there is few scientific information about rose cider, this technology needs further research. The aim of the Master's thesis is to explore the technology of making apple and rose cider, the possibilities of using rose petals in the manufacture of cider and to determine whether the phenolic compounds found in rose water and the added sugar have an effect on the cider fermentation process. In the course of Master’s thesis experiments, ciders containing different concentrations of rose water, apple juice and sugar were prepared and fermented for 21 days. During the three weeks of fermentation, the number of bacteria and yeast, pH, sugar content, acidity and antioxidant activity were determined to evaluate the effect of rose water on the cider fermentation process. In addition, rose water samples were analyzed to determine if the rose water contained phenolic compounds. Microbiological analysis revealed that both apple cider and rose cider were favourable growth media for the microorganisms. The number of yeasts and bacteria increased during the 21-day fermentation (p < 0,05), but the number did not depend on the amount of rose water added. The added sugar inhibited the growth of microorganisms – the higher the sugar content, the lower number of both bacteria and yeasts. Chemical parameters such as pH and acidity depended on the amount of rose water added. In samples that did not contain sugar, the decrease of pH and increase of acidity were accompanied by a decrease in sugar content, being the opposite in samples where sugar was added. Heat-treated rose water contained higher amounts of phenolic compounds than unheated rose water. Cider samples containing rose water showed a higher DPPH radical neutralizing effect. Greater DPPH radical neutralizing capacity was noted in samples containing rose water.
Recently much has been said about the use of rose petals in food and therefore there has been growing interest in bringing an apple cider made of rose water containing Rosa damascena Mill petals to the food industry's product range. Rose petals contain essential oils which have beneficial effect and thus it is possible to use rose petals for producing rose oil and rose water. As rose cider is not very common and there is few scientific information about rose cider, this technology needs further research. The aim of the Master's thesis is to explore the technology of making apple and rose cider, the possibilities of using rose petals in the manufacture of cider and to determine whether the phenolic compounds found in rose water and the added sugar have an effect on the cider fermentation process. In the course of Master’s thesis experiments, ciders containing different concentrations of rose water, apple juice and sugar were prepared and fermented for 21 days. During the three weeks of fermentation, the number of bacteria and yeast, pH, sugar content, acidity and antioxidant activity were determined to evaluate the effect of rose water on the cider fermentation process. In addition, rose water samples were analyzed to determine if the rose water contained phenolic compounds. Microbiological analysis revealed that both apple cider and rose cider were favourable growth media for the microorganisms. The number of yeasts and bacteria increased during the 21-day fermentation (p < 0,05), but the number did not depend on the amount of rose water added. The added sugar inhibited the growth of microorganisms – the higher the sugar content, the lower number of both bacteria and yeasts. Chemical parameters such as pH and acidity depended on the amount of rose water added. In samples that did not contain sugar, the decrease of pH and increase of acidity were accompanied by a decrease in sugar content, being the opposite in samples where sugar was added. Heat-treated rose water contained higher amounts of phenolic compounds than unheated rose water. Cider samples containing rose water showed a higher DPPH radical neutralizing effect. Greater DPPH radical neutralizing capacity was noted in samples containing rose water.
Kirjeldus
Magistritöö
Toiduainete tehnoloogia õppekaval
Märksõnad
magistritööd, õunasiider, roosisiider, Rosa damascena roosi kroonlehed, fermentatsiooniprotsess