Starterkultuuride mõju kombucha fermentatsioonile
Laen...
Kuupäev
2019
Kättesaadav alates
31.08.2019
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Teeseenejoogi ehk kombucha tarvitamine on muutunud viimastel aastatel väga populaarseks
nii mujal maailmas kui ka Eestis. Probleemiks on aga see, et nii Eestis kui mujal maailmas on
teeseenega seoses läbi viidud väga vähe teaduslikke uurimistöid ning seetõttu on seoses
teeseenega kerkinud esile mitmeid küsimusi ja probleeme, mis vajaksid täiendavat uurimist.
Bakalaureusetöö eesmärgiks on nii teaduskirjanduse kui eksperimentaalse töö alusel koostada
ülevaade teeseenest, teeseenes ja teeseene kasvulahuses (e. teeseenejoogis e. kombuchas)
esinevatest mikroobidest ning tuvastada kultuurpärmide mõju kombucha fermentatsioonile.
Töö raames viidi läbi katseseeriad, mille käigus mõõdeti teeseente kasvulahuste pH väärtust,
suhkrusisaldust, määrati mikroobide üldarvud ja kirjeldati mikroobide morfoloogiat ning
isoleeriti ja säilitati mikroobide puhaskultuurid. Viimase katseseeria alguses lisati teeseene
lahustesse kultuurpärme ning katseseeria lõpus viidi läbi sensoorne analüüs.
Kokkuvõtteks leiti, et teeseente kasvulahuste pH jäi vahemikku 2,66-3,39 ning
suhkrusisalduseks oli 8-13,8 0
Bx. Proovid, millele lisati veinipärmi kultuuri, olid kõige
madalama pH ja suhkrusisaldusega. Hallitus-ja pärmseente ning bakterite üldarv oli teeseentes
suurem kui teeseente kasvulahustes.
Teeseentes esines läbi katseseeriate baktereid 1,9 x 105 … 6,4 x 108 PMÜ/g ning hallitus- ja
pärmseeni 1,2 x 105 PMÜ/g … 1,1 x 108 PMÜ/g. Kombuchas jäi bakterite hulk vahemikku 3,6
x 103 … 3,5 x 106 PMÜ/ml ning hallitus- ja pärmseente sisaldus oli 4,1 x 103 … 4,7 x 106
PMÜ/ml. Kultuurpärmide lisamine teeseene lahustesse ei avaldanud mikroobide üldarvule
statistiliselt olulist mõju, küll aga mõjutasid erinevalt kombucha maitse- ja lõhnaomadusi. Töö
raames isoleeritud mikroobide puhaskultuurid säilitatakse tulevaste identifitseerimiskatsete
jaoks glütseroolis -80 0
C juures.
The consumption of kombucha has become very popular in recent years both in the world and in Estonia. The problem, however, is that very little scientific research has been carried out in relation to the tea fungus (SCOBY) in Estonia and elsewhere in the world, and so many issues and problems related to the tea fungus need further investigation. The aim of the Bachelor’s thesis is to compile an overview of SCOBY, the microbes present in SCOBY and kombucha, based on scientific literature and experimental work, and to investigate the effect of starter cultures on fermentation of kombucha. At the end of each series of experiments, the pH value and sugar content in kombucha were measured, the total number of microbes was determined, the morphology of the microbes was described and microbial cultures were isolated and stored. At the beginning of the last test series, the starter cultures were added to the kombucha solutions and a sensory analysis was performed at the end of the test series. In conclusion, the pH of the fermented tea ranged from 2,66-3,39 and the sugar content was 8- 13,8 0 Bx. Samples to which wine yeast culture was added had the lowest pH and sugar content. The total number of mold and yeast and bacteria was higher in SCOBYs than in kombucha solutions. During the test series, the amount of bacteria in tea fungus samples was between 1,9 x 105 … 6,4 x 108 cfu/g while the content of yeasts and molds was 1,2 x 105 … 1,1 x 108 cfu/g. In kombucha the bacterial count ranged from 3,6 x 103 … 3,5 x 106 cfu/ml, and 4,1 x 103 … 4,7 x 106 cfu/ml for the yeasts and molds. The addition of industrial yeast cultures to kombucha did not have statistically significant effect on the overall microbial count, but they affected the taste and smell properties of kombucha. The cultures of microbes isolated during the work are stored for future identification experiments in glycerol at -80 ° C.
The consumption of kombucha has become very popular in recent years both in the world and in Estonia. The problem, however, is that very little scientific research has been carried out in relation to the tea fungus (SCOBY) in Estonia and elsewhere in the world, and so many issues and problems related to the tea fungus need further investigation. The aim of the Bachelor’s thesis is to compile an overview of SCOBY, the microbes present in SCOBY and kombucha, based on scientific literature and experimental work, and to investigate the effect of starter cultures on fermentation of kombucha. At the end of each series of experiments, the pH value and sugar content in kombucha were measured, the total number of microbes was determined, the morphology of the microbes was described and microbial cultures were isolated and stored. At the beginning of the last test series, the starter cultures were added to the kombucha solutions and a sensory analysis was performed at the end of the test series. In conclusion, the pH of the fermented tea ranged from 2,66-3,39 and the sugar content was 8- 13,8 0 Bx. Samples to which wine yeast culture was added had the lowest pH and sugar content. The total number of mold and yeast and bacteria was higher in SCOBYs than in kombucha solutions. During the test series, the amount of bacteria in tea fungus samples was between 1,9 x 105 … 6,4 x 108 cfu/g while the content of yeasts and molds was 1,2 x 105 … 1,1 x 108 cfu/g. In kombucha the bacterial count ranged from 3,6 x 103 … 3,5 x 106 cfu/ml, and 4,1 x 103 … 4,7 x 106 cfu/ml for the yeasts and molds. The addition of industrial yeast cultures to kombucha did not have statistically significant effect on the overall microbial count, but they affected the taste and smell properties of kombucha. The cultures of microbes isolated during the work are stored for future identification experiments in glycerol at -80 ° C.
Kirjeldus
Bakalaureusetöö
Toiduainete tehnoloogia õppekaval
Märksõnad
bakalaureusetööd, teeseen