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Įvairių pasterizacijos režimų ir sausųjų baltyminių medžiagų įtaka kefyro kokybei / The influence of various pasteurization modes and albuminous milk products on the quality of kefirZinkutė, Vaida 15 April 2005 (has links)
The aim of this work is to research various pasteurization regimes and albuminous milk products influence on the quality of kefir. The research was made in the Food Institute of Kaunas Technology University, 8 aliquots of kefir were made and evaluated in laboratory conditions. These raw milk pasteurization regimes were applied- instantaneous pasteurization (in 87-90°C temperature), pasteurization maintaining to 30 min. (in 87-90°C temperature), pasteurization maintaining to 60 min. (in 87-90°C temperature). The raw milk of these aliquots was enriched with 1%, 2%, 3% fat-free milk powder and with 1%, 2%, 3% whey powder ripening the mixture to 60 min. in 87- 90°C pasteurization temperature. Physical and chemical, microbiological indicators and sensual qualities were determinated by standard methods.
It is determinated that the long-lasting milk pasteurization (maintaining to 30-60 min. in 87- 90° C pasteurization temperature), compared with the instantaneous pasteurization, increases viscosity of the product and enriches sensual qualities. Enriching of milk with whey powder in production of kefir stimulates the activity of milk acid bacteria. In comparison, aliquots enriched with 1%, 2%, 3% whey powder, it is determinated that the best is aliquot of kefir among which production it is interspersed 3% whey powder; physical-chemical and sensual qualities of the product signally better then. In comparison all the data of the experiment, the kefir characterized with the best... [to full text]
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Actividad biológica de péptidos de amaranto obtenidos por acción de microorganismosOrosco Condori, Eugenia Alejandra 31 March 2014 (has links)
El objetivo general de este trabajo fue generar conocimientos que sirvan de base para desarrollar ingredientes biológicamente activos derivados de proteínas de amaranto mediante hidrólisis con microorganismos proteolíticos. Se proponen estudiar dos actividades biológicas: actividad antitrombótica y actividad antimicrobiana.
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Antitumor properties of kefir : possible bioactive component(s) and mechanism(s)Chen, Chujian, 1966- January 2005 (has links)
Research on the putative health benefits has indicated that kefir, a traditional fermented milk, might have antimutagenic and antitumor properties. The major objective of the present thesis was to isolate and identify antitumor compounds in cow's milk kefir and investigate the possible mechanisms involved. High speed centrifugation (HSC), molecular weight cut-off filtration (MWCO), size exclusion high performance liquid chromatography (SEC-HPLC) and reverse phase-HPLC (RP-HPLC) were utilized for fractionation of kefir and a cell culture model was developed to screen for the antiproliferative effects of the kefir fractions. The antiproliferative effects of bacteria-free extracts from different fermentation stages of kefir production, as well as bacteria-free extracts from milk and yogurt were compared. The results showed that extracts from an early stage of fermentation (i.e., kefir mother culture) and the final commercial kefir product both exerted dose-dependent inhibition effects on human mammary tumor MCF-7 cells, yogurt extracts showed less potent antiproliferative effects, while pasteurized milk extracts showed no antiproliferative effects. No antiproliferative effects of the kefir extracts were observed on human mammary epithelial cells (HMEC) whereas the yogurt extracts showed antiproliferative action in HMEC cells at a high dose. A fraction of the kefir mother culture isolated by HSC, MWCO and RP-HPLC contained components that inhibited MCF-7 cell growth and had no effect on HMEC cells. Characterization of the bioactive fraction using mass spectrometry (MS) indicated that the main components in the fraction are likely fragments of kefiran and/or ceramide containing compounds such as gangliosides. The growth inhibitory effect may be mainly caused by the induction of TNF-alpha in MCF-7 cells. Whole extracts of kefir depleted glutathione (GSH) in MCF-7 cells, while the SEC-HPLC Fraction 7 and the RP-HPLC Fraction 30 induced GSH produc
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Influence of different preservation techniques and packaging materials on the activity of stored Kepi grainsCilliers, Annamie 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: Kepi is a refreshing, fermented dairy beverage that has been consumed for
centuries and is traditionally made by incubating Kepi grains in milk. The Kepi
grain is a complex starter culture consisting of a variety of lactic acid bacteria and
yeasts. The successful marketing of the grains requires the effective preservation
of the microbes present in the grains as well as an appropriate packaging that will
retain the acidification activity of the preserved grains over an extended period of
time. The aim of this study was to evaluate different preservation techniques and
packaging materials in terms of their respective abilities to retain grain viability and
activity over an extended storage period. Four different preservation techniques
(freezing at -18°C, refrigeration at 4°C, air-drying and Iyophilisation) and three
packaging materials including a low density polyethylene film (LOPE), an oriented
polyester film (OPET) and a metallised oriented polyester film (MOPET), were
evaluated.
Activity tests were used to evaluate the impact of the preservation
techniques in terms of the retainment of the acidification activity of the preserved
grains, and the storage potential of the preserved and packaged grains. The
activity tests included changes in pH, %TA, lactic acid production and lactose and
volatile compound content over an 18 h fermentation period. In addition, the
microbial viability of the packaged Iyophilised grains after two months of storage,
was also investigated. Frozen and refrigerated grains showed the best retainment
of the acidification activity over a 10-month storage period. Air-drying and
Iyophilisation showed a good retention of the activity up to three months of
storage, but the application of these techniques both resulted in a retarded initial
acidification activity. After 10 months of storage, the air-dried and Iyophilised
grains showed only a low acidification activity. No volatile compounds could be
detected during the course of the fermentation period, due to the relative short
fermentation period of 18 h.
Overall, the best retainment of the fermentation activity was given by the
LOPE and the OPET packaging films. However, the storage period had a
considerable influence on the retention of the activity of the packaged Iyophilised grains. The viability study of the Iyophilised packaged Kepi grains after two
months of storage showed leuconostocs and lactobacilli to be the prevalent
microbes in the grains. Low microbial counts were obtained from the lactococciselecting
medium for all three of the differently packaged Kepi grains, whereas no
growth was observed on the media that selected for the propionibacteria and
yeasts. The OPET packaging film provided the best preservation of the microbial
composition.
It was, therefore, concluded that all four preservation techniques would be
suitable for the preservation of Kepi grains and the subsequent storage at room
temperature for three months. However, for storage periods of 10 months or
longer the use of freezing and refrigeration are recommended as most suitable
preservation techniques. All three of the packaging materials proved to be
suitable for the packaging and storage of the Iyophilised Kepi grains for periods of
up to one month. However, for storage periods of two months or longer, the use of
the OPET film for the packaging and retainment of the acidification activity of the
Iyophilised grains, can be recommended. / AFRIKAANSE OPSOMMING: Kepi is 'n eeu-oue verfrissende, gefermenteerde suiweldrankie wat tradisioneel
vervaardig word deur Kepikorrels in melk te inkubeer. Hierdie Kepikorrels bestaan
uit 'n komplekse samestelling van hoofsaaklik melksuurbakteriee en giste. Die
effektiewe preservering en verpakking van die korrels is belangrike voorvereistes
vir die suksesvolle bemarking daarvan. Dis belangrik dat die preserverinq en die
verpakking van die korrels 'n positiewe bydrae sal lewer tot die behoud van die
fermentasie-aktiwiteit van die mikrobes in die korrels oar 'n verlengde
opbergingsperiode. Die doel van hierdie studie was om die opbergingspotensiaal
van verskillend gepreserveerde en -verpakte Kepikorrels te evalueer in terme van
die behoud van die lewensvatbaarheid en fermentasie-aktiwiteit van die
samestellende mikrobes. Vier verskillende preserveringstegnieke (bevriesing by
-18°C, verkoeling by 4°C, lugdroging en vriesdroging) en drie verskillende tipes
verpakkingsmateriale, nl. 'n "low density polyethylene film" (LOPE), 'n "oriented
polyester film" (OPET) en 'n "metallised oriented polyester film" (MOPET) was
qeevalueer.
Aktiwiteitstoetsing was gebruik om die impak van die verskillende
preserveringstegnieke en die verpakkingsmateriale op die behoud van die
fermentasie-aktiwiteit van die Kepikorrels te ondersoek. Die verskillende
aktiwitieitstoetse wat gedoen is, het die meting van die verandering in pH, %TA,
melksuur- en laktosekonsentrasie oor 'n fermentasieperiode van 18 h ingesluit.
Tesame met die aktiwitietstoetsing IS die lewensvatbaarheid van die
gevriesdroogde, verpakte Kepikorrels na twee maande van opberging ook
ondersoek. Die bevrore en verkoelde Kepikorrels het die beste behoud van
aktiwitiet na 'n 10-maande opbergingsperiode getoon. Die gelugdroogde en
gevriesdroogde korrels het 'n goeie behoud van aktiwiteit getoon vir 'n
opbergingstydperk van tot drie maande, maar beide die lugdroging- en
vriesdrogingstegnieke het 'n aanvanklik vertraagde fermentasie-aktiwitieit getoon.
Na 'n : opbergingsperiode van 10 maande het beide die gelugdroogde en
gevriesdroogde korrels egter 'n lae fermentasie-aktiwiteit getoon. As gevolg van 'n relatiewe kort fermentasieperiode van 18 h kon geen vlugtige komponente in die
Kepimonsters gevind word nie.
Die LDPE- en OPET-verpakkingsmateriale het die beste behoud van die
fermentasie-aktiwiteit van die gevriesdroogde korrels getoon. Die
opbergingsperiode het egter 'n aansienlike impak op die aktiwitietsbehoud van die
korrels gehad. Die lewensvatbaarheidstudie het aangetoon dat Leuconostoc- en
Lactobacillus-spesies die oorheersende mikrobes in die verpakte, gevriesdroogde
Kepikorrels na 'n opbergingsperiode van twee maande was. Lae mikrobiese
tellings vir al drie van die verpakkingsmateriale was gevind op die Lactococcusselekterende
medium, en geen mikrobegroei kon op die giste- en
propionibakteriee-selekteringsmedium waargeneem word nie. Die beste behoud
van die mikrobiese samestelling in die verpakte, gevriesdroogde Kepikorrels was
gevind vir die OPET-verpakkingsmateriaal.
Die gevolgtrekking kan gemaak word dat al vier die preserveringstegnieke
geskik is vir die preservering van die Kepikorrels en die daaropvolgende opberging
van drie maande by kamertemperatuur. Vir opbergingsperiodes van 10 maande
en langer word die gebruik van bevriesing en verkoeling aanbeveel as die mees
geskikte preserveringstegnieke. AI drie verpakkingsmateriale kan gebruik word vir
die verpakking en opberging van gevriesdroogde Kepikorrels vir 'n tydperk van
een maand. Indien 'n opbergingsperiode van twee maande of langer verlang
word, word die OPET-verpakkingsmateriaal aanbeveel vir die suksesvolle behoud
van die fermentasie-aktiwiteit van die Kepikorrels.
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Optimisation of kefir biomass and metabolite production in conjunction with sensory evaluationCerff, Jeanne 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: Developing countries such as South Africa are in dire need of nutritionally adequate
dairy food and beverage sources that are ambient stable due to minimal access to
refrigeration. One such product is Kefir, a naturally fermented milk beverage that
originated in Caucasian China many centuries ago. The microorganisms responsible
for fermentation of the milk are held together in a carbohydrate matrix in the form of
small grains. These grains are then removed from the beverage prior to
consumption, and added to fresh milk for new fermentations. This beverage holds
great potential for large scale development due to the self-propagating nature of the
grains, the lack of sophisticated equipment and knowledge necessary for production,
and the appealing sensory characteristics of this beverage. This study was therefore
performed as an initial investigation to determine the optimum fermentation
conditions for large-scale grain production and optimal sensory appeal.
Kefir grain production was found to be proportional to incubation temperature
in the range studied (18°, 22°, 25° and 30°C), with maximum grain biomass
increases of 500% for the Kefir incubated at 30°C over the 10 d trial.
During fermentation of Kefir grains in milk, lactic acid and other metabolites
are produced. Lactic acid results in coagulation of the milk, necessary to provide the
characteristic texture and flavour of Kefir, as well as exerting a preservative effect.
Lactic acid production was found to be strongly proportional to both incubation
temperature and inoculum concentration. The samples containing 2% (w/v) Kefir
grain inoculum concentration that were incubated at 25°C for 24 h were found to
have optimum lactic acid levels for good quality Kefir (pH of 4.4 - 4.6 and TA of 1.0 -
1.15%).
The other metabolites produced during Kefir fermentation are responsible for
the specific flavour of Kefir, and include acetaldehyde, diacetyl, ethanol, acetone and
2-butanone. These compounds were studied using headspace gas chromatography
over the fermentation period, which yielded good resolution and separation of all
these compounds, however, only acetaldehyde, ethanol and acetone were found to
be major metabolites in this study, These analytical results were then further
compared to sensory results for key identified attributes, as obtained from a trained
sensory panel, to enable recommendations for optimum fermentation conditions to be made. The studied attributes included sourness, sweetness, butteriness,
creaminess, yoghurt flavour, cowiness, effervescence, yeastiness, smoothness and
overall acceptability. It was apparent from this study that correlations between
analytical and sensory data could be drawn, and that panellists were particularly
accurate in detecting the attribute sourness resulting from the accumulated lactic acid
in the Kefir. Overall acceptability also seemed to be intricately linked to the attribute
creaminess, hence the regular literature references to full-cream Kefir as optimum for
best sensory appeal.
From this study, it was evident that Kefir with optimal sensory appeal is
obtained with incubation for 18 h at moderate temperatures (22° or 25°C) and grain
inoculum concentrations (0.8% w/v). / AFRIKAANSE OPSOMMING: In ontwikkelende lande soos Suid-Afrika, bestaan daar 'n groot behoefte aan
voedsame suiwelprodukte wat stabiel is by kamer temperatuur aangesien 'n groot
deel van die bevolking beperkte toegang tot verkoelingsfasiliteite het. Een so 'n
produk is Kefir, 'n natuurlike gefermenteerde suiwelproduk wat sy oorsprong eeue
gelede in China gehad het. Die mikroorganismes wat verantwoordelik is vir die
fermentasie, is saamgebind in 'n koolhidraat matriks in die vorm van klein korrels.
Hierdie korrels word verwyder uit die drankie voordat dit gedrink word, en word dan
weer by vars melk bygevoeg vir 'n verdere fermentasie. Hierdie gefermenteerde
produk het baie potensiaal vir massa-produksie, omdat die korrels natuurlik
vermeerder, geen gesofistikeerde toerusting of kennis nodig is nie, en die finale
produk hoogs aanvaarbare sensoriese eienskappe het. Die doel van die studie was
om 'n inleidende ondersoek uit te voer om die optimum fermentasie toestande vir
massakweking van korrels en die mees aanvaarbare sensoriese eienskappe te
bepaal.
Uit hierdie studie is gevind dat Kefirkorrel vermeerdering proporsioneel is tot
die verhoging in inkubasie temperatuur in die gebied 18°, 22°, 25° en 30°C, met
maksimum biomassa toenames van tot 500% vir Kefir wat vir 10 dae by 30°C
geïnkubeer was.
Gedurende fermentasie van Kefirkorrels in melk, word melksuur en ander
metaboliete gevorm. Melksuur lei tot die verlaging van die pH van die melk, en
veroorsaak stolling, wat noodsaaklik is vir die kenmerkende tekstuur en geur van
Kefir, maar dien ook as 'n preserveermiddel. Daar is ook gevind dat melksuur
produksie 'n direkte verband het met die inkubasie temperatuur en inokulum
konsentrasie. Die monsters met Kefirkorrel inokulum konsentrasie van 2% (miv) wat
vir 24 h by 25°C geïnkubeer is, het die optimale melksuur konsentrasies vir goeie
kwaliteit Kefir bevat (pH van 4.4 - 4.6 en TA van 1.0 - 1.15%).
Ander metaboliete wat belangrike geurkomponente van Kefir is, is
asetaldehied, diasetiel, etanol, asetoon en 2-butanoon. Hierdie metaboliete is bepaal
en geëvalueer met bodamp gaschromatografiese tegnieke gedurende die
fermentasie, wat 'n goeie resolusie en skeiding gelewer het. In hierdie studie is slegs asetaldehied, etanol en asetoon as hoof Kefir metaboliete gevind. Die analitiese
data is verder vergelyk met die sensoriese data van die hoof sensoriese
komponente, soos bepaal deur 'n opgeleide sensoriese paneel, om die mees
gunstigde fermentasie parameters te bepaal. Die geëvalueerde eienskappe was
suurheid, soetheid, botterigheid, romerigheid, joghurt geur, koeismaak, gas inhoud,
gisagtigheid, gladheid en algehele aanvaarbaarheid. Uit hierdie data is gevind dat
daar wel 'n sterk korrelasie bestaan tussen die analitiese en sensoriese resultate, en
dat paneellede in staat was om die suurheid, as gevolg van die gevormde melksuur,
te bepaal. Algehele aanvaarbaarheid is definitief gekoppel aan romerigheid, daarom
word volroommelk Kefir verkies bo die wat met afgeroomde melk berei is.
Die data uit hierdie studie het ook getoon dat Kefir met optimale sensoriese
eienskappe verkry is na 'n inkubasietyd van 18 h by "matige temperature" (22° of
25°C) en 'n Kefirkorrel inokulum van 0.8% (mIv).
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PCR-based DGGE typification of the microbial community in Kepi grainsGarbers, Ilze-Mari 12 1900 (has links)
Thesis (MSc Food Sc )--Stellenbsosch University, 2003. / ENGLISH ABSTRACT: Kepi is a fermented milk beverage that originated in Eastern Europe. Traditional
Kepi is a lightly acidic, carbonated beverage, with a slight yeasty taste. The starter
used to produce this beverage is an irregularly shaped, yellowish-white grain-like
structure similar in appearance to a cauliflower floret. The characteristic flavour of
Kepi is produced by a complex spectrum of microbial species that include species
of yeasts, lactic acid bacteria, acetic acid bacteria and mycelial fungi. At the end
of the fermentation process the grainy starter can be recovered and re-used, since
the microbes can easily be recovered as a solid matrix.
The microbes comprising Kepi grains have only been identified using
classical identification techniques such as selective growth media, morphological,
physiological and biochemical characteristics. In this study, polymerase chain
reaction (PCR)-based denaturing gradient gel electrophoresis (DGGE) analysis
was used to typify and identify the complex microbial consortium present in the
Kepi grains. A part of the 168 ribosomal RNA (rRNA) gene from the microbial
population in mass-cultured, traditionally cultured and Irish Kepi grains were
amplified using 'Eubacterial' specific primers and a part of the 268 rRNA gene was
amplified using yeast specific primers. The PCR fragments were resolved by
DGGE, resulting in unique fingerprints for the Eubacteria and yeasts present in the
different Kepi grain types. The traditionally cultured Kepi grains were found to
incorporate the most Eubacteria and yeast species, while the mass-cultured Kepi
grains contained the lowest number of Eubacteria and yeast species.
The different Eubacteria and yeast species were identified by cloning the
PCR products and sequencing the cloned inserts. The obtained DNA sequences
were compared to sequences available on the NCBI website. 8ix lactobacilli were
identified: Lb. crispatus (KC-4); three Lb. species (KC-36, KC-38 and KC-43); and
two unculturable lactobacilli (KC-2 and KC-3). The yeasts were identified as
Saccharomyces cerevisiae (KC-y18) and Candida lambica (KC-y1). Unidentified
isolates from kefiran strings that could not be identified using traditional methods
were also identified by cloning the PCR products and sequencing the cloned
inserts. The four isolates were identified as Lb. kefiri (KGI-A), Lb. parakefiri (KGIB),
Lb. gallina rum (KGI-D) and an unculturable Lactobacillus (KGI-5). The phylogenetic relationship between the identified lactobacilli and the
lactobacilli commonly found in Kepi grains was determined. The identified
lactobacilli were grouped together in a clade with a bootstrap support value of
84%. The clade also contained representatives of Lb. delbrueckii subsp. lactis,
Lb. acidophilus, Lb. gallinarum, Lb. helveticus, Lb. crispatus, Lb. species and
unculturable lactobacilli. The bands in the peR-based DGGE fingerprints of the
Eubacteria and the yeasts were identified, and a DGGE marker was subsequently
constructed for the rapid identification of the Eubacteria present in mass-cultured
Kepi grains.
The data obtained in this study clearly showed that Kepi grains that are
cultured differently, as well as Kepi grains from different origins have unique peRbased
DGGE banding patterns for both the Eubacteria and yeasts present in the
grains. The complex microbial consortium comprising Kepi grains could be
typified and identified using PeR-based DGGE, DNA cloning and sequencing.
The identification of the members of the microbial consortium is of importance for
the future commercialisation of the mass-cultured Kepi grains. / AFRIKAANSE OPSOMMING: Kepi is 'n gefermenteerde melkdrankie wat sy oorsprong het in Oos Europa.
Tradisionele Kepi is 'n effens suur, gekarboneerde drankie wat effens na gis
smaak. Die beginkultuur wat gebruik word om dié drankie te maak is 'n
oneweredige, geel-wit korrelagtige struktuur wat baie lyk soos 'n blomkoolkoppie.
Die karakteristieke smaak van Kepi word geproduseer deur 'n komplekse
spektrum mikrobiese spesies wat giste, melksuur- en asynsuurbakterieë en
~.
misillêre fungi insluit. Aan die einde van die fermentasieproses kan die
korrelagtige beginkultuur herwin word en weer gebruik word, aangesien die
mikrobes maklik herwin kan word as 'n soliede matriks.
Die mikrobes waaruit Kepikorrels bestaan, is nog slegs met behulp van
klassieke identifikasiemetodes soos selektiewe groeimedia, morfologiese,
fisiologiese and biochemiese eienskappe geïdentifiseer. In hierdie studie is
polimerase kettingreaksie (PKR)-gebaseerde denaturerende gradiënt
jelelektroforese (DGGE) analise gebruik om die komplekse mikrobiologiese
konsortium in die Kepikorrels te tipeer en te identifiseer. 'n Gedeelte van die 16S
ribosomale RNS (rRNS) geen van die mikrobiologiese populasie in
massagekweekte, tradisioneel gekweekte en Ierse Kepikorrels is geamplifiseer
met 'Eubakferiële' spesifieke peilers en In gedeelte van die 26S rRNS geen is
geamplifiseer met gis spesifieke peilers. Die PKR fragmente is onderskei deur
DGGE, wat unieke vingerafdrukke vir die Eubakteriële- en gisspesies in die
verskillende Kepikorrel tipes gelewer het. Die tradisioneel gekweekte Kepikorrels
het die meeste Eubakteriële- en gisspesies geïnkorporeer, terwyl die Ierse
Kepikorrels die minste Eubakteriële- en gisspesies geïnkorporeer het.
Die verskillende Eubakteriële- en gisspesies is geïdentifiseer deur klonering
van die PKR produkte en deur die gekloneerde insetsels se volgordes te bepaal.
Die ONS volgordes is dan vergelyk met volgordes wat op die NCSI webwerf
beskikbaar is. Ses lactobacilli is geïdentifiseer: Lb. ctispetus (KC-4); drie Lb.
spesies (KC-36, KC-38 en KC-43); en twee onkultiveerbare lactobacilli (KC-2 en
KC-3). Die giste is geïdentifiseer as Saccharomyces cerevisiae (KC-y18) en
Candida lambica (KC-y1). Ongeïdentifiseerde isolate van kefiranstringe is ook
geïdentifiseer deur klonering van die PKR produkte en deur die gekloneerde insetsels se volgorde te bepaal. Dié vier isolate is geïdentifiseer as Lb. kefiri (KGIA),
Lb. parakefiri (KGI-B), Lb. gallina rum (KGI-D) en 'n onkultiveerbare
Lactobacillus (KGI-5).
Die filogenetiese verwantskap is bepaal tussen die geïdentifiseerde
lactobacilli en lactobacilli wat geredelik in Kepikorrels gevind word. Die
geïdentifiseerde lactobacilli was saam in 'n groep gegroepeer met 'n bootstrap
waarde van 84%. Die groep het ook verteenwoordigers van Lb. delbrueckii subsp.
lactis, Lb. acidophilus, Lb. gallina rum, Lb. helveticus, Lb. crispatus, Lb. species en
'n onkultiveerbare laktobacilli ingesluit. Die bande in die PKR-gebaseerde DGGE
vingerafdrukke van die Eubakterieë en die giste is geïdentifiseer, en 'n DGGE
merker is gemaak vir die vinnige identifikasie van die Eubakterieë wat in die
massagekweekte Kepikorrels teenwoordig is.
Die data wat in die studie verkry, is wys duidelik dat Kepikorrels wat op
verskillende maniere gekweek is, en wat verskillende oorspronge het, unieke
PKR-gebaseerde DGGE bandpatrone het vir beide die Eubakterieë en giste wat in
die korrels teenwoordig is. Die komplekse mikrobiologiese konsortium waaruit
Kepikorrels bestaan kon getipeer en geïdentifiseer word deur PKR-gebaseerde
DGGE, klonering van DNS en volgordebepaling. Die identifikasie van lede van die
mikrobiologiese konsortium is belangrik vir die toekomstige kommersialisasie van
die massagekweekte Kepikorrels.
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Extração enzimática em cascas de uva: processo sustentável para obtenção de corante antociânicoMontibeller, Maria Jara January 2017 (has links)
A cada ano a indústria de vinhos descarta uma alta quantidade de resíduos líquidos e sólidos, constituído em grande parte por bagaço de uva. Este resíduo pode ser considerado um subproduto da indústria e apresenta quantidades significativas de antocianinas, as quais podem apresentar diversas aplicações. Apesar da extração de antocianinas ser um passo importante na recuperação de pigmentos em matrizes vegetais não existe um método de extração padrão na literatura. Dessa forma, existem estudos tanto em relação ao uso de métodos tradicionais quanto emergentes, sendo estes últimos normalmente mais favoráveis ao Meio Ambiente. Neste estudo foi usado o método de extração enzimática, técnica emergente, que se baseia em alterações da parede celular de matrizes alimentares para exposição dos materiais intracelulares. Assim, o objetivo geral do trabalho foi realizar a extração enzimática de antocianinas presentes em casca de uva para posterior aplicação como corante alimentício em quefir e bebida carbonatada. Foram encontrados diferentes temperaturas e porcentagens de preparado enzimático ótimos dependendo do cultivar analisado. Após aperfeiçoamento foi selecionado o uso de casca de Cabernet Sauvignon, a uma temperatura de 40 oC e 0,25 % de Pectinex Ultra Color®. O corante natural produzido foi aplicado em bebida carbonatada e quefir, ambos sob análises de tempo de meia-vida de antocianinas e parâmetros físico-químicos durante 16 dias de armazenagem. Dentre os resultados obtidos foi destacado que o quefir com adição do corante manteve características semelhantes ao encontrado na literatura para quefir natural. Em análises em bebida carbonatada, houve maior estabilidade de antocianinas nas amostras armazenadas sem presença de luz. A aplicação do extrato antociânico foi favorável em ambas matrizes alimentares, sendo recomendado estudos futuros visando o aumento do tempo de meia vida da estabilidade das antocianinas. / Every year, wine industry discards a high amount of liquid and solid waste, consisting largely of grape pomace. This residue can be considered a by-product of the industry and presents significant quantity of anthocyanins, which can provide several applications. Despite the extraction of anthocyanins be an important step on the recovery of pigments in vegetables, there is not a standard extraction method in the literature. In this way, there are studies regarding the use of traditional and emerging methods, which the latter usually being more environmentally friendly. In this study, controlled enzymatic extraction method was used, an emerging technique that is based on alterations of the cell wall of alimentary matrices for exposure of the intracellular materials. Thus, the aim of this study was to perform the enzymatic extraction of anthocyanins present in grape skins for subsequent application as a food dye in kefir and carbonated beverage. Eight different samples of grape pomace were used to improvement the extraction process. Preliminary responses of the study defined that low extraction times are required for the enzymatic extraction process, where the maximum ones being found when the process was conducted for thirty minutes using Pectinex Ultra Color®. In addition, different temperatures and percentages of enzyme preparation were found depending on the variety analyzed. After improvement, the use of Carbenet Sauvignon skin was selected, at a temperature of 40 ° C and 0.25% of enzymatic preparation. The natural dye produced was applied in carbonated beverage and kefir, both under analysis of the half-life of anthocyanins and physical- chemical parameters during 16 days of storage. Among the results obtained, it was pointed out that kefir with dye addition maintained similar characteristics to that found in the literature for natural kefir. In analyzes in carbonated beverage, there was greater stability of anthocyanins when the samples were stored without light. The application of the anthocyanin extract was favorable in both food matrices, and future studies are recommended aiming to increase the half-life of the stability of anthocyanins.
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Efeito do kefir de água no estresse oxidativo, na inflamação e na esteatose hepática em ratos wistar / Effect of water kefir in oxidative stress, inflammation and hepatic steatosis in wistar ratsSilveira, Carlos Mário Martins 28 November 2017 (has links)
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Previous issue date: 2017-11-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A obesidade é uma doença multifatorial, e o acúmulo excessivo de gordura no tecido adiposo está na gênese de distúrbios metabólicos e inflamatórios. O kefir de água é uma bebida fermentada que contém micro-organismos com potencial ação probiótica. O objetivo do estudo foi avaliar o efeito do kefir de água no metabolismo lipídico e na inflamação, no fígado e no tecido adiposo, em ratos alimentados com dieta de cafeteria. O experimento teve duração de 15 semanas e os animais foram divididos em seis grupos: G1-Dieta comercial; G2–Dieta comercial e 1 mL de kefir de água; G3–Dieta de cafeteria; G4–Dieta de cafeteria e 1 mL de kefir de água administrado antes da indução da obesidade; G5–Dieta de cafeteria e 1 mL de kefir de água administrado após a indução da obesidade e G6–Dieta de cafeteria e 2 mL de kefir de água administrado após a indução da obesidade. O kefir de água foi administrado 1 vez ao dia por gavagem. Ao final do experimento foram coletados o sangue, o fígado e o tecido adiposo. Analisou- se enzimas antioxidantes e da peroxidação lipídica no plasma, a expressão de genes envolvidos na inflamação e no metabolismo lipídico no fígado e no tecido adiposo, os teores de lipídeos no fígado e a histomorfometria no fígado e no tecido adiposo. O kefir de água aumentou a atividade da glutationa S-transferase (GST) e reduziu a concentração de malondialdeído (MDA) no plasma, quando administrado após a indução da obesidade, na dose de 2 mL, reduziu a expressão de TNFα no fígado e no tecido adiposo nos ratos obesos, aumentou a expressão dos genes envolvidos na oxidação de ácidos graxos hepáticos ADIPO R2, PPARα e CPT 1A, reduziu o teor de triacilglicerol e o percentual de gordura hepática quando administrado antes da indução da obesidade, e os teores de colesterol em todos os ratos obesos. Além disso, o kefir de água foi capaz de reduzir a expressão do gene adipogênico Fas e aumentar as expressões de LpL e adiponectina no tecido adiposo. Estes resultados demonstram potenciais efeitos benéficos do kefir de água nas complicações metabólicas relacionadas à obesidade e esteatose hepática. / Obesity is a multifactorial disease, and the excessive fat accumulation in adipose tissue is at the genesis of metabolic and inflammatory disorders. Water kefir is a fermented beverage that contains microorganisms with potential probiotic action. The objective of this study was to evaluate the effect of water kefir on lipid metabolism and on inflammation, liver and adipose tissue in rats fed by a cafeteria diet. The experiment lasted 15 weeks and the animals were divided into six groups: G1 - commercial diet; G2 - commercial diet and 1 mL water kefir; G3 - Cafeteria diet; G4 - Cafeteria diet and 1 mL water kefir administered before the induction of obesity; G5 - Cafeteria diet and 1 mL water kefir administered after the induction of obesity and G6 - Cafeteria diet and 2 mL water kefir administered after the induction of obesity. Weight and food consumption were monitored weekly. Water kefir was given once a day by gavage. At the end of the experiment, the blood, liver and adipose tissue were collected. Analyses of antioxidant enzymes and lipid peroxidation in plasma, expression of genes involved in inflammation and lipid metabolism in liver and adipose tissue, lipid levels in the liver and Histomorphometry in liver and adipose tissue were performed. Water kefir increased the activity of the glutathione S-transferase (GST) enzyme and reduced the concentration of malondialdehyde (MDA) in plasma, when administered after the induction of obesity at the dose of 2 mL, reduced TNFα expression in liver and adipose tissue in all groups of obese rats increased the expression of the genes involved in the oxidation of fatty liver fatty acids ADIPO R2, PPAR and CPT 1A, reduced the triacylglycerol ester and the percentage of hepatic fat when administered before the induction of obesity, and the cholesterol levels in all groups of obese rats. In addition, water kefir could reduce the expression of the adipogenic Fas gene and increase the expressions of LpL and adiponectin in adipose tissue. These results demonstrate potential beneficial effects of water kefir on metabolic complications related to adipogenesis and inflammation in obesity and hepatic steatosis.
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Extração enzimática em cascas de uva: processo sustentável para obtenção de corante antociânicoMontibeller, Maria Jara January 2017 (has links)
A cada ano a indústria de vinhos descarta uma alta quantidade de resíduos líquidos e sólidos, constituído em grande parte por bagaço de uva. Este resíduo pode ser considerado um subproduto da indústria e apresenta quantidades significativas de antocianinas, as quais podem apresentar diversas aplicações. Apesar da extração de antocianinas ser um passo importante na recuperação de pigmentos em matrizes vegetais não existe um método de extração padrão na literatura. Dessa forma, existem estudos tanto em relação ao uso de métodos tradicionais quanto emergentes, sendo estes últimos normalmente mais favoráveis ao Meio Ambiente. Neste estudo foi usado o método de extração enzimática, técnica emergente, que se baseia em alterações da parede celular de matrizes alimentares para exposição dos materiais intracelulares. Assim, o objetivo geral do trabalho foi realizar a extração enzimática de antocianinas presentes em casca de uva para posterior aplicação como corante alimentício em quefir e bebida carbonatada. Foram encontrados diferentes temperaturas e porcentagens de preparado enzimático ótimos dependendo do cultivar analisado. Após aperfeiçoamento foi selecionado o uso de casca de Cabernet Sauvignon, a uma temperatura de 40 oC e 0,25 % de Pectinex Ultra Color®. O corante natural produzido foi aplicado em bebida carbonatada e quefir, ambos sob análises de tempo de meia-vida de antocianinas e parâmetros físico-químicos durante 16 dias de armazenagem. Dentre os resultados obtidos foi destacado que o quefir com adição do corante manteve características semelhantes ao encontrado na literatura para quefir natural. Em análises em bebida carbonatada, houve maior estabilidade de antocianinas nas amostras armazenadas sem presença de luz. A aplicação do extrato antociânico foi favorável em ambas matrizes alimentares, sendo recomendado estudos futuros visando o aumento do tempo de meia vida da estabilidade das antocianinas. / Every year, wine industry discards a high amount of liquid and solid waste, consisting largely of grape pomace. This residue can be considered a by-product of the industry and presents significant quantity of anthocyanins, which can provide several applications. Despite the extraction of anthocyanins be an important step on the recovery of pigments in vegetables, there is not a standard extraction method in the literature. In this way, there are studies regarding the use of traditional and emerging methods, which the latter usually being more environmentally friendly. In this study, controlled enzymatic extraction method was used, an emerging technique that is based on alterations of the cell wall of alimentary matrices for exposure of the intracellular materials. Thus, the aim of this study was to perform the enzymatic extraction of anthocyanins present in grape skins for subsequent application as a food dye in kefir and carbonated beverage. Eight different samples of grape pomace were used to improvement the extraction process. Preliminary responses of the study defined that low extraction times are required for the enzymatic extraction process, where the maximum ones being found when the process was conducted for thirty minutes using Pectinex Ultra Color®. In addition, different temperatures and percentages of enzyme preparation were found depending on the variety analyzed. After improvement, the use of Carbenet Sauvignon skin was selected, at a temperature of 40 ° C and 0.25% of enzymatic preparation. The natural dye produced was applied in carbonated beverage and kefir, both under analysis of the half-life of anthocyanins and physical- chemical parameters during 16 days of storage. Among the results obtained, it was pointed out that kefir with dye addition maintained similar characteristics to that found in the literature for natural kefir. In analyzes in carbonated beverage, there was greater stability of anthocyanins when the samples were stored without light. The application of the anthocyanin extract was favorable in both food matrices, and future studies are recommended aiming to increase the half-life of the stability of anthocyanins.
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Spray Drying of Kefir with Encapsulating Agents to Mitigate Undesirable Volatile Flavor CompoundsDong, Tianrui January 2020 (has links)
No description available.
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