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Avaliação do emprego do arroz preto (Oryza sativa L.) submetido a hidrólise enzimática como adjunto na fabricação de cerveja / Assessment of the use of black rice (Oryza sativa L.) submitted to enzymatic hydrolysis as adjunct on beer manufacturingClaudio Donato de Oliveira Santos 29 April 2011 (has links)
Segundo a legislação brasileira, em uma cerveja, parte do malte de cevada pode ser substituído por cereais maltados ou não, e por carboidratos de origem vegetal, transformados ou não, conhecidos como adjuntos. Os adjuntos tem por finalidade contribuir como fonte alternativa de substrato, por geralmente terem preços inferiores ao malte de cevada e proporcionar à bebida características sensoriais peculiares. Este trabalho teve como objetivo utilizar a quirera de arroz preto (Oryza sativa L.), que não apresenta valor comercial, com o propósito de aumentar a contribuição de açúcares deste adjunto em 45 % no extrato de um mosto primitivo de uma cerveja. O arroz foi caracterizado em relação aos teores de amido total (83,20 % ± 1,41, b.s.) e suas frações, ao teor de metais e da temperatura de gelificação (78,68 °C). A ?-amilase termoestável utilizada no processo também foi caracterizada em relação ao teor de proteínas (20,5 ± 1,2 mg de proteína/mL de extrato), atividade amilásica (112 000 UI/mL de extrato) e atividade específica (5 463 UI/mg de proteína). Foram otimizadas as condições de hidrólise em relação ao tempo de processamento e concentração da enzima, segundo um planejamento experimental fatorial completo 22 com três pontos centrais e estudo rotacionado. A levedura (Saflager S-23) utilizada no processo foi selecionada por apresentar melhor desempenho fermentativo dentre 4 cepas avaliadas. Os ensaios de fermentação foram executados em escala de bancada e ampliados para a escala piloto, na qual foi obtida excelente eficiência de mosturação (73,71 % ± 4,69). A cerveja obtida foi avaliada do ponto de vista sensorial e físico-químico. O processo apresentou bom rendimento fermentativo (0,37 ± 0,04 g/g), eficiência de fermentação (72,48 % ± 7,61) e produtividade em álcool (0,32 g.L-1.h-1± 0,02). Concluiu-se que o processo pode resultar num produto com bom rendimento e características sensoriais muito intensas e agradáveis, similar a uma cerveja forte, consumida tipicamente durante o inverno. / As cited on Brazilian legislation, in a beer, part of the malt can be substituted by malted or non-malted cereals, and by carbohydrates from vegetal sources, called adjuncts. Adjuncts have the purpose of contributing as an altenative and cheaper source of sugars, when compared to barley malt, and provide peculiar sensory characteristics. This work aimed to use the black rice (Oryza sativa L.) grits, which does not have economic value, and use this raw material on the proportion of 45% on the primitive extract of a beer. On black rice, it was quantified starch (83,20 % ± 1,41, d.b.) and metal content, and measured the gelatinization temperature (78,68 °C). The enzyme (Brautec Alfa-TF) used in this work was characterized on protein content (20,5 ± 1,2 mg protein/mL de enzyme extract), activity (112000 IU/mL of extract) and specific activity (5463 IU/mg of protein). The enzymatic hydrolysis conditions were optimized using a full factorial 22 central composite design with star points aiming at it the sugar concentrations response on hydrolysate regarding the factors: enzyme concentration and processing time at 95 °C. The yeast strain was selected among 4 strains regarding the factors: alcohol yield (g/g), fermentation efficiency (%) and alcohol productivity (g.L-1.h-1). Assays were carried out on benchtop scale and scaled up to pilot scale, and showed excellent mashing efficiency (73,71 % ± 4,69). Beer was evaluated physico-chemically and sensorially and showed a good alcohol yield (0,37 ± 0,04 g/g), fermentation efficiency (72,48 % ± 7,61) and alcohol productivity (0,32 g.L-1.h-1 ± 0,02). It could be concluded that this process can result in product with good yield and very intense and pleasant sensory characteristics, similar to stronger beers, tipically consummed during the winter.
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Cultivo em estado sólido de aspergillus brasiliensis em bagaço de malte para a produção de lipasesEichler, Paulo January 2018 (has links)
Tendo em vista a atual crise energética e anseios por novas tecnologias de produção de biocombustíveis de forma sustentável, estudos de eficiência de produção de biocatalisadores têm se mostrado mais frequentes. Biocatalisadores como lipases, usadas na produção de biodiesel, têm alta eficiência de conversão, pouca formação de subprodutos, operação em condições mais amenas e podem ser produzidos de forma sustentável. A produção de lipases no cultivo em estado sólido é bem estudada por apresentar vantagens econômicas em aplicações industriais, como tratamento de efluentes e produção de biodiesel. O bagaço de malte é o principal subproduto da indústria de cervejaria, que representa cerca de 85 % do total de resíduos neste setor industrial, tendo excelentes perspectivas para os processos de biorrefinaria por seu baixo custo e presença de açúcares fermentescíveis. O objetivo deste trabalho foi avaliar condições ideais de produção de lipase por Aspergillus brasiliensis cultivado em estado sólido sobre bagaço de malte usando planejamento experimental e, após, realizar cultivos em biorreator cilíndrico com passagem forçada de ar e biorreator de tambor agitado em escala piloto com condições otimizadas para avaliar melhores cenários de produção de lipase para aplicações industriais. A produção de lipase por cultivo em estado sólido foi otimizada usando análise do Delineamento Composto Central, metodologia de superfície de resposta e validada, com parâmetros ótimos obtidos de pH de 7,71, 11,34 % de óleo de soja a 32,74 ºC, apresentando atividade máxima, em 96 h, para esse cultivo de 8,17 U.g-1 As condições ótimas obtidas na análise estatística foram utilizadas para produzir lipase em diferentes tipos de biorreatores de estado sólido, obtendo resultados de produção maiores em biorreator com leito fixo e aeração forçada, com 9,83 U.g-1 de atividade de lipase. Além disso, foi utilizado o bagaço de malte fermentado liofilizado, chamado de Preparado Enzimático Sólido (PES), para avaliar a atividade da lipase e a conversão da reação de transesterificação. Resultados obtidos de atividade de lipase no fermentado sólidofoi de 7,35 U.g-1 de substrato, e obteve-se 2,15 % de conversão da transesterificação em 18 h de reação. Apesar de ser relativamente baixo o valor de conversão de ésteres etílicos, como a reação não foi otimizada, mais experimentos seriam necessários para avaliar a possibilidade de uso deste bagaço fermentado para produção de biodiesel. Apesar disso, valores de atividade de lipase no preparado enzimático foram relativamente parecidos com os valores encontrados nos extratos dos cultivos em bancada, mostrando ser possível o uso para finalidades como tratamento de efluentes oleosos ou biorremediação. / In view of current energy crisis, desire for new sustainable technologies for production of biofuels, biocatalysts efficiency studies appears more frequent. Biocatalysts such as lipases, used in production of biodiesel, have high conversion efficiency, less by-product formation, operation under milder conditions and can be produced in a sustainable way. The production of lipases in solid state cultivation is well studied because it presents economic advantages in industrial applications such as effluent treatment and biodiesel production. Malt bagasse is the main by-product of brewery industry, which accounts for about 85 % of total waste in this industrial sector, and has excellent prospects for biorefinery processes due to its low cost and presence of fermentable sugars. The objective of this work was to evaluate optimal conditions of lipase production by Aspergillus brasiliensis, grown in solid state cultivation of malt bagasse, using experimental design and, afterwards, perform cultivation in cylindrical bioreactor with forced aeration and pilot scale agitated drum bioreactor under optimal conditions to evaluate better scenarios of lipase production for industrial applications. The production of lipase in the solid state culture was optimized using Central Composite Design analysis and validated, with optimum parameters obtained as pH 7.71, 11.34 % of soybean oil at temperature of 32.74 ºC, presenting maximum lipase activity at 96 h, with 8,17 U.g-1 In addition, the optimal conditions obtained in the statistical analysis were used to produce lipase in different types of solid state bioreactors, obtaining higher production results in bioreactor with fixed bed and forced aeration, with 9.83 U.g-1 of lipase activity. Finaly, a Solid Enzymatic Preparation (SEP) was used to evaluate lipase activity and conversion of transesterification reaction. Results obtained for lipase activity of the fermented solid was 7.35 U.g-1, and 2.15% transesterification conversion was achieved in 18 h of reaction. Although conversion value of ethyl esters was relatively low, but as the reaction was not optimized, more experiments would be necessary to evaluate the possibility of using this fermented solid for biodiesel production. Nevertheless, values of lipase activity in the enximatic preparation were relatively similar with results found in the extracts of the bench scale cultures, showing that it is possible to use them for purposes such as treatment of oily effluents or bioremediation.
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Avaliação do emprego do arroz preto (Oryza sativa L.) submetido a hidrólise enzimática como adjunto na fabricação de cerveja / Assessment of the use of black rice (Oryza sativa L.) submitted to enzymatic hydrolysis as adjunct on beer manufacturingSantos, Claudio Donato de Oliveira 29 April 2011 (has links)
Segundo a legislação brasileira, em uma cerveja, parte do malte de cevada pode ser substituído por cereais maltados ou não, e por carboidratos de origem vegetal, transformados ou não, conhecidos como adjuntos. Os adjuntos tem por finalidade contribuir como fonte alternativa de substrato, por geralmente terem preços inferiores ao malte de cevada e proporcionar à bebida características sensoriais peculiares. Este trabalho teve como objetivo utilizar a quirera de arroz preto (Oryza sativa L.), que não apresenta valor comercial, com o propósito de aumentar a contribuição de açúcares deste adjunto em 45 % no extrato de um mosto primitivo de uma cerveja. O arroz foi caracterizado em relação aos teores de amido total (83,20 % ± 1,41, b.s.) e suas frações, ao teor de metais e da temperatura de gelificação (78,68 °C). A ?-amilase termoestável utilizada no processo também foi caracterizada em relação ao teor de proteínas (20,5 ± 1,2 mg de proteína/mL de extrato), atividade amilásica (112 000 UI/mL de extrato) e atividade específica (5 463 UI/mg de proteína). Foram otimizadas as condições de hidrólise em relação ao tempo de processamento e concentração da enzima, segundo um planejamento experimental fatorial completo 22 com três pontos centrais e estudo rotacionado. A levedura (Saflager S-23) utilizada no processo foi selecionada por apresentar melhor desempenho fermentativo dentre 4 cepas avaliadas. Os ensaios de fermentação foram executados em escala de bancada e ampliados para a escala piloto, na qual foi obtida excelente eficiência de mosturação (73,71 % ± 4,69). A cerveja obtida foi avaliada do ponto de vista sensorial e físico-químico. O processo apresentou bom rendimento fermentativo (0,37 ± 0,04 g/g), eficiência de fermentação (72,48 % ± 7,61) e produtividade em álcool (0,32 g.L-1.h-1± 0,02). Concluiu-se que o processo pode resultar num produto com bom rendimento e características sensoriais muito intensas e agradáveis, similar a uma cerveja forte, consumida tipicamente durante o inverno. / As cited on Brazilian legislation, in a beer, part of the malt can be substituted by malted or non-malted cereals, and by carbohydrates from vegetal sources, called adjuncts. Adjuncts have the purpose of contributing as an altenative and cheaper source of sugars, when compared to barley malt, and provide peculiar sensory characteristics. This work aimed to use the black rice (Oryza sativa L.) grits, which does not have economic value, and use this raw material on the proportion of 45% on the primitive extract of a beer. On black rice, it was quantified starch (83,20 % ± 1,41, d.b.) and metal content, and measured the gelatinization temperature (78,68 °C). The enzyme (Brautec Alfa-TF) used in this work was characterized on protein content (20,5 ± 1,2 mg protein/mL de enzyme extract), activity (112000 IU/mL of extract) and specific activity (5463 IU/mg of protein). The enzymatic hydrolysis conditions were optimized using a full factorial 22 central composite design with star points aiming at it the sugar concentrations response on hydrolysate regarding the factors: enzyme concentration and processing time at 95 °C. The yeast strain was selected among 4 strains regarding the factors: alcohol yield (g/g), fermentation efficiency (%) and alcohol productivity (g.L-1.h-1). Assays were carried out on benchtop scale and scaled up to pilot scale, and showed excellent mashing efficiency (73,71 % ± 4,69). Beer was evaluated physico-chemically and sensorially and showed a good alcohol yield (0,37 ± 0,04 g/g), fermentation efficiency (72,48 % ± 7,61) and alcohol productivity (0,32 g.L-1.h-1 ± 0,02). It could be concluded that this process can result in product with good yield and very intense and pleasant sensory characteristics, similar to stronger beers, tipically consummed during the winter.
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Evaluation of DNA Quality of Beer IngredientsRamberg, Anna January 2006 (has links)
<p>The project aim is to determine if good quality DNA can be extracted from barley, malt and hop, ingredients used in beer brewing. Good quality DNA is important in DNA fingerprinting techniques which can be used for identification of ingredients. The 3 methods tested are the cetyltrimethylammonium bromide (CTAB) method, QIAGEN DNeasy Plant Mini Kit and Meyer’s method as published in 1996 with QIAGEN DNeasy Plant Mini Kit in combination. To evaluate the DNA quality after extraction we used 3 different techniques:</p><p>(i) spectrophotometry to estimate purity by using the ratio A260/A280; (ii) agarose gel electrophoresis after DNA extraction to determine the success of the extraction and evaluate the amount of high molecular weight DNA and degradation; and (iii) the polymerase chain reaction with 4 different primer pairs, together with agarose gel electrophoresis, to determine if the extracted DNA could be used in downstream applications, see the effect of inhibitors and estimate the fragmentisation of the DNA. The results achieved using the above mentioned methods were then used to evaluate the success of each of the extraction methods in their function of extracting high quality DNA from barley, malt and hop as well as determining whether the treatment of the ingredients has an effect on the DNA quality.</p>
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Evaluation of DNA Quality of Beer IngredientsRamberg, Anna January 2006 (has links)
The project aim is to determine if good quality DNA can be extracted from barley, malt and hop, ingredients used in beer brewing. Good quality DNA is important in DNA fingerprinting techniques which can be used for identification of ingredients. The 3 methods tested are the cetyltrimethylammonium bromide (CTAB) method, QIAGEN DNeasy Plant Mini Kit and Meyer’s method as published in 1996 with QIAGEN DNeasy Plant Mini Kit in combination. To evaluate the DNA quality after extraction we used 3 different techniques: (i) spectrophotometry to estimate purity by using the ratio A260/A280; (ii) agarose gel electrophoresis after DNA extraction to determine the success of the extraction and evaluate the amount of high molecular weight DNA and degradation; and (iii) the polymerase chain reaction with 4 different primer pairs, together with agarose gel electrophoresis, to determine if the extracted DNA could be used in downstream applications, see the effect of inhibitors and estimate the fragmentisation of the DNA. The results achieved using the above mentioned methods were then used to evaluate the success of each of the extraction methods in their function of extracting high quality DNA from barley, malt and hop as well as determining whether the treatment of the ingredients has an effect on the DNA quality.
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Endogenous and exogenous factors involved in sorghum germination with reference to malting.Dewar, Janice. January 1997 (has links)
In Africa, the grain sorghum (Sorghum bicolor (L.) Moench), is malted to provide
the most important ingredient in brewing, malt, which is used primarily for the
production of traditional (opaque) sorghum beer. Malting is the germination of
cereal grain in moist air under controlled conditions, the primary objective being
to promote the development of hydrolytic enzymes which are not present in the
ungerminated grain. The malting process can be physically split into three distinct
unit operations (viz. steeping, germination and drying). To date, little attention has
been given to optimising the conditions of steeping for sorghum. The effects of
different steeping variables (time, temperature and aeration) on the quality (in
terms of diastatic power (amylase activity), free amino nitrogen and hot water
extract) of sorghum malt for brewing were investigated. Malt quality was found to
increase with steeping time, over the range 16-40 hours and the optimum steeping
temperature was found to be in the range 25 to 30°C. Aeration during steeping
appeared to be necessary to maximise the malt quality, particularly when steeping
was conducted for long periods at high temperatures. Of particular significance
was the observation that final sorghum malt quality was highly significantly
correlated (p<0.01) with grain moisture content at steep-out (the end of the
imbibition period). When steeping conditions based on these findings were used,
a germination temperature of 25-30°C was found to be optimal for sorghum malt
quality. As with steep-out moisture, green malt (grain after the specified
germination time) moisture content was correlated Significantly (p<0.01) with final
sorghum malt quality. The finding that sorghum malt quality is related to steepout
moisture content was given further substance when it was shown that the
stimulatory effect on sorghum malt quality of steeping sorghum in a dilute solution
of alkali, actually increases the amount of water taken up during steeping probably
because the alkali disrupted the pericarp cell wall structure of the grain.
Barley malting practices have taken advantage of the knowledge that the
exogenous application of gibberellic acid can enhance the synthesis of the
critically important malt hydrolytic enzyme, a-amylase. To date, literature on the
effect of exogenous application of gibberellic acid on sorghum malt quality has
been inconclusive; with reports both of no effects, and of positive effects, on
amylase activity. To elucidate the possible control mechanisms involved in
sorghum germination, a combined HPLC-radioimmunoassay technique was used
to determine the levels of selected plant growth regulators from the groups auxin,
cytokinins, gibberellins and abscisic acid in sorghum at various stages of
germination. Levels of gibberellic acid were low throughout germination. During
germination the levels of the other plant growth regulators declined, but a peak in
cytokinins followed the first visible signs of root protrusion. The high level of the
germination inhibitor and gibberellic acid antagonist, abscisic acid, in the germ
(embryo inclusive of scutellum) portion of the mature non-germinated grains was
noteworthy. Based on these findings, it was determined that sorghum malt quality
could in fact be improved significantly by the application of exogenous gibberellic
acid. However, this was effective only if it was administered during the end of
steeping or at the beginning of the germination step.
By optimising the conditions of steeping and germination and by steeping in dilute
NaOH or in gibberellic acid not only should it be possible to enhance the quality
of sorghum malt, it should be possible to reduce the time required to obtain the
specific quality, thereby offering a saving to the sorghum maltster in terms of
operation costs and enhancing the total throughput possible from the malting
plant. / Thesis (Ph.D.)-University of Natal, Durban, 1997.
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Effects of Liming on Soil Respiration, Fungi Diversity and Abundance in a Metal-Contaminated Region in Northern OntarioGoupil, Kassandre 16 May 2014 (has links)
At present, little is known concerning the fungi communities inhabiting the Greater Sudbury Region. This study aimed at identifying the fungal species and abundance in limed and unlimed areas contaminated with metals. Samples were collected from the LFH soil layer from Wahnapitae Hydro-Dam, Daisy Lake, Kingsway, Kelly Lake, Hagar, Onaping Falls and Capreol. Limed and unlimed areas were compared for soil metals, pH, fungi diversity, abundance and seasonal soil respiration. Fungi from soil samples were cultured using Sabouraud Dextrose Agar and Malt Extract Agar. A total of 52 fungi species from 34 genera were identified. There was a significantly higher fungal diversity in the limed areas compared to the samples from unlimed sites based on SDA medium data. Fungi abundance followed the same trend. Significantly higher soil respiration rates were recorded for limed sites compared to unlimed sites. Summer soil respiration rates correlated (r = 0.50) with total fungal abundance.
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Evaluation of malted barley with different degrees of fermentability using the Rapid Visco Analyser (RVA)Visser, Magdalena Johanna 03 1900 (has links)
Thesis (MSc Food Sc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The relationship between malt fermentability and rheological variables, measured by means
of the Rapid Visco Analyser (RVA) and application of multivariate data analysis, was
investigated.
The RVA Kilned Malt method was optimised to achieve maximum rheological
discrimination between malt samples, differing in fermentability. Five concentrations and two
particle sizes were used to investigate each malt sample. Data were analysed by two
different data analysis techniques, namely principal component analysis (PCA) and analysis
of variance (ANOVA). Rheological variables for peak-height, -width, -area and time
occurrence, were able to discriminate between high (Metcalfe, Flagship), intermediate (SSG
585, PUMA) and low malt fermentability (SSG 506, SSG 564). Variation in particle size
showed insignificant (P>0.05) fermentability discrimination. The malt to water ratio of 1:1.5
provided the best discrimination in fermentability. PCA applied to the entire dataset was the
superior data analysis technique.
Partial least squares (PLS) regression and Soft Independent Modeling of Class Analogy
(SIMCA) were applied to predict malt fermentability. Recorded RVA data was regressed with
both apparent attenuation limit (AAL) and free amino nitrogen (FAN), independently.
Developed PLS calibration models were validated by test set and segmented crossvalidation
for AAL and FAN, respectively. The SIMCA classification model developed was
based on different malt fermentability classes, each PCA validated independently by test set
validation. A strong correlation between RVA analysis and AAL was obtained (r=0.92), while
FAN delivered a weak correlation (r=0.59). Regarding the SIMCA model; the proportion of
test set samples correctly classified in terms of malt fermentability was 83%. South African
malt blends were predicted to have low malt fermentability. Simulated blends were predicted
to have high fermentability when using a minimum of 80% Metcalfe blended with SSG 506.
Blends containing higher percentages of the low malt fermentability cultivar (SSG 506) were
predicted to have an overall intermediate fermentability.
Different experimental conditions were investigated during RVA analysis (i.e. instrument
model; time/temperature profile, enzyme activity and heating/cooling rate). Rheological
measurement using different RVA models gave similar PCA results, indicating adequate
sensitivity of the older instrument for discrimination purposes. Matching the time/temperature
profile used in the commercial brewery mashing process was rejected due to increased
analysis time and rheological noise while reducing fermentability discrimination. Inactivating
malt enzymes prior to RVA analysis provided useful sample information, such as the large
starch granule’s mean diameter, extract and starch content, by measuring peak height and
iv
time to peak. The amount of starch damage inflicted on a malt sample increased after
repeated centrifugal milling, but was unaffected by the sieve size used.
Multivariate data analysis is a suitable statistical technique applied to rheological data
and provided more relevant information than traditional univariate techniques. The RVA can
be considered an ideal instrument within a grain laboratory as it allowed the investigation of
different operating conditions. It is beneficial to use an inexpensive, routine method of
analysis to measure various interacting factors. RVA rheological measurement demonstrated
to be a decisive monitor of malt fermentability and is highly recommended to be incorporated
within the barley breeding, malting and brewing industries. / AFRIKAANSE OPSOMMING: Die verwantskap tussen mout fermenteerbaarheid en reologie-veranderlikes, gemeet met
die “Rapid Visco Analyser” (RVA) en toepassing van meerveranderlike data analise is
ondersoek.
Die RVA “Kilned Malt” metode is geoptimeer om maksimum reologiese diskriminasie,
tussen gars kultivars van verskillende fermenteerbaarheid, te lewer. Vyf konsentrasies en
twee partikel groottes is gebruik in die ondersoek vir elke mout monster. Data is deur beide
hoof komponent analise (HKA) en variansie-analise (ANOVA) ondersoek om die verskillende
data analise metodes met mekaar te vergelyk. Reologiese veranderlikes vir piek-hoogte, -
wydte, -area en -vormingstyd, kon diskrimineer tussen hoë (Metcalfe, Flagship), intermediêre
(SSG 585, PUMA) en lae (SSG 506, SSG 564) mout fermenteerbaarheid. Variasie in partikel
grootte kon nie beduidende diskriminasie in fermenteerbaarheid aantoon nie. Die mout-totwater
konsentrasie van 1:1.5 het die beste diskriminasie in fermenteerbaarheid gelewer. Die
toepassing van HKA op die hele datastel was die beter analitiese tegniek.
Parsiële kleinste kwadrate (PKK) regressie en Sagte Onafhanklike Modellering van Klas
Analogie (SIMCA) is toegepas om mout fermenteerbaarheid te voorspel. Regressie tussen
RVA data en skynbare attenuasie limiet (AAL), sowel as vrye amino stikstof (FAN) inhoud, is
afsonderlik uitgevoer. Die geldigheid van regressie modelle is deur middel van toets stel en
gesegmenteerde kruis-validasie vir AAL en FAN onderskeidelik uitgevoer. SIMCA
klassifikasie modelle is gebaseer op verskillende mout fermenteerbaarheids-klasse, waarvan
elke HKA klas individueel geldig is. RVA analise het ‘n sterk korrelasie met AAL (r=0.92),
maar ‘n swak korrelasie met FAN (r=0.59) getoon. Die SIMCA model het 83% van toets stel
monsters as korrek geklassifiseer in terme van mout fermenteerbaarheid. Suid Afrikaanse
mout mengsels is voorspel as swak fermenteerbaar. Nagebootste mengsels is voorspel as
hoogs fermenteerbaar wanneer minimum 80% Metcalfe met SSG 506 vermeng word. Sodra
‘n hoër persentasie van die swakker fermenteerbaarheids-kultivar (SSG 506) bygevoeg is,
word intermediêre fermenteerbaarheid voorspel.
Tydens RVA analise is verskillende eksperimentele toestande ondersoek (byvoorbeeld
instrument model; tyd/temperatuur profiel; ensiem aktiwiteit en verhittings/verkoelings
tempo). Die gebruik van verskillende RVA modelle het soortgelyke HKA resultate gelewer.
Dus bevat die ouer instrument aanvaarbare sensitiwiteit vir diskriminasie doeleindes.
Nabootsing van die tyd/temperatuur profiel in die kommersiële brouproses is verwerp,
aangesien analise tyd en reologiese geraas toegeneem het, terwyl fermenteerbaarheidsdiskriminasie
verminder het. Inaktivering van mout ensieme voor RVA analise lewer nuttige
monster inligting; deur veranderlikes soos piek-hoogte en piek-tyd te meet, kan die groot
stysel korrel se gemiddelde deursnit, ekstrakwaarde en stysel inhoud verkry word. Herhaalde
sentrifugale maling van ‘n mout monster lei tot beskadiging van stysel, maar dit word nie
deur sif grootte beïnvloed nie.
Die toepassing van meerveranderlike data analise op reologiese data is waardevol en
lewer meer relevante inligting in vergelyking met tradisionele eenveranderlike data analise.
Die RVA is ‘n ideale instrument vir gebruik in ‘n graan laboratorium aangesien dit
verskillende operatiewe kondisies kan ondersoek. Die gebruik van ‘n enkele, goedkoop,
roetine analitiese metode is voordelig en het die potensiaal om ‘n magdom interaktiewe
faktore te meet. RVA reologiese meting demonstreer die vermoë as ‘n deurslaggewende
tegniek vir die bepaling van mout fermenteerbaarheid, gevolglik word toepassing sterk
aanbeveel binne die gars teëlings-, vermoutings- en brouers-industrieë.
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Identification of bacteria isolated from malt, with the emphasis on lactic acid bacteria and their influence on brewer's yeastBooysen, Clifford 12 1900 (has links)
Thesis (MScAgric.)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Changes in the bacterial population throughout the malting process of two barley cultivars, i.e.
Clipper (local cultivar) and Prisma (imported cultivar), malted at Southern Associated Maltsters
(SAM), Caledon, South Africa, were studied. Samples were taken from four individual runs of each
cultivar at ten different stages, i.e. dry barley before steep, water from the first steep water-stand,
barley after draining the first steep, water from the second steep water-stand, barley from the second
steep water-stand, barley after draining of the second steep, barley from the first, second and third
days of germination in the germination vessels (GV), and malt after kilning. Emphasis was placed
on the taxonomy and composition of the lactic acid bacteria (LAB) isolated from the ten different
phases.
The LAB were identified to species level by using numerical analysis of total soluble cell protein
patterns, RAPD-PCR banding patterns and 16S rRNA sequencing. The Gram-negative bacteria were
identified to genus level by using the API 20E system and included Citrobacter spp., Enterobacter
spp., Pantoea spp., Proteus spp., Seratia spp., Kluyvera spp., Klebsiella spp., Vibrio spp. and
Escherichia coli. The number of viable bacteria throughout the malting process of the two cultivars
did not differ significantly, although the LAB counts in the barley before steep and on the kilned
malt were higher in Prisma than in Clipper. Leuconostoc argentinum, Leuconostoc laetis and
Weissella confusa were the most predominant in both cultivars. A few strains of Weissella
paramesenteroides, Lactobacillus casei, Lactococcus laetis and Lactobacillus rhamnosus were also
isolated. Lb. casei and Lb. rhamnosus were not isolated from the Prisma cultivar, whilst W
paramesenteroides and Le. laetis were absent in the Clipper cultivar. Kilned malt of the Clipper
cultivar contained predominantly Le. argentinum, whereas the Prisma cultivar contained mainly Le.
lactis.
The effect of these bacteria on the fermenting ability of the brewer's yeast Saccharomyces
cerevisiae SAB 05, was also studied. Fermentations were conducted in wort prepared from Clipper
and Prisma malt. Yeast in combination with the different bacteria were used in the fermentation
studies. Wort with only yeast was used as control. Emphasis was placed on the effect the bacteria
has on the gravity, pH, yeast- and bacterial- counts and the different volatile aroma compounds produced throughout the fermentations.
The presence of LAB and Gram-negative bacteria had no effect on the yeast to reduce the gravity of
the fermenting wort, whilst the LAB caused a decrease in the pH of the fermentations in both
Clipper and Prisma wort. The cell numbers of the Gram-negative bacteria decreased throughout the
fermentations, whilst the LAB cell numbers remained constant. Comparisons could be drawn
between the volatile aroma compounds produced in the control fermentation and fermentations with
yeast and Gram-negative bacteria, yeast and Lactobacillus spp. and yeast and Weissella spp.
Leuconostoc spp. had a much greater influence on the aromatic composition of fermented malt, with
much more clear variations between Prisma and Clipper. No major differences were recorded in the
aroma profiles of Prisma and Clipper malt fermented in the presence and absence of Lactococcus
spp. The Gram-negative bacteria had no significant effect on the volatile aroma compounds
produced by the yeast, whilst the LAB had a definite effect on aroma composition in both cultivars.
The levels of four of the five principle aroma compounds, present in beer, were in the acceptable
concentration range on the fmal day of fermentation. The compounds with the highest
concentrations were iso-amyl alcohol, acetic acid and acetoin, with acetic acid being present in the
highest concentration in all the fermentations. / AFRIKAANSE OPSOMMING: Veranderinge in die bakteriese populasie van die gars kultivars, Clipper (plaaslik) en Prisma
(ingevoer), vermout by Southern Associated Maltsters (SAM), Caledon, Suid Afrika, is ondersoek.
Monsters is van vier individuele lopies van elke kultivar en tydens tien verskillende fases van die
vermoutingsproses geneem. Die tien verskillende stadia het die volgende ingesluit: Droë gars voor
benatting, water van die eerste benattingsfase, gars nadat water van die eerste benattingsfase
gedreineer is, water van die tweede benattingsfase, gars van die tweede benattingsfase, gars na die
dreinering van water in die tweede benattings fase, gars na die eerste, tweede en derde dag van
ontkieming binne die ontkiemingstenke, en mout na droging. Klem is geplaas op die taksonomie en
samestelling van melksuurbakterieë (MSB) wat tydens die tien verskillende fases geïsoleer is.
Die MSB is tot spesievlak geïdentifiseer deur gebruik te maak van numeriese analise van totale
oplosbare selproteïen bandpatrone, RAPD-PKR bandpatrone en 16S rRNA volgorde-bepaling.
Gram-negatiewe bakterieë is tot op genusvlak geïdentifiseer deur gebruik te maak van die API 20E
toetssisteem. Spesies van die genera Citrobacter, Enterobacter, Pantoea, Proteus, Seratia,
Kluyvera, Klebsiella, Vibrio asook Escherichia coli is geïdentifiseer. Tydens die vermoutingsproses
van die twee kultivars is geen beduidende verskille in die lewensvatbare bakterietellings gevind nie,
alhoewel die MSB-tellings in die gars voor benatting en mout na droging in Prisma hoër was as in
Clipper. Leuconostoc argentinum, Leuconostoc laetis en Weissella confusa het die meeste
voorgekom in beide kultivars. Kleiner hoeveelhede van Weissella paramesenteroides, Lactobacillus
casei, Lactococcus laetis en Lactobacillus rhamnosus is ook geïsoleer. Lb. casei en Lb. rhamnosus
het nie in die Prisma-kultivar voorgekom nie, terwyl W paramesenteroides en Le. laetis nie in die
Clipper-kultivar teenwoordig was nie. Le. argentinum het meestal in die gedroogde mout van die
Clipper-kultivar voorgekom, terwyl Le. laetis meestal in die Prisma-kultivar waargeneem is.
Die effek van hierdie bakterieë op die fermentasievermoë van die brouersgis Saccharomyces
cerevisiae SAB 05 is ook bestudeer. Die fermentasies is in Clipper- en Prisma- wort gedoen. Vir die
fermentasiestudies is gis in kombinasie met verskillende bakterieë gebruik. Wort met slegs gis het as
kontrole gedien. Klem is geplaas op die effek van die bakterieë op die digtheid, pH, gis- en bakterietellings
en die verskillende vlugtige komponente wat tydens die fermentasies geproduseer is. Die
teenwoordigheid van MSB en Gram-negatiewe bakterieë het geen effek gehad op die vermoë van die gis om die digtheid van die gefermenteerde wort te verlaag nie. Die MSB het wel 'n verlaging
van die pH in beide Clipper- en Prisma- wort teweeggebring. Tydens die fermentasie het die Gramnegatiewe
bakterietellings verminder, terwyl die MSB-tellings konstant gebly het. 'n Verband is
gevind tussen vlugtige komponente geproduseer in die kontrole-fermentasie en fermentasies met gis
en Gram-negatiewe bakterieë, gis en Lactobacillus spp. en gis en Weissella spp. Leuconostoc spp.
het groter veskille in die samestelling van die gefermenteerde wort teweeg gebring met duidelike
verskille tussen Clipper en Prisma. Die teenwoordigheid van Lactococcus spp. het nie groot
verskille in die samestelling van die gefermenteerde wort getoon nie. Op die laaste dag van die
fermentasies was die vlakke van vier uit die vyfbelangrikste vlugtige aroma komponente wat in bier
voorkom in die kontrole fermentasies in aanvaarbare konsentrasies teenwoordig. Die Gramnegatiewe
bakterieë het geen beduidende invloed gehad op die vlugtige aroma komponente wat deur
die gis geproduseer is nie, terwyl die MSB 'n besliste effek in die aroma-samestelling van beide die
kultivars gehad het. Die komponente met die hoogste konsentrasies was, isoamiel-alkohol, asynsuur
en asetoin. Asynsuur was in al die fermentasies in die hoogste konsentrasie teenwoordig.
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Cultivo em estado sólido de aspergillus brasiliensis em bagaço de malte para a produção de lipasesEichler, Paulo January 2018 (has links)
Tendo em vista a atual crise energética e anseios por novas tecnologias de produção de biocombustíveis de forma sustentável, estudos de eficiência de produção de biocatalisadores têm se mostrado mais frequentes. Biocatalisadores como lipases, usadas na produção de biodiesel, têm alta eficiência de conversão, pouca formação de subprodutos, operação em condições mais amenas e podem ser produzidos de forma sustentável. A produção de lipases no cultivo em estado sólido é bem estudada por apresentar vantagens econômicas em aplicações industriais, como tratamento de efluentes e produção de biodiesel. O bagaço de malte é o principal subproduto da indústria de cervejaria, que representa cerca de 85 % do total de resíduos neste setor industrial, tendo excelentes perspectivas para os processos de biorrefinaria por seu baixo custo e presença de açúcares fermentescíveis. O objetivo deste trabalho foi avaliar condições ideais de produção de lipase por Aspergillus brasiliensis cultivado em estado sólido sobre bagaço de malte usando planejamento experimental e, após, realizar cultivos em biorreator cilíndrico com passagem forçada de ar e biorreator de tambor agitado em escala piloto com condições otimizadas para avaliar melhores cenários de produção de lipase para aplicações industriais. A produção de lipase por cultivo em estado sólido foi otimizada usando análise do Delineamento Composto Central, metodologia de superfície de resposta e validada, com parâmetros ótimos obtidos de pH de 7,71, 11,34 % de óleo de soja a 32,74 ºC, apresentando atividade máxima, em 96 h, para esse cultivo de 8,17 U.g-1 As condições ótimas obtidas na análise estatística foram utilizadas para produzir lipase em diferentes tipos de biorreatores de estado sólido, obtendo resultados de produção maiores em biorreator com leito fixo e aeração forçada, com 9,83 U.g-1 de atividade de lipase. Além disso, foi utilizado o bagaço de malte fermentado liofilizado, chamado de Preparado Enzimático Sólido (PES), para avaliar a atividade da lipase e a conversão da reação de transesterificação. Resultados obtidos de atividade de lipase no fermentado sólidofoi de 7,35 U.g-1 de substrato, e obteve-se 2,15 % de conversão da transesterificação em 18 h de reação. Apesar de ser relativamente baixo o valor de conversão de ésteres etílicos, como a reação não foi otimizada, mais experimentos seriam necessários para avaliar a possibilidade de uso deste bagaço fermentado para produção de biodiesel. Apesar disso, valores de atividade de lipase no preparado enzimático foram relativamente parecidos com os valores encontrados nos extratos dos cultivos em bancada, mostrando ser possível o uso para finalidades como tratamento de efluentes oleosos ou biorremediação. / In view of current energy crisis, desire for new sustainable technologies for production of biofuels, biocatalysts efficiency studies appears more frequent. Biocatalysts such as lipases, used in production of biodiesel, have high conversion efficiency, less by-product formation, operation under milder conditions and can be produced in a sustainable way. The production of lipases in solid state cultivation is well studied because it presents economic advantages in industrial applications such as effluent treatment and biodiesel production. Malt bagasse is the main by-product of brewery industry, which accounts for about 85 % of total waste in this industrial sector, and has excellent prospects for biorefinery processes due to its low cost and presence of fermentable sugars. The objective of this work was to evaluate optimal conditions of lipase production by Aspergillus brasiliensis, grown in solid state cultivation of malt bagasse, using experimental design and, afterwards, perform cultivation in cylindrical bioreactor with forced aeration and pilot scale agitated drum bioreactor under optimal conditions to evaluate better scenarios of lipase production for industrial applications. The production of lipase in the solid state culture was optimized using Central Composite Design analysis and validated, with optimum parameters obtained as pH 7.71, 11.34 % of soybean oil at temperature of 32.74 ºC, presenting maximum lipase activity at 96 h, with 8,17 U.g-1 In addition, the optimal conditions obtained in the statistical analysis were used to produce lipase in different types of solid state bioreactors, obtaining higher production results in bioreactor with fixed bed and forced aeration, with 9.83 U.g-1 of lipase activity. Finaly, a Solid Enzymatic Preparation (SEP) was used to evaluate lipase activity and conversion of transesterification reaction. Results obtained for lipase activity of the fermented solid was 7.35 U.g-1, and 2.15% transesterification conversion was achieved in 18 h of reaction. Although conversion value of ethyl esters was relatively low, but as the reaction was not optimized, more experiments would be necessary to evaluate the possibility of using this fermented solid for biodiesel production. Nevertheless, values of lipase activity in the enximatic preparation were relatively similar with results found in the extracts of the bench scale cultures, showing that it is possible to use them for purposes such as treatment of oily effluents or bioremediation.
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