• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 11
  • 10
  • 6
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 37
  • 10
  • 9
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Maximização da produção de astaxantina por Phaffia rhodozyma (Xanthophyllomyces dendrohous) utilizando água de parboilização do arroz

Silva, Danielle Alves da January 2009 (has links)
Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Engenharia e Ciência de Alimentos, Escola de Química e Alimentos, 2009. / Submitted by Caroline Silva (krol_bilhar@hotmail.com) on 2012-09-04T20:03:07Z No. of bitstreams: 1 danielle.pdf: 1295792 bytes, checksum: e255e078050df8af82b19c58f6dcc0f3 (MD5) / Approved for entry into archive by Bruna Vieira(bruninha_vieira@ibest.com.br) on 2012-09-22T18:42:17Z (GMT) No. of bitstreams: 1 danielle.pdf: 1295792 bytes, checksum: e255e078050df8af82b19c58f6dcc0f3 (MD5) / Made available in DSpace on 2012-09-22T18:42:17Z (GMT). No. of bitstreams: 1 danielle.pdf: 1295792 bytes, checksum: e255e078050df8af82b19c58f6dcc0f3 (MD5) Previous issue date: 2009 / O interesse na produção de astaxantina por fontes naturais vem aumentando significativamente nos últimos anos, devido a possibilidade de atuar como corante e sua capacidade antioxidante biológica potente. É o carotenóide principal encontrado na levedura Phaffia rhodozyma, sendo esse microrganismo adequado para o uso como fonte do pigmento industrial em razão de seu metabolismo heterotrófico, padrão de crescimento relativamente rápido, qualidade nutricional e seguro como aditivo alimentar. A presente dissertação teve como objetivo principal realizar cultivos utilizando a levedura Phaffia rhodozyma, estudando diferentes meios de cultura, empregando a água de parboilização do arroz como substrato. Inicialmente selecionou-se dentre 3 cepas de P. rhodozyma: NRRL Y-17268, NRRL Y-10921 e NRRL Y-10922, a mais promissora quanto a produção de astaxantina, utilizando glicose e sacarose como fonte de carbono. Os cultivos foram realizados em frascos agitados a 25ºC, 150rpm, por um período de 168h. Através do acompanhamento da bioprodução de astaxantina, a levedura P. rhodozyma NRRL Y-17268 foi selecionada, pois se destacou como boa produtora do carotenóide, alcançando 7,0g.L-1 de biomassa, 350,2μg.g-1 de produção de astaxantina específica e 2,4μg.mL-1 de astaxantina volumétrica, utilizando sacarose. Utilizou-se a metodologia de planejamento experimenta e análise de superfície de resposta para verificar os efeitos das variáveis em estudo e as condições que levaram a melhor bioprodução da astaxantina. Um planejamento experimental fracionário 2IV 6-2 foi realizado para determinar as variáveis que mais influenciavam na produção da astaxantina. As variáveis independentes estudadas foram concentrações de extrato de levedura (1 a 10g.L-1), extrato de malte (1 a 10g.L-1), peptona (1 a 10g.L-1), sacarose (5 a 20g.L-1), efluente da parboilização do arroz (0 a 180g.L-1) e o pH inicial do meio (4 a 6), tendo como resposta a produção de biomassa, produção de astaxantina específica e produção de astaxantina volumétrica. Os valores máximos obtidos foram 8,9g.L-1 de biomassa, 538,4μg.g-1 de astaxantina específica e 3,1μg.mL-1 de astaxantina volumétrica, em diferentes condições de composição de meio de cultivo. O extrato de levedura não apresentou efeito significativo em nenhuma das respostas avaliadas, sendo realizado um teste de Tukey na faixa de 0 a 1g.L-1. A concentração de extrato de levedura não apresentou diferença significativa, sendo retirado do meio de cultivo. No segundo planejamento foram ampliadas as faixas de estudo das variáveis selecionadas: concentrações de extrato de malte (8,75 a 16,25g.L-1), sacarose (15 a 35g.L-1), peptona (8,75 a 16,25g.L-1) e o pH mantido no ponto central 5,0. A partir dos resultados, verificou-se um incremento na concentração máxima de biomassa obtida, alcançando 10,9g.L-1 e na produção de astaxantina específica para 628,8μg.g-1. As melhores condições encontradas através das superfícies de resposta para maximização da produção de astaxantina volumétrica foram: 16,25g.L-1 de extrato de malte, 8,75g.L-1 de peptona, 15g.L-1 de sacarose e 87,5g.L-1 de água de parboilização do arroz, alcançando em torno de 5,4μg.mL-1. / The interest in astaxanthin production by natural sources has increased significantly in the last few years, because of its possibility of acting as corants and its powerfull biological antioxidant capacity. It’s the most important carotenoid found in the yeast Phaffia rhodozyma and this microorganism is appropriate to use in the source of industrial pigment due to its heterotrophic metabolism, relatively rapid growth, nutritional quality and safe as a food additive. The present dissertation had as main objective, through fermentation, using the yeast Phaffia rhodozyma studying different culture medium and the rice parboilization wastewater as a substrate. Firstly, the greatest astaxanthin producer, using glucose and sucrose as carbon source was selected amongst three strains of Phaffia rhodozyma: NRRL Y-17268, NRRL Y-10921 and NRRL Y-10922. The cultivation condition was realized in a rotatory flasks, at 25ºC, 150rpm, for 168h. Through the accompaniment of the bioproduction of astaxanthin, the yeast P. rhodozyma NRRL Y-17268 was selected, because it stood out as a good producer of the carotenoid, 7.0g.L-1 of biomass, 350.2μg.g-1 of specific production of astaxanthin and 2.4μg.mL-1 of volumetric production of astaxanthin, using sucrose. The techniques of experimental design and analysis of response surfaces were used to verify the effects of the studied variables and the condictions wich led to the best production of astaxanthin. A fractional experimental design 2IV 6-2 was used to determine the independents variables that most influenced in the production of astaxanhin. The studied independents variables were yeast extract concentration (1 to 10g.L-1), malt extract (1 to 10g.L-1), peptone (1 to 10g.L-1), sucrose (5 to 20g.L-1), rice parboilization wastewater (0 to 180g.L-1) and the initial pH (4 to 6), having as answer the biomass production, specific production of astaxanthin and volumetric production of astaxanthin. The highest values obtained were 8.9g.L-1 of biomass, 538.4μg.g-1 of specific astaxanthin and 3.1μg.mL-1 of volumetric astaxanthin, in differents conditions of composition of cultivation medium. The yeast extract didn’t show significant effect in any answer, being made a Tukey test in the range of 0 to 1g.L-1. In this test the yeast extract concentration didn’t show significant difference, then it was removed from the cultivation medium. In a second design the range were amplied: malt extract concentration (8.75 to 16.25g.L-1), sucrose (15 to 35g.L-1), peptone (8.75 to 16.25g.L-1) and the pH was maintained in the central point (5.0). From the results, verify an increased in the maximum biomass concentration obtained, reaching 10.9g.L-1 and in a specific production of astaxanthin to 628.8μg.g-1. The better conditions found through of response surface to the maximization of volumetric production of astaxanthin was: 16.25g.L-1 of malt extract, 8.75g.L-1 of peptone, 15g.L-1 of sucrose and 87.5g.L-1 of rice parboilization waste water, reaching around 5.4μg.mL-1.
12

Optimalizace podmínek kultivace řasových kultur ve fotobioreaktorech / OPtimization od cultivation od microalgae cultures in photobioreactors

Byrtusová, Dana January 2016 (has links)
Presented diploma thesis is focused on the optimisation of Haematococcus pluvialis cultivations in different photobioreactors and on biotechnological production of astaxanthin. Theoretical part summarized the knowledge about optimal growth and production conditions of secondary metabolites. Followed research was focused on actual cultivation systems and on the possibilities of metabolite and nutrient monitoring. In experimental part the growth characteristic of the strain from Březova nad Svitavou (HMP-CCALA 375) was analyzed under optimal cultivation conditions on white and red light. During culture growth the profile and the concentration of carotenoid pigments were determined. The best yield of biomass was achieved in the cultivation on white light (0,939 g/l),carotenoids lutein and -carotene were observed as dominant pigments. In the next experiments optimal growth medium, temperature and light intensity were determined for cultivations of four chosen HMP strains from Germany, America, Africa and Switzerland. The most suitable cultivation medium was found BBM, oppositely the worst results were obtained with BG11. In previous experiments cultivation temperature 22 °C was determined as optimal value for comparative strain HMP – CCALA 375. Selected four strains were cultivated at 22 °C, as well as at 25 °C. Higher temperature was more optimal mainly for Switzerland, German and Africa strains. By analyzing of light intensity influence, it was found that the best increase of biomass was induced by the adaptation of culture on lower illumination (50 µmol photones•m^-2•s^-1) followed by higher light intensity (100 - 150 µmol photones•m^-2•s^-1). HMP from Switzerland showed the best growth results during all cultivation experiments, so this strain could be perhaps useful for industrial production of astaxanthin. In the last part of work, the influence of stress conditions on astaxanthin production by strain from Březova nad Svitavou (HMP – CCALA 375) was studied. Followed stress factors were used: high intensity of light (1 000 µmol photones•m^-2•s^-1), low nitrogen concentration (32,96 mg/l), addition of sodium chloride (0,5%), influence of sodium acetate (2,2 mM) and combination of sodium chloride and sodium acetate (0,5% NaCl, 2mM NaAc). Due to strong illumination (1 000 µmol photones•m^-2•s^-1) the best yield of astaxanthin was obtained (more than 20 mg/g). According to literature [103, 105] significant amount was also observed by addition of sodium acetate (9,2 mg/g). Oppositely minimal astaxanthin production was showed in presence of salt stress (3,8 mg/g). In followed experiments should be studied the influence of stress combinations on HMP – CCALA 375 strain as well as on other suitable strains of H. pluvialis with the aim to achieve the maximal yield of astaxanthin significant for large scale cultivation.
13

Ultraviolet Radiation Tolerance in High Elevation Copepods from the Rocky Mountains of Colorado, USA

Hudelson, Karista 12 1900 (has links)
Copepods in high elevation lakes and ponds in Colorado are exposed to significant levels of ultraviolet radiation (UV), necessitating development of UV avoidance behavior and photoprotective physiological adaptations. The copepods are brightly pigmented due to accumulation of astaxanthin, a carotenoid which has photoprotective and antioxidant properties. Astaxanthin interacts with a crustacyanin-like protein, shifting its absorbance from 473 nm (hydrophobic free form, appears red) to 632 nm (protein-bound complex, appears blue). In six sites in Colorado, habitat-specific coloration patterns related to carotenoprotein complex have been observed. The objective of this study was to determine whether pigment accumulation or carotenoprotein expression has a greater effect on resistance to UV exposure. For each site, copepod tolerance to UV was assessed by survivorship during UV exposure trials. Average UV exposure was determined for each habitat. Astaxanthin profiles were generated for copepods in each site. Ability to withstand UV exposure during exposure trials was significantly different between color morphs (p < 0.0001). Red copepods were found to tolerate 2-fold greater levels of UVB than blue or mixed copepods. Additionally, red copepods have much higher levels of total astaxanthin than blue or mixed copepods (p < 0.0001) and receive a higher daily UV dose (p < 0.0003). Diaptomid carotenoprotein sequence is not homologous with that of other crustaceans in which crustacyanin has been characterized which prevented quantification of carotenoprotein transcript expression. Overall, diaptomid color morph may be an important indicator of UV conditions in high elevation lentic ecosystems.
14

Inhibition of Soluble Epoxide Hydrolase by Astaxanthin for Anti-Depressant Effects

Agboinghale, Precious 09 August 2023 (has links)
The enzyme soluble epoxide hydrolase (sEH) plays a major role in the pathogenesis and pathophysiology of neurodegenerative diseases like depression by catalyzing the hydrolysis of epoxyeicosatrienoic acids (EETs) into dihydroxyicosatrienoicacids (DHETs), its less biologically active form, influencing the anti-inflammatory system and promoting inflammation. Therefore, inhibiting sEH leads to increased levels of EETs, reducing inflammation, especially in the brain and can help mitigate neurodegenerative diseases. This study investigated sEH inhibition by a phenolic carotenoid compound, astaxanthin and its inhibitory mechanism of action. Enzyme inhibitory activity and kinetics demonstrated that astaxanthin had a half-maximal inhibitory concentration (IC50) of 26 ± 0.92 μM and is a mixed-non-competitive inhibitor of sEH. In silico ADME/tox analysis showed that astaxanthin is bioavailable, biostable, and non-toxic when taken orally. Molecular docking study demonstrated that astaxanthin binds to an allosteric site of sEH and formed a contact and clashing-only interaction with the ASP333 residue of the hydrolase pocket of sEH. In this study, we highlight the potential therapeutic application of astaxanthin as a natural sEH inhibitor in the treatment of inflammation-related diseases, particularly neurodegenerative diseases.
15

Carotenoid value addition to distillers dried grain with solubles by red yeast fermentation

Nanjundaswamy, Ananda January 1900 (has links)
Doctor of Philosophy / Department of Grain Science and Industry / Praveen V. Vadlani / Distillers Dried grain with Solubles (DDGS) is a co-product of grain-based ethanol and is primarily used as livestock feed. With increasing production of DDGS, it is imperative to produce value-added products and/or find new applications of DDGS to help sustain the biofuel industry. Carotenoids are expensive yet essential feed additives. Since animals cannot synthesize carotenoids and animal feeds including DDGS are generally poor in carotenoids, about 30-120 ppm of total carotenoids is added to animal feed to improve animal health. The objectives of this study were to 1) produce carotenoid (astaxanthin and β-carotene)-enriched DDGS by Phaffia rhodozyma and Sporobolomyces roseus monoculture and mixed culture submerged fermentation of whole stillage, 2) optimize fermentation media by response surface methodology (RSM) and mixture design followed by validation, 3) evaluate the nutritional profile of carotenoid-enriched DDGS, 4) improve carotenoid production by the use of precursors, and 5) develop carotenoid-enriched feeds namely, wheat bran, rice bran and soybean products. Carotenoid-enriched DDGS was produced from both monoculture and mixed culture fermentation with yields ranging from 17-233 µg/g. Upon media optimization, astaxanthin and β-carotene yields, especially in P. rhodozyma were enhanced by 177% and 164% to yield 98 and 275 µg/g respectively. Nutrition profiling of the carotenoid-enriched DDGS showed that the secondary fermentation resulted in low fiber, protein and %N and enhanced fat. Fiber was reduced by 77% and 66% by P. rhodozyma and S. roseus respectively, whereas the crude fat increased by 80% in mixed culture fermentation. Additionally, abundant vaccenic acid, a monounsaturated fatty acid was seen in S. roseus and mixed culture fermented DDGS. Vaccenic acid is a precursor of conjugated linolenic acid which is known to confer numerous health benefits. Fermentation of milo DDGS, wheat bran, rice bran and soybean products also resulted in carotenoid enrichment, with the best astaxanthin yield of 80 µg/g in rice bran, and best β-carotene yield of 837 µg/ g in soy flour. Precursors like mevalonic acid, apple pomace and tomato pomace increased carotenoid yield in DDGS and other substrates, with the yield increment depending on the substrate. Mevalonic acid resulted in the best astaxanthin and β-carotene yield increment by 140% and 236% resulting in 220 µg/g and 904 µg/g respectively in corn DDGS. Apple pomace and tomato pomace resulted in 29% carotenoid yield increment. Numerous studies thus far have used cheap agricultural substrates to produce carotenoids especially astaxanthin using P. rhodozyma with the intent of extracting the carotenoids for use in animal feed. However, by fermenting the animal feed directly, carotenoid-enriched feed can be produced without the need for extraction. By this simple yet novel carotenoid value addition, premium feeds or feed blends can be developed. Apart from carotenoid enrichment, low-fiber DDGS can help expand the market base of DDGS for use in non-ruminant feeds. Carotenoid value addition of DDGS can not only help sustain the biofuel industry but can also capture the aquaculture feed base which heavily relies on astaxanthin supplementation.
16

Effects of birth weight, finishing feeder design, and dietary astaxanthin and ractopamine HCl on the growth, carcass, and pork quality characteristics of pigs; and meta-analyses to improve the prediction of pork fat quality

Bergstrom, Jonathan Robert January 1900 (has links)
Doctor of Philosophy / Department of Animal Sciences and Industry / Jim L. Nelssen / Eleven-thousand one-hundred eighty-five pigs were used in 11 experiments to determine effects of birth-weight, feeder design, and dietary astaxanthin (AX) and ractopamine HCl (RAC) on growth, carcass, and pork quality characteristics of pigs. Also, data from 27 experiments were used in meta-analyses to improve prediction of pork fat iodine value (IV). In Exp. 1, increased birth-weight resulted in greater (quadratic, P < 0.05) pre-weaning survivability, ADG, final BW, and likelihood of achieving full-value market at 181-d of age. In Exp. 2, 3, 4, 6, 7, and 8, pigs using the wet-dry feeder (WD) had greater (P < 0.05) ADG, ADFI, and final BW than those using the conventional dry feeder (CD). Pigs using WD had poorer (P < 0.05) G:F in Exp. 3 and 4, and increased (P < 0.05) HCW and backfat depth in Exp. 3, 4, 6, and 7, compared to pigs fed using CD. In Exp. 5, pigs using WD from 19 to 38 kg had decreased (P < 0.02) ADFI and better G:F than pigs using CD. Increased feeder opening of WD increased (P < 0.05) ADG, ADFI, and final BW in Exp. 5, 6, and 7; as well as HCW and backfat depth in Exp. 6 and 7. Reducing WD opening at 28- and 56-d in Exp. 7 decreased (P < 0.05) ADG, ADFI, and backfat depth. Different openings of CD had little effect on performance in Exp. 5 and 6. In Exp. 8, changing water-source of WD to a separate location during late-finishing reduced (P < 0.05) overall ADG, ADFI, and final BW. Limited responses to AX were observed in Exp. 9, 10, and 11, but ADG, G:F, final BW, HCW, and fat-free lean were improved (P < 0.05) for pigs fed RAC in Exp. 10 and 11. Total color change during retail display of LM chops for gilts and pigs fed RAC was reduced (P < 0.05) in Exp. 10 and 11, indicating their color shelf-life improved. In the meta-analyses, models using dietary PUFA with ADG, BW, or backfat depth improved the fat IV prediction from R2 = 0.45 to R2 = 0.90.
17

Mate Choice in a Sexually Dimorphic Marine Bird, the Great Frigatebird (Fregata minor)

Juola, Frans Aaron 15 December 2010 (has links)
Darwin's theory of sexual selection explains the existence of sexual dimorphism, or within-species sex differences in shape, color, size, and behavior. In some cases, sexually dimorphic traits, especially extravagant male ornaments, seem maladaptive and thus in opposition to natural selection. The crux of Darwin's theory was that sexual selection arises from individual differences in reproductive success that result from competition for mates. In this dissertation, I investigated several aspects of sexual selection and the evolution of female mating preferences and male ornaments in the great frigatebird (Fregata minor). Frigatebirds as a group (family Fregatidae) are the most ornamented of any seabirds, and are among the most ornamented of any animal group. Their most prominent ornament is a gular (throat) pouch which becomes red in males during the breeding season, and which is inflated and displayed to females during courtship. Male courtship display also includes a warble vocalization and extension and trembling of the wings. I investigated the following issues concerning sexual selection and ornamentation in great frigatebirds: 1) the source of ornamental coloration in male great frigatebird gular pouches. I determined that this was a carotenoid-based color display; 2) the relationship of male mating success to gular pouch size and coloration. I determined that mating success was not related to the size or color of this ornament; 3) the relationship between male vocal display traits and female preferences. Again, I found no relationship between vocal display traits and female preferences, and finally, 4) the role of a major histocompatibility complex (MHC) locus in female mate choice. The MHC is a highly polymorphic multi-gene family associated with immune defense and has been proposed to play a role in mate choice. I found a significant disassortative mating pattern amongst mated pairs compared to random pairings based on MHC genotypes. In summary, I found no evidence for female mating preferences based on visual or auditory display traits associated with male ornamentation. However, I did find evidence for female mating preferences based on genetic dissimilarity at an MHC locus.
18

Funkcine dispepsija sergančių pacientų skrandžio gleivinės histomorfologiniai pakitimai bei jų dinamika vartojant augalinės kilmės antioksidantą astaksantiną / Histomorphological Changes of Gastric Mucosa in Functional Dyspepsia Patients and Their Dynamics After Treatment With The Natural Antioxidant Astaxanthin

Jančiauskas, Dainius 06 September 2010 (has links)
Darbo tikslas - įvertinti sergančiųjų funkcine dispepsija skrandžio gleivinės morfologinius pakitimus bei jų pokyčius gydant skirtingomis augalinės kilmės antioksidanto astaksantino dozėmis. Tikslui pasiekti buvo nustatyti ir išspręsti šie uždaviniai: įvertinti infekuotumą Helicobacter pylori mikroorganizmais bei skrandžio gleivinės histomorfologinius pakitimus pagal Sidnėjaus ir OLGA klasifikacijas sergantiesiems funkcine dispepsija; ištirti funkcine dispepsija sergančių ligonių uždegimo žymenų IL-4, IL-6, IL-8, IL-10, IFN-γ bei lastelių žymenų CD4, CD8, CD14, CD19, CD25, CD30 raišką skrandžio gleivinėje; palyginti funkcine dispepsija sergančių ligonių, gydytų augalinės kilmės antioksidanto astaksantino skirtingomis dozėmis ir placebu, skrandžio gleivinės morfologinius pokyčius; palyginti funkcine dispepsija sergančių ligonių, gydytų augalinės kilmės antioksidantu astaksantinu ir placebu, uždegimo žymenų IL-4, IL-6, IL-8, IL-10, IFN-γ bei lastelių žymenų CD4, CD8, CD14, CD19, CD25, CD30 raišką skrandžio gleivinėje. / The aim of the study was to evaluate histomorphological changes of the gastric mucosa in functional dyspepsia patients and their dynamics after treatment with the natural antioxidant astaxanthin. The following objectives were established and reached: to determine the presence of Helicobacter pylori infection and evaluate the histomorphological changes of gastric mucosa in functional dyspepsia patients; to evaluate interleukins IL-4, IL-6, IL-8, IL-10 and interferon-γ as well as the cell markers CD4, CD8, CD14, CD19, CD25 and CD30 in functional dyspepsia patients; to evaluate histomorphological changes of the gastric mucosa in functional dyspepsia patients after treatment with the natural antioxidant astaxanthin; to evaluate interleukins IL-4, IL-6, IL-8, IL-10 and interferon-γ as well as the cell markers CD4, CD8, CD14, CD19, CD25 and CD30 in functional dyspepsia patients and their dynamics after treatment with the natural antioxidant astaxanthin.
19

Produção de astaxantina por Mucor javanicus (UCP 69), a partir de meio definido e utilizando resíduo industrial (milhocina e quirera de milho) / Produção de astaxantina por Mucor javanicus (UCP 69), a partir de meio definido e utilizando resíduo industrial (milhocina e quirera de milho)

Aline Alves Barbosa da Silveira 08 August 2007 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Com a recente substituição dos pigmentos sintéticos pelos carotenóides naturais, pesquisas têm sido desenvolvidas para viabilizar uma maior produção destas substâncias, através de fontes biológicas alternativas. Neste trabalho foi estudada a produção de astaxantina por uma amostra de Mucor javanicus utilizando o meio definido Hesseltine e Anderson (1957) modificado por Andrade (2000) e meios utilizando resíduos de milho (milhocina e quirera), em concentrações distintas (4%, 7% e 10%), pH 6,5, 120 rpm, 25C. Foram analisada também a influência do tempo de cultivo da amostra durante 48h, 72h e 96h, na presença e ausência de luz azul. Ao término do processo fermentativo, a astaxantina foi extraída em solução de Hexano/metanol e analisada por espectroscopia UV- visível (470 nm). Todos os parâmetros estudados nos experimentos foram combinados através de um planejamento fatorial 33 e analisados no Software Statistica 5.0. No meio Hesseltine e Anderson o melhor rendimento de astaxantina foi verificado no tempo de 96h (26,7 &#61676;g/g), na ausência de luz e quando se utilizou luz azul (37,7 &#61676;g/g), obteve-se um aumento de 41%. A melhor condição para a produção da astaxantina com a milhocina deu-se na concentração de 4%, 96h, com luz (55,8 &#61676;g/g), aumentando em quase 100%, quando comparada com as culturas crescidas na ausência de luz (28,0 &#61676;g/g). A quirera na concentração de 7% apresentou melhor rendimento de astaxantina, no tempo de 96h, com luz (18,4 &#61676;g/g), aumentando 37%, quando comparada com as culturas crescidas na ausência de luz (13,4 &#61676;g/g). O melhor rendimento de astaxantina com milhocina e quirera deu-se na concentração de 7%, 96h, com luz (33,8 &#61676;g/g), aumentando em quase 47%, quando comparada com as culturas crescidas na ausência de luz (22,9 &#61676;g/g). As concentrações que mais favoreceram ao aumento do rendimento da astaxantina foram: milhocina 4%, quirera 4% e milhocina com quirera 7%, todos na presença de luz azul, demonstrando que a luz azul interfere diretamente na síntese de astaxantina. Bem como que os resíduos utilizados possuem potencial para a produção de astaxantina. As análises no Statistica 5.0, demonstram a necessidade da realização de outros estudos para obtenção da produtividade máxima de astaxantina por M. javanicus, nos meios alternativos. / With the recent substitution of synthetic pigments for the natural carotenoids, research has been effected in the direction to make possible the production of these substances through alternative considered biological sources. In this work was studied the production of astaxanthin for the sample of Mucor javanicus (CPU - 69), using the media definite Hesseltine and Anderson (1957) modified by Andrade (2000) and using different corn waste media (corn steep liquor .CSL and .quirera.) in three different concentrations (4, 7 and 10%), pH 6,5, 120 rpm, 25C. It was analyzed, also, the influence of the time of culture of the sample (48h, 72h and 96 h) and the presence and absence of blue Light. To the ending of the fermentative process, the astaxanthin, was extracted in solution of Hexano/methanol (1: 1, v/v), centrifuged in 2000 rpm/10 minutes and analyzed by UV-visible spectrophotometry (470 nm). All the parameters studied in the experiments had been combined through a factorial design 33 and analyzed in Software Statistica 5,0. With Hesseltine and Anderson the condition that more favored the increase of the income of the astaxanthin was with in the time of 96h (26,7 &#61676;g/g) in the absence of light and with the presence of light (37,7 &#61676;g/g) increase almost 41%. With CSL the best condition for the production of the astaxanthin was with in the time of 96h (55,8 &#61676;g/g) in the absence of light and with the presence of light (28,0 &#61676;g/g) increase almost 100%. The .quirera. in the concentration of 7%, presented astaxanthin income better, in the time of 96h, with light (18,4 &#61676;g/g) increase 37%, when compared with the cultures growth in the absence of light (13,4 &#61676;g/g). The best income of astaxanthin with CLS and .quirera. was in the concentration of 7%, 96h, with light (33,8 &#61676;g/g), increase almost 47% in when compared with the cultures growth in the absence of light (22,9 &#61676;g/g). The concentrations that more favored the income of astaxanthin was: CSL 4%, .quirera. 7% and CSL with .quirera. 7%, both in the presence of blue light, demonstrate the blue light intervenes directly with the astaxanthin synthesis. Also, the wastes utilizes have been potential for the astaxanthin production. The analyses in Statistica 5,0, demonstrate that other studies are necessary for attainment of the maximum productivity of astaxanthin for M. javanicus,
20

Avaliação de um processo de extração e recuperação dos carotenóides presentes no resíduo da industrialização do camarão-rosa (Farfantepenaeus paulensis)

Bertolo, Adilson Luís January 2007 (has links)
Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Engenharia e Ciência de Alimentos, Escola de Química e Alimentos, 2007. / Submitted by Caroline Silva (krol_bilhar@hotmail.com) on 2012-09-25T22:01:19Z No. of bitstreams: 1 avaliao de um processo de extrao e recuperao dos carotenides presentes no resduo da industrializao do camaro-rosa farfantepenaeus paulensis.pdf: 1948791 bytes, checksum: 9ef49c6fc9309bc36c75d41139143d07 (MD5) / Approved for entry into archive by Bruna Vieira(bruninha_vieira@ibest.com.br) on 2013-06-12T18:09:40Z (GMT) No. of bitstreams: 1 avaliao de um processo de extrao e recuperao dos carotenides presentes no resduo da industrializao do camaro-rosa farfantepenaeus paulensis.pdf: 1948791 bytes, checksum: 9ef49c6fc9309bc36c75d41139143d07 (MD5) / Made available in DSpace on 2013-06-12T18:09:40Z (GMT). No. of bitstreams: 1 avaliao de um processo de extrao e recuperao dos carotenides presentes no resduo da industrializao do camaro-rosa farfantepenaeus paulensis.pdf: 1948791 bytes, checksum: 9ef49c6fc9309bc36c75d41139143d07 (MD5) Previous issue date: 2007 / A astaxantina é um carotenóide da classe das xantofilas, amplamente distribuída em animais marinhos e aquáticos, sendo muito utilizada em formulações para aqüicultura e por suas propriedades antioxidantes, podendo também ser utilizada como corante alimentício por sua coloração avermelhada. Este carotenóide pode ser extraído de algas, bactérias e também de crustáceos como o camarão-rosa. Este crustáceo é amplamente capturado na região sul do Rio Grande do Sul, sendo que seu processamento gera mais de 60% de resíduos. O aproveitamento destes resíduos surge como uma alternativa a problemas de impacto ambiental, oriundos do seu despejo na lagoa dos Patos, bem como uma fonte alternativa de recursos para as indústrias e pescadores locais. Neste contexto, o objetivo deste trabalho foi a obtenção de carotenoproteína, utilizando resíduos provenientes da industrialização do camarãorosa(Farfantepenaeus paulensis) por meio de hidrólise enzimática com adição da enzima proteolítica Flavourzyme, e a partir dela, a purificação química da astaxantina, visando avaliar quais variáveis do processo possuíam efeito significativo, e depois de obtido o extrato, foi estudada sua estabilidade frente à luz e temperatura, utilizando astaxantina dissolvida em óleo de soja, como oleoresina. Para analisar quais as variáveis que realmente influenciam no processo de obtenção da carotenoproteína, optou-se pela utilização do planejamento experimental saturado 23 com três pontos centrais, onde se têm três variáveis independentes em dois níveis: tempo (2 e 3 h), temperatura (40 e 50ºC) e concentração de enzima/substrato (0,1 e 0,3%); e como variáveis dependentes: rendimento, porcentagem de proteína e de lipídios. As condições ótimas para o processamento foram: tempo de hidrolise de 2 horas, temperatura de hidrólise de 50°C e concentração de Enzima/Substrato de 0,3%, obtendo um rendimento do processo 9,4% , um teor de proteínas de 70,9% e teor de lipídios de 1,6%. Já para o processo de purificação química da carotenoproteína também foi utilizado um planejamento experimental quadrático completo do tipo 23, com três variáveis independentes em dois níveis, sendo elas: tempo de extração (80 e 280 min), temperatura de extração (26,6 e 43,4°C) e proporção de hexano/ acetona (8 e 92%) e como variáveis dependentes a concentração de astaxantina com três pontos centrais e dois axiais, sendo que com um tempo de extração química de 120 mim, temperatura de extração de 30 °C e com uma proporção de Hexano e Acetona de 25% foi obtida a maior concentração de astaxantina que foi de 197,41 ppm.15. Finalmente foi estudada a estabilidade da oleoresina frente ao calor, apresentando-se estável durante as 8 primeiras horas de exposição à temperatura de 105°C. Já na estabilidade frente à luz, a oleoresina mostrou-se estável por um período de 7 dias. / The Astaxanthin is a carotenoide of the xanthophylls class, widely distributed in marine and aquatic animals, and is often used in formulations for aquaculture and for their antioxidant properties and may also be used as food coloring on its reddish color. Astaxanthin can be extracted of seaweed, bacteria and also of crustaceans as the pink-shrimp. The pink-shrimp is amply captured in the southern region of Rio Grande do Sul, where their processing generates more than 60% of waste. The use of such waste emerges as an alternative to problems of the environmental impact of their eviction from the Pato´s lagoon, as well as an alternative source of resources for industries and local fishermen. In this context, the aim of this study is the obtainment of carotenoprotein using wastes from pink-shrimp processing (Farfantepenaeus Paulensis) through the proteolitic enzyme Flavourzyme, and its chemical purification, aiming to evaluate which of the process variables have significant effects. Once obtained the extract, its stability was studied faced to light and temperature, using astaxanthin dissolved in soy resin oil. To analyze the variables that really influenced the process of carotenoprotein obtainment, it was used an experimental design saturated 23, with three independent variables in two levels: time (2 and 3h), temperature (40 and 50°C) and concentration enzyme/substrate (0.1 and 0.3%) and as dependent variables the yield, lipids and proteins percentage, with three central points. The best conditions for processing were hidrolysys time of 2 hours and 50ºC of temperature, concentration enzyme/substrate of 0.3%, and the yield obtained on the process was 9.4%, protein level of 70,9% and lipids of 1.6%. To the process of chemical purification of the carotenoprotein it was also used an experimental design saturated 23, with three independent variables in two levels: time of extraction (80 and 280 minutes), temperature of chemical extraction (26,6 and 43,4°C) and hexane and acetone proportion (8 and 92%) and as dependent variable the astaxanthin concentration, with three central points and two axial points considering 16 an chemical extraction time of 120 minutes, extraction temperature of 30ºC and hexane and acetone in a 25% proportion the highest astaxanthin concentration gained was 197,41 ppm. Finally the stability of the resin oil faced to heat was studied, presenting stable during the 8 early hours of exposure to temperature of 105ºC. Faced to light, the oil resin became stable during 7 days.

Page generated in 0.0518 seconds