• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • 6
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 20
  • 20
  • 6
  • 6
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 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.
1

The Effects of Cofermentation of Cider and Apple Pomace on Cider Attributes

Affonso, Abigail D 01 June 2022 (has links) (PDF)
Phenolics are critical to the sensory attributes and health benefits of hard cider due to their contribution to the flavor, mouthfeel, and antioxidant activity. With the increase in demand for cider, the use of dessert apple varieties has become more common leaving ciders lacking in phenolics. However, a promising method to increase their phenolic content is through maceration with apple pomace. This study evaluated the effect maceration with apple pomace during cider fermentation on the extraction of phenolic compounds, as well as its effect on the sensory properties of the final product. For this study, ciders were fermented with 0% (control), 20%, 35%, and 50% of the average pomace created during production of the apple must. After fermentation, the ciders were analyzed for acid content, total phenolic content (TPC), alcohol by volume (ABV), color, volatile profile, and sensory properties. The ciders fermented with apple pomace went through malolactic fermentation. During the maceration phenolics were extracted which resulted in an increase in phenolic content in cider. Compared to the control, the treatment ciders were also seen to have higher ABV and TPC, lower acidity, and a different aromatic profile: decreased acetaldehyde and increased ethyl acetate, isoamyl alcohol, and phenylethyl alcohol. The color measurements suggests that treatment ciders were lighter, with a higher red and yellow color compared to the control cider. The sensory analysis revealed the treatment ciders were perceived as less acidic and astringent, but more bitter than the controls. This study shows the addition of apple pomace in its native state increases total phenolic content and could be favorable to produce well rounded ciders. This study shows maceration is a promising technique for increasing phenolic content in ciders.
2

Application of Apple pomace for Fungal Cultivation / Användning av Äpplepressmassa för svampodling

Floberg Karlsson, Bill, Viitala, Jonatan January 2019 (has links)
Apple pomace is a solid by-product acquired from pressing and crushing millions of tons of apple in juice-industries. It represents 25-30 % of the original fruit and consists of peels, seeds and pulp. This raw material has multiple applications due to its high carbohydrate and moisture content. This bachelor thesis evaluated the use apple pomace acquired from Herrljunga cider for the cultivation of a filamentous fungus to produce biomass and ethanol. Different pretreatment strategies were applied to the apple pomace to extract as much sugars as possible. Several batches were made by mixing pomace and distilled water at different ratios (g pomace per g water) and different water temperatures. Apple juice was produced by filtering soaked pomace using a fine fabric. Apple pomace suspensions were made by adding pomace and water without mixing it (non-homogenised) and homogenised suspensions by mixing with a kitchen blender. Some apple juice batches were pH adjusted to 5.5 to investigate the effect on the fungal growth. The batches were put in Erlenmeyer flasks, sterilised and inoculated with the fungal strain Rhizomucor that has been isolated from Indonesian leaves used for tempe preparation. The Erlenmeyer flasks were incubated in a water shake for 72 h. Samples were taken every 24 h to follow sugar and ethanol concentrations. The samples were analysed by HPLC (High-Performance Liquid Chromatography). The results showed that apple pomace suspension did not perform well compared to the apple juice since the suspension was too viscous and lacked oxygen for the fungus to grow properly in the solution. The apple juice did show a significant improvement compared to the suspension, however pH adjustment to 5.5 had a negative impact on the fungal growth. Cold pre-treatment with an apple pomace to water ratio of 1 g pomace /g water produced the most biomass, with a yield of 9.7 g biomass per kg dry apple pomace. For ethanol production, an apple pomace to water ratio of 1 g pomace /g water using hot water had the highest yield of 11.2 g ethanol per kg dry apple pomace. / Äppelpressmassa är en solid biprodukt, producerad genom att pressa och trycka milliontals ton äpple i bland annat juiceindustrier. Den kvarstående massan motsvarar 25-30 % av äpplet och består utav skal, frön och fruktkött. Denna råvara har många tillämpningar då den har ett högt kolhydrat- och vätskeinnehåll. Detta examensarbete utvärderade användningen av äppelpressmassa från Herrljunga cider för att odla en filamentös svamp i syfte att producera biomassa och etanol. Massan blev utsatt för olika förbehandlingar för att extrahera så mycket socker som möjligt. Olika satser gjordes genom att blanda äppelpressmassa med vatten i olika förhållanden (g äppelpressmassa per g vatten) och olika vattentemperaturer. Äppeljuice producerades genom att filtrera blöt massa med ett fint tyg. Suspensioner gjordes genom att tillsätta vatten till massan och inte blanda det (icke-homogent). En annan variant gjordes genom att blanda äppelpressmassa och vatten med en mixer (homogent). Några utav äppeljuicesatserna pH justerades till 5.5 för att se hur det påverkade svamptillväxten. Satserna flyttades till Erlenmeyer flaskor, steriliserades och ympades med den filamentösa svampen Rhizomucor. Erlenmeyer flaskorna flyttades till ett skakvattenbad för att jäsa i 72 timmar. Prover togs var 24:e timma för att se socker- och etanolkoncentrationerna ändras. Detta analyserades med hjälp utav en HPLC. Resultaten visade att suspensionssatserna inte presterade bra jämfört med äppeljuicesatserna. Detta misstänks bero på att innehållet var väldigt visköst och hade lågt syreinnehåll för svampen att kunna växa. Att justera pH till 5.5 för äppeljuicesatserna visade sig inte vara bra, de presterade sämre jämfört med justerade satser. Förbehandlingen med en äppelpressmassa till vatten förhållandet på 1 g äppelpressmassa/1 g kallt vatten producerade mest biomassa med ett utbyte av 9.7 g torr biomassa per kg torr äppelpressmassa. För etanolproduktion hade förbehandlingsmetoden med en äppelpressmassa till vatten förhållandet på 1 g äppelpressmassa/1 g varmt vatten högst utbyte med 11.2 g etanol per kg torr äppelpressmassa.
3

Production of bio-plastic materials from apple pomace : A new application for the waste material / Produktion av bio-plast material från äpplerester

Gustafsson, Jesper, Landberg, Mikael January 2018 (has links)
Extensive quantities of apple pomace are generated annually but disposal of this waste is still much disputed. In EU alone, 500 000 tons are produced every year. Without further treatment, the acidic character of apples with their high sugar and low protein content makes the pomace unsuitable for landfilling and animal feedstock. However, further treatment is usually not economically feasible. This study addresses this issue by introducing a new approach for the apple pomace to produce sustainable materials.  The high content of sugars in apple pomace which can be reshaped and reformed at higher temperatures makes the waste material suitable for plastic production. Other components found in apple pomace are 5 % proteins and 1.5 % fats. Fibers are abundant, dietary fibers amounts for more than half (55 %) the original apple pomace weight. Phenols, sorbitol and acids can be found in minor mount, 2 % or less. The apple pomace itself is a mixture of mostly pulp and peel which corresponds to 9/10 of the total mass. Whereas seeds, seed core and stalk are the remaining 1/10. The possibilities of utilizing apple pomace to produce biofilms and 3D shapes have been investigated. The effects of introducing orange pomace, another waste material produced in extensive quantities, to apple pomace samples has also been studied.  Two methods were used to produce bioplastic materials; solution casting and compression molding. Glycerol was used as a plasticizer. Apple pomace, either washed or not washed, was oven-dried and milled into a fine powder. Using compression molding, plates or cups of the two powders with different amounts of glycerol were prepared. Mixtures of apple pomace and orange pomace, with or without glycerol, were prepared in the same way. The apple pomace was also used in a film casting method to produce plastic films. Applying laser cutting to the plates and plastic films, dog-bone specimens were created whose mechanical properties were analysed using a universal testing machine.  Highest values in terms of tensile strength and elongation at max was reached with bioplastics produced from solution casting where the values varied in the range 3.3 – 16 MPa and 11 – 55 % respectively. The compression molding approach resulted in tensile strength values in the range 0.94 – 5.9 MPa whereas the elongation at max was in the range 0.30 – 1.9 %. A possible application for this material could be disposable tableware which does not require high mechanical strength.  It was shown that it is possible to produce 3D structures and plastic films from apple pomace. Washed apple pomace with glycerol has similar properties as not washed apple pomace without the plasticizer. Adding orange pomace to apple pomace samples increases the tensile strength at the expense of the elongation at max. The pressing conditions and powder size greatly effects the mechanical properties, where a larger powder size lower the values for the mechanical properties. This new approach paves the way for a new utilization of apple pomace to replace some petroleum-based materials and at the same time solve the disposal problem of apple pomace.
4

Potencial da Farinha de Bagaço de Maçã no tratamento dietoterápico de pessoas idosas Ponta Grossa 2007

Coelho, Laylla Marques 23 August 2007 (has links)
Made available in DSpace on 2017-07-21T18:53:07Z (GMT). No. of bitstreams: 1 LAYLLAMARQUES.pdf: 1145086 bytes, checksum: c1ab51b02d49ea74dbcec3569b8c3d6c (MD5) Previous issue date: 2007-08-23 / The industrialization of the apple, in particular of the juice, generates in the processing, as main residue, or by-product, the pomace, for which the concern in managing it adequately must be enters the priorities of the processing industries. The composition physicist-chemistry of the apple pomace flour in this study presented 43% of staple fibers in dry base. The studies on staple fibers demonstrate that they show a hypocholesterolemic action, therefore reduce the digestion and the absorption of the dietary lipids, increases the fecal eliminate acid biliary and steroid the neutral ones, increases the production of acid of short chain in colon and diminishes the percentage of biliary elementary schools in bile. The objective of this study was to develop an alimentary product for an assay of cost evaluation/benefit, with group of aged in confinement, being used 30 g/day apple pomace flour, supplemented in products daily. The research counted on the free participation of 31 citizens that had carried through laboratories examinations of glucose, cholesterol and fractions and triglycerides and had answered questions on intestinal functioning. The averages of the results of total cholesterol and LDLcholesterol shown that in the group it was controlled did not have reduction during the intervention with the apple pomace flour and in the group in intervention of the apple pomace flour in its feeding had reduction of up to 14,71% and 14,69% respectively. Proving that the apple pomace flour can constitute potential alternative source of the alimentary fiber for the food formularization and demonstrates to trend in the reduction of the total cholesterol and LDL-cholesterol. / A industrialização da maçã, em particular do suco, gera como principal resíduo, ou subproduto, o bagaço, sendo que a preocupação em gerenciá-lo adequadamente deve estar entre as prioridades das indústrias processadoras. A composição físico-química da farinha de bagaço de maçã neste estudo apresentou 43% de fibras em base seca. Os estudos sobre as fibras demonstram que elas exercem uma ação hipocolesterolêmica, pois reduzem a digestão e a absorção dos lipídeos dietéticos, aumentam a excreção fecal dos ácidos biliares e esteróis neutros, aumentam a produção de ácidos graxos de cadeia curta no cólon e diminuem a porcentagem de ácidos biliares primários na bile. O objetivo deste estudo foi desenvolver um produto alimentar, num ensaio de avaliação de custo/benefício, com grupo de idosos em confinamento, utilizando 30g de farinha de bagaço de maçã/dia, suplementados em produtos do cotidiano. A pesquisa contou com a livre participação de 31 idosos, que realizaram exames laboratoriais de glicemia, colesterol e frações e triglicerídeos e responderam questões sobre seu funcionamento intestinal. As médias dos resultados de colesterol total e LDLcolesterol mostraram que no grupo controle não houve redução durante a intervenção com a farinha de bagaço de maçã e no grupo em intervenção da farinha de bagaço de maçã em sua alimentação houve redução de até 14,71% e 14,69% respectivamente, comprovando que a farinha de bagaço de maçã pode constituir fonte alternativa potencial da fibra alimentar para a formulação de alimentos e demonstra tendência na redução do colesterol total e LDL-colesterol.
5

Beta-frutofuranosidase de aspergillus versicolor utilizando fonte de carbono alternativa: produção, purificação e caracterização enzimática / Beta-frutoranosidade de aspergillus versicolor using alternative carbon source: production, purification and enzymatic characterization

Dapper, Taiomara Butzke 27 February 2015 (has links)
Made available in DSpace on 2017-07-10T14:38:25Z (GMT). No. of bitstreams: 1 taiomara.pdf: 1065464 bytes, checksum: af0fbef1e995478eaa14a58b94c0cbd0 (MD5) Previous issue date: 2015-02-27 / Extracellular β-fructofuranosidase production from Aspergillus versicolor was significantly increased after optimization of culture conditions by Central Composite Rotational Design (CCRD). The variables studied were apple pomace, initial pH and cultivation time, and in response to enzymatic activity of β-fructofuranosidase. The maximum yield of β-fructofuranosidase was obtained when the fungus was grown for 12 days in medium supplemented with 3% (w/v) apple pomace as carbon source and the initial medium pH 7.0. In the purification procedure, the extracellular crude extract of A. versicolor was precipitated with ammonium sulfate 75%, and applied to the ion exchange chromatography DEAE-Sephadex, which resulted in two peaks of enzyme activities, named β-fructofuranosidase-I and II. The β-frutofuranosidase- I exhibited optimum temperature and pH of 55°C and 6.0, respectively. The enzyme was stable at temperatures from 40 to 60°C and the pH in a range from 3.0 to 6.0. The activity of β-fructofuranosidase-I was increased in the presence of the Fe2+ ion, and inhibited by Hg2+. The kinetic parameters Vmax and Km with sucrose as substrate were 26.71 mm and 56.980 μmol.min-1, respectively. These biochemical characteristics of the β-fructofuranosidase demonstrate the potential application of this enzyme in the ethanol production industry, which requires high temperature stability and acidic pH. / A produção de β-frutofuranosidase extracelular de Aspergillus versicolor foi significativamente elevada após otimização das condições de cultivo através do Delineamento Composto Central Rotacional (DCCR). As variáveis estudadas foram: bagaço de maçã, pH inicial do meio mineral e tempo de cultivo, tendo como resposta a atividade enzimática da β-frutofuranosidase. A produção máxima de β-frutofuranosidase foi obtida quando o fungo foi cultivado por 12 dias, em meio suplementado com 3% (p/v) de bagaço de maçã como fonte de carbono e pH inicial 7,0 do meio mineral. No procedimento de purificação, o extrato bruto extracelular do A. versicolor foi precipitado com sulfato de amônio 75%, em seguida submetido à cromatografia de troca iônica DEAE-Sephadex, que resultou em dois picos de atividade enzimática, denominadas de β-frutofuranosidase I e II. A β-frutofuranosidase I exibiu temperatura e pH ótimos de 55ºC e 6,0, respectivamente. A enzima mostrou estabilidade nas temperaturas de 40 a 60ºC e foi estável em pH na faixa de 3,0 a 6,0. A atividade da β-frutofuranosidase I foi aumentada na presença do íon Fe2+, mas inibida pelo íon Hg2+. Os parâmetros cinéticos Km e Vmáx utilizando sacarose como substrato, foram 26,71 mM, e 56,980 μmol.min-1, respectivamente. Estas características bioquímicas da β-frutofuranosidase evidenciam o potencial de aplicação desta enzima na indústria de produção de etanol, que exige estabilidade a temperatura alta e pH ácido.
6

Multivalorizaiton of beverage industry waste streams for the development of bioplastics and food ingredients

Williamson, Kathryn January 2021 (has links)
No description available.
7

Investigation of the binding effect of fungal fiber (grown on apple pomace) in the formation of lyocell nonwoven textiles and their potential applications

Luo, Xue January 2021 (has links)
This project combines nonwoven technology, biological technology and food waste management and seeks for this feasibility to use fungal microfiber (FM) as a binder for lyocell pro-duction and the characterizations for possible applications. Rhizopus delemar was cultivated apple pomace in liquid-state fermentation to obtain mycelia biomass. The biomass was later blended in a kitchen blender for one minute. The blended FM was later mixed with 6 mm lyocell fibre at different FM dry weight percentage and water to make nonwoven webs by wet-laid method. The feasibility of using fungal microfiber as a binder for lyocell nonwovens was confirmed in this study. It is not possible to make nonwoven webs using lyocell short fibre without any binder applied. With 5%_FM, the tensile strength of lyocell nonwoven webs reached 0.0989 MPa. A clear increasing tensile strength was recorded as the increasing of FM weight per-centage and resulted a highest tensile strength at 9.38 MPa when applying 60%_FM. The re-sult of water contact angle proved that the increasing FM could decrease the hydrophobicity of nonwoven samples. Abrasion test showed that FM could improve the abrasion resistance of the lyocell nonwoven samples. Porosity test showed that lyocell nonwoven samples with a higher FM ended up with smaller mean flow pore size diameter (MFP) that nonwoven samples with 65%_FM has an average MFP at 7.26 m m. The SEM images reviled that FM bonded nonwoven webs had a fibrous structure, which is due to binding effect of fungal microfiber on lyocell short fibers. These characterizations have demonstrated the mechanism of using fungal microfiber as a binder for lyocell nonwovens in this project. In this thesis project, FM bonded lyocell nonwoven webs showed a great potential on the application of nonwoven applications such as interior materials or filtration materials.
8

Production of textile fibres from filamentous fungi grown on apple pomace : invertase pre-treatment

Berg, Sofia January 2023 (has links)
In this work Rhizopus Delemar was grown on an apple pomace medium, a waste product from the juice industry. The apple pomace was pre-treated with the enzyme invertase to hydrolyse the sucrose available in the waste to glucose and fructose, which are digestible by the fungus. Combination of invertase pre-treatment and yeast extract supplementation, resulted in highest biomass growth which was 4.3 ± 0.5 g/l biomass. The fungal cell wall was separated from fungal biomass using an alkali treatment. A hydrogel was formed from the cell wall material and used for spinning of filaments using dry gel spinning. The average dry weight percentage of the gel was 11.6 ± 1.3 %. The gel was spun through a needle to a collecting rotating surface to make filaments. The filaments were easy to spin and to collect continuous fibres. The spun filaments had a rubber-like texture. All the tested filaments had an ultimate tensile strength approximately 2-3 MPa and 10 – 12% elongation at break. The conclusion of this work is that it is possible to produce fibers from fungi grown in apple waste and that it is possible to improve fungal growth using invertase and yeast extract. The tensile strength of the filaments needs further improvement to compete with other materials used in woven fabrics.
9

Avaliação do desempenho das leveduras Candida guilliermondii e Kluyveromyces marxianus em hidrolisado de bagaço de maça / Evaluation of the performance of the yeasts Candida guilliermondii and Kluyveromyces marxianus in apple pomace hemicellulosic hydrolysate

Dalanhol, Katia Caroline França 11 August 2014 (has links)
Em um contexto de sustentabilidade onde resíduos devem ser aproveitados na tentativa de gerar novos produtos, energéticos ou não encontra-se o bagaço de maçã, o resíduo oriundo da prensagem do fruto no processo de produção de suco. Tal biomassa é composta por cascas, polpa, talos e sementes. Representa cerca de 30% da produção anual de maçã no Brasil e tem como opção de utilização, suplementação de ração animal e adubação orgânica. Uma alternativa de aproveitamento para esta biomassa está na sua utilização em bioprocessos como na produção de etanol, xilitol, dentre outros. O xilitol e o etanol vêm sendo amplamente investigados, o xilitol por suas diversas aplicações nos setores odontológico, farmacêutico e alimentício e o etanol pela sua utilização em substituição aos combustíveis fósseis. Desta forma o presente trabalho avaliou o aproveitamento do bagaço de maçã como matéria-prima em bioprocessos. Para tanto, foram desenvolvidas etapas de caracterização da biomassa; obtenção por hidrólise ácida (1% H2SO4, 121?C, 20 min.), concentração a vácuo e, destoxificação (1% de carvão vegetal ativo e ajuste de pH), do hidrolisado hemicelulósico; e fermentação deste hidrolisado por Candida guilliermondii e Kluyveromyces marxianus. As fermentações foram desenvolvidas em frascos Erlenmeyer (125mL), em shaker rotatório (200 rpm, 30°C) por 96 horas, empregando como meio de cultivo o hidrolisado hemicelulósico suplementado com (g.L-1) solução de extrato de farelo de arroz (20); CaCl2.2H2O (0,1) e (NH4)2SO4 (2,0). No presente trabalho, o bagaço de maçã apresentou teores (%) de 32,62 de celulose, 25,38 de lignina e 23,60 de hemicelulose, enquanto o hidrolisado o qual foi destoxificado em separado para as fermentações com as leveduras teve como constituintes (g.L-1): xilose (29,65), glicose (20,79), arabinose (19,93), ácido acético (2,07), furfural (0,03) e hidroximetilfurfural (0,11). Foi constatado que ambas as leveduras consumiram totalmente a glicose (12h) e parcialmente as pentoses, xilose e arabinose, sendo a última consumida lentamente por C. guilliermondii e apenas nas últimas 24 horas de cultivo por K. marxianus Como resultado, C. guilliermondii produziu xilitol (9,35g.L-1) e K. marxianus tanto xilitol (9,10g.L-1) quanto etanol (10,47 g.L-1) como principais bioprodutos. As máximas atividades enzimáticas (U/mgprot) de xilose redutase (XR) e xilitol desidrogenase (XDH) das leveduras empregadas foram 0,23 e 0,53 para C. guilliermondii e 0,08 e 0,08 para K. marxianus, respectivamente. Baseando-se nos resultados obtidos no presente trabalho, pode-se afirmar que o bagaço de maçã é uma biomassa promissora para ser aproveitada como matéria-prima em bioprocessos que visam a produção de xilitol e/ou etanol. / In a sustainability context in which residues must be used for obtaining new energetic or non-energetic products, vegetal biomass becomes an important feedstock for bioprocess. One of those residues is apple pomace, which is produced in the fruit milling during the juice production process. This biomass is composed by skin, pulp, stalk and seeds. It represents about 30% of apple annual production in Brazil, and the conventional uses are animal feeding and organic fertilization. One alternative to use this biomass is its utilization as feedstock in bioprocesses, such as ethanol and xylitol production. Extensive research is being performed in xylitol and ethanol production due to the important applications of xylitol in odontological, pharmaceutical and food industries, as well as because of the utilization of ethanol as substitute of fossil fuels. In this way, the present work evaluated the use of apple pomace as feedstock for bioprocess, through the development of stages of biomass characterization; dilute-acid hydrolysis (1% H2SO4, 121?C, 20 min.), vacuum concentration and detoxification (pH adjustment and activated charcoal adsorption) of the hemicellulosic hydrolysate and fermentation of this hydrolysate by Candida guilliermondii and Kluyveromyces marxianus. The fermentations were performed in Erlenmeyer flasks (125mL) in a rotatory shake (200rpm, 30ºC) for 96h, employing as culture medium the hemicellulosic hydrolysate supplemented with (g.L-1) rice bran extract (20), CaCl2·2H2O (0.1) and (NH4)2SO4 (2.0). In this work, the composition (%) of apple was 32.62 of cellulose, 25.38 of lignin and 23.60 of hemicellulose. The hydrolysate was separately detoxified for the fermentations with the yeasts, and has the following composition (g.L-1): xylose (29.65), glucose (20.79), arabinose (19.93), acetic acid (2.07), furfural (0.03) and 5-hydroxymethylfurfural (0.11). It was verified that both yeasts consumed totally glucose (12h) and partially pentoses, i.e. xylose and arabinose, the latter being consumed slowly by C. guilliermondii and only in the last 24h of fermentation by K. marxianus. The main products for C. guilliermondii was xylitol (9.35g.L-1) while for K. marxianus it was ethanol (10.47g.L-1) and xylitol (9.10 g.L-1) as well. The maximum enzymatic activities (U/mgprot) of Xylose Reductase (XR) and Xylitol Dehydrogenase (XDH) were 0.23 e 0.53 for C. guilliermondii and 0.08 and 0.08 for K. marxianus, respectively. Based on the results of the present work, it can be stated that apple pomace is a promissory biomass to be used as feedstock in bioprocess for xylitol and/or ethanol production.
10

Avaliação do desempenho das leveduras Candida guilliermondii e Kluyveromyces marxianus em hidrolisado de bagaço de maça / Evaluation of the performance of the yeasts Candida guilliermondii and Kluyveromyces marxianus in apple pomace hemicellulosic hydrolysate

Katia Caroline França Dalanhol 11 August 2014 (has links)
Em um contexto de sustentabilidade onde resíduos devem ser aproveitados na tentativa de gerar novos produtos, energéticos ou não encontra-se o bagaço de maçã, o resíduo oriundo da prensagem do fruto no processo de produção de suco. Tal biomassa é composta por cascas, polpa, talos e sementes. Representa cerca de 30% da produção anual de maçã no Brasil e tem como opção de utilização, suplementação de ração animal e adubação orgânica. Uma alternativa de aproveitamento para esta biomassa está na sua utilização em bioprocessos como na produção de etanol, xilitol, dentre outros. O xilitol e o etanol vêm sendo amplamente investigados, o xilitol por suas diversas aplicações nos setores odontológico, farmacêutico e alimentício e o etanol pela sua utilização em substituição aos combustíveis fósseis. Desta forma o presente trabalho avaliou o aproveitamento do bagaço de maçã como matéria-prima em bioprocessos. Para tanto, foram desenvolvidas etapas de caracterização da biomassa; obtenção por hidrólise ácida (1% H2SO4, 121?C, 20 min.), concentração a vácuo e, destoxificação (1% de carvão vegetal ativo e ajuste de pH), do hidrolisado hemicelulósico; e fermentação deste hidrolisado por Candida guilliermondii e Kluyveromyces marxianus. As fermentações foram desenvolvidas em frascos Erlenmeyer (125mL), em shaker rotatório (200 rpm, 30°C) por 96 horas, empregando como meio de cultivo o hidrolisado hemicelulósico suplementado com (g.L-1) solução de extrato de farelo de arroz (20); CaCl2.2H2O (0,1) e (NH4)2SO4 (2,0). No presente trabalho, o bagaço de maçã apresentou teores (%) de 32,62 de celulose, 25,38 de lignina e 23,60 de hemicelulose, enquanto o hidrolisado o qual foi destoxificado em separado para as fermentações com as leveduras teve como constituintes (g.L-1): xilose (29,65), glicose (20,79), arabinose (19,93), ácido acético (2,07), furfural (0,03) e hidroximetilfurfural (0,11). Foi constatado que ambas as leveduras consumiram totalmente a glicose (12h) e parcialmente as pentoses, xilose e arabinose, sendo a última consumida lentamente por C. guilliermondii e apenas nas últimas 24 horas de cultivo por K. marxianus Como resultado, C. guilliermondii produziu xilitol (9,35g.L-1) e K. marxianus tanto xilitol (9,10g.L-1) quanto etanol (10,47 g.L-1) como principais bioprodutos. As máximas atividades enzimáticas (U/mgprot) de xilose redutase (XR) e xilitol desidrogenase (XDH) das leveduras empregadas foram 0,23 e 0,53 para C. guilliermondii e 0,08 e 0,08 para K. marxianus, respectivamente. Baseando-se nos resultados obtidos no presente trabalho, pode-se afirmar que o bagaço de maçã é uma biomassa promissora para ser aproveitada como matéria-prima em bioprocessos que visam a produção de xilitol e/ou etanol. / In a sustainability context in which residues must be used for obtaining new energetic or non-energetic products, vegetal biomass becomes an important feedstock for bioprocess. One of those residues is apple pomace, which is produced in the fruit milling during the juice production process. This biomass is composed by skin, pulp, stalk and seeds. It represents about 30% of apple annual production in Brazil, and the conventional uses are animal feeding and organic fertilization. One alternative to use this biomass is its utilization as feedstock in bioprocesses, such as ethanol and xylitol production. Extensive research is being performed in xylitol and ethanol production due to the important applications of xylitol in odontological, pharmaceutical and food industries, as well as because of the utilization of ethanol as substitute of fossil fuels. In this way, the present work evaluated the use of apple pomace as feedstock for bioprocess, through the development of stages of biomass characterization; dilute-acid hydrolysis (1% H2SO4, 121?C, 20 min.), vacuum concentration and detoxification (pH adjustment and activated charcoal adsorption) of the hemicellulosic hydrolysate and fermentation of this hydrolysate by Candida guilliermondii and Kluyveromyces marxianus. The fermentations were performed in Erlenmeyer flasks (125mL) in a rotatory shake (200rpm, 30ºC) for 96h, employing as culture medium the hemicellulosic hydrolysate supplemented with (g.L-1) rice bran extract (20), CaCl2·2H2O (0.1) and (NH4)2SO4 (2.0). In this work, the composition (%) of apple was 32.62 of cellulose, 25.38 of lignin and 23.60 of hemicellulose. The hydrolysate was separately detoxified for the fermentations with the yeasts, and has the following composition (g.L-1): xylose (29.65), glucose (20.79), arabinose (19.93), acetic acid (2.07), furfural (0.03) and 5-hydroxymethylfurfural (0.11). It was verified that both yeasts consumed totally glucose (12h) and partially pentoses, i.e. xylose and arabinose, the latter being consumed slowly by C. guilliermondii and only in the last 24h of fermentation by K. marxianus. The main products for C. guilliermondii was xylitol (9.35g.L-1) while for K. marxianus it was ethanol (10.47g.L-1) and xylitol (9.10 g.L-1) as well. The maximum enzymatic activities (U/mgprot) of Xylose Reductase (XR) and Xylitol Dehydrogenase (XDH) were 0.23 e 0.53 for C. guilliermondii and 0.08 and 0.08 for K. marxianus, respectively. Based on the results of the present work, it can be stated that apple pomace is a promissory biomass to be used as feedstock in bioprocess for xylitol and/or ethanol production.

Page generated in 0.04 seconds