Digestive proteases were isolated from the pancreas of the stomachless cunner fish (Tautogolabrus adspersus) and characterized in terms of their physicochemical properties, their ability to hydrolyze native pectin methylesterase (PME) from orange and polyphenol oxidases (PPO) from mushroom and the ability of the cunner enzyme(s) to maintain the stability of orange juice cloud. / The cunner trypsin fraction exhibited exceptional capacity to hydrolyze native proteins versus the bovine trypsin. Incubation of native PME with cunner or bovine trypsin resulted in a loss of 75% or 35% in PME activity respectively. Similarly, a 75% or 55% loss in PPO activity was observed after treatment with cunner and bovine trypsin respectively. Bovine trypsin, however, hydrolyzed the heat-denatured PME and PPO better than the cunner trypsin. Also, there was no reactivation of both PME and PPO activity after treatment with either the cunner or bovine enzyme during storage at 4$ sp circ$C for 3 weeks. However, PPO retained up to 20% or 50% of the initial activity after treatment with cunner or bovine trypsin, respectively. / A 3 x 3 factorial design involving the factors of temperature, enzyme concentration and incubation time carried out gave an r$ sp2$ of 0.92 and 0.95 for cunner and bovine trypsin treated PME respectively. On the other hand, an r$ sp2$ of 0.91 and 0.94 was obtained for the combined effects using cunner and bovine trypsin for PPO inactivation. Validation of the model of PME inactivation measured as the % cloud remaining revealed that the cunner trypsin fraction upheld the cloud stability of cloud juice better than bovine trypsin, with cunner trypsin retaining more than 90% of the cloud whereas the juice treated with bovine trypsin only resulted in a 70% retention of the juice cloud. (Abstract shortened by UMI.)

Energy utilization is a determining factor for the standards of living around the world, and the current primary source of energy is fossil fuels. A potential source of liquid fuels that could ease the strain caused by diminishing petroleum resources is bioethanol. Effective exploitation of biomass materials requires a pretreatment to disrupt the lignin and cellulose matrix. The pretreatment utilized for this research was oxygen delignification, which is a standard process stage in the production of bleached chemical pulp. The model substrate utilized as a feedstock for bioethanol was recovered fibre. An analysis of the substrates digestibility resulted in a hexose yield of approximately 23%, which justified the need for an effective pretreatment. An experimental design was performed to optimize the delignification conditions by performing experiments over a range of temperature, caustic loadings, and reaction times. Equations were developed that outline the dependence of various response parameters on the experimental variables. An empirical model that can predict sugar concentrations from enzymatic hydrolysis based on the Kappa number, enzyme loading, and initial fibre concentration was also developed. A study of hydrolysis feeding regimes for untreated recovered fibre (87 Kappa), pretreated recovered fibre (17 Kappa), and bleached pulp (6 Kappa) showed that the batch feeding regime offers reduced complexity and high sugar yields for lower Kappa substrates. In order to evaluate the possibility of lignin recovery, the pH of delignification liquor was reduced by the addition of CO₂ and H₂SO₄, resulting in up to 25% lignin yield. An experiment that looked at effect of post-delignification fibre washing on downstream hydrolysis found that a washing efficiency of approximately 90% is required in order to achieve a hexose sugar yield of 85%.

Thesis (Ph.D.)--McMaster University, 2002. / Advisor: R.S. Gupta. Includes bibliographical references. Also available via World Wide Web.

Thesis (Ph.D.)--McMaster University, 2002. / Advisor: R.S. Gupta. Includes bibliographical references. Also available via World Wide Web.

Thesis (M.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 98-108). Also available in electronic format on the Internet.

Thesis (Ph.D.) -- University of Rhode Island, 2008. / Typescript. Includes bibliographical references (leaves 107-114).

Thesis (Ph. D.)--Lund University, 1997. / Published dissertation.

Thesis (Ph. D.)--Lund University, 1997. / Published dissertation.

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-03-23T20:07:03Z No. of bitstreams: 1 MARCIO JOSÉ VASCONCELOS DA SILVA – TESE (PPGEP) 2017.pdf: 2886790 bytes, checksum: 4e2912ac8b6df6d1df2aeb12d63b2646 (MD5) / Made available in DSpace on 2018-03-23T20:07:03Z (GMT). No. of bitstreams: 1 MARCIO JOSÉ VASCONCELOS DA SILVA – TESE (PPGEP) 2017.pdf: 2886790 bytes, checksum: 4e2912ac8b6df6d1df2aeb12d63b2646 (MD5) Previous issue date: 2017-12-05 / Na busca por fontes de energia renováveis e alternativas que reduzam a emissão de gases nocivos ao meio ambiente, diminuindo assim o uso de combustíveis fósseis em face da conscientização global, os biocombustíveis são uma fonte alternativa de energia, sendo principal destaque o etanol de 1ª e 2ª geração. Objetivou-se neste trabalho avaliar o potencial de diferentes cultivares de sorgo doce (Sorghum bicolor (L.) Moench.) para produção de etanol de 1ª geração a partir da fermentação do caldo dos colmos e etanol de 2ª geração a partir do substrato (bagaço). Para obtenção dos açúcares fermentescíveis a partir do bagaço, utilizou-se pré-tratamento ácido seguido de básico com auxílio de uma matriz de planejamento experimental 2³+3 pontos centrais para avaliar os efeitos das variáveis de entrada, tempo, temperatura e concentrações de ácido e base, verificando a solubilização da hemicelulose e lignina. Para avaliar a hidrólise enzimática verificou-se, por meio da aplicação de uma matriz de planejamento experimental 2²+3 pontos centrais, o efeito da carga enzimática e a razão massa seca de bagaço de sorgo e extrato enzimático. Foram usadas as enzimas comerciais Celluclast 1.5L da Novozyme e betaglicosidase da Prozyn na hidrólise enzimática para obtenção de açúcares fermentescíveis. A pesquisa foi desenvolvida no laboratório de engenharia bioquímica – LEB, na Universidade Federal de Campina Grande – UFCG, no estado da Paráiba e no Instituto Agronômico de Pernambuco – IPA, ambas localizadas na região do nordeste Brasileiro, a colheita das progens foi realizada na Estação Experimental do IPA no município de Vitória de Santo Antão, localizado na Zona da Mata de Pernambuco (lat: 35° 22' W, long: 08° 08' S, altitude: 146 m) no período de março/2013 a setembro/2017. Os resultados referentes aos dados agronômicos apresentaram diferenças significativas para um intervalo de confiança de 95% pelo teste Tukey. Dentre as sete cultivares pesquisadas as que obtiveram maiores teores de sólidos solúveis totais em campo foram entre BRS506, IPA2502, IPA EP17, IPA P222, IPA P134, IPA P228 e IPA SF15 com valores entre 12,3±0,08; 5,1±0,10; 16,8±0,40; 14,8±0,11; 7,1±0,10; 9,2±0,10 e 13,6±0,27 ºBrix, respectivamente. Os resultados referentes a fração sacarina (caldo do sorgo sacarino) foram analisados usando o teste de Tukey para um intervalo de confiança de 95%. Nos dados encontrados para concentração de etanol de 1ª geração, obtidos na fermentação dos caldos das cultivares que se destacaram foram IPA SF15, BRS506, IPA EP17, IPA P222 e IPA P134 com valores entre 55,72 ± 0,24; 45,46 ± 1,5; 44,6 ± 0,18; 33,78 ± 0,57 e 31,78 ± 0,28 g.L-1 respectivamente. As frações (bagaço) para avaliação na produção de etanol de 2ª geração, as cultivares IPA EP17 e BRS506, após pré-tratamento ácido seguido de básico, mostraram-se eficientes em concentrar a celulose, pela solubilização da hemicelulose e lignina, acarretando um aumento da celulose de 31,70 ± 0,49 para 60,42 ± 0,91% na variedade IPA-EP17 e para variedade BRS506 de 40,6 ± 1,1 para 64,52 ± 0,82% respectivamente. Os resultados encontrados no processo de hidrólise enzimática dos bagaços das variedades IPA EP17 para produção de glicose foi de 26,23 g L-1, nas condições de carga enzimática e razão (relação massa seca de bagaço) por volume de meio reacional (25 FPU/g e 2%) no tempo de 36 h de hidrólise e rotação constante de 150 RPM, e para BRS506 a produção de glicose foi de 25,17 g L-1, nas condições de carga enzimática e razão (relação massa seca de bagaço) por volume de meio reacional (25 FPU/g e 2%) no tempo de 36 h de hidrólise. / In the search for renewable energy sources and alternatives that reduce the emission of harmful gases to the environment, thus reducing the use of fossil fuels in the face of global awareness, biofuels present as an alternative, the main highlight being ethanol. The objective of this work was to evaluate the potential of different cultivars of sweet sorghum (Sorghum bicolor (L.) Moench.) For the production of ethanol of 1st generation from the fermentation of the broth the 2st generation ethanol from the substrate (bagasse). To obtain the fermentable sugars from the bagasse, acid pretreatment followed by base with the aid of experimental planning 2³ + 3 central points was applied to evaluate the effects of the variables of entry, time, temperature and acid and base concentrations, verifying the solubilization of hemicellulose and lignin. In order to evaluate the enzymatic hydrolysis, the effect of the enzymatic loading and the dry mass ratio of sorghum bagasse and enzyme extract wereverified using experimental planning design 2² + 3 central points. The commercial enzymes Celluclast 1.5L from Novozyme and beta-glucosidase from Prozyn wereused in the enzymatic hydrolysis to obtain fermentable sugars. The research was carried out at the biochemical-engineering laboratory - LEB, at the Federal University of Campina Grande - UFCG, in the state of Paráiba and at the Agronomic Institute of Pernambuco - IPA, both located in the northeast region of Brazil. The progenies were collected at the IPA Experimental Station in the city of Vitória de Santo Antão, located in the Zona da Mata of Pernambuco (lat: 35 ° 22 'W, long: 08 ° 08' S, altitude: 146 m) from March / 2013 to September / 2017. The results concerning agronomic data presented significant differences for a 95% confidence interval by the Tukey test. Among the seven cultivars studied, the highest soluble solids in the field were BRS506, IPA2502, IPA EP17, IPA P222, IPA P134, IPA P228 and IPA SF15 with values between 12,3 ± 0,08; 5,1 ± 0,10; 16,8 ± 0,40; 14,8 ± 0,11; 7,1 ± 0,10; 9,2 ± 0,10 and 13,6 ± 0,27 °Brix, respectively. Results for saccharin fraction (sorghum broth) were analyzed using the Tukey's test for a 95% confidence interval. In the data obtained for the concentration of ethanol of 1st generation, obtained in the fermentation of the broths of the cultivars that stood out were IPA SF15, BRS506, IPA EP17, IPA P222 and IPA P134 with values between 55,72 ± 0,24; 45,46 ± 1,5; 44,6 ± 0,18; 33,78 ± 0,57 and 31,78 ± 0,28 g.L-1 respectively. The fractions (bagasse) for evaluation in the production of second generation ethanol, IPA EP17 and BRS506, after acid pretreatment followed by basic, were efficient in concentrating the cellulose by the solubilization of hemicellulose and lignin, resulting in an increase of cellulose from 31,70 ± 0,49 to 60,42 ± 0,91% in the variety IPA-EP17 and for the BRS506 variety from 40,6 ± 1,1 to 64,52 ± 0,82% respectively. The results obtained in the enzymatic hydrolysis process for the IPA EP17 variety in the glucose production were 26,23 g L-1, for enzyme loading conditions and ratio (bagasse dry mass ratio) per reaction medium volume (25 FPU / and 2%) in the time of 36 hours of hydrolysis and constant rotation of 150 RPM, for BRS506 variety the glucose production was 25,17 g.L-1, for the conditions of enzymatic loading and ratio (bagasse dry mass ratio) by volume of reaction medium (25 FPU / g and 2%) in the time of 36 hours of hydrolysis.

Master of Science / Department of Grain Science and Industry / Yonghui Li / Antioxidants are widely used in food industries to delay lipid oxidation and prevent oxidative deterioration. In recent years, growing interests in developing safe and efficient antioxidants from natural sources due to the health-related risks associated with synthetic antioxidants. Recently, peptide antioxidants have drawn growing interests as since proteins are a macronutrient with various functionalities and high consumer acceptability. A lot of dietary proteins have been validated for their antioxidant potentials especially those obtained from animal proteins, nuts and pulses. Relatively less information is available on characterizing the antioxidant profile of cereal protein, and even less for sorghum protein. Sorghum is the fifth largest crop worldwide and is the third in United States. U.S. is leading in global sorghum production and distribution, and the state of Kansas is producing nearly half of U.S. sorghum. Currently, about one third of the U.S. sorghum is being used for ethanol production, resulting in more than 450 kilotons of by-products (e.g., DDGS) annually, which were often discarded or underutilized. DDGS is a premium protein source (~ 30% protein) that could be potentially modified into value-added products such as peptide antioxidants. In this study, relevant literatures detailing the extraction of cereal proteins, enzymatic hydrolysis of proteins, purification and characterization of hydrolysates, and evaluation of antioxidant profiles were extensively reviewed in Chapter 1. As preliminary experiments, sorghum kafirin protein was extracted from defatted sorghum white flour and hydrolyzed by 10 different types of enzymes from microbial, plant and animal sources. Hydrolysates prepared with Neutrase, Alcalase, and Papain displayed the most promising antioxidant activities as well as total protein recovery were primarily selected and investigated in depth described in Chapter 2, Chapter 3, and Chapter 4. The reaction conditions including substrate content, enzyme-to-substrate ratio, and hydrolysis time are critical parameters in producing peptides with desired activity and consistency, were therefore examined and optimized for each case of kafirin hydrolysates. The antioxidant capacity of the resulting hydrolysates was measured for antioxidant capacity through in vitro assays (DPPH, ABTS, ORAC, reducing power, and metal chelating) and then demonstrated in model systems (oil-in-water emulsion and ground meat). The fractions of hydrolysates possessing strongest activities were further fractionated by gel filtration and HPLC. Peaks representing the largest areas from HPLC were identified for major sequences by MALDI-TOF-MS. The experiment results indicated that all the three selected fractions of kafirin hydrolysates revealed excellent inhibition effects against oil and fat oxidations, which could be employed as tools to predict their performances in real food products. In addition, the structure studies showed that medium-sized hydrolysates of Neutrase (3 – 10 kDa) and Alcalase (5 – 10 kDa), and small-sized hydrolysates of Papain (1 – 3 kDa) exhibited relatively stronger activities. This study provided a workable processing method and critical reaction parameters for the production of peptide antioxidants from sorghum protein. The experiment results revealed that the sorghum peptide antioxidant could act through multiple mechanisms including free radical scavenging, metal ion chelation, hydrogen donating, and forming physical barriers to minimize the contact of oxidative agents to targets. These antioxidative peptides are a promising ingredient that can be potentially incorporated to food and feed products as alternatives to synthetic antioxidants or synergetic elements to nonpeptic antioxidants for protection of susceptible food ingredients. This study also made a positive impact to sorghum ethanol industry by guiding the conversion of sorghum protein-rich by-products into value-added antioxidant products as an additional revenue stream.