A demanda por antioxidantes naturais vem aumentando devido à toxicidade de alguns antioxidantes sintéticos. Estudos vêm identificando antioxidantes de origem natural, como a proteína da soja, que é capaz de contribuir na melhoria de propriedades funcionais e biológicas de alimentos. A hidrólise enzimática da proteína de soja aumenta sua atividade antioxidante, assim como a capacidade emulsificante e a capacidade de formação de espuma. O objetivo deste trabalho foi o estudo da hidrólise da proteína de soja através de uma protease produzida por Chryseobacterium sp., a verificação da capacidade antioxidante e aplicação do hidrolisado em diferentes tipos de carnes para evitar a oxidação lipídica. A eficácia da hidrólise foi determinada através da proteína solúvel utilizando o método de Folin enquanto que a atividade antioxidante foi avaliada pelos métodos referentes à captura do radical DPPH e ABTS. Os hidrolisados foram adicionados em carne de porco e peixe e foi verificada a inibição da oxidação lipídica. A influência de três parâmetros (temperatura, pH, relação enzima/substrato) na hidrólise foi estudada através um experimento fatorial 23 . Como respostas foram avaliadas a atividade antioxidante (DPPH e ABTS), atividade quelante de ferro, proteína solúvel, capacidade de formação de espuma e capacidade emulsificante. Observou-se um aumento na concentração de proteína solúvel em função do tempo, sendo que os hidrolisados foram capazes de inibir tanto o radical DPPH quanto o ABTS. Os hidrolisados inibiram em parte a oxidação lipídica em carne suína e peixe. Ainda foi possível concluir que dependendo da finalidade para que se deseja o hidrolisado, diferentes condições devem ser utilizadas. Os resultados demonstram uma potencial aplicação da protease microbiana para gerar hidrolisados antioxidantes da proteína de soja. / The demand for natural antioxidants has been increasing due to the toxicity of some synthetic antioxidants. Studies have identified naturally occurring antioxidants, such as soy protein, which can contribute to improve functional and biological properties of food. Enzymatic hydrolysis of soy protein increases its antioxidant activity, as well as emulsifying capacity and foaming capacity. The purpose of this work was to study the hydrolysis of soy protein, verifying the antioxidant capacity, application of the hydrolysate in different types of meat and optimization of hydrolysis. The efficiency of hydrolysis was determined by the soluble protein by the method of Folin while the antioxidant activity was evaluated by the methods related to the capture of the radical DPPH and ABTS. The hydrolysates were added to pork and fish and the extent of lipid oxidation was determined by TBARS. In optimizing of the hydrolysis three parameters were varied (T, pH, enzyme substrate), it was applied to a surface response methodology for conducting trials using a 23 factorial experiment. As answers were evaluated antioxidant activity (DPPH and ABTS), iron chelating activity, Lowry, foaming capacity and emulsifying capacity. There was an increase in soluble protein concentration versus time, and the hydrolysates were able to inhibit both the ABTS and the DPPH radical. The hydrolysates were able of inhibit lipid oxidation in pork and fish. Was still possible to conclude that depending on the finality that will be given to hydrolysates different treatment conditions should be used. The results demonstrate a significant potential for application of microbial protease to generate antioxidants of hydrolyzed soy protein.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / The species Lippia alba (erva cidreira) is widely used in folk medicine. The composition of essential oil varies quantitative and qualitative, leading to the classification of different chemotypes. A rich pharmacological potential is related to the wide variation in chemical composition of these oils, which arouses the interest of researchers in establishing scientific explanations for such activities. The objective of this study was to evaluate the antimicrobial and antioxidant activities of essential oils of chemotype I, II and III, leaves of L. alba, and to investigate their possible relationships with the chemical composition of their essential oils. The chemical characterization of constituents of essential oils was performed using GC-MS by determining the percentage of constituents present in the samples. The antimicrobial activity of oils was determined by agar diffusion, and MIC and CLM methods by microdilution broth culture and plated on agar, respectively. The antioxidant activity was assessed by measurement of TBARS and by determining the activity of removal of free radicals by DPPH. Essential oils from leaves of L. alba were recognized by the presence of its major constituents in chemotype I (citral-myrcene), chemotype II (citral-limonene) and chemotype III (carvone-limonene). The three essential oils showed activity against S. aureus, even resistant, and C. albicans. For Gram-negative bacteria, the three chemotypes present action on the A. lwoffi; the chemotypes II and III inhibited the growth of A. baumannii, and only the chemotype II was that acted on E. coli ATCC 10536. The lowest MIC obtained for CLM and essential oils of chemotypes I, II and III were 0,312 and 0,625mg/mL, 0,312 and 0,312mg/mL and 0,625 and 0,625mg/mL, respectively. The diffusion technique in agar served as a preliminary step in determining the antimicrobial activity and MIC determination by broth dilution accompanied by reading of optical densities of cultures showed absorbance values similar to the positive control group by a certain concentration and then increased indicating a higher microbial growth. Three chemotypes of OELA reduced lipid peroxidation induced in the hippocampus and brain of rats, but showed no scavenging activity of free radicals measured by the DPPH test. Thus, the results suggest that essential oils of chemotype I, II and III of L. alba, have excellent antimicrobial activity, especially on S. aureus and C. albicans, whereas the diffusion method is an excellent screening method, the dilution method, by visual inspection and reading of absorbance, in addition to determine the MIC, the CLM and evaluate the kinetics of inhibition of microbial growth, the antioxidant potential shown OELA by the hippocampus and cortex of rats makes these products a potential pharmacological tool in the treatment of neurodegenerative diseases, however, for that additional studies are needed, and that differences in the composition of the oil is a factor to be considered important in studies pharmacological. / A espÃcie Lippia alba (erva-cidreira) à muito usada na medicina popular. A composiÃÃo de seu Ãleo essencial apresenta variaÃÃes quantitativas e qualitativas, levando à classificaÃÃo de diferentes quimiotipos. Um rico potencial farmacolÃgico està relacionado à ampla variaÃÃo na composiÃÃo quÃmica desses Ãleos, o que desperta o interesse de pesquisadores em estabelecer explicaÃÃes cientÃficas para tais atividades. O objetivo do trabalho foi avaliar as atividades antimicrobiana e antioxidante dos Ãleos essenciais dos quimiotipo I, II e III, de folhas, de L. alba, bem como investigar suas possÃveis relaÃÃes com a composiÃÃo quÃmica de seus Ãleos essenciais. A caracterizaÃÃo quÃmica dos constituintes dos Ãleos essenciais foi realizada utilizando a CG-MS, determinando-se a porcentagem dos constituintes presentes nas amostras. O potencial antimicrobiano dos Ãleos foi determinado pelo mÃtodo de difusÃo em Ãgar, e as CIM e CLM pelos mÃtodos da microdiluiÃÃo em caldo de cultura e do plaqueamento em Ãgar, respectivamente. A atividade antioxidante foi avaliada pela dosagem de TBARS e pela determinaÃÃo da atividade de remoÃÃo de radicais livres pelo DPPH. Os Ãleos essenciais das folhas de L. alba foram reconhecidos pela presenÃa de seus constituintes majoritÃrios em quimiotipo I (citral-mirceno); quimiotipo II (citral-limoneno) e quimiotipo III (carvona-limoneno). Os trÃs Ãleos essenciais apresentaram atividade sobre S. aureus, mesmo as multirresistentes, e C. albicans. Para as bactÃrias Gram-negativas, os trÃs quimiotipos apresentaram aÃÃo sobre o A. lwoffi; os quimiotipos II e III inibiram o crescimento do A. baumannii; e apenas o quimiotipo II foi que teve aÃÃo sobre E. coli ATCC 10536. As mais baixas CIM e CLM obtidas para os Ãleos essenciais dos quimiotipos I, II e III, foram de 0,312 e 0,625mg/mL, 0,312 e 0,312mg/mL e 0,625 e 0,625mg/mL, respectivamente. A tÃcnica de difusÃo em Ãgar serviu como uma etapa preliminar na determinaÃÃo do potencial antimicrobiano e a determinaÃÃo da CIM por diluiÃÃo em caldo acompanhada de leitura das densidades Ãticas das culturas, mostrou valores de absorbÃncias semelhantes ao grupo controle positivo atà uma determinada concentraÃÃo e entÃo aumentaram, indicando um maior crescimento microbiano. Os trÃs quimiotipos do OELA reduziram a peroxidaÃÃo lipÃdica induzida no hipocampo e cÃrebro de ratos, contudo nÃo apresentaram atividade seqÃestradora de radicais livres mensuradas atravÃs do teste do DPPH. Assim, os resultados sugerem que os Ãleos essenciais dos quimiotipo I, II e III de L. alba, possuem excelente atividade antimicrobiana, principalmente sobre S.aureus e C. albicans; que o mÃtodo de difusÃo à um excelente mÃtodo de triagem; que o mÃtodo da diluiÃÃo, por inspeÃÃo visual e leitura de absorbÃncia, permite determinar alem da CIM, a CLM e avaliar a cinÃtica de inibiÃÃo de crescimento microbiano; o potencial antioxidante mostrado pelo OELA no hipocampo e cÃrtex de rato, torna esses produtos uma ferramenta farmacolÃgica em potencial no tratamento de doenÃas neurodegenerativas, contudo, para isso estudos adicionais sÃo necessÃrios; e que as diferenÃas na composiÃÃo do Ãleo à um fator que deve ser considerado importante nos estudos farmacolÃgicos.

Os neutrófilos ou leucócitos polimorfonucleares (PMNs) são células fagocíticas com funções bactericida e fungicida altamente potentes. A destruição dos microrganismos invasores é realizada através da liberação de substâncias tóxicas presentes em seus grânulos e das espécies reativas de oxigênio (EROs) produzidas durante o metabolismo oxidativo dessas células. Apesar dos benefícios da atividade antimicrobiana, em situações de intensa ativação celular, a grande produção e liberação de compostos citotóxicos podem causar efeitos deletérios sobre os tecidos do hospedeiro, como parece ocorrer em doenças por imunocomplexos. O grande potencial dos antioxidantes para o tratamento e prevenção dessas doenças tem levado à pesquisa de novos compostos que atuam no processo inflamatório em que estão envolvidos os neutrófilos ativados. Dentre estes, destacam-se os naturais, em que se encontra a planta Baccharis dracunculifolia (Asteraceae), principal fonte botânica da própolis verde, sendo que a própolis possui diversas atividades biológicas conhecidas. Entretanto, a produção de metabólitos secundários pelas plantas pode ser modificada de acordo com fatores sazonais o que dificulta os estudos e pode acarretar em alterações de atividade biológica. Desta forma, este trabalho avaliou o efeito da sazonalidade no perfil químico de B. dracunculifolia e na atividade desta planta sobre o metabolismo oxidativo de PMNs. Para isso, extratos etanólicos brutos das folhas de B. dracunculifolia (EEBBd), colhidas mensalmente durante 14 meses foram submetidos à ensaios de cromatografia líquida de alta eficiência (CLAE), e avaliados quanto à capacidade de inibir a quimioluminescência dependente de luminol (QLlum) e de lucigenina (QLluc) produzida por PMNs estimulados. Além disso, para desvendar o(s) possível(is) mecanismo(s) de ação responsável(is) pela atividade antioxidante, foram realizados, com a amostra mais ativa em inibir a QL, ensaios para avaliar a citotoxicidade, a atividade scavenger de radicais livres (DPPH) e a ação sobre a atividade da enzima NADPH oxidase. Os resultados mostraram que todos os EEBBd inibiram tanto a QLlum quanto a QLluc de forma dependente da concentração e que para ambos os ensaios houve variação na eficiência deste efeito biológico ao longo do período de tempo estudado, demonstrando que a sazonalidade desempenhou um papel importante na intensidade da atividade antioxidante dos extratos. O ensaio de CLAE permitiu análise dos seguintes compostos: ácido caféico, ácido p-cumárico, aromadendrina-4-metil éter, isosakuranetina e artepilin C, e revelaram que apesar de não haver notória variação qualitativa entre os componentes, foi observada grande diferença quantitativa. As análises com a amostra do mês de maior atividade antioxidante (Maio/07) revelou que esta foi colhida durante um período de baixo índice pluviométrico, temperaturas amenas e apresentou a menor concentração da maioria dos compostos fenólicos estudados, evidenciando que tais compostos não foram os maiores responsáveis pela atividade biológica da amostra e que alguns desses compostos podem ter atuado como pró-oxidantes. Além disso, foi verificado que esta amostra atuou de forma não tóxica sobre as células, através da captação de parte das EROs geradas no meio reacional e de inibição parcial da atividade da NADPH oxidase. / Neutrophils or polymorphonuclear (PMN) are phagocytic cells with potent bactericidal and fungicidal functions. The destruction of invading microorganisms is made by the release of toxic substances contained within their granules and by the reactive oxygen species (ROS) produced during the oxidative metabolism of these cells. Despite the benefits of antimicrobial activity, in situations of intense cellular activation, large production and release of toxic compounds may cause deleterious effects on host tissue, as it seems to occur in immune complex diseases. The great potential of the antioxidants for the treatment and prevention of these diseases has led to the search of new compounds that act in the inflammatory process where are involved the activated neutrophils. Within this context, natural products are highlighted, mainly plants, among which is the Baccharis dracunculifolia (Asteraceae), the main botanical source of green propolis, which has several activities already known. However, secondary metabolites of plants can be modified according to seasonal factors, what can difficult the studies and alter the biological activity results. Thus, this study evaluated the effect of seasonality in the chemical profile of B. dracunculifolia and in the activity of this plant on the oxidative metabolism of PMNs. For this, crude ethanolic extracts of B. dracunculifolia leaves (CEEBd), harvested monthly for 14 months were analyzed in high performance liquid chromatography (HPLC) and evaluated for their ability to inhibit the luminol- and lucigenin-dependent chemiluminescence (CLlum and CLluc, respectively) produced by stimulated PMNs. In addiction, to understand the possible mechanisms of action responsible for antioxidant effect, the most active sample in the CL test was evaluated for the following proprieties: cytotoxic, scavenger of free radicals (DPPH) and action on the NADPH oxidase activity. The results showed that all CEEBd inhibited both CLlum and CLluc in a concentration-dependent manner and that in both trials it was found variation in the biological effect over the study period, indicating that the seasonality played an important role on the intensity of the antioxidant activity of the extracts. The HPLC assay allowed the analysis of the following compounds: caffeic acid, p-coumaric acid, aromadendrin-4\'-methyl ether, isosakuranetin and artepillin C, and showed that although there was no evident variation in qualitative profile, it was observed large quantitative differences. The analysis of the sample of greatest antioxidant activity (May/07) revealed that it was harvested during a period of low rainfall, mild temperatures and had lower concentrations of most compounds studied, indicating that these compounds were not the most responsible for the biological activity of the sample and that some of these substances may have acted as pro-oxidants molecules. Furthermore, it was found that this sample works in a non-toxic manner on cells, by capturing some of the ROS generated in the reaction medium and by partial inhibition of NADPH oxidase activity.

Honey has been shown to have bioactivity. Fynbos (FB) honey was investigated for its bioactivity as this vegetation type is from a unique bio diverse region in the Cape Floristic Kingdom. Six FB and one medical grade Manuka (MAN) UMF 15+ honeys that were of quality grade (Codex Alimentarius) were used. Each honey sample was subjected to in vitro simulated gastro-duodenal digestion and the antioxidant and anti-inflammatory activity of each fraction was determined. These fractions were undigested/raw honey (UD), gastric digest (GD) and gastro-duodenal digest (GDD). Included were pH and digestive enzyme controls. The total polyphenol and the flavonoid content (TPC and TFC) were determined with the Folin-Ciocalteu (F-C) and aluminium chloride methods respectively. Antioxidant activity was measured with the trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays. Cellular antioxidant activity (CAA) in the Caco-2 and SC-1 cell lines using the dichloroflourescein diacetate (DCFH DA) assay was investigated. Nitric oxide (NO) scavenging activity was determined with the sodium nitroprusside (SNP) assay. Pro-inflammatory and anti-inflammatory effects of honey were evaluated in non-stimulated and stimulated with LPS/IFN γ murine macrophage RAW 264.7 cells, respectively. Cell viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was done. TPC and TFC of MAN were higher than that of FB honeys. With GD, TPC and TFC of MAN increased and following GDD, TPC decreased and TFC remained unchanged. In contrast TPC and TFC of FB honey were maintained with GD and GDD. TEAC assay revealed activity by MAN being higher than that of FB honeys. With GD digestion, the antioxidant activity of MAN was unchanged but following GDD, activity was reduced. For FB honeys, TEAC was maintained with GD and GDD. ORAC assay revealed that the activity of MAN was similar to that of FB. Digestion had no effect on activity of both MAN and FB honeys. CAA in the Caco-2 and SC-1 cell line was higher for MAN compared to FB honey. In both cell lines a similar trend was observed where with GD, CAA was unchanged while with GDD, CAA was reduced. This loss of CAA following GDD was found to be due to H2O2 formation as a result of polyphenol degradation in an alkaline environment containing sodium bicarbonate and pancreatin. NO scavenging activity of MAN was greater than FB. For both types of honey with GD, NO scavenging activity was unchanged and with GDD for MAN was reduced and for FB unchanged. Digestion showed an increased pro-inflammatory effect for MAN, FB1, FB2 and FB3. The UD fractions of MAN, FB1 and FB6 had anti-inflammatory effects. FB5 and FB6 honeys showed increased anti-inflammatory activity after GD and GDD. All honey fractions did not show any cytotoxicity. In conclusion, FB honey has antioxidant, pro- and anti-inflammatory properties. With digestion, GD activity was either increased or unchanged while with GDD activity was reduced, lost or unchanged. Observed effects were either due to pH and/or digestive enzyme activity. FB honey with its shown bioactivity could be an important local nutraceutical product. / Dissertation (MSc)--University of Pretoria, 2017. / Anatomy / MSc / Unrestricted

Magister Scientiae - MSc / The overall aims of this project were to assess the pharmaceutical quality and consistency of commercially available solid dose Sutherlandia frutescens containing products (viz. tablets & capsules) by exploring the use of monitoring the pharmaceutical presentation, flavonoid profile and antioxidant activity levels and to develop/or adapt methods and specifications that may be used for the quality control of such products.Stability tests were conducted on all of the selected SCP. The products were stored under elevated temperatures and environmental humidity conditions and total phenol, antioxidant and chromatographic analysis was conducted on these samples. Samples of each of the SCP were hydrolyzed using HCL and then analyzed using HPLC to test the stability of the flavonoids present in each product. The SCP investigated in this study physically appeared to be of quite good “pharmaceutical” quality, but generally lacked information on the date of manufacture and lacked package inserts, or when these were present they contained insufficient information. Based on the results obtained, it is recommended that, the manufacturers of SCP pay more attention to the information provided on the package inserts and the storage conditions for their products. Further the levels of antioxidant activity, total phenols and flavonoid (sutherlandins A to D) be used as specifications to control the quality of commercially available solid dose Sutherlandia frutescens containing preparations on an individual basis. / South Africa

>Magister Scientiae - MSc / Flavonoids, one of the biggest classes of secondary metabolites, are found abundantly in nature in a broad range of fruits, vegetables and beverages such as tea, coffee, beer, wine and fruit drinks. Flavonoids have been reported to exert multiple biological functions as well as tremendous pharmacological activity, including anticancer activity, protection, antioxidant activity, cardiovascular protection, antibacterial, antifungal and antiviral activity. The antioxidant activity of flavones is reported to be associated with those bearing hydroxyl functions. In the present study, several reaction steps have been carried out to synthesize three sub classes of flavonoids namely; chalcones, dihydrochalcones and flavanones with various substituents attached. The first step involved protection of hydroxyl groups of acetophenone and benaldehyde as starting materials. Thereafter the Clasien Schmidt condensation reaction, under basic conditions, was performed to afford chalcone intermediates. Treatment of these chalcones with sodium acetate, under reflux, afforded flavanones as a single product in high yields. Thereafter all protecting groups where removed to yield the final products. All products and intermediates where purified by column chromatography and were characterized by Nuclear Magnetic Resonance Spectroscopy (NMR) (1H NMR and 13C NMR). An electrochemical analysis on all flavonoid compounds was performed by Cyclic Voltammetry (CV) and Square Wave Voltammetry (SWV) to give information on the accessible redox couples identified by their oxidation potentials. Oxidation potentials, which gave valuable information about reducing ability and hence the antioxidant activity, where used to compare all compounds. The antioxidant activity was observed to increase with the addition of hydroxyl groups on the B-ring. Compounds with a combination of hydroxyl groups on the A-ring and methoxy groups on the B-ring showed increased antioxidant activity when compared to those with only hydroxyl groups on the base structure. 2, 5, 4’-trihydroxy dihydrochalcone showed moderate antioxidant ability. However the 2, 5, 4’-trihydroxychalcone, containing the α, β unsaturated double bond, proved to have the greatest antioxidant ability.

Phenolics in finger millet (FM) grain, including tannins, may impact significantly on its antimicrobial properties, functionality and health-promoting potential. Unfortunately, the location of tannins in the grain is unknown and there is limited information on the influence of variety on grain phenolic composition and antioxidant activity (AA). The effect of phenolics in FM grain on its malt fungal load and on the functional quality of its food products, including baked goods, is barely known. Twenty two FM grain types of varied visual kernel colour were analysed to determine the influence of grain type on phenolic composition, AA, and tannin localisation in the grain. Condensed tannins, anthocyanins and flavan-4-ols were detected. Light coloured grain types had no tannins and had much lower total phenolics (TP) relative to the pigmented types, and types that stained black with the Bleach test had much higher tannin content and much higher AA. The grains that stained black with the Bleach test and had high tannin content (0.60 to 2.08 mg catechin eqivalents/100 mg, db) had a dark coloured testa layer, indicating that the tannins were located in that layer. The results indicate that occurrence of tannins in FM is a varietal property and the tannins are predominantly responsible for the AA of the grain. Germinative energy (GE), enzymic activity, and total fungal count [TFC], and infection levels of 12 FM grain types of varied phenolic content were measured to determine the impact of phenolics in FM grain on its malt quality. The malt quality of high-phenol FM types was much higher than that of the low-phenol types, with respect to enzymic activity. TFC was negatively correlated with grain total phenolics (TP) and amount of phenolic type (APT) and there were some negative correlations between fungal species infection levels and TP and APT (p<0.05). GE and enzymic activity were positively correlated with TP and APT (p<0.05) and negatively correlated with TFC (p<0.01). The data indicate that phenolics in FM grain impact positively on its malt quality by contributing to its antifungal activity. Cookies in which wheat cake flour was substituted with 15, 35 and 55% (w/w) of either a non-tannin or a high-tannin FM flour were analysed to assess the impact of FM phenolics on cookie quality and AA (health-promoting potential). FM-substituted cookies, particularly those with high levels of the high-tannin FM, were inferior to cake flour cookies (control), with respect to spread, texture and integrity and their dark colour decreased their acceptance by a consumer panel. However, the acceptability of cookies containing up to 35% of either FM type was similar to that of control cookies. Cookies containing the high-tannin FM had antioxidant activities that were similar to or higher than the antioxidant activities of several plant products on the market. Thus, potentially health-promoting cookies can be made by substituting up to approximately 35% wheat with a high-tannin FM. The study indicates that high-phenol FM grain types have good malt quality, which is partly due to the antifungal activity of their phenolics. Although FM phenolics, particularly tannins, seem to affect cookie quality negatively, they contribute significantly to their health-promoting potential. / Thesis (PhD)--University of Pretoria, 2009. / Food Science / unrestricted

Amongst cereals, sorghum is one of the major sources of phenolic compounds. South African cultivars have not been profiled for their phenolic content and antioxidant activity to highlight their potential benefits. Thus, South African sorghum cultivars representing different sorghum types were evaluated for total phenolic content, condensed tannin content and antioxidant activity and the effect of cultivar on their antioxidant activity. The presence of phenolic antioxidants in the different sorghum cultivars, created an opportunity to develop a sorghum product as a vector of the antioxidants. Cookies were a product of choice due to their shelf stability and high nutrient density. Sorghum cookies were produced from 70%, 90% and 100% extraction rate flours. The effects of flour extraction rates and cultivar on the total phenolic content, condensed tannin content and antioxidant activity of the cookies were determined. Consumer sensory evaluation was used to evaluate sorghum cookie acceptability against a wheat flour cookie. Total phenolic content of the cultivars, determined by the Folin-Ciocalteu method was 0.20 to 1.42 g catechin equivalents (CE)/100 g. The total phenolic content was 3 to 7 times higher in condensed tannin cultivars than in tannin-free cultivars. Using the modified Vanillin-HCl method, condensed tannins were only measurable in the condensed tannin cultivars. They ranged between 5.16 and 8.39 g CE/100 g. Subsequently, the antioxidant activity of the condensed tannin cultivars measured by the ABTS radical scavenging assay was up to 4 times higher than in the tannin-free cultivars. The high phenolic content and antioxidant activity of condensed tannin cultivars was attributed to the contribution of condensed tannins. Therefore, condensed tannin cultivars are a major source of antioxidants compared to tannin-free cultivars. For each sorghum cultivar, cookies of 100% extraction rate flours had 2 to 3 times higher total phenolics compared to those of 70% extraction rate flours, while antioxidant activity was 2 to 10 times higher. Cookies of the condensed tannin sorghum had 2 to 5 times more phenolics compared to those of condensed tannin-free sorghum. Antioxidant activity was 145 to 227 ìMol Trolox equivalents (TE)/g in cookies of condensed tannin sorghum compared to 10 to 102 ìMol TE/g in those of condensed tannin-free sorghum. Processing sorghum flours to cookies seemed to reduce phenolic and antioxidant activity, but considering the flour component in the formula, cookie antioxidant activity was slightly higher than that of flours. The texture of all sorghum cookies was less acceptable compared to that of wheat cookies. The consumers showed a slight overall liking of the condensed tannin-free sorghum and wheat flour cookies. The cookies from condensed tannin flours were neither liked nor disliked. Since generally wheat flour is used for making cookies, the similarities in the overall liking of the condensed tannin-free sorghum cookies and the wheat flour cookies indicate strong potential of sorghum flour for cookie making. Therefore, sorghum cookies have a potential as a functional ready-to-eat snack, with target consumers such as school children in feeding schemes to improve their health and nutrition status. / Dissertation (MSc)--University of Pretoria, 2009. / Food Science / unrestricted

O pequi caracteriza-se por possuir expressiva quantidade de compostos fenólicos, que por apresentarem propriedades antioxidantes estão associados com a prevenção da formação de radicais livres. Além de ser consumido in natura, é também comumente consumido na forma processada. No entanto, sabe-se que os antioxidantes presentes nos vegetais podem ser afetados pela forma de processamento e provocam alterações dos teores de fenólicos totais (FT) bem como da sua atividade antioxidante. Este trabalho objetivou avaliar o teor de FT e as propriedades antioxidantes da polpa do pequi processado e in natura. Foram obtidos os extratos alcoólicos (EALC) e aquosos (EAQ), a partir de amostras liofilizadas de diversas polpas de pequi processado (em conserva) e também do in natura, bem como as frações de ácidos fenólicos livres (AFL), ésteres solúveis de ácidos fenólicos (AFS) e ésteres insolúveis de ácidos fenólicos (AFI) de pequi processado (CB1). Os EALC e EAQ, além dos líquidos provenientes das conservas (LC), foram avaliados quanto aos teores de FT, onde se verificou que os EAQ do pequi in natura, principalmente, e do processado tiveram um maior conteúdo de FT quando comparados aos EALC. Os LC, por sua vez, apresentaram valores médios ainda maiores que os EAQ. Com relação ao teor de FT das frações, a AFL se destacou diante da AFS e AFI. Os extratos, LC e frações foram avaliados quanto à atividade antioxidante in vitro pelo sistema &#946;-caroteno/ácido linoléico e também pelo ensaio do radical DPPH&#8226; (2,2 difenil-1-picril-hidrazila). No primeiro, verificou-se que os EAQ e LC do pequi apresentaram maior atividade que os EALC. Foi observada ainda atividade elevada em todas as frações analisadas. No segundo ensaio pelo método do radical DPPH&#8226;, pode-se observar que os extratos aquosos do pequi in natura apresentaram maior atividade, enquanto que, no pequi processado, os extratos alcoólicos e os líquidos das conservas tiveram melhores resultados. Verificou-se também que a AFL possui atividade superior às outras frações. De uma maneira geral, os resultados do pequi processado foram inferiores aos do pequi in natura tanto em relação aos teores de FT como na atividade antioxidante. Verificando-se ainda, que isto se deve principalmente à perda dos FT da polpa, indicando que houve lixiviação destes compostos para os LC. / Pequi characterized by having a significant amount of phenolic compounds, that are related with its antioxidant properties that are associated with the prevention of free radicals. Besides being eaten fresh, it is also widely consumed in processed form. However, it is known that the antioxidants present in plants can be affected by processing form and cause changes in the levels of total phenolic content (FT) and the antioxidant activity. The objective of this study was to evaluate the content of phenolic compounds and the antioxidant properties of the pequi pulp processed and fresh. Were obtained the alcoholic (EALC) and aqueous (EAQ) extracts from lyophilized samples of various pulps pequi processed (canned) and also in nature, as well as the fractions of free phenolic acids (AFL), soluble esters of phenolic acids (AFS) and insoluble esters of phenolic acids (AFI) of processed pequi (CB1). The EALC and EAq, besides the liquid from the canned (LC) were evaluated for the levels of FT, where it was found that the EAQ of the pequi in nature, mainly, and of the processed had, in general, a higher content of FT compared to EALC. The LC, in turn have showed that even greater EAQ. Regarding the content of FT of the fractions, the AFL stood in front of the AFS and AFI. The extracts, LC and fractions were also evaluated for their antioxidant activity in vitro by the system &#946;-caroteno/ linoleic acid and by test DPPH&#8226; (2,2-diphenyl-1-picryl hydrazyl). At first, it was found that the LC and EAQ of the pequi showed greater activity than the EALC. Still high activity was observed in all fractions analyzed. In the second test, we can observe that the EAQ of the pequi in nature showed greater activity, whereas in pequi processed, the EALC and LC had better results. It was also noted that the AFL has superior activity to other fractions. In general, the results of pequi processed were lower than in fresh pequi both in relation to content of FT as antioxidant activity. Verifying also, that this is mainly due to the loss of FT of the pulp, indicating that there was leaching of these compounds to the LC.

O crescimento da produção e comercialização de pescado gera um aumento considerável na quantidade de resíduos. A escassez de reutilização e as formas incorretas de descarte tem sido preocupação constante das indústrias e dos pesquisadores, que buscam soluções para a melhor destinação dos mesmos. Buscando o conceito de empresa eco eficiente, são propostos tratamentos que levem à obtenção de coprodutos. A produção de \"farinha de peixe\" é a forma de aproveitamento do resíduo mais utilizada, porém apresenta baixo valor comercial. A elaboração de hidrolisados proteicos apresenta-se como uma alternativa de maior valor agregado. A clivagem proteica realizada por enzimas específicas pode gerar peptídeos biologicamente ativos, que apresentam propriedades funcionais e medicinais, bem como atividade antioxidante. O objetivo deste trabalho foi a elaboração e caracterização de hidrolisados proteicos de cabeças de tilápia (Oreochromis niloticus), a aferição da atividade antioxidante destes e sua relação com o tamanho de peptídeos, como forma de se obter e disponibilizar coprodutos, visando a sustentabilidade da cadeia produtiva desta espécie. O hidrolisado proteico de tilápia (HPT) foi obtido por hidrólise enzimática e empregando as enzimas Neutrase (Protemax NP-800), Papaína (Brauzyn-100) e Pepsina nos tempos 30, 60 e 120 minutos. O grau de hidrólise foi determinado através da metodologia com utilização do o-ftaldialdeído. A atividade antioxidante foi avaliada pelos ensaios do DPPH e ABTS+. O perfil de peptídeos foi avaliado através da separação por cromatografia em gel com coluna Superdex peptide. O grau de hidrólise para os tratamentos com a neutrase (30 min, 60 min, 120min) variou de 11,3% a 14,1%. No tratamento com a papaína (30 min, 60 min, 120 min) o grau de hidrólise foi superior ao observado com a enzima neutrase, apresentando variação de 21,14%a 25,28%. A variação para o tratamento com a pepsina (30 min, 60 min e 120 min) foi de 10,18% a 14,97% Todos os hidrolisados apresentaram propriedade antioxidante através da inibição de radicais livres, mesmo a concentrações baixas de hidrolisado. A inibição de 50% (EC50) dos radicais na metodologia de DPPH ocorreu com concentrações inferiores a 3mg/mL para todos os tratamentos, sendo a menor concentração 1,36 mg/mL (pepsina 120 min) e a maior 2,70 mg/mL (neutrase 30 min). Na metodologia de ABTS, concentrações superiores foram necessárias para a inibição de 50% dos radicais, porém ainda assim foram inferiores a 5%. A menor concentração foi 3,58 mg/mL (pepsina 120 min) e a maior foi de 4,49 mg/mL (neutrase 60 min). O tamanho das cadeias de peptídeos para a maioria dos tratamentos se situou entre cadeias de 1000 a 10000Da, sendo que o tratamento com pepsina promoveu porcentagem de peptídeos com maior peso molecular seguido pela neutrase. A papaína foi a enzima que promoveu maior clivagem de proteína e menores tamanhos de peptídeos, localizados na faixa de 100 a 1000 Da, valor relacionado ao seu maior grau de hidrólise. As propriedades observadas nos hidrolisados elaborados indicam que este pode ser um potencial suplemento alimentício devido ao seu elevado valor proteico, aditivos para conservação de alimentos e ainda aplicados na indústria farmacêutica. / The growth in production and marketing of fish generates a considerable increase in the amount of waste. The scarcity of re-used products and incorrect disposal forms has been a constant concern of industries and researchers who seek solutions for better allocation thereof. Seeking an efficient eco company concept, proposed treatments are leading to obtaining co-products. The production of \"fish meal\" with the residues is the most common use for the waste, but has a low commercial value. The preparation of protein hydrolysates is presented as an alternative with higher added value. The protein cleavage performed by specific enzymes can generate biologically active peptides which exhibit functional and medicinal properties as well as antioxidant activity. The objective of this work was the preparation and characterization of protein hydrolysates of tilapia (Oreochromis niloticus) , the measurement of antioxidant activity of these and its relation to the size of peptides as a way to obtain and provide co-products , aimed at the sustainability of the chain production of this species. The protein hydrolyzate of tilapia (HPT) was obtained by enzymatic hydrolysis and employing the enzyme Neutrase (Protemax NP- 800), Papain (Brauzyn - 100) and Pepsin at 30, 60 and 120 minutes. The degree of hydrolysis was determined using o- phthaldialdehyde . In the treatment with papain (30 min, 60 min, 120 min) the degree of hydrolysis was higher than that observed with Neutrase enzyme, showing variation of 21.14% to 25.28%. The variation for treatment with pepsin (30 min, 60 min and 120 min) was 10.18% and 14.97% hydrolyzed. All samples showed antioxidant properties through inhibition of free radicals, even at low concentrations hydrolyzate. The 50% inhibition (EC50) of the DPPH radical methodology occurred at concentrations below 3 mg / ml for all treatments, being the lowest concentration 1.36 mg / ml (lot 120 min) and the largest 2.70 mg / ml (Neutrase 30 min). In the ABTS method, higher concentrations were required for 50% inhibition of the radical, but still was less than 5%. The lowest concentration was 3.58 mg / mL (120 pepsin min) and the largest was 4.49 mg / mL (Neutrase 60 min). The size of the peptide chains to most treatments ranged from 1000 to 10000Da chains, whereas treatment with pepsin promoted percentage of peptides of higher molecular weight followed by Neutrase. The papain was the enzyme cleavage that generated more protein and peptides of smaller size, situated in the range from 100 to 1000 Da, which is related to the higher degree of hydrolysis. The properties observed in hydrolysates produced indicate that this is a potential food supplement because of its high protein value for food preservation additives, and applied in the pharmaceutical industry.