Reações de oxidação lipídica são responsáveis pelo desenvolvimento de sabores e odores desagradáveis tornando os alimentos impróprios para consumo, sendo necessário o uso de antioxidantes. O ácido ascórbico (AA) é um antioxidante muito eficaz, que exibe função vitamínica, no entanto é relativamente instável. Com o objetivo de aumentar a estabilidade do AA e, consequentemente, facilitar sua aplicação em produtos alimentícios, os métodos de encapsulação por coacervação complexa e por dispositivos microfluídicos foram testados. Primeiramente foi apresentada a Revisão Bibliográfica no Capítulo 1, e em seguida, a encapsulação por coacervação complexa, como será visto no Capítulo 2. Neste caso, nove tratamentos foram obtidos utilizando-se gelatina e goma arábica como materiais de parede e analisados com relação à morfologia, por microscopia ótica e eletrônica de varredura, umidade, atividade de água, higroscopicidade, solubilidade, potencial zeta, espectroscopia no infravermelho por transformada de Fourier (Ftir), tamanho e distribuição de tamanho de partículas, cor instrumental, eficiência de encapsulação e estabilidade do material encapsulado. No capítulo 3 serão apresentados resultados obtidos na encapsulação do AA pelo método de dispositivos microfluídicos. Cinco tratamentos foram obtidos, sendo analisados com relação à morfologia, por microscopia ótica, eletrônica de varredura e confocal, eficiência de encapsulação, tamanho e distribuição de tamanho de partícula e estabilidade do material encapsulado. A obtenção das microcápsulas de AA pelos dois métodos citados foi viável uma vez que apresentaram altos valores de eficiência de encapsulação e ótima atuação em relação à proteção do AA durante estocagem. Comparando-se os dois métodos, as cápsulas obtidas por dispositivos microfluídicos conferiram melhor estabilidade ao ácido ascórbico, no entanto amostras obtidas por coacervação complexa foram aplicadas em salsicha devido a maior quantidade de AA presente em sua constituição. O efeito da aplicação das microcápsulas nas salsichas foi avaliado durante 40 dias de armazenamento refrigerado como será visto no Capítulo 4. Cinco tratamentos foram elaborados e analisados de acordo com a estabilidade da emulsão cárnea durante o processamento, umidade, atividade de água, alteração do pH, determinação da cor instrumental, perfil de textura instrumental, estabilidade oxidativa pelo método de substâncias reativas ao ácido tiobarbitúrico (TBARS) e aceitação sensorial. A aplicação das microcápsulas de AA em salsicha foi possível sem comprometer a qualidade do produto final. Todos os dados obtidos foram analisados estatisticamente por análise de variância ANOVA e teste de Tukey, ao nível de 5% de significância com auxílio do programa SAS. Os experimentos relacionados à encapsulação por coacervação complexa e aplicação das microcápsulas em salsicha foram realizados no Laboratório de Produtos Funcionais, nas dependências do Departamento de Engenharia de Alimentos da FZEA/USP. Os experimentos relacionados à utilização de dispositivos microfluídicos foram realizados nos laboratórios do professor David A. Weitz, da Escola de Engenharia e Ciências Aplicadas de Harvard, da Universidade de Harvard, Cambridge, Estados Unidos. / Lipid oxidation reactions are responsible for the development of unpleasant tastes and odors making food unfit for consumption. For this reason, the use of antioxidant is necessary. Ascorbic acid (AA) is a very effective antioxidant with vitamin function, however it is relatively unstable. With the aim of increasing the stability of AA and thus improve its application in food products, the methods of encapsulation by complex coacervation and microfluidic devices were tested. First of all the Literature Review is presented in Chapter 1. The encapsulation by complex coacervation can be seen in Chapter 2. For this methodology, nine treatments were obtained using gelatin and gum Arabic as encapsulant agent and analyzed regarding to morphology by optical and scanning electron microscopy, moisture, water activity, hygroscopicity, solubility, Zeta Potential, Fourier transform infrared Spectroscopy (FTIR), particle size and particle size distribution, instrumental color, encapsulation efficiency and stability of the encapsulated material. The results obtained for AA encapsulation by microfluidic device will be presented in Chapter 3. Five treatments were obtained and analyzed regarding to morphology by optical, scanning electron and confocal microscopy, encapsulation efficiency, particle size and particle size distribution and stability of the encapsulated material. The production of AA microcapsules by the two methods mentioned was feasible once that showed high levels of encapsulation efficiency and optimal performance regarding to the protection of AA during storage. Comparing the two methods, the microcapsules obtained by microfluidic device conferred better stability to AA, however samples obtained by complex coacervation were applied in sausage due to the greater amount of AA in its constitution. The effect of the application of microcapsules in sausages was evaluated during 40 days at refrigerated storage as it will be seen in Chapter 4. Five treatments were prepared and analyzed according to the stability of the meat emulsion during processing, moisture, water activity, pH changes, determination of instrumental color, instrumental texture profile, oxidative stability by the method of thiobarbituric acid reactive substances (TBARS) and sensory acceptance. The application of AA microcapsules in sausage was possible without compromising the quality of the final product. All data were statistically analyzed by ANOVA and Tukey test, at 5% of significance with the use of SAS software. The experiments related to encapsulation by complex coacervation and application of microcapsules in sausage were carried out at Laboratory of Functional Products, at Department of Food Engineering, FZEA / USP. The experiments related to the use of microfluidic devices were performed in the laboratories of Professor David A. Weitz, at School of Engineering and Applied Sciences of Harvard, at Harvard University, Cambridge, USA.

This master's thesis deals with the characterization of elderberry fruit (Sambucus nigra L.) with emphasis on the aroma active compounds (AAC) and vitamin C (ascorbic acid (AA), dehydroascorbic acid (DHA)). The theoretical part gives a brief outlook on the chemical composition and attributes of Sambucus berries, its healing properties and the means of processing. The rest of the theoretical part thoroughly examines the AAC and vitamin C. The suitable assessment methods are also discussed. The experimental part of the work consists of two main tasks. The first one was to assess the aroma profile of Sambucus berries using the HS-SPME-GC-FID. 18 samples were examined (the wild elderberry and 17 cultivated varieties). In total, 24 different volatile aroma active compounds were identified and quantified, 12 of which belonged to alcohols, 5 to aldehydes, 4 to esters, 1 to acids and 2 “other” compounds (linalool and -damascenone). The chemical composition of the individual samples was not uniform; no single sample contained all of the identified compounds. The second task was to assess the total vitamin C content (the sum of DHA and AA) using the HPLC. For the purpose of reducing DHA to AA three reducing agents were examined (DTT, TCEP and L-cysteine) at two different pH levels (7 and 4). TCEP at pH 4 turned out to be most efficient and was subsequently applied on the samples of 5 selected elderberry varieties. The measured vitamin C content was within the range of 5,1 – 13,0 mg per 100 g of fruit.

Objetivos: La presente tesis tuvo como objetivo general caracterizar nutricionalmente un néctar elaborado a partir de lactosuero dulce, y Myrciaria dubai (camu - camu) edulcorado con Sstevia rebaudiana (stevia). Materiales y métodos: Fue un estudio experimental de laboratorio, donde se evaluó el efecto de las dosis de lactosuero (30%, 50% y 70%) y pulpa de camu camu (70%, 50% y 30%) sobre sus propiedades nutricionales y sensoriales. Resultados: Los análisis físicoquímicos de las tres formulaciones cumplieron con los estándares de calidad para bebidas de frutas. La evaluación sensorial se realizó a 79 panelistas no entrenados, los cuales determinaron que la formulación que contenía 70% pulpa de camu - camu y 30% lactosuero fue la que presentó el mayor puntaje en la evaluación sensorial siendo solo de 2,5/7 en una escala hedónica, por lo que se recomienda mejorar las formulaciones. Discusión: El análisis físico químico de las bebidas formuladas mostró que el néctar a base de lactosuero con camu camu presentó en 100 gramos de producto un bajo nivel de calorías un promedio de 23 Kcal/ 100g, 5,3% de carbohidratos, 0,4% de proteína, 0,1% de grasa, 93,8% de agua, 0,4% de cenizas. El análisis microbiológico indicó que cumplen con la Norma sanitaria que establece los criterios microbiológicos de calidad para néctares, lo que garantiza la inocuidad del producto. Se realizó el análisis de vitamina C en la pulpa de camu-camu, la mezcla de la bebida antes de la pasteurización y luego de la pasteurización siendo estos: 195,8mg/100g, 180,7 mg/100g, 168,3mg/100g respectivamente observándose que en el producto final existe una disminución de alrededor del 14,04% con respecto al contenido inicial en el camu-camu. Conclusión: Las características nutricionales del néctar elaborado a partir de lactosuero, camu camu edulcorado con Stevia presentó un leve incremento en el valor de proteínas (0,3g/100ml) que los néctares comerciales (0g/100ml) que se expenden en el país, pero destaca por su contenido alto de vitamina C (168,3mg/100ml), sin embargo, la incorporación del lactosuero no resultó en una clara aceptabilidad sensorial en jóvenes por ende se rechaza la hipótesis que el lactosuero aumenta la aceptabilidad sensorial. Asimismo, se acepta la hipótesis que aumenta la calidad nutricional del néctar en comparación con bebidas similares que se expenden en el mercado nacional. / Objective: The aim of this thesis was to characterizing nutritionally a nectar elaborated from whey and Myrciaria dubai (camu - camu) sweetened with Stevia rebaudiana (stevia).Materials and Methods: It was an experimental laboratory study, where was evaluated the effect of the dose of whey (30%, 50% and 70%) and camu camu pulp (70%, 50% and 30%) on its sensory and nutritional properties. Results: The physical-chemical results of the three formulations got the quality standards for fruit beverage. The sensory evaluation was performed with 79 untrained panelists, who determined that the formulation contained 70% of camu-camu pulp and 30% of of whey it was the one that presented the highest score in the sensory evaluation being only 2.5 / 7 on a hedonic scale, so it is recommended to improve the formulations. Discussion: The physical chemical analysis of the formulated beverages showed that the whey-based nectar with camu camu showed a low calorie level in 100 grams of product, an average of 23 Kcal / 100g, 5.3% carbohydrates, 0.4% of protein, 0.1% fat, 93.8% water, 0.4% ash. The microbiological analysis indicated that they satisfy the sanitary norm that establishes the microbiological criteria of quality for nectars, which guarantees the safety of the product. We realized the analysis of vitamin C in the camu-camu pulp, in the mixture of the beverage, before the pasteurization and after the pasteurization, being these: 195,8mg / 100g, 180,7 mg / 100g, 168,3mg / 100g respectively, evidencing that in the final product there is a decrease of about 14,04% with respect to the initial content of camu -camu. Conclusion: The nutritional characteristics of the nectar made from whey, camu camu sweetened with Stevia presented a slight increase in the value of proteins (0.3g / 100ml) than commercial nectars (0g / 100ml) that are sold in the country, but it stands out Due to its high content of vitamin C (168.3mg / 100ml), however, the incorporation of whey did not result in a clear sensory acceptability in young people, therefore the hypothesis that whey increases sensory acceptability is rejected. Likewise, the hypothesis that increases the nutritional quality of nectar in comparison with similar beverages that are sold in the national market is accepted. / Tesis

This thesis deals with the evaluation of the available books and possibilities of the growing of sea buckthorn (Hippophaë rhamnoides L.) in the Czech Republic. Physical and chemical values which are necessary for planting sea buckthorn in the area of Lednice were measured and specified. The female plants of the species of ´Buchlovsky 1´, ´Hergo´, ´Leikora´, ´Vitamínová´, and the male plant of ´Buchlovsky 2´, ´Pollmix´ and ´Ruský´ were studied and evaluated. As for the products made of sea buckthorn, speads and juices with various amount of sugar, baked tea and sweetened sea buckthorn powder were evaluated from the sensory point of view. The issues of the growing and processing of s ea buckthorn were discussed with the producers of planting stock, commercial croppers and manufacturers within the whole Czech Republic. Sea buckthorn is not widespead and commercial area for growing does not meet the needs of the manufacturers. If all biotic and abiotic factors are taken into account, the growing of sea buckthorn is recommended in the Czech Republic.

The Diploma Thesis is focused on the analysis of the antioxidant qualities and attributes of different kinds of tea under their specific methods of preparation. Literature overview provides history, processing technology, distribution and the most common means of tea preparation as well as its content substances. The Thesis discusses the overall containment of polyphenols and antioxidant capacity based on the FRAP and DPPH methods but also the amount of vitamin C in the tea samples. The Thesis elaborates on the undertaken sensor analysis of chosen samples and examines the tea content substances during its traditional preparation as well as during its preparation in a non-typical way.

In the literary part this work focuses on the history, botanical classification and description of plants. The method of cultivation and harvesting is summarized. Described are varieties that can be use the practical part. It is the use of seabuckthorn and its contents. The experimental parts summarize and evaluate the possibilities of growing seabuckthorn on the experimental plot in Žabčice. Here were observed female varieties ´Aromat´, ´Augustinka´, ´Buchlovický 1´, ´Habeg´, ´Hergo´, ´Krasavice´, ´Leicora´, ´Perčik´, ´Sibirskij rumjaněc´, ´Sluníčko´, ´Trofimofský´ and ´Vitamínová´, male varieties ´Buchlovický 2´, ´Gnom´ and ´Polmix´. Habitat conditions of varieties and phenological phase were observed. The color, shape, weight and size of the fruit were assessed. Furthermore, yield and cubature shrubs. Vitamin C, dry matter and refractometric dry matter values were determined. Sensory properties of products were assessed.

The submitted thesis on the topic of Evaluation of Growth and Harvest Data of Kamchatka blueberries is focused on the description of possibilities of cultivation and using of individual varieties of edible honeysuckle. The evaluation and monitoring of planting took place on the property school agricultural enterprise in Žabčice, the laboratory pat and the evaluation of results took place in the laboratory of Mendel University in Brno. This thesis includes characteristic of genus Lonicera L., botanical description of genus Lonicera kamtschatica L., growing demands, multiplication possibilities, description of the most famous variety and results of observation of 27 varieties of edible honeysuckle. The height of the bush, cubic capacity of bush, annual increment and phenological phases were evaluated. To harvest parameters were monitored a height, fruit width, fruit weight, fruit shape shrub yield, content of refractometric dry matter,content of ascorbic acid and the total dry matter content of the fruit. The annex of this thesis comprise graphs and tables of recording of results. During the observation, a continuous documentation was taken, and it is used in the thesis.

The thesis „Determination of Vitamin C in Food Supplements“ is concerned with the comparison of vitamin C concentration levels in effervescent tablets and bulk mixtures stored in tubes with different closures (molecular sieve, silica gel, and the solitary closure) after a certain storage time. Two batches of dietary supplements for adult and juvenile populations were analyzed (Revital vitamin C 500 mg and MaxiVita Kids Multivitamin containing 40 mg of vitamin C). Measurements were taken 6 months after production, then after 10 months and after 14 months of storage. The content of vitamin C was determined by the titration method and high performance liquid chromatography (HPLC). The types of closures, batches of products, individual measurements and methods of vitamin C determination were compared. Based on the measurements, it was found that after some time the concentration of vitamin C decreased significantly. Nevertheless, the type of closure did not significantly affect the vitamin C level in effervescent tablets and bulk mixtures.

The ability of freshly prepared spinach or poke weed (Phytolacca americana) chloroplasts to photoreduce triphosphopyridine nucleotide (TPN) under anaerobic conditions decreased in the presence of ascorbate and 2,6-dichlorophenolindophenol (DPIP). On .aging the chloroplasts, however, addition of DPIP and ascorbate was required for a high rate of TPN photoreduction. Qualitatively similar results were obtained for photoreduction of DPN, indigo carmine, riboflavin-5'-phosphate and vitamin K3 . Addition of 3-(3,4-dichlorophenyl)-1,l-dimethylurea (DCMU) at 10-5 M to freshly prepared chloroplasts inhibited the photoreduction of TPN by more than 98 %, and activity was restored to 94 %o f the original value by addition of ascorbate and.DPIF. Hydroxylamine at 10-3 Mand ammonium ion at 0.17 M produced similar effects. Qualitatively similar results were obtained with .these three inhibitors for photoreduction of DPN, indigo , carmine, .riboflavin-5 1 -phosphate, vitamin K3, methyl red and tetrazolium blue. Cesium ion and orthophenanthroline produced inhibitory effects similar to those of DCMU, hydroxylamine and ammonium ion which responded analogously to the DPIP-ascorbate couple. The data substantiate the previously proposed idea that ascorbate is photooxidized in the absence of oxygen by the photochemical oxidizing equivalents produced by illuminated chloroplasts, with the dye DPIP· acting as intermediate electron carrier. With intact .chloroplasts 2 the oxidizing equivalents are utilized preferentially for oxidation of water to produce oxygen. Only after the oxygen-evolution .system becomes .inoperativec1;1.n the ascorbate-DPIP couple compete successfully for the oxidizing equivalents. ExPosure of chloroplasts . to . light for 20 minutes _prior to ,adding .a Hill oxidant resulted in a reduced photoreducin,g capacity in the Hill reaction with TPN, indigo .carmine .and tetrazoli:um blue. However, such a treatment .actually increased the photoreducing _ability of the chloroplasts in the presence of DPIP and .ascorbate. Chloroplasts were inactivated toward the Hill reaction .by a pH of 7.7 at 30°. This inactivation was .readily overcome by addition of ascorbate and DPIP, indicating that .the principal effect of this treatment was to inactivate the oxygen-evolution system. Since indigo carmine photoreduction is stabili.z-ed· much more by the presence of sucrose in the reaction mixture than the photoreduction of DPIP it is indicated that there are components in the electron transport system leading from the site of DPIP photoreduction to that of indigo carmine photoreduction which .are sensitiye to distilled water dilution. The photoreduction of TPN, PPN .and indigo carmine was stimulated by addition of cysteine, whereas reduced glutathione was without effect. Cysteine was unable to overcome the inhibitions of DCMU, hydroxylamine and ammonium ion and no stimulation was observed when cysteine was .added to the inhibited systems containing DPIP and ascorbate even though cysteine was capable of stimulating the uninhibited reaction containing the DI"IP-ascorbate couple. It was there3 fore concluded that cysteine acts by stabilizing or reacting with the oxygen-evolving system. Chloride-deficient chloroplasts .were stimulated by added chloride and cyanide in Hill reaction activities. Reaction .mixtures containing sufficient chloride to provide maximal stimulation were further stimulated by added cyanide, versene and Tris.

INTRODUCTION Tuberculosis remains a major public health threat globally and the Human Immunodeficiency Virus (HIV) pandemic afflicting developing and developed countries has resulted in enormous increases in tuberculosis infections worldwide. Researchers have previously documented very low plasma vitamin C levels in patients with active pulmonary tuberculosis. This was attributed to a number of factors including: accelerated turnover of vitamin C, shifts in plasma concentrations, increased collagen formation and tissue repair and decreased vitamin C intake. Vitamin C appears to have a role in steroid-genesis and catecholamine synthesis. Decreased plasma vitamin C levels may therefore impact on the stress hormone response and acute phase reaction of patients with active tuberculosis. AIM The primary aims of the study were to measure plasma vitamin C levels, as well as stress hormone levels and acute phase reaction in patients with newly diagnosed active pulmonary tuberculosis and control patients (without tuberculosis), to determine if there was any relationship between vitamin C levels and the levels of these other variables. METHODS AND MATERIALS This was a prospective study of seventy one (71) consecutive patients admitted to Helen Joseph Hospital (between March and October 2002) with newly diagnosed active pulmonary tuberculosis and eighty nine (89) control patients with medical conditions other than tuberculosis. Demographic, clinical and laboratory data were captured and analyzed using SPSS 7.5 soft-ware. Continuous variables were analyzed using students t-test. Categorical data were analyzed by non parametric analysis and Pearsons linear regression model was used to determine the correlation between vitamin C and the other variables in the two groups. RESULTS There were no differences in race, gender, age, suburb of residence and occupational distributions in the study group with tuberculosis compared to the control group. There were more smokers and consumers of alcohol in the control group (54 and 62 patients respectively) than in the study group (28 and 31 patients respectively). The study patients had lower blood pressure (average 90/40 mmHg versus 100/60 mmHg of controls), higher mean pulse rate (101.87 ± 15.14 beats/minute versus 82.92 ± 8.88 beats/minute, p< 0.01), higher mean temperature (38.66 ± 0.67oC versus 37.14 ± 0.44oC, p< 0.01), and lower body mass index (18.29 ± 3.80 Kg/ M2 versus 23.20 ± 5.35 Kg/ M2, p< 0.01). Laboratory data comparing study group and controls also showed marked differences as follows: White cell count (WCC) 8.68×106 / L ± 5.44 versus 11.00×106 / L ± 4.94, p = 0.01; Haemoglobin 9.56gm / dl ± 1.93 versus 12.92gm / dl ± 2.34, p < 0.01 and platelet count 369.21× 106/L ± 190.71 versus 295.94×106 / L ± 94.64, p = 0.01. White cell vitamin C levels (normal range – 20-40 μg/108 leucocytes) were low in half of the patients in both groups (study patients mean 29.85 ± 28.70μg/108 leucocytes versus controls 31.39 ± 30.24μg/108 leucocytes, p = NS). Plasma vitamin C levels were reduced (normal range 10-20 mg/ml) in both groups but more so in the controls (mean 3.87 ± 2.82 mg/ml versus 4.81 ± 3.21 mg / ml in study patients, p= 0.053). Mean cortisol levels were slightly higher in the study patients (448.11 ± 197.41ηmol/L) than controls (392.70 ± 191.25ηmol/L, p = NS). Norepinephrine levels were slightly higher in the study patients than controls (study patients mean 2531.61 ± 2043.60 ρmol/L versus 2178.98 ± 1719.98 ρmol/L of controls, p = NS). Dopamine levels were higher in the study patients than in the controls (468.42 ± 377.57 ρmol/L in study patients versus 293.37 ± 355.84 ρmol/L in controls, p = 0.01). Epinephrine levels were higher in the controls (control patients mean 680.64 ± 743.78 ρmol/L versus 449.41 ± 380.04 ρmol/L of the study patients, p = 0.03). Ferritin levels were much higher in the study patients compared with controls (study patients mean 3005.87 ± 5023.26 μg/L versus 466.51 ± 1774.76 μg/L of the controls, p<0.01) as were CRP levels (125.91 ± 54.77 mg/L in the study patients versus 77.22 ± 81.17 mg/L in the controls, p=0.01). Mean urine cotinine levels were 16.42 ± 24.26μM/L for controls and 9.28 ± 11.59 μM / L for the study patients (p=0.027). Correlation studies did not show any significant differences between the different variables. There was an inverse correlation between CRP levels and urine cotinine levels in the control group (R squared=0.058 and p= 0.024). DISCUSSION There were no differences in the demographic profile of the two groups. Smoking and alcohol consumption were more common in the control group than in the study patients. Over 90 % of patients in both groups had low plasma vitamin C levels, while half of the patients in each group had low white cell vitamin C levels. The low levels of vitamin C could be due to some of the reasons given above or possibly due to the fact that generally there are low levels in Africans for reasons that are not apparent. The control group had increased mean urine cotinine levels suggesting a possible influence of cigarette smoking on vitamin C homeostasis in these patients. In both groups, the majority of patients had normal cortisol levels as well as normal to high catecholamine levels. Also, Ferritin and CRP levels were much higher in the study group than in the controls. The low levels of vitamin C did not, however, have any relationship with stress hormone levels and acute phase reactants. CONCLUSION This study has reaffirmed low plasma and white cell vitamin C levels in patients with new onset pulmonary tuberculosis but has also found low levels in control patients with diseases other than pulmonary tuberculosis. The study demonstrates adequate stress hormone responses in tuberculosis patients, which was not different from non- tuberculosis patients. Acute phase responses were found to be of higher magnitude in tuberculosis patients than in the controls. There were, however, no correlations between plasma vitamin C and stress hormones or acute phase reactants.