Yeung Kit Ying. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 98-106). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / List of Abbreviations --- p.iv / List of Tables --- p.v / List of Figures --- p.vi / Chapter 1 --- Introduction / Chapter 1.1 --- Botany --- p.1 / Chapter 1.2 --- Food additives and food preservation --- p.2 / Chapter 1.2.1 --- Lipid peroxidation --- p.2 / Chapter 1.2.2 --- Role of food antioxidant --- p.4 / Chapter 1.2.3 --- Microbial spoilage --- p.5 / Chapter 1.2.4 --- Additives in future --- p.6 / Chapter 1.3 --- Antioxidant and health benefits effects --- p.7 / Chapter 1.4 --- Measurement of antioxidants --- p.7 / Chapter 1.4.1 --- Trolox equivalent antioxidant capacity (TEAC) assay --- p.8 / Chapter 1.4.2 --- DPPH radical scavenging assay --- p.9 / Chapter 1.4.3 --- β-carotene bleaching assay --- p.9 / Chapter 1.4.4 --- Assay for erythrocyte hemolysis mediated by peroxyl free radicals --- p.10 / Chapter 1.4.5 --- Measurement of lipid peroxidation in foods --- p.10 / Chapter 1.5 --- Antiproloiferative studies --- p.12 / Chapter 1.5.1 --- MTT assay --- p.12 / Chapter 1.5.2 --- Cell Proliferation ELISA-BrdU (chemiluminescence) assay --- p.13 / Chapter 1.5.3 --- Cytotoxicity detection assay (LDH) --- p.13 / Chapter 1.6 --- Characterization of phenolic compounds --- p.14 / Chapter 1.6.1 --- Sephadex column chromatography --- p.14 / Chapter 1.6.2 --- Folin and Ciocalteu's assay --- p.15 / Chapter 1.7 --- Research objectives --- p.15 / Chapter 2 --- Materials and Methods / Chapter 2.1 --- Standards and reagents --- p.22 / Chapter 2.2 --- Plant materials --- p.23 / Chapter 2.3 --- Pigment preparation --- p.23 / Chapter 2.4 --- Determination of antioxidant activity --- p.25 / Chapter 2.4.1 --- Trolox equivalent antioxidant capacity (TEAC) assay --- p.25 / Chapter 2.4.2 --- DPPH. radical scavenging assay --- p.26 / Chapter 2.4.3 --- β-carotene bleaching assay --- p.26 / Chapter 2.4.4 --- Assay for erythrocyte hemolysis mediated by peroxyl free radicals --- p.27 / Chapter 2.4.4.1 --- Determination of IC50 --- p.28 / Chapter 2.5 --- Evaluation of CP as antioxidant in various food models --- p.28 / Chapter 2.5.1 --- Preparation of food samples --- p.28 / Chapter 2.5.2 --- Butter cookies --- p.29 / Chapter 2.5.3 --- Salad dressing --- p.29 / Chapter 2.5.4 --- Fried potato chips --- p.29 / Chapter 2.5.5 --- PeroXOquant´ёØ quantitative peroxide assay --- p.29 / Chapter 2.5.6 --- Statistical analysis --- p.30 / Chapter 2.6 --- Determination of antimicrobial activity --- p.31 / Chapter 2.6.1 --- Determination of antimicrobial activity --- p.31 / Chapter 2.6.1.1 --- Bacterial stock --- p.31 / Chapter 2.6.1.2 --- Preparation of nutrient agar plate --- p.31 / Chapter 2.6.1.3 --- Minimal inhibiting concentration (MIC) --- p.31 / Chapter 2.6.2 --- Determination of antifungal activity --- p.32 / Chapter 2.6.2.1 --- Fungi stock --- p.32 / Chapter 2.6.2.2 --- Preparation of potato dextrose agar plates --- p.32 / Chapter 2.6.2.3 --- Growth inhibition effect --- p.32 / Chapter 2.6.3 --- Statistical analysis --- p.33 / Chapter 2.7 --- In vitro effect on human cell lines --- p.34 / Chapter 2.7.1 --- Cell lines --- p.34 / Chapter 2.7.2 --- Maintenance of cell lines --- p.34 / Chapter 2.7.3 --- MTT assay --- p.35 / Chapter 2.7.4 --- Cell Proliferation ELISA-BrdU (chemiluminescence) assay --- p.36 / Chapter 2.7.5 --- Determination of IC50 --- p.37 / Chapter 2.7.6 --- Cytotoxicity detection assay --- p.37 / Chapter 2.7.6.1 --- Optimal cell concentration --- p.37 / Chapter 2.7.6.2 --- LDH detection assay --- p.38 / Chapter 2.7.7 --- Statistical analysis --- p.39 / Chapter 2.8 --- Fractionation and characterization --- p.40 / Chapter 2.8.1 --- Sephadex column chromatography --- p.40 / Chapter 2.8.2 --- Fourier transform infrared (FT-IR) spectra --- p.40 / Chapter 2.8.3 --- Folin and Ciocalteu's assay --- p.40 / Chapter 2.8.4 --- Statistical analysis --- p.41 / Chapter 3 --- Results / Chapter 3.1 --- Determination of antioxidant activity --- p.43 / Chapter 3.1.1 --- Trolox equivalent antioxidant capacity (TEAC) assay --- p.43 / Chapter 3.1.2 --- DPPH.radical scavenging assay --- p.43 / Chapter 3.1.3 --- β-carotene bleaching assay --- p.44 / Chapter 3.1.4 --- Assay for erythrocyte hemolysis mediated by peroxyl free radicals --- p.44 / Chapter 3.2 --- Potential application as food antioxidant --- p.45 / Chapter 3.2.1 --- Peroxide standard curve --- p.45 / Chapter 3.2.2 --- Inhibition of lipid peroxidation in different food items --- p.45 / Chapter 3.3 --- Potential application as food preservative --- p.46 / Chapter 3.3.1 --- Antibacterial activity --- p.46 / Chapter 3.3.2 --- Antifungal activity --- p.46 / Chapter 3.4 --- In vitro effect on human cell lines --- p.47 / Chapter 3.4.1 --- Effect on the growth of human cancer cells --- p.47 / Chapter 3.4.2 --- Antiproliferative effect on selected human cancer cells --- p.48 / Chapter 3.4.3 --- Cytotoxicity effect on selected human cancer cells and normal fibroblast --- p.48 / Chapter 3.4.3.1 --- Optimal cell density for cytotoxicity determined assay --- p.48 / Chapter 3.4.3.2 --- Cytotoxic effect --- p.48 / Chapter 3.5 --- Fractionation and characterization --- p.49 / Chapter 3.5.1 --- Percentage of yield --- p.49 / Chapter 3.5.2 --- Fourier transform infrared (FT-IR) spectra --- p.49 / Chapter 3.5.3 --- Determination of total phenolic content --- p.49 / Chapter 3.5.4 --- Determination of antioxidant activity --- p.50 / Chapter 3.5.5 --- Relationship between total phenolics and antioxidant activity --- p.50 / Chapter 3.5.6 --- Antiproliferative effect on cancer cell --- p.50 / Chapter 3.5.7 --- Cytotoxic effect --- p.51 / Chapter 3.5.7.1 --- HepG2 human cancer cell line --- p.51 / Chapter 3.5.7.2 --- Hs68 human normal fibroblast --- p.51 / Chapter 4 --- Discussion / Chapter 4.1 --- Application of CP as a natural food additive with multi-functions --- p.87 / Chapter 4.1.1 --- CP as a natural food antioxidant --- p.88 / Chapter 4.1.2 --- CP as a natural food preservative --- p.90 / Chapter 4.2 --- Potential health-beneficial --- p.91 / Chapter 4.2.1 --- CP as dietary antioxidant --- p.91 / Chapter 4.2.2 --- Antiproliferative activity of CP --- p.92 / Chapter 4.3 --- Further characterization of CP --- p.94 / Chapter 4.4 --- Future perspectives --- p.96 / Chapter 5 --- Conclusion --- p.97 / References --- p.98

Red radish anthocyanin extract (RAE) was investigated for coloring brined cherries as an alternative to FD&C Red No. 40. Red radish (Raphanus sativus L.) anthocyanins were extracted from liquid nitrogen powdered epidermal tissue using acetone, partitioned with chloroform, and isolated using C-18 resin. The monomeric anthocyanin content was determined by pH differential to be 154 ± 13 mg/100 g of epidermal tissue (on pelargonidin-glucoside basis). The major pigments were identified as pelargonidin-3-sophoroside-5-glucoside monoacylated with p-coumaric or ferulic acids by HPLC and spectral analyses. Primary and secondary bleached cherries were sweetened to 40° Brix (pH of 3.50), and colored using two concentrations of RAE (600 and 1200 mg/L syrup, designated Cl and C2) and FD&C Red No. 40 (200 ppm). Color was measured for both cherries and syrup. Reflectance measurements (CIE L*, a*, b*), chroma and hue angle, showed that RAE imparted red color to the cherries and syrup extremely close to that of FD&C Red No. 40. RAE C2 gave the primary bleached cherries the closest color characteristics (L*= 18.20, a*= 20.00, b*= 8.47) to FD&C Red No. 40 (L*= 18.00, a*= 24.35, b*= 12.13). RAE Cl gave the secondary bleached cherries the closest color characteristics (L*= 15.27, a*= 16.21, b*= 5.21) to FD&C Red No. 40 (L*= 16.38, a*= 19.91, b*= 8.99). Color and pigment stability of secondary bleached cherries were evaluated during a year of storage in the dark at 25°C. Monomeric anthocyanin degradation followed first-order kinetics and the half-lives were 29 and 33 weeks for syrups colored with RAE Cl and RAE C2, respectively. However, cherry color showed no significant changes in hue, color intensity nor lightness during storage. Color changes of syrup samples over time were dependant on anthocyanin concentration, higher anthocyanin concentration exerted a protective effect on color stability. Haze formation was observed in syrup samples colored with RAE, possibly due to pigment polymerization. Syrup samples colored with RAE and FD&C Red No. 40 were also exposed to light for a year at 25°C. Light had a small but significant effect on L*, a*, and monomeric anthocyanin content. From color and pigment stability data and visual observations we concluded that RAE was effective in coloring secondary bleached cherries with results very similar to those of FD&C Red No. 40 for 6 months of storage. / Graduation date: 1995

Graduation date: 1940

Graduation date: 1951

Thesis (M.S.)--University of Michigan, 1984.

Thesis (M.S.)--University of Michigan, 1984.

The coloring matter in flowers has been used for centuries as a dye. Early man did not know the chemical nature of these coloring matters. Recent investigations have shown that the dark pigments whereas the lighter pigments of flowers are in the anthoxanthin group of pigments. Both of these groups of pigments have a heterocyclic structure. A large number of these pigments have been isolated and identified. The object of this research was to isolate and identity the coloring matter in the Camillia japonica (Belgian red) flowers. This was done by extracting the pigment with methanol and then crystallizing the pigment as a chloride. Color reactions, solubility, spectra, and other physical properties were obtained for this pigment.

Chipping varieties and model systems were used to determine the role of potato constituents on chip color. Composition was evaluated by HPLC and chip color measured using a ColorQuest colorimeter. Reducing sugar (RS) content did not completely explain color quality when present in low concentrations (<60 mg/lOOg). Levels of ascorbic acid, glutamine and a chlorogenic acid isomer, along with RS, showed high correlation with color. Sucrose was a poor estimator of chip color. Model systems used leached potato slices infiltrated with solutions containing sucrose, RS, ascorbic, chlorogenic and amino acids. Linear association of RS with L* and hue angle and quadratic relationship with chroma of chips were found. Ascorbic acid affected chroma and hue at low RS levels while chlorogenic acid was not involved in color development. Red potatoes {Solarium tuberosum and Solarium stenotomum) were evaluated as potential source of natural red colorant. Cultivars (33) were screened for anthocyanin content and qualitative composition. Monomeric anthocyanin content, determined by pH differential, ranged between 4 and 40 mg/lOOg fresh weight (fw) tuber. Varieties 5847-1 and ND04069-4 showed high anthocyanin content (>35 mg/lOOg). Anthocyanin composition was characterized by HPLC, spectral analysis and Mass Spectroscopy (MS). The major anthocyanin was pelargonidin-3-rutinoside-5-glucoside acylated with p-coumaric acid. The presence of glycoalkaloids (α-solanine and α-chaconine) was detected by MS and quantified by HPLC. Varieties NDO4069-4 and 5847-1 showed glycoalkaloid levels of 13 and 7 mg/lOOg fw, respectively. Glycoalkaloids were precipitated from pigment concentrates by alkaline treatment. The best results were obtained at pH 8.0 with 30% monomeric anthocyanin degradation and 90% glycoalkaloid precipitation. The color and pigment stability of chemically related anthocyanin extracts (red-fleshed potatoes and radishes), the effect of pigment purity, and temperature were evaluated in model juices (pH 3.5). Color (CIELch) and anthocyanin degradation was monitored for 65 wks of storage. All model juices showed color similar to FD&C Red # 40. Excellent stability was obtained with all treatments in refrigeration. Anthocyanin structure and extraction method affected pigment stability. At 25°C, higher stability was obtained on juices colored with chemically purified radish anthocyanins (22 wk half-life) and lowest with potato vegetable juice (10 wk half-life). / Graduation date: 1999

Orientador: Fernando Lucas Primo / Banca: Alberto Colli Badino Júnior / Banca: Ariela Veloso de Paula / Resumo: O controle da qualidade dos resultados de análises químicas tem sido cada vez mais exigido devido ao grande prejuízo que dados analíticos não confiáveis podem gerar, principalmente quando se diz respeito à segurança do produto, e às consequências financeiras irreversíveis que pode causar. Para garantir a confiabilidade dos resultados obtidos durante as etapas analíticas é necessário que o método empregado seja validado. Neste contexto, o presente trabalho visa desenvolver e validar um método espectroanalítico para determinação de corantes vermelho e derivados livre e nanoencapsulado, por espectroscopia de absorção e emissão de fluorescência no UV-Vis, como métodos alternativos aos cromatográficos tradicionais. A partir da espectroscopia de absorção e emissão de fluorescência no UV-visível utilizando-se o espectrofotômetro modelo Genesys 10s da Thermo Scientific e espectrofluorímetro Shimadzu RF6000 desenvolveu-se um protocolo experimental para determinação da curva de correlação entre máximo de emissão de absorção e emissão de fluorescência em função de diferentes concentrações de quinizarina. O método foi determinado com número de repetição (n) igual a 3. Os parâmetros de aquisição dos espectros de fluorescência foram fixados com um comprimento de onda de excitação igual a 480 nm, fendas de excitação e emissão igual a 10/10 nm, respectivamente, com emissão na faixa de 520 a 680 nm. As amostras foram preparadas com auxílio de uma micropipeta (10,0 uL Eppendorf) a partir de di... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Quality control of chemical analysis results has been increasingly required because of the great harm that unreliable analytical data can generate, especially when it comes to product safety, and the irreversible financial consequences it can cause. To guarantee the reliability of the results obtained during the analytical steps it is necessary that the method employed be validated. In this context, the present work aims to develop and validate a spectroanalytical method for the determination of red dyes and free and nanoencapsulated derivatives, by absorption spectroscopy and UV-Vis fluorescence emission, as alternative methods to traditional chromatographic methods. UV-visible fluorescence emission and absorption spectroscopy using the Genesys 10s spectrophotometer from Thermo Scientific and Shimadzu RF6000 spectrofluorimeter was developed an experimental protocol for determination of the correlation curve between maximum emission of absorption and emission of fluorescence as a function of different concentrations of quinizarin. The method was determined with repeat number (n) equal to 3. The acquisition parameters of the fluorescence spectra were set with an excitation wavelength equal to 480 nm, excitation and emission slots equal to 10/10 nm, respectively, with emission in the range of 520 to 680 nm. The samples were prepared using a micropipette (10.0 μL Eppendorf) from infinite dilution in acetonitrile (2.0 mL), directly into a 10 mm optical path quartz cuvette, starting with an initial solution of quinizarin 1.00 mg / mL in dimethylsulfoxide. The methods showed linearity in the range of... (Complete abstract click electronic access below) / Mestre

Orientador: Rodrigo Braga Moruzzi / Banca: Luiza Cintra Campos / Banca: Gustavo Henrique Ribeiro da Silva / Resumo: As indústrias têxteis caracterizam-se pelos elevados volumes de água consumida e de efluente lançado, o qual, por possuir coloração intensa, reduz a penetração da luz solar nos corpos hídricos receptores e afeta a fotossíntese. Nesse trabalho, avaliou-se a adsorção do corante Azul Reativo 19 (RA19) por carvão ativado comercial (CAP), CAP tratado por ozônio (CAP - O3), lama vermelha (LV) e LV tratada por ozônio (LV - O3). Os adsorventes foram caracterizados quanto ao pH, condutividade elétrica, número de iodo, índice de azul de metileno, granulometria, composição química, mineralogia e micromorfologia. Investigou-se a influência do pH e da temperatura no processo de adsorção. Além disso, analisou-se a cinética da adsorção de RA19 a diferentes concentrações iniciais (300, 500, 1000, 2000 e 3000 mg/L), por meio dos modelos de pseudo primeira ordem, pseudo segunda ordem, difusão intrapartículas e Elovich; e avaliou-se a capacidade de adsorção dos quatro adsorventes, por isotermas de Langmuir e Freundlich. Os resultados indicaram que o tratamento por ozônio não altera significativamente a composição química do CAP e da LV, mas possivelmente reduz o volume de mesoporos do CAP. A eficiência de remoção do RA19 por CAP independe do pH inicial da solução, mas por LV, é favorecida em pH mais baixo (igual a 3). Observou-se que 120 minutos são suficientes para atingir o equilíbrio da reação; e que o aumento da concentração inicial de corante reduz a eficiência de remoção, mas aumenta a ca... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Textile industries are characterized by high water consumption and by large effluent release, which is strongly colored and therefore reduces sunlight penetration into water and affects photosynthesis. This study evaluated the adsorption of Reactive Blue 19 (RB19) by commercial activated carbon (PAC), PAC treated by ozone (PAC - O3), red mud (RM) and RM treated by ozone (RM - O3). The adsorbents were characterized by pH, electric conductivity, iodine number, Methylene Blue index, granulometry, chemical and mineralogical composition and micromorphology. Influence of pH and temperature was investigated. Additionally, the RB19 adsorption kinetics was evaluated at different initial concentrations (300, 500, 1000, 2000 and 3000 mg/L) with the pseudo first order, pseudo second order, intraparticle diffusion and Elovich models; and the adsorptive capacity of the adsorbents was investigated by Langmuir and Freundlich isotherms. The results showed that ozone treatment does not significantly change the chemical composition of PAC and RM, but it possibly reduces PAC's mesopore volume. The initial pH does not influence the efficiency of RB19 removal by PAC, but it influences the removal by RM, being higher at lower pH (equal to 3). The adsorption reached an equilibrium state at about 120 minutes from the beginning of the experiments; and it was observed that increasing initial dye concentration, removal efficiency was reduced, while adsorption capacity was improved. The experimental data fitted well to the pseudo second order and Elovich kinetics models, which indicate that the process is controlled by chemisorption. The RB19 removal obeys the Freundlich isotherm model, showing multilayer adsorption on heterogeneous surface. The thermodynamic studies indicated that RB19 has affinity to the adsorbents, and the reaction occurs spontaneously... (Complete abstract electronic acess below) / Mestre