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Characterization of anthocyanins in fruit juices and natural colorantsHong, Victor 17 December 1987 (has links)
A method for separation and characterization of individual anthocyanins was
developed. High Performance Liquid Chromatography (HPLC) with a polymer based
reversed-phase column was used to separate the pigments while on-line Photodiode
Array Detection (PDA) was employed to record the UV and Visible spectrum of the
individual peaks. Spectral information obtained from on-line PDA detection provided
information about: 1) the nature of the aglycone, 2) the sugar substitution pattern
and 3) the presence or absence of hydroxy aromatic organic acids. The nature of the
glycosidation can be determined from the HPLC retention characteristics.
The HPLC/PDA methods were employed to characterize the anthocyanin
profiles of the pigments in cranberry, roselle, cherry, bilberry, grape, red cabbage,
black raspberry, blackberry, elderberry, plum, blackcurrant and strawberry. The
anthocyanidin profiles were also determined for the samples for purposes of
confirmation of the anthocyanin data.
In addition to the anthocyanin and anthocyanidin profiles, the general coloring
properties for most of the samples were also determined. Included were Hunter L, a, b values, total anthocyanin pigment concentration, wavelength maxima, percent
tannin measurements, tinctoral strength, pH measurements and titratable acidity. / Graduation date: 1988
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REGULATION OF DEGREENING AND REGREENING OF CITRUS PEEL WITH SELECTED CARBOHYDRATE AND NITROGEN COMPOUNDS IN VITRO.Ahmed, Omer Khidir January 1986 (has links)
The regulation of citrus fruit color by various concentrations of sugars, sugar metabolites, and nitrogen compounds was investigated in peel segments of Citrus paradisi Macf. (cv. Marsh) cultured on modified media of Murashige and Tucker. Green and yellow peel segments were cultured for degreening and regreening studies, respectively, and chlorophyll level in the individual peel segments was measured with a reflectometer. Degreening was significantly promoted by 150 mM sucrose, 300 mM glucose and fructose, or 50 mM citrate but not by 300 mM of the hexoses galactose and mannose, 300 mM of the pentoses xylose and ribose, or 25, 50, and 100 mM succinate. Regreening was significantly inhibited by 150 mM sucrose, 300 mM glucose and fructose, or 50 mM citrate and malate. Succinate and α-ketoglutarate at concentrations of 50 mM did not inhibit regreening. The inhibition of regreening by 300 mM sucrose was reduced by 33 percent with the glycolytic inhibitor iodoacetic acid at 1 mM but not by DL-glyceraldehyde at 50 mM. Neither ethanol nor potassium bicarbonate inhibited regreening, suggesting that the regulation of citrus fruit color is specific to sugars or sugar metabolites. However, pyruvate did not promote degreening or inhibit regreening because it was probably not absorbed from the media by the flavedo of the peel. These results suggest that sucrose, glucose, fructose, and citrate maintain carotenoid synthesis and accumulation in both cultured green and yellow peel segments but cause the loss of chlorophyll from green peel segments. Treatment of either the green or yellow segments with sucrose or citrate may increase the partitioning of these compounds into the mevalonic acid pathway to provide carbon for synthesis or carotenoids, resulting in degreening of the green peels and maintaining the yellow color in the yellow peels. Malonate inhibited regreening when incorporated in media at concentrations of 4 mM. This inhibition was reversed by 60 mM glutamine but not by 5 mM glutamine or KNO₃. The action of malonate on regreening may be a specific effect of malonate on plastid development rather than by modifying the partitioning of sugar metabolites into the carotenoid synthetic pathway.
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Stability and safety assessment of the exudates from Lentinula edodes sp. used as a food colorant.January 2010 (has links)
Jin, Lei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 150-170). / Abstracts in English and Chinese. / THESIS COMMITTEE --- p.II / ABSTRACT --- p.IV / 摘要 --- p.VI / TABLE OF CONTENTS --- p.VIII / LIST OF TABLES --- p.XII / LIST OF FIGURES --- p.",XIV" / LIST OF ABBREVIATIONS --- p.XVII / Chapter CHAPTER 1 --- GENERAL INTRODUCTION --- p.1 / Chapter 1.1 --- Background of Mushroom --- p.1 / Chapter 1.1.1 --- Mushroom --- p.1 / Chapter 1.1.2 --- Shiitake Mushroom --- p.2 / Chapter 1.1.3 --- Production of Shiitake mushroom --- p.3 / Chapter 1.1.4 --- Taxonomy of Shiitake --- p.4 / Chapter 1.1.5 --- Nutrients of Shiitake --- p.5 / Chapter 1.1.6 --- Taste Substances of Shiitake --- p.10 / Chapter 7.1.7 --- Aroma Components of Shiitake --- p.11 / Chapter 1.1.8 --- Color of Shiitake --- p.12 / Chapter 1.2 --- Food Additives --- p.13 / Chapter 1.2.1 --- Food Additives --- p.13 / Chapter 1.2.2 --- Definition of Food Additives Given by FA O/WHO Joint Expert Committee for Food Additives (JECFA) --- p.13 / Chapter 1.2.3 --- Definition of Food Additives Given by the Commission of the European Union --- p.14 / Chapter 1.3 --- Food Colorants and Stability Assessment --- p.15 / Chapter 1.3.1 --- "Define a Color: Color Space, Hue, and Chroma" --- p.15 / Chapter 1.3.2 --- Natural Pigment --- p.17 / Chapter 1.3.3 --- Food Color and use of Colorant --- p.17 / Chapter 1.3.4 --- Microbial Colors as Food Colorant --- p.19 / Chapter 1.3.5 --- Stability of Food Colorant --- p.23 / Chapter 1.4 --- Food Safety and Risk Assessment --- p.23 / Chapter 1.4.1 --- Food Safety --- p.23 / Chapter 1.4.2 --- The Codex Alimentarius --- p.24 / Chapter 1.4.3 --- National and Regional Authorities --- p.24 / Chapter 1.4.4 --- The Acceptable Daily Intake (ADI) and Other Related Safety Levels --- p.25 / Chapter 1.4.5 --- Toxicity Tests for Safety Assessment --- p.26 / Chapter 1.4.6 --- Sensitive Organs to Toxin (Liver and Kidney) --- p.29 / Chapter 1.5 --- Safety Assessment of Food Color Additives --- p.31 / Chapter 1.5.1 --- Color Additives (Food) --- p.31 / Chapter 1.5.2 --- Regulation of Color Additives --- p.33 / Chapter 1.6 --- Characterization of Natural Food Colorants --- p.33 / Chapter 1.6.1 --- Composition of Natural Food Colorants --- p.33 / Chapter 1.6.2 --- Fungal Pigments as Unique Alternatives of Authorized Natural Food Colorants --- p.34 / Chapter 1.6.3 --- Fungal Pigmentation and Phenolic Metabolism --- p.35 / Chapter CHAPTER 2 --- STABILITY ASSESSMENT OF THE EXUDATES FROM L. EDODES MYCELIA --- p.40 / Chapter 2.1 --- Introduction --- p.40 / Chapter 2.1.1 --- General Information --- p.40 / Chapter 2.1.2 --- Natural Sources of Food Colorant --- p.40 / Chapter 2.1.3 --- Application of Natural Pigments --- p.41 / Chapter 2.1.3 --- Objectives --- p.41 / Chapter 2.2 --- Material and Methods --- p.42 / Chapter 2.2.1 --- Cultivation of Shiitake Mushroom --- p.42 / Chapter 2.2.2 --- Collection of the Exudates --- p.42 / Chapter 2.2.3 --- Commercial Colorant --- p.42 / Chapter 2.2.4 --- Buffer Systems --- p.43 / Chapter 2.2.5 --- Soft Drink Medium --- p.43 / Chapter 2.2.6 --- Pigment Solution Sample Preparation --- p.44 / Chapter 2.2.7 --- Measurements of Physicochemical Parameters --- p.44 / Chapter 2.2.8 --- pH Stability --- p.45 / Chapter 2.2.9 --- Thermal Stability --- p.46 / Chapter 2.2.10 --- Light Stability --- p.46 / Chapter 2.2.11 --- Statistical Methods --- p.47 / Chapter 2.3 --- Results --- p.50 / Chapter 2.3.1 --- Physicochemical Characteristics --- p.50 / Chapter 2.3.2 --- pH Stability --- p.51 / Chapter 2.3.2 --- Thermal Stability --- p.53 / Chapter 2.3.3 --- Light Stability --- p.54 / Chapter 2.4 --- Discussion --- p.67 / Chapter 2.4.1 --- Physicochemical Characteristics --- p.67 / Chapter 2.4.2 --- pH Stability --- p.69 / Chapter 2.4.3 --- Thermal Stability --- p.71 / Chapter 2.4.4 --- Light Stability --- p.73 / Chapter CHAPTER 3 --- TOXICOLOGICAL STUDIES ON THE EXUDATES FROM L. EDODES MYCELIA --- p.76 / Chapter 3.1 --- Introduction --- p.76 / Chapter 3.1.1 --- L. edodes Mycelial Exudates ´ؤ a Promising Natural Food Colorant --- p.76 / Chapter 3.1.2 --- Regulatory Toxicology (Hazard Assessment) --- p.76 / Chapter 3.1.3 --- Acute and Sub-acute Toxicity Tests --- p.77 / Chapter 3.1.4 --- Color Additive Petitions --- p.78 / Chapter 3.1.5 --- Objectives --- p.80 / Chapter 3.2 --- Material and Methods --- p.80 / Chapter 3.2.1 --- Cultivation of Shiitake Mushroom and Test Substances --- p.80 / Chapter 3.2.1 --- Acute Toxicity Test --- p.81 / Chapter 3.2.1.1 --- Animals --- p.81 / Chapter 3.2.1.2 --- Limit Test --- p.81 / Chapter 3.2.1.3 --- Main Test --- p.82 / Chapter 3.2.2 --- Sub-acute Toxicity Test --- p.82 / Chapter 3.2.2.1 --- Animals and Administration of Test Substance --- p.82 / Chapter 3.2.2.2 --- Survival and Clinical Observations --- p.83 / Chapter 3.2.2.3 --- Body Weights and Food Consumption --- p.83 / Chapter 3.2.2.4 --- Hematology --- p.84 / Chapter 3.2.2.5 --- Clinical Chemistry --- p.84 / Chapter 3.2.2.6 --- Macroscopic Examination --- p.85 / Chapter 3.2.2.7 --- Histopathology --- p.85 / Chapter 3.2.3 --- Statistical Methods --- p.86 / Chapter 3.3 --- Results --- p.87 / Chapter 3.3.1 --- Oral Acute Toxicology Study in BALB/c Mice --- p.87 / Chapter 3.3.2 --- Oral Sub-acute Toxicology Study in SD Rat --- p.90 / Chapter 3.3.2.1 --- Survival and Clinical Observations --- p.90 / Chapter 3.3.2.2 --- Body Weights and Food Consumption --- p.90 / Chapter 3.3.2.3 --- Hematological and Clinical Biochemical Data --- p.92 / Chapter 3.3.2.4 --- Organ Weights --- p.92 / Chapter 3.3.2.5 --- Histopathological Examination --- p.92 / Chapter 3.4 --- Discussion --- p.103 / Chapter 3.4.1 --- General Aspects --- p.103 / Chapter 3.4.2 --- Oral Acute Toxicology Study in BALB/c Mice --- p.104 / Chapter 3.4.3 --- Oral Sub-acute Toxicology Study in SD Rat --- p.105 / Chapter CHAPTER 4 --- GENERAL CHARACTERIZATION AND APPLICATION OF EXUDATES FROM L. EDODES MYCELIA --- p.109 / Chapter 4.1 --- Introduction --- p.109 / Chapter 4.1.1 --- Pigmentation of Lentinula edodes --- p.109 / Chapter 4.1.2 --- Achieving Greater Bioavailability by Enzymatic Hydrolysis of Phenolics in Conjugated Forms --- p.110 / Chapter 4.1.3 --- Fourier Transform Ion Cyclotron Resonance Mass Spectrometry --- p.111 / Chapter 4.1.3 --- Objectives --- p.113 / Chapter 4.2 --- Material and Methods --- p.114 / Chapter 4.2.1 --- Cultivation of Fungus --- p.114 / Chapter 4.2.2 --- Sample Preparation of Fruiting Bodies and Mycelia --- p.114 / Chapter 4.2.3 --- Total Water-soluble Polysaccharide Content --- p.115 / Chapter 4.2.4 --- Total Protein Content --- p.115 / Chapter 4.2.5 --- Total Phenolic Content --- p.116 / Chapter 4.2.6 --- Enzymatic Hydrolysis of Glycosidically Bound Phenolic Compounds --- p.117 / Chapter 4.2.7 --- Measurement of Color Parameters --- p.117 / Chapter 4.2.8 --- Preparation of Exudates for FTICR-MS Analysis --- p.117 / Chapter 4.2.9 --- FTICR-MS Instrumentation --- p.118 / Chapter 4.2.10 --- FTICR-MS Calibration --- p.118 / Chapter 4.2.11 --- Quantitative Analysis of FTICR-MS --- p.119 / Chapter 4.2.12 --- Data Processing --- p.119 / Chapter 4.2.13 --- Sensory Evaluation --- p.120 / Chapter 4.3 --- RESULTS --- p.122 / Chapter 4.3.1 --- Major Chemical Groups of L. edodes --- p.122 / Chapter 4.3.2 --- Change in Color and Total Phenolic Content after Addition of Enzymes --- p.122 / Chapter 4.3.3 --- Detection of Metabolites Using FTICR-MS --- p.126 / Chapter 4.3.4 --- Phenolic Compound Identification --- p.129 / Chapter 4.3.5 --- Sensory Evaluation --- p.137 / Chapter 4.4 --- Discussion --- p.138 / Chapter 4.4.1 --- Total Phenolic Content and Pigmentation --- p.138 / Chapter 4.4.2 --- FTICR-MS Application on Studying Enzymatic Hydrolysis --- p.140 / Chapter 4.4.3 --- Sensory Evaluation --- p.147 / Chapter 4.4.4 --- Overall Conclusion --- p.147 / Chapter CHAPTER 5 --- CONCLUSION --- p.148 / REFERENCES --- p.150 / APPENDIX --- p.171
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List circular coloring of even cyclesYang, Chung-ying 27 June 2004 (has links)
Suppose G is a graph and p >= 2q are positive integers. A
color-list is a mapping L: V --> P(0, 1,...,p-1) which assigns to each vertex a set L(v) of
permissible colors. An L-(p, q)-coloring of G is a (p,
q)-coloring h of G such that for each vertex v,
h(v) in L(v). We say G is L-(p, q)-colorable if
such a coloring exists. A color-size-list is a mapping f: V -->{0, 1, 2,..., p}, which assigns to each vertex v a
non-negative integer f(v). We say G is f-(p, q)-colorable
if for every color-list L with |{L}(v)| = f(v), G is
L-(p, q)-colorable. For odd cycles C, Raspaud and Zhu
gave a sharp sufficient condition for a color-size-list f under
which C is f-(2k+1, k)-colorable. The corresponding
question for even cycles remained open. In this paper, we
consider list circular coloring of even cycles. For each even cycle C of length n and for each positive integer k, we
give a condition on f which is sufficient and sharp for C to
be f-(2k+1, k)-colorable.
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Almost regular graphs and edge-face colorings of plane graphsMacon, Lisa Fischer. January 2009 (has links)
Thesis (Ph.D.)--University of Central Florida, 2009. / Adviser: Yue Zhao. Includes bibliographical references (p. 102-104).
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Approximate edge 3-coloring of cubic graphsGajewar, Amita Surendra. January 2008 (has links)
Thesis (M. S.)--Computing, Georgia Institute of Technology, 2009. / Committee Chair: Prof. Richard Lipton; Committee Member: Prof. Dana Randall; Committee Member: Prof. H. Venkateswaran. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Fractionally total colouring most graphsMeagher, Conor John. January 1900 (has links)
Thesis (M.Sc.). / Title from title page of PDF (viewed 2008/01/30). Written for the School of Computer Science. Includes bibliographical references.
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The topology of graph homomorphisms /Dochtermann, Anton, January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 107-111).
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On the structure of counterexamples to the coloring conjecture of HajósZickfeld, Florian. January 2004 (has links) (PDF)
Thesis (M.S.)--School of Mathematics, Georgia Institute of Technology, 2005. Directed by Xingxing Yu. / Xingxing Yu, Committee Chair ; Robin Thomas, Committee Member ; Prasad Tetali, Committee Member ; Anurag Singh, Committee Member. Includes bibliographical references.
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The dye injection method for circulatory studies a critical evaluation of the technique, apparatus and results.Falholt, Walther. January 1958 (has links)
Afhandling - Copenhagen. / Summary in Danish.
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