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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Radish anthocyanin extract as a natural red colorant for maraschino cherries

Hundskopf, Maria Monica Giusti 07 April 1995 (has links)
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
12

Some factors affecting the stability of erythrosine dye in cherry tissue

Van Blaricom, Lester Oscar 06 1900 (has links)
Graduation date: 1940
13

Diffusion rate of dye in preparation of maraschino cherries

Henney, Edward Nathan 01 May 1951 (has links)
Graduation date: 1951
14

The potato : composition, non-enzymatic browning and anthocyanins

Rodriguez-Saona, Luis Enrique 04 June 1998 (has links)
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
15

Analysis of flavor precursors in radish and radish color extracts

Kucza, Myriam M. 13 December 1996 (has links)
Radish anthocyanin extract has potential as a natural colorant because of its pigment stability and attractive red hue. Presence of undesirable aroma compounds could limit its applications in foods. The pungent principle of radish, 4-methylthio-3-butenyl isothiocyanate (MTBI), is produced enzymatically upon cell injury from its glucosinolate precursor, 4-methylthio-3-butenyl glucosinolate (MTBG), and undergoes subsequent degradation to produce a number of volatiles. To evaluate the potential of flavor formation, juices were prepared from winter and spring radish cultivars. Whole radishes, peels and flesh, as well as radish extracts, were analyzed for glucosinolates and isothiocyanates. Aroma intensities of radish juice extracts were evaluated using sensory analysis. MTBI was monitored by HPLC (detection level 160 ppb). MTBG was extracted from freeze-dried radish tissue with boiling methanol, purified by anion exchange and enzymatically desulfated. DesulfoMTBG was quantified by HPLC, using desulfosinigrin as internal standard. Identification was performed by fast atom bombardment and electrospray mass spectroscopy. MTBI formation was higher in winter than in spring cultivars (1.5-2.8 and 0.8-1.3 mg/100g fresh weight, respectively), and higher in flesh than in peels. MTBG ranged from 30-65 mg (spring cultivars) to 260-320 mg/100g fresh weight (winter cultivars) with greater concentration in peels than in flesh. Isothiocyanates and glucosinolates were not detected in radish juices. Overall aroma intensities of radish juice concentrates, diluted to 150, 300, 600 and 1200 mg anthocyanin/L in water, were rated using a 16-point scale. Radish concentrates from cultivars Fuego (pigmented peels) and Red Meat Takii (whole red flesh) were compared to commercial red cabbage and radish colorants. Aroma intensities followed first order relationships with anthocyanin concentrations. The commercial colorants were rated slight to moderate, while radish extracts (Fuego and Takii) were rated moderate to large. The aroma intensity of red flesh radish extract was more potent than those prepared from radish peels. Further work includes development of purification techniques which would provide an odorless aqueous extract. / Graduation date: 1997
16

A study of use levels, quality characteristics and natural cure colorants in mechanically deboned poultry meat summer sausages II. Evidence of toxin production by salmonella.

Dhillon, Avtar Singh, January 1975 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
17

The effect of time, temperature, and level of ascorbic acid fortification on the color of tomato juice /

Flinn, Gary Lee January 1973 (has links)
No description available.
18

Characterization and toxicological studies of pigment from Castanea mollissima.

January 2001 (has links)
Leung Bo-Shan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 148-159). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.v / List of Abbreviations --- p.vi / List of Tables --- p.viii / List of Figures --- p.ix / Chapter 1 --- Introduction / Chapter 1.1 --- Food colorants --- p.1 / Chapter 1.2 --- Caramel --- p.3 / Chapter 1.2.1 --- Classes of caramel --- p.3 / Chapter 1.2.2 --- Toxicological studies of caramel --- p.5 / Chapter 1.3 --- Castanea mollissima --- p.9 / Chapter 1.4 --- Antioxidants --- p.10 / Chapter 1.4.1 --- Background --- p.10 / Chapter 1.4.2 --- Methods used to evaluate the antioxidative activity --- p.12 / Chapter 1.4.2.1 --- DPPH* scavenging method --- p.13 / Chapter 1.4.2.2 --- High performance liquid chromatography (HPLC) --- p.13 / Chapter 1.5 --- Microtox® test --- p.19 / Chapter 1.6 --- Mutatox® test --- p.19 / Chapter 1.7 --- Methods used to evaluate the functions of major organs --- p.20 / Chapter 1.7.1 --- Liver --- p.20 / Chapter 1.7.2 --- Kidneys --- p.23 / Chapter 1.8 --- Toxicology --- p.25 / Chapter 1.8.1 --- Acute toxicity test --- p.25 / Chapter 1.8.2 --- Chronic toxicity test --- p.26 / Chapter 1.9 --- Objective --- p.27 / Chapter 2 --- Materials and Methods --- p.28 / Chapter 2.1 --- Plant materials --- p.28 / Chapter 2.2 --- Sample preparation --- p.28 / Chapter 2.3 --- Pigment characterization --- p.30 / Chapter 2.3.1 --- Stability test --- p.30 / Chapter 2.3.2 --- HPLC separation of CP --- p.31 / Chapter 2.3.3 --- Determination of antioxidative activity with the DPPH* scavenging method --- p.31 / Chapter 2.4 --- Microtox® test --- p.33 / Chapter 2.5 --- Mutatox® test --- p.34 / Chapter 2.6 --- Acute toxicity test --- p.35 / Chapter 2.6.1 --- Animals --- p.35 / Chapter 2.6.2 --- Housing and maintenance --- p.35 / Chapter 2.6.3 --- Experimental design --- p.37 / Chapter 2.6.4 --- Chemicals --- p.39 / Chapter 2.6.5 --- Clinical pathology test --- p.41 / Chapter 2.6.5.1 --- Haematology --- p.41 / Chapter 2.6.5.2 --- Blood chemistry --- p.45 / Chapter 2.6.5.3 --- Urinalysis --- p.55 / Chapter 2.6.6 --- Histological study --- p.57 / Chapter 2.6.7 --- Statistical analysis --- p.57 / Chapter 2.7 --- Chronic toxicity test --- p.59 / Chapter 2.7.1 --- Animals --- p.59 / Chapter 2.7.2 --- Housing and maintenance --- p.59 / Chapter 2.7.3 --- Experimental design --- p.59 / Chapter 2.7.4 --- Chemicals --- p.60 / Chapter 2.7.5 --- Clinical pathology test --- p.61 / Chapter 2.7.5.1 --- Haematology --- p.61 / Chapter 2.7.5.2 --- Blood chemistry --- p.62 / Chapter 2.7.5.3 --- Urinalysis --- p.62 / Chapter 2.7.6 --- Histological study --- p.62 / Chapter 2.7.7 --- Statistical analysis --- p.62 / Chapter 3 --- Results --- p.63 / Chapter 3.1 --- Pigment characterization --- p.63 / Chapter 3.1.1 --- Stability test --- p.63 / Chapter 3.1.2 --- HPLC separation of CP --- p.63 / Chapter 3.1.3 --- Antioxidative activities of CP preparations --- p.63 / Chapter 3.2 --- Microtox® test --- p.65 / Chapter 3.3 --- Mutatox® test --- p.65 / Chapter 3.4 --- Acute toxicity test --- p.66 / Chapter 3.4.1 --- Growth rate --- p.66 / Chapter 3.4.2 --- Food and fluid consumption --- p.66 / Chapter 3.4.3 --- Organ-weight --- p.66 / Chapter 3.4.4 --- Clinical pathology tests --- p.68 / Chapter 3.4.4.1 --- Haematology --- p.68 / Chapter 3.4.4.2 --- Blood chemistry --- p.70 / Chapter 3.4.4.3 --- Urinalysis --- p.76 / Chapter 3.4.5 --- Histological study --- p.76 / Chapter 3.5 --- Chronic toxicity test --- p.77 / Chapter 3.5.1 --- Growth rate --- p.77 / Chapter 3.5.2 --- Food and fluid consumption --- p.77 / Chapter 3.5.3 --- Organ-weight --- p.77 / Chapter 3.5.4 --- Clinical pathology tests --- p.78 / Chapter 3.5.4.1 --- Haematology --- p.78 / Chapter 3.5.4.2 --- Blood chemistry --- p.80 / Chapter 3.5.4.3 --- Urinalysis --- p.82 / Chapter 3.5.5 --- Histological study --- p.82 / Chapter 4 --- Discussion --- p.137 / Chapter 4.1 --- Pigment characterization --- p.137 / Chapter 4.2 --- Toxicological studies of CP --- p.140 / Chapter 5 --- Conclusion --- p.147 / References --- p.148
19

Mutagenicidade do corante alimentício tartrazina no ensaio de Salmonella/microssoma / Mutagenicity of food dye tartrazine in assay Salmonella/microssome

Resende, Marielly Reis, 1987- 27 August 2018 (has links)
Orientadores: Nelma de Mello Silva Oliveira, Gisela de Aragão Umbuzeiro, Simone Valente Campos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Tecnologia / Made available in DSpace on 2018-08-27T02:06:39Z (GMT). No. of bitstreams: 1 Resende_MariellyReis_M.pdf: 1924615 bytes, checksum: 1591718b0b86c23e64a29629b4589246 (MD5) Previous issue date: 2015 / Resumo: Embora tenha grande utilidade e diversas aplicações nos setores industriais, há anos a discussão sobre o potencial genotóxico do corante tartrazina vem sendo abordada, uma vez que há vários resultados controversos descritos na literatura. É provável que a presença de impurezas nas amostras possa ser uma das causas do possível potencial mutagênico. Dessa forma, esse estudo visa avaliar a atividade mutagênica do corante tartrazina com diferentes graus de pureza e possíveis interferentes presentes nas amostras, utilizando o ensaio Salmonella/microssoma a partir das linhagens recomendadas pela OECD 471. Os resultados obtidos demonstraram que o corante tartrazina ?99 % e o corante tartrazina comercial 90%, não apresentaram atividade mutagênica para as linhagens TA97a, TA98, TA100, TA1535 e TA102 demonstrando ausência de impurezas mutagênicas ou que as mesmas estejam em baixas concentrações nas amostras avaliadas / Abstract: Although very useful and diverse applications in industry, for years the discussion on the genotoxic potential of the dye tartrazine has been addressed, since there are several controversial results in the literature. It is likely that the presence of impurities in the samples may be a cause of the possible mutagenic potential. Thus, this study aims to evaluate the mutagenic activity of the dye tartrazine with different degrees of purity and possible interferences present in the samples, using the Salmonella / microsome test from the lines recommended by the OECD 471. The results showed that the dye tartrazine ?99 % and the dye tartrazine commercial 90% showed no mutagenic activity for the strains TA97, TA98, TA100, TA1535 and TA102 showing absence of mutagenic impurities or that they are in low concentrations in the analyzed samples / Mestrado / Tecnologia e Inovação / Mestra em Tecnologia

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