Pelargonidin 3-glucoside (pgd 3-glu), pelargonidin 3-sophoroside (pgd 3-soph), and pelargonidin 3-sophoroside 5-glucoside acylated with cinnamic and malonic acids (acyl-pgd 3-soph 5-glu) were extracted from strawberries (Fragaria anannassa cv, Totem), nasturtium flowers (Tropaeolum majus), and radish peel (Raphanus sativus L. cv, fuego), respectively. Their stability was studied in natural and model systems. Natural systems consisted of strawberry juice at 8 °brix and strawberry concentrate at 65 °brix that were spiked with the anthocyanins (ACNS) to double the initial pigment concentration. Model systems at low, intermediate, and high water activity levels consisted of pH 3.4 citrate buffer, glycerol, and pigment. Changes in pigment, degradation index, color, and relative peak area were monitored during storage in the dark at 25°C. Ascorbic acid degradation was also monitored in the natural systems. Anthocyanin (ACN) degradation followed first order kinetics. No difference in stability of the samples was found with fortified pgd derivatives; however, there was significant difference in the degradation of ACNS between natural and model systems. The half life (t [subscript 1/2]) of the ACNS ranged from 3.5 to 5 days in the concentrate, from 8 to 12 days in juice, and from 58 to 934 days in model systems. In general, high Aw increased ACN degradation. Ascorbic acid degradation followed first order kinetics and was accompanied by ACN degradation. / Graduation date: 1999

Carrots were cooked to the just tender stage in a saucepan and in a pressure saucepan for appropriate lengths of time to make them approximately equal in tenderness as determined by a panel of judges and the Kramer Shear Press. A third lot of carrots was cooked in a pressure saucepan for approximately twice as long to represent overcooked carrots. Judges and the Hunter Color Meter indicated that the carrots cooked in the saucepan were more typically red-orange and bright and the carrots overcooked in the pressure saucepan were more yellow and dull. Pigments extracted from the carrots from the three cooking treatments were chromatographed on a magnesia column and the principle fractions, α-carotene and β-carotene, eluted. The β-carotene was rechromatographed on an alumina column to separate it into all-trans-β-carotene and neo-β-carotene B. In absolute amounts, carrots cooked in the saucepan had the highest concentration of all-trans-β-carotene and the highest total of all-trans-β-carotene, neo-β-carotene B and α-carotene, followed by those carrots cooked in the pressure saucepan for 50 seconds, with those cooked in the pressure saucepan for two minutes being lowest in both all-trans-β-carotene and total carotenes. However, when the a-carotene, the neo-pcarotene B and the all-trans-β-carotene were considered as percentages of the total, the percentage of α-carotene remained constant in the three treatments. Carrots cooked in the pressure saucepan for two minutes had a lower percentage of all-trans-β-carotene and a higher percentage of neo-β-carotene B than did carrots from the other two treatments. Thus, longer cooking in the pressure saucepan caused greater conversion of the more vivid all-trans-β-carotene to the paler cis-isomer, neo-β-carotene B. This isomerization plus loss of total pigment accounts for the differences in color of the cooked carrots from the three treatments. / Graduation date: 1964

Digitized by Kansas Correctional Industries

Thesis (Ph. D.)--University of Wisconsin--Madison, 1962. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

The effect of varying combinations of irradiation treatment, freezing procedures and duration of storage on the color of naturally and artificially pigmented egg yolk determined by two objective methods was studied. The relationship between the two methods of color evaluation was also determined. Naturally pigmented yolks were obtained from eggs laid by pullets of a single strain of Single Comb White Leghorn fed a standard diet. Artificially pigmented yolk was prepared by addition of either beta-carotene or canthaxanthin to the naturally pigmented material. Color of yolk was assessed: 1. On the basis of pigment concentration determined by absorbance of acetone extract and expressed as beta-carotene equivalent (BCE) and 2. On the basis of chromaticity coordinates (x,y), lightness (%Y), dominant wavelength (DWL) and excitation purity (EP) determined by reflectance spectrophotometry. Both irradiation dose (0, 0.5, 1.0 and 2.0 Mrad) and time of irradiation (before or after freezing) had significant effect on the chromaticity coordinates, BCE values and excitation purity of naturally and artificially pigmented yolk samples. Higher radiation doses and irradiation before freezing were associated with decreased chromaticity coordinates, BCE values and excitation purity. In artificially pigmented samples increases in irradiation dose and irradiation before freezing resulted in significant decreases in lightness. Samples frozen and stored at -10 F° had consistently higher mean chromaticity values and lower excitation purity than those at -35 F°. The temperature effect on BCE values was inconsistent among experiments. After 30 days storage mean x-values were lower and mean y-values were higher than after 10 days storage. These changes were associated with almost no change in DWL or EP. Nitrogen-packed samples had consistently lower BCE values than air-packed and this difference was significant in all but Experiment 1. No corresponding differences were found in chromaticity coordinates, lightness, DWL or EP. Correlation analyses revealed highly significant (P≤0.01) linear relationships between BCE and both chromaticity values and lightness ranging from + 0.09 to + 0.79. / Land and Food Systems, Faculty of / Graduate

Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed Nov. 11, 2008). Includes bibliographical references.

Phenolic and color parameters of Marechal Foch and deChaunac wines of 1980 through 1983 vintages were analysed to determine variety and aging effects. Centroid Mapping Optimization together with the Simultaneous Factor Shift algorithm were used to determine the HPLC operating conditions which resolved the maximum number of phenolic components of whole red wine. A ternary gradient system using 1 % acetic acid : methanol : acetonitrile was changed from 100:0:0 to 4.8:82.8:12.4 in 130.6 minutes. A flow rate of 1.1 mL/min and a temperature of 32.9 °C were used. The HPLC system was used to separate at least 50 components from each injection of wine and of an ethyl acetate extract of wine. Foch wines were found to have more catechin and epicatechin than deChaunac wines. Peak areas for the ethyl acetate extracts common to all wines, and areas of peaks in the chromatograms of the whole wine, not present in the neutral extract, were used to form a data set for multivariate analyses. Strong linear correlations were found between tristimulus and spectrophotometry measurements for each wine. The color of Foch wines was more stable and contained more brown and yellow hues than deChaunac wines, as determined by tristimulus measurements. Total pigment levels of each wine and various fractions of the total, including ionized, un-ionized, polymeric and sulfur dioxide-bound anthocyanins, were determined spectro-photometrically. Total anthocyanin levels (un-ionized and ionized) in deChaunac wines decreased significantly with increasing age but remained constant in Foch wines. Tannin levels as determined by absorbance readings at 280 nm and by the Folin-Coicalteu reagent method were highly correlated. Foch had more flavonoid and less nonflavonoids than deChaunac wines. The different color parameters, pigment and tannin fractions, as well as titratable acidity, pH and individual organic acids were used as a second data set of analytical parameters for multivariate analyses. A third data set composed of the combination of the analytical data and the HPLC peak areas was also used. Differences between the four vintages of wines, the two varieties, and between old and young wines within varieties were found using stepwise discriminant analysis (SDA). Discrimination of variety differences was more successful (100% correct classification by the jackknife procedure) and required fewer variables than classification by age. Cluster analyses, performed with variables chosen by SDA, gave similar results to the SDA. / Land and Food Systems, Faculty of / Graduate