Browsing by Subject "color"
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Item Biochemical, raw, and cooked color characteristics of individual bovine muscles in oxygen permeable and modified atmosphere packages(Texas A&M University, 2004-09-30) Mies, Patrick DanielColor stability and cooked muscle color were evaluated in relation to myoglobin content, oxygen consumption rate, pH, lipid oxidation, oxygen penetration depth, metmyoglobin reductase activity, Hunter L*- a*- b*- values, discoloration, and degree of doneness for the M. Infraspinatus (IF), M. Triceps brachii (TB), M. Teres major (TM), M. Rectus femoris (RF), M. Vastus lateralis (VL), M. Semimembranosus (SM), M. Biceps femoris (BF), M. Semitendinosus (ST), M. Gluteus medius (GM), as well as the M. Psoas major (PM), and M. Longissimus lumborum (LL). Steaks from these muscles were segmented into a low oxygen dark, low oxygen light, high oxygen, and PVC overwrap packaging environment for six days of retail display. There were no major differences in pH, oxygen consumption rate, or myoglobin reductase acitivity between shelf-life days and packaging environments for the muscles used in the study. The VL, TB, ST, SM, and the GM had higher levels of lipid oxidation in the later days of shelf-life storage and were higher (P < 0.05) in high oxygen packaging compared to the other three treatments. Oxygen penetration depth was greater (P < 0.05) over all storage days for the high oxygen treatment in the TB and LL as compared to the other treatments. Hunter CIE a* and b* values significantly decreased across all muscles for the high oxygen and PVC treatments. Discoloration increased significantly as storage days increased in the high oxygen and PVC treatments for the TB, SM, VL, BF, IF, GM, PM, and TM. Degree of doneness was higher (P < 0.05) for the PM, TB, and SM muscles in a high oxygen atmosphere as compared to the low oxygen light and low oxygen dark treatments. Aerobic reducing ability tended to decrease as retail shelf-life day increased. A high oxygen environment increased rancidity, oxygen penetration depth, redness values, and degree of doneness (P < 0.05) when compared to a low oxygen light and low oxygen dark modified atmosphere package.Item Color, the Visual Arts, and Representations of Otherness in the Victorian Novel(2012-07-16) Durgan, JessicaThis dissertation investigates the cultural connections made between race and color in works of fiction from the Victorian and Edwardian era, particularly how authors who are also artists invent fantastically colored characters who are purple, blue, red, and yellow to rewrite (and sometimes reclaim) difference in their fiction. These strange and eccentric characters include the purple madwoman in Charlotte Bront??s Jane Eyre (1847), the blue gentleman from Wilkie Collins?s Poor Miss Finch (1872), the red peddler in Thomas Hardy?s The Return of the Native (1878), and the little yellow girls of Arthur Conan Doyle?s ?The Yellow Face? (1893) and Frances Hodgson Burnett?s The Secret Garden (1911). These fictional texts serve as a point of access into the cultural meanings of color in the nineteenth century and are situated at the intersection of Victorian discourses on the visual arts and race science. The second half of the nineteenth century constitutes a significant moment in the history of color: the rapid development of new color technologies helps to trigger the upheavals of the first avant-garde artistic movements and a reassessment of coloring?s prestige in the art academies. At the same time, race science appropriates color, using it as a criterion for classification in the establishment of global racial hierarchies. By imagining what it would be like to change one?s skin color, these artist-authors employ the aesthetic realm of color to explore the nature of human difference and alterity. In doing so, some of them are able to successfully formulate their own challenges to nineteenth-century racial discourse.Item Effect of sorghum bran addition on lipid oxidation and sensory properties of ground beef patties differing in fat levels(Texas A&M University, 2006-10-30) Hemphill, Susan PatriciaOxidation of lipids influences the color and sensory qualities of meat products. Meat with a high fat content, such as ground meat, is susceptible to lipid oxidation that leads to the development of negative flavor and color changes. Antioxidants, such as butylated hydroxanisole (BHA), butylated hydroxytolune (BHT) and extracts of rosemary, are used in meat products to control the effects of lipid oxidation. Awika (2000, 2003) found that sorghum bran phytochemicals have high antioxidant properties. Our objective is to evaluate the pH, color, sensory and antioxidant effect of 10, 20 and 30% ground beef patties containing rosemary, BHA/BHT, and three levels of sorghum bran during 5 d of aerobic storage at 4????C. Beef trimmings containing either 50% or 90% lean were formulated into three meat blocks containing either 10, 20 or 30% lipid. Within a fat content, ground beef was equally divided into one of six treatments: 1) control-no added ingredients; 2) BHA and BHT at .01% of the meat weight; 3) rosemary at 0.2% of the meat weight; 4) high level of sorghum at 1.0% of the meat weight; 5) medium level of sorghum at 0.5% of the meat weight; and, 6) a low level of sorghum at 0.25% of the meat weight. The ground beef was aerobically packaged and stored for 0, 1, 3, or 5 days at 4????C. pH, thiobarbituric acid reactive substances (TBARS), fatty acid methyl esters (FAME), sensory color, Minolta color space values and descriptive sensory evaluations were determined. Antioxidant addition reduced TBARS values and increased hardness (P<0.020) and springiness (P=0.002) over time compared to controls. The addition of the high sorghum bran level resulted in lower raw color scores (2.0 vs. 2.9) (P<0.0001) and slightly increased bitter basic taste (2.47 vs. 2.65) (P=0.0069) when compared to control patties. The high sorghum level slightly increased pH (6.33 vs. 6.41) (P<0.0001) and resulted in darker (P<0.0001) and less yellow colored (P<0.0001) patties. With storage, patties had higher pH (P<0.0001) and color space values decreased (P<0.0001). Sensory properties of the patties differed across fat levels (P<0.05); however, interactions between fat level and antioxidant treatment were not significant (P>0.05). Moreover, the addition of sorghum bran at low levels can retard oxidative rancidity in ground beef patties without causing detrimental color changes and negatively affecting sensory attributes.Item Effects of Storage Container Color and Shading on Water Temperature(2012-07-16) Clayton, James BrentRainwater harvesting (RWH) is a method of capturing rainfall from a catchment surface and storing it for later use. Though it has been around for thousands of years, its popularity and use has been increasing in recent years and water quality within RWH systems has become a concern. Water temperature is a parameter of water quality and storage container color and shading affect this temperature. Four different colors and three different shadings were applied to twelve rainwater storage barrels. Water temperature of these barrels was measured over twenty weeks during a Texas summer. During the initial ANOVA model, it was determined that the color and shade variables had an interaction and thus both together had an effect on the water temperature. Though the individual treatment variables could not be analyzed and compared statistically, the trends showed that light colors and higher shading caused lower water temperatures in the storage containers. Also, the color had more pronounced effect than shading on water temperature inside the barrels.Item Improving the Flavor of Ground Beef by Selecting Trimmings from Specific Locations(2012-08-17) Harbison, Amanda 1989-We hypothesized that carcass subcutaneous fat location would affect sensory and quality traits. Five carcass fat sources were tested: brisket, chuck, plate, flank, and round. Ground beef was formulated using each fat source and extra-lean beef trim (>95% lean) to contain 80% lean trim and 20% fat trim. Patties (100 g) were evaluated for color, lipid oxidation, fatty acid composition and consumer evaluation. Flavor was analyzed using a Gas chromatography with mass spectrometry (GC/MS) on the headspace above a cooked (74 degrees C) patty in a heated (60 degrees C) 473 mL glass jar with a solid phase micro-extraction (SPME) fiber. Color, thiobarbituric acid reactive substance assay (TBARS), consumer sensory, and cook/freezer loss data showed no differences (P > 0.05) among carcass locations. Percentage stearic acid was lower (P = 0.044) in the brisket than in the chuck and flank. The brisket was higher in percentage cis-vaccenic acid (P = 0.016) and in the saturated fatty acid to monounsaturated fatty acid ratio (P = 0.018), and lower (P = 0.004) in the percentage of total saturated fatty acids than all other sources of subcutaneous fat. Butanedione was highest (P = 0.013) in the flank and plate fat. Brisket tended to be higher (P = 0.054) than flank, plate, and round in 1-octen-3-ol. Brisket was higher (P = 0.008) than chuck, flank, and round, but not different (P > 0.05) than plate in octanedione. Brisket was higher (P = 0.003) than all other sources for beefy aroma. Flank was higher (P = 0.047) than chuck and round for chemical aroma. Brisket was higher (P = 0.004) than all other sources except flank for floral aromas. Plate was higher (P = 0.029) than all other sources for heated oil aromas. For secondary aroma descriptor, round was higher (P < 0.001) than flank, plate, and chuck for dairy. While differences in some key fatty acids and aromatics existed among carcass locations, when the fat was diluted with a common lean source, fat source did not have a negative effect on sensory or quality traits. Therefore, formulating ground beef using subcutaneous fat from specific locations on a carcass may improve the beef aromatics without negatively affecting sensory or quality traits.Item Lactate dehydrogenase regulation of the metmyoglobin reducing system to improve color stability of bovine muscles through lactate enhancement(2009-05-15) Kim, Yuan HwanThe primary objectives of this research were to characterize the involvement of lactate dehydrogenase (LDH) in color stability of physiologically different bovine muscles, and to investigate the influence of lactate enhancement on the myoglobin redox state of bovine muscles. In experiment 1, three different bovine muscles; Longissimus lumborum (LD), Semimembranosus (SM), Psoas major (PM) were (n=7 respectively) cut into steaks, and displayed for 7 days. Instrumental color, LDH-B, LDH isozyme expression, and NADH were measured. In experiment 2, strip steaks (n=8) were cut into half, and one side was injected with oxamate (LDH inhibitor), and the other was injected with water. Surface color, LDH, and NADH were measured after 10 days. In experiment 3, the three bovine muscles (n=10) were enhanced with solutions containing lactate and/or phosphate. Steaks were stored and displayed for 14 days. Instrumental color, LDH-B, total reducing activity (TRA), and NADH were measured. In experiment 4, fifteen beef strip loins were divided individually into four equal sections, and one of six treatments containing phosphate and/or calcium lactate with or without irradiation (2.4 kGy) randomly assigned to each loin section (n=10). Steaks were packaged in highoxygen modified atmosphere package, irradiated, stored in the dark at 1?C for 14 days. Instrumental color, TRA, lipid oxidation, and NADH were measured. LD remained the most red, whereas PM was most discolored. LD had a significantly higher level of LDH-1 responsible for LDH-B activity as compared to SM and PM. Consequently, LD had a higher LDH-B, and more NADH (p < 0.05). Inclusion of oxamate inhibited LDH-B, decreased NADH, and consequently discolored more. Potassium lactate enhancement led to more NADH through elevated LDH flux and subsequently increased (p < 0.05) color stability of LD and PM throughout display. Loins with calcium lactate/phosphate maintained the most stable red color during display. Calcium lactate/phosphate in loins increased NADH concentration, TRA, and were the least oxidized over display. These results confirm the involvement of LDH in meat color stability through replenishment of NADH. Lactate enhancement promotes meat color stability by providing superior antioxidant capacity and increased reducing activity of myoglobin by elevating NADH concentration.Item Pax7 Expression and Color Pattern Development in Two Populations of Metriaclima ‘msobo’ from Lake Malawi, AfricaAnzaldua, Sonya; Kidd, Michael R.In Lake Malawi, 450-600 species have evolved from one riverine ancestor within the past million years. The dynamic speciation of Lake Malawi’s endemic fauna has coincided with a diversification of color patterns, driven by sexual selection. Little is known about the genes determining male color pattern, despite its importance during population divergence and speciation. This study attempts to identify genes underlying the divergence of male color patterns between two populations of Metriaclima ‘msobo’ from Lake Malawi. Adult males from the Lundo population display blue and black vertical bars, while adult males from the Magunga population have blue and black blotches. The Magunga color pattern is similar to the common orange-blotch (OB) pattern observed in female cichlids, which is controlled by overexpression of the Pax7 gene. The major time points for individual color pattern development were on days 11, 16, and 23. The role of Pax7 was tested on the Magunga specific color pattern using qPCR to examine gene expression during color pattern development between the barred and blotchy populations. Primers for Pax7, as well as for two housekeeping genes (GAPDH and beta-actin), were designed and optimized to normalize qPCR data. Several embryos from three Metriaclima ‘msobo’ species—each from days 11, 16, and 23—were sampled in preparation for qPCR. The total RNA from each of these embryos was analyzed through the Experion chamber and was of optimum purity. cDNA samples were run through qPCR with the optimized primers, combined with SYBR Green fluorescent dye. Bio-Rad qPCR software was used to calculate the amount of Pax7 expression relative to that of the housekeeping genes. The analysis of variance showed that while there was a trend of expression within the Magunga embryos, the standard devations and errors were too large. However, there was no significant difference in Pax7 expression between the Magunga and Lundo populations.Item The relationship between cheliped color and body size in female Callinectes sapidus and its role in reproductive behavior(Texas A&M University, 2004-11-15) Williams, Kirsten LaureneMany species use color during courtship displays, with the more colorful individuals often selected as potential mates. Female blue crabs, Callinectes sapidus, display prominent red markings on their chelipeds, which is absent in males. I tested the hypothesis that females use this sexual dimorphism as an effective signal to potential mates. Body size was positively correlated with size of the colorful pattern on the crusher dactyl. Digital imaging techniques were used to examine and quantify a pattern of coloration in the female blue crab. Morphometric measurements were made using digital images of the carapace and chelae of crabs collected along the Gulf of Mexico coast in Galveston, Texas. Color complexity was examined on digital images of the chelae using Adobe? Photoshop? and Image J. Specific wavelengths were selected and their presence within the attribute quantified and evaluated. To determine whether male blue crabs prefer more colorful females, males were given a choice between females of different female coloration. Males displayed more often and directed more courtship displays towards the more colorful females. I hypothesize that male blue crabs use cheliped coloration as a visual cue for mate selection.