Philosophiae Doctor - PhD / The disposal of brine effluent from inland wastewater desalination plants is a growing global problem with adverse economic and environmental implications because of the substantial cost associated with its disposal and the potential for polluting groundwater resources. Currently, the best and most economical option for brine disposal from inland desalination plants is the use of evaporation ponds, which concentrate the liquid until getting a solid waste that can be valued or directly managed by an authorized company. The effectiveness of these ponds is therefore dependent on the evaporation rate, which has previously been improved by the addition of dyes such as methylene blue. However, the addition of chemical dyes to the evaporation ponds poses a threat to the environment, wildlife, and humans.

Food security is a major concern of the 21st century, given climate change and population growth. In addition, high salt concentrations in soils affect ~20% of irrigated land and cause a substantial reduction in crop yield. Cultivating salt-tolerant crops could enable the use of salt-affected agricultural land, reduce the use of fresh water and alleviate yield losses. Innovative methods need to be developed to study traditional and novel traits that contribute to salinity tolerance and accurately quantify them. These studies would eventually serve for developing new salt tolerant crops, adapted to the harsh arid and semi-arid climate conditions. A study of 200 accessions of the wild tomatoes (Solanum pimpinellifolium) was conducted in field conditions with phenotyping using an unmanned aerial vehicle (UAV)-mounted hyperspectral camera. Six genotypes with different levels of salt tolerance were sampled for leaf pigment analyses, revealing a clear pattern for the high salt tolerant accession M007, where pigment content in the salt-treated plants significantly increased compared to their control counterparts only in harvesting campaigns 3 and 6, each performed two days after the first and second salt stress application events. Moreover, the light harvesting capacity was found to be better maintained under salt stress in the medium (M255) and highly salt tolerant (M007 and M061) accessions. Pigment quantitation data will contribute towards the groundtruthing of hyperspectral imaging for the development of remote sensing-based predictive pigment mapping methods. This work establishes a reliable quantification protocol for correlating pigment content with vegetation indices. Hence, pigment content captured by imaging techniques and validated using biochemical analysis would serve in developing a high-throughput method for pigment quantitation in the field using UAV-based hyperspectral imaging. This would serve as a tool for measuring pigment content in large number of genotypes in the field which would eventually lead to new salt-tolerant genes.

The pigments responsible for pink or red discoloration in cooked vacuum-packaged meat products {bratwurst (pork and beef), ground pork, and pork roasts} were investigated. In bratwurst, this study attempted to characterize the red pigment that appears upon refrigerated storage, and to determine the effect of pH, cooking and storage temperature, and sodium lactate on incidence of red discoloration. Myoglobin was identified in the exudate of samples with red discoloration. Myoglobin levels of cooked products were significantly lower in samples of low initial pH (5.5) or cooked to higher than normal internal temperature (74°C). Red discoloration was associated with microbial growth. Frozen samples had no red discoloration after 4 weeks storage. Microbial plate count and incidence of red discoloration were lower in samples of lower pH (5.5 vs 5.8 or 6.2), samples cooked to higher internal temperature (74° vs 68°C), and samples containing 3% sodium lactate. Further, the effects of microbial growth in raw materials (ground pork) on cooked pork color were investigated. In two trials with sow meat held aerobically at 2°C for 3 weeks, microbial load reached spoilage levels (107 cfu/g), pH increased to 6.46, and samples cooked to 71°C had red exudate, shown by absorption spectroscopy to contain myoglobin and cytochrome c. Samples cooked to 82°C received high panel ratings for red color, due to red, flocculent precipitate in exudate, but samples containing undenatured myoglobin levels received low panel ratings. In sow meat held frozen or vacuum packaged at 2°C, pH after 3 weeks was 6.03 and 6.18, and plate counts were 104 and 107, respectively, but exudates after cooking were much less red. In five trials with fresh U. S. #1 pork legs, plate counts also reached 107 cfu/g by 3 weeks storage, and pH increased from 5.99 to 6.37, but cooked samples were not red. Higher myoglobin levels in sow meat probably accounted for the red color and the high level of undenatured myoglobin remaining after cooking of high pH, spoiled samples. Finally, pink or red discoloration was investigated in the cooked U. S. #1 pork roasts. Myoglobin was the pigment responsible for pink color in pork roasts cooked to 65°C. Roasts cooked to 82°C had gray internal color after cooking, but developed pink internal color after refrigerated storage. Reflectance spectra of pink slices from roasts, cooked to 82°C, then stored for 12 days at 2°C, were charactetistic of denatured globin hemochromes or related non-nitrosyl hemochromes.

The present thesis is devoted to synthesis, through the environmentally friendly citrate sol-gel route, of YIn0.9O3 −ZnO near infrared reflective based pigments, having different chromophore elements (Mn, Cu, Fe), with the aim to add in binder and obtaining cool coatings. A “cool” coating for roofing consists of paint (or glaze) containing color pigments, which do not absorb the infrared portion of the solar spectrum. Cool coatings applied over buildings surface provide an effective solution for passive cooling of building indoors and influencing local outdoor microclimate, mitigating urban heat islands effect (UHIE). The primary purpose is to produce pigments according to an environmentally friendly route, using non-toxic raw materials, as well as short times and low temperatures for synthesis, and without residual waste. The resulting pigments must have high reflectance in the near-infrared so that they can be used in the field of cold paints. To realize the corresponding coatings, pigments were dispersed in two different binders (standard PMMA and industrial binder). For the most interesting pigments, in terms of NIR reflectance, other property, was decided to explore, which define these NIR reflective pigments as smart pigments for building application: the photocatalytic ability.

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The pink color defect in cooked, uncured turkey is a sporadic problem which can result in consumer dissatisfaction. Nicotinamide hemochrome may be one of the major pigments responsible for this defect. Reflectance (400-700 nm) methodology was developed to reliably and easily quantify (%R 537 nm/%R 553 nm; r = 0.993) the presence of nicotinamide hemochrome. Fourteen ligands were tested in a ground turkey system to determine their ability to reduce pinking in control samples and in the presence of pinking agents (1.0% nicotinamide or 150 ppm sodium nitrite). Trans 1,2-diaminocyclohexane-N,N,N’,N’ tetraacetic acid monohydrate (CDTA); diethylenetriamine pentaacetic acid (DTPA), ethylenedinitrilo-tetraacetic acid disodium salt (EDTA), and calcium reduced non-fat dry milk (NFDM) were the most effective at reducing pinking with and without pinking agents. These four ligands were evaluated in intact turkey breasts with and without added pinking agents (1.0% nicotinamide or 20 ppm, 100 ppm sodium nitrite). Ligands were evaluated at various levels (50, 100, 200 ppm; except NFDM 1.0% or 2.0%), over three storage times (1, 14, 21 days), and after two minutes of exposure to light and air. When ligands were evaluated without pinking agents, samples were generally lighter and less pink than controls. In the presence of added pinking agents, the ligands were more successful at reducing nicotinamide pink than nitrite pink. As storage time increased, samples became more pink and the addition of ligands was only successful in delaying this affect. One of the most effective ligands, DTPA, reduced the sample CIE a* value 31.7% when tested alone and 30.8% in the presence of nicotinamide. NICHEM was also effectively reduced by DTPA. In general, 50 ppm of added ligand was sufficient to produce a significant reduction in pinking. / Master of Science

No / The crystal structure of the I-phase of quinacridone was determined from non-indexed X-ray powder data by means of crystal structure prediction and subsequent Rietveld refinement. This I-phase is another polymorph than the -phase reported by Lincke [G. Lincke and H.-U. Finzel, Cryst. Res. Technol. 1996, 31, 441¿452.]. The crystal structures of the and polymorphs were determined from single crystal data. The knowledge of the crystal structures can be used for crystal engineering, i.e., for targeted syntheses of pigments having desired properties, especially for the syntheses of new red pigments.

No / Raman spectroscopic analysis of the pigments on an Italian painting described as a “Full Length Portrait of a Gentleman”, known also as the “Malatesta”, and attributed to the Renaissance period has established that these are consistent with the historical research provenance undertaken earlier. Evidence is found for the early 19th Century addition of chrome yellow to highlighted yellow ochre areas in comparison with a similar painting executed in 1801 by Sir Thomas Lawrence of John Kemble in the role of Hamlet, Prince of Denmark. The Raman data are novel in that no analytical studies have previously been made on this painting and reinforces the procedure whereby scientific analyses are accompanied by parallel historical research.

No / Raman spectroscopy is a rapid nondestructive technique providing spectroscopic and structural information on both organic and inorganic molecular compounds. Extensive applications for the method in the characterization of pigments have been found. Due to the high sensitivity of Raman spectroscopy for the detection of chlorophylls, carotenoids, scytonemin, and a range of other pigments found in the microbial world, it is an excellent technique to monitor the presence of such pigments, both in pure cultures and in environmental samples. Miniaturized portable handheld instruments are available; these instruments can be used to detect pigments in microbiological samples of different types and origins under field conditions.