Gelatin was extracted from shark and salmon skins by an enzyme aided process. A three factor, two level central composite rotatable design was used to optimize the process. The factors were namely, enzyme: dry fish skin weight ratio, incubation time, and temperature. The data were analyzed by response surface methodology to determine the optimum conditions for the deproteinization, demineralization and extraction process variables. / Optimum conditions for deproteinization of shark skin by trypsin was about 25°C for 3h, and an E/S ratio of 0.08% (w/w). That for salmon was optimum at 25°C for 1 h with an E/S ratio of 1:1000. The ash content of the shark skins was reduced to over 80% at optimum demineralization conditions of 0.7M citric acid at 25°C for 3h. / Demineralised salmon skins treated with pepsin at an E/S ratio of 0.02% (w/w) for 1h at 25°C resulted in maximum gelatin yield ranging from 7--8%. For shark, the maximum yield was between 18--20% at an E/S ratio of 0.02% (w/w) for 3h at 25°C. The chemical and enzyme treatments had an effect on the viscosity, bloom value and molecular weight for both salmon and shark gelatins.

Cast iron pipes were installed broadly in North American water utilities. Many of these cast iron pipes are corroded and are continuous sources of Fe(II) ions in drinking water distribution systems. Recent studies have reported that soluble or particulate iron decreases water quality in distribution systems. In this study, an array of bench scale experiments were conducted to evaluate the impact of most common water parameters (e.g., pH, PO4, Cl2, and DOM) on the oxidation rate of Fe(II) ions, and on the formation of iron suspense in synthetic water samples. This was accomplished using a 24 full factorial design approach at a 95% confidence level. This study demonstrated that a lower content of iron suspension color, turbidity, and smaller particle size would appear to be obtained in presence of a phosphate based corrosion inhibitor at a pH value of 6.5 compared to a pH value of 8.5. To investigate the impact of Fe(II) ions, phosphate, pH and reaction time, and their interaction on DBPs formation in water samples, this study was conducted following an experimental design approach. Considering all the significant (α = 0.05, p < 0.05) factors, mathematical models for HAAs and THMs prediction were developed using 80 experiments. The models’ adequacy was checked thorough the statistical and graphical diagnostics. Different sources of natural water samples collected from three main water treatment plants in Halifax, Canada, were used to validate the models. This study suggested that the models’ performance were found to be excellent under a wide range of studied variables. Consequently, the most predominant iron oxides (goethite and magnetite) were used to investigate their impact on chlorine decay and DBPs formation study. Goethite and magnetite were also used for the adsorption of DBPs precursor (DOM). The DOM adsorption data illustrated to fit well with the Langmuir adsorption isotherm, indicating monolayer coverage. Molecular weight (MW) distributions of DBPs precursor (DOM) revealed that the higher molecular weight fractions adsorbed preferentially onto goethite followed by magnetite surface. The change of MW distribution of DOM was found to be in reasonable agreement with the change of DBPs formation in iron-water systems.

A growing interest in sustainable development has made efficient utilisation of starting materials and, if they occur, by-products become increasingly important. Vast amounts of by-products are generated by the forestry and food industry. Incineration for energy production is one way to make use of these by-products but some of them contain compounds that would have an increased value if they were extracted, so called “high value species”. The by-products are often very complex, so reliable methods for analysis of the high value species are required in the development of processes to utilise them. A wide range of compounds can be analysed using chromatographic separation coupled to mass spectrometry, making it a powerful tool in the evaluation of methods for extracting high value species from industry by-products. This thesis is based on four studies of potential high value species. In the first study, methods were developed to differentiate isobaric flavonoids and then use this knowledge to determine the identity of the flavonoids in three different plant extracts. In the second study, three different methods to extract betulin from birch bark were evaluated regarding extracted amount and purity of betulin. One of the methods was then investigated in industrial scale using a model approach. In the third study, the flavonoid contents of lovage were determined and other major extracted compounds were investigated by high performance liquid chromatography coupled to electrospray ionisation mass spectrometry. Gas chromatography and supercritical fluid chromatography were used to obtain complementary information about major components. In the fourth study, high resolution mass spectrometry utilising two different types of fragmentation was used with the purpose of overcoming the shortcomings of the methods developed in the first study. The results indicated that it would be possible to develop methods compatible with chromatographic separation for differentiating different types of isobaric substituents. The ability of performing sequential fragmentation was used to investigate some isobaric aglycones by creating spectral trees, and unique pathways were found for each of them.

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Proximate analysis of the commercial shrimp meat waste samples indicated the presence of 94.6% protein and 4.2% fat on a dry basis. The HPLC analysis revealed the presence of 17 amino acids (proline most abundant) and 7 sugars (ribose being the most abundant). The changes in the concentration of the amino acids and sugars after heat treatment, are explained based on their interaction through the Maillard reaction and by the thermal hydrolysis of proteins and polysaccharides present in tissue. Carotenoid pigments ($ beta$-carotene, canthaxanthin, astacene, and astaxanthin monopalmitate) were extracted and separated by thick layer chromatography. Their structures were identified tentatively by thick layer chromatography (TLC) and subsequently confirmed by Fourier transformed infrared (FT-IR) spectroscopy. Lipids were separated and categorized into glycerides, sterols, and phospholipids by thin layer chromatography while flavor-active components were extracted by different organic solvents into acidic, basic, and neutral fractions and their sensory properties determined. The flavor profile of the raw and cooked shrimp meat waste revealed the presence of 59 compounds in raw shrimp compared to 44 in cooked. The components identified were of different functional groups, including fatty acid esters, long chain alcohols, aldehydes, ketanes and hydrocarbons. Many fractions provided desirable aroma (nutty, fruity, floral, green woody, meaty) indicating the presence of important flavor compounds in the commercial shrimp waste. / Model studies were carried out under different experimental conditions (water content, pH), to observe the influence of these parameters on the formation of Maillard reaction products. Furthermore, a comparative study between direct injection of the aqueous solutions and its organic extracts was conducted. The direct injection of aqueous solutions revealed the presence of many water soluble components that were not detected by organic solvent extraction such as droserone and 3,9-diazatricyclo$ lbrack7.3.0.0 sp{*}.3 sp{*}.7 sp{ *} rbrack$-dodecan-2,8-dione while maltoxazine and acetanilide are example of compounds identified only in the dichloromethane extracts. Results also demonstrated that monosaccharides affected the yield of the compounds produced whereas the amino acids influenced the sensory properties of these models. Fructose and ribose were found to be the most reactive sugars in their respective categories. Thiazoles were found to be more water soluble whereas $ beta$-carbolines were more abundant in the organic extracts. The influence of water content was investigated in model systems containing fructose or glucose. It was found that water free systems decreased the yield of pyrazines and thiazoles while the formation of pyrrole and pyridine derivatives increased under dry heating conditions. The formation of Maillard reaction products were studied under different pH conditions in order to assess the effect of pH on the formation of heterocyclic compounds. Pyrazine and furan derivatives were the most affected by pH and alanine was found to be a better nitrogen source than lysine in the formation of pyrazines under different pH conditions. Finally, based on energy minimization studies using MM2 force field, a plausible mechanism was proposed for the formation of maltol in Maillard model systems.

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 69-72). / vii, 89 leaves, bound ill. 29 cm

Hemp is a plant containing many active substances and it is widely used in industry. The most common applications are the food, pharmaceutical, textile and cosmetics industries. This diploma thesis dealt with the characterization of hemp fractions, which are created during hemp processing and their potential applications. The theoretical part was focused on the description of the plant, its chemical composition and the research of the active substances in hemp. Also, its industrial use, the technique of hemp processing and the current applications of individual fractions were summarized. In the experimental part, hemp fractions were analysed in terms of nutrient content. Hemp extracts were prepared using three solvents - hexane, 70% ethanol and distilled water, which were compared based on the extraction yield of polyphenols, flavonoids, antioxidants, chlorophylls and cannabinoids. Antimicrobial effects were analysed in hexane and ethanol extracts. By-products of hemp processing were used in some screening application in biotechnology, cosmetics and nutrition. The results show that the extract with 70% ethanol had the highest content of active substances. From the hemp fractions, hemp trichomes and Fedora flowers had the highest content of active substances. Cannabis by-products have the potential to become valuable substrates for yeast cultivation. Face scrub containing hemp flour as an abrasive component had favourable results and was acceptable to consumers, as was the prepared hemp flour raw bar, which was evaluated to be comparable to commercially available hemp protein raw bars.

Proteins in catfish by-products were extracted by two methods: Alkaline extraction (AE) and salt extraction (SE). Properties of the fish protein isolate (FPI) were measured by protein yield and content, moisture content, SDS-PAGE protein patterns, color and texture profile, and compared with commercial surimi products. Our results showed that catfish frame had higher protein yield and color similarity with commercial products than the head; AE-FPI had higher yield and gel strength than SE-FPI; SDS-PAGE protein patterns of FPI from catfish frame by SE method was comparable with commercial surimi products. Based on the results, further optimization of the recovery yield of protein extracted by alkaline extraction method, and effect of microbial transglutaminase (MTGase) on gelation properties under various concentration and reaction time was investigated. Results indicate that the protein yield reached up to 60%, and the addition of MTGase in protein isolate effectively improved the gel forming ability.

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No description available.