Boston University. University Professors Program Senior theses. / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-02

<p>A common modification of starch is esterfication with anhydrous octenyl succinic acid (OSA).  The modification makes the polymer surface active and it also incorporates a carboxyl group to the starch, which can be negatively charged. The characteristics of OSA starch make it interesting for usage in combination with egg yolk proteins in food emulsions. It is not only the individual ingredients that affect the product; interactions between ingredients and ingredient-dispersion medium have a great impact on factors such as structure and stability. Knowledge about how the interactions affect emulsion properties would make it possible to predict the behavior of an emulsion, which would be a great advantage in the formulation of food emulsions. Therefore, this is a subject of interest.</p><p>The purpose of this master thesis was to further investigate the interactions between OSA starch and α – β-livetin in solutions and in emulsions. First, the charges of the macromolecules were studied by titration. Interactions in solution were then analyzed through turbidity and solubility measurements. The adsorption of OSA starch onto livetin and the interfacial rheology were also studied. Finally, an emulsion stability experiment was made.</p><p>Strong interactions between the two macromolecules were observed in solutions at pH 4.0. This was probably due to hydrophobic interaction; however it could also be explained by electrostatic interaction. In the emulsions the adsorption of starch onto livetin was highest at pH 4.5, and then decreased with increasing pH values. The absence of OSA starch adsorption at pH 4.0, despite the strong interaction in solution, could be explained by complex formation immediately in solution. Less starch would then be able to reach the interface and adsorb. In the interfacial rheology experiments, an indication of decreased complex dilational modulus of the interfacial layer, caused by OSA starch addition was seen at low pH values. This could be due to aggregation of the proteins and formation of an uneven interfacial layer. OSA starch would then be able to adsorb and disturb the elasticity. Some differences in the stability of an emulsion only containing livetin, and an emulsion with both livetin and OSA starch could be observed. However, more investigations are needed to be made to understand the underlying mechanisms.</p>

A common modification of starch is esterfication with anhydrous octenyl succinic acid (OSA).  The modification makes the polymer surface active and it also incorporates a carboxyl group to the starch, which can be negatively charged. The characteristics of OSA starch make it interesting for usage in combination with egg yolk proteins in food emulsions. It is not only the individual ingredients that affect the product; interactions between ingredients and ingredient-dispersion medium have a great impact on factors such as structure and stability. Knowledge about how the interactions affect emulsion properties would make it possible to predict the behavior of an emulsion, which would be a great advantage in the formulation of food emulsions. Therefore, this is a subject of interest. The purpose of this master thesis was to further investigate the interactions between OSA starch and α – β-livetin in solutions and in emulsions. First, the charges of the macromolecules were studied by titration. Interactions in solution were then analyzed through turbidity and solubility measurements. The adsorption of OSA starch onto livetin and the interfacial rheology were also studied. Finally, an emulsion stability experiment was made. Strong interactions between the two macromolecules were observed in solutions at pH 4.0. This was probably due to hydrophobic interaction; however it could also be explained by electrostatic interaction. In the emulsions the adsorption of starch onto livetin was highest at pH 4.5, and then decreased with increasing pH values. The absence of OSA starch adsorption at pH 4.0, despite the strong interaction in solution, could be explained by complex formation immediately in solution. Less starch would then be able to reach the interface and adsorb. In the interfacial rheology experiments, an indication of decreased complex dilational modulus of the interfacial layer, caused by OSA starch addition was seen at low pH values. This could be due to aggregation of the proteins and formation of an uneven interfacial layer. OSA starch would then be able to adsorb and disturb the elasticity. Some differences in the stability of an emulsion only containing livetin, and an emulsion with both livetin and OSA starch could be observed. However, more investigations are needed to be made to understand the underlying mechanisms.

The purpose of this study is to investigate the wintertime distribution of the fish eggs along the coast of southwestern Taiwan, and to elucidate the fish spawning ground in this area. Moreover, the distribution of striped mullet eggs was also investigated. Two kinds of sampling methods were used in this study, including the surface and vertical trawling. The former applied vertical and oblique towing along the coastline. One sampling was proceeded in November, December 2000, and January 2002 by R/V Ocean Researcher 3 at three transects vertically along the coastline at 10 to 1140 meters deep in Budai, Jiading, and Fangliau. The other was proceeded in November 2000, January, December 2001, and January 2002 parallelly along the coastline at 8 sites from Budai to Fangliau. Besides, the vertical sampling employed in December 2001 and January 2002 by R/V Ocean Researcher 1 in the Taiwan Strait was also analyzed. A total of 5909 fish eggs were obtained from three sampling nets, NORPAC, cyclindricalconic net, and bongo net. All together 4 families, 2 genera, and 2 species of fish eggs, including Myctphiformes Synodontidae, Engraulidae, Tetraodontiformes Tetraodontidae, Scorpaeniformes Triglidae, Muglidae, Clupeiformes chirocentru hyposelosoma, Salmoniformes Polyipnus polli, and Allopus japonicus were found. The fish eggs that couldn¡¦t be identified were sorted into 41 groups by the egg shape, size, and membrane pattern. The four most abundant fish eggs were Muglidae, Engraulidae, dead eggs, and group CV. The fish eggs abundance decreased from inshore to offshore at two transects in Jiading and Fangliau. But it was contrary at the transect of Budai. The same pattern also appeared in the distribution of Muglidae eggs. In the area of inshore water where waterdepth from 15 to 25 meters, higher abundance of total eggs, Muglidae, and Engraulidae were found at the southern site. Muglidae eggs were the most abundant in December, but Engraulidae eggs didn¡¦t appear in this month. 33 fish eggs that might be striped mullet were sampled by OR1 at the edge of 21 ¢J isotherm where China Coastal Current met Kuroshio Current. The hydrographic variation in the year from 2000 to 2001 was affected by tides and topography, whereas in the year from 2001 to 2002 was influenced by Kuroshio. Higher fish eggs abundance found at Linyuan may due to the turbulence of Kao-Ping submarine canyon.

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Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaf 68). Also available via the Internet.