Graduation date: 1948

Thesis (Ph. D.)--Columbia University, 1913. / Biographical. "Reprinted from the Biochemical bulletin. 1913, III."

Fish meals, particularly British Columbia herring meals, and condensed herring solubles have been studied for their nutritive properties as supplements in poultry rations. Both commercially and experimentally prepared herring meals were used in the study. Protein quality in fish meals was investigated to ascertain what degree of variability exists in commercial samples and to obtain information regarding the effects of raw material, processing temperature and storage. On the basis of the Protein Index Values commercial fish meals appeared to vary in the quality of their protein content. Much of the variability amongst different meals could be ascribed to the nature of the raw material. Experiments were carried out in which herring meals prepared under controlled conditions from material of known origin were compared. It was shown that the value as a protein source for the growing chick of meals produced under a considerable range of drying temperatures was similar. Differences in the vitamin content of fish meal were found to be responsible for differences in the rates of growth of chicks fed herring meals which had been dried at high and low temperatures. With the basal rations employed, folic acid was the limiting nutrient when herring meal was used as the sole source of supplementary protein. The folic acid content of meals prepared from similar raw material was found to be markedly affected by the temperature at which the meals were dried. Chicks and poults fed rations formulated to be complete in the known nutrients grew at a faster rate when 2.5 to 5.0 percent of herring meal was added to the rations. It was concluded that herring meal contains a factor(s) not identified with any of the known vitamins. Condensed herring solubles was shown to be an effective vitamin supplement to practical type poult rations whether or not the ration contained herring meal. Extraction of the oil from herring meals did not improve the growth response of chicks to the use of the meals as protein supplements. Normal and extracted commercial flame-dried meal and experimentally prepared low-temperature-dried meal were compared in this regard. Storage of herring meals for one year at -25°, 21° and 37°, respectively, did not appear to affect the nutritive value of the meals as protein supplements for chick rations. Chemical changes did occur in the fat present in herring meals during storage. The amount of ether-soluble material decreased with the length of the storage period and the iodine value of the ether extract decreased. The addition to the meal of 0.15 percent butylated hydroxytoluene before storage prevented any decrease in ether extractability of the fat during a 9-month storage period and considerably reduced the drop in iodine value of the extract. / Land and Food Systems, Faculty of / Graduate

Certain compounds having the "carbonyl enediol" structure ( Formula omitted) , and also sodium chloride, were studied for use in glazes for frozen whole dressed fish. Incorporation of these compounds caused, in general, formation of thicker, glazes on the fish than did water alone and the glazes so formed were relatively non-cracking. The cyclic compounds, reductinic acid (in concentration 0.6475% or 0.00568M), and 1-ascorbic acid (1.0% or 0.00568M), afforded satisfactory protection against oxidative rancidity for periods of the order of 5 to 6 months. On the other hand, the acyclic compounds, reductone (0.5% or 0.00568M), diammonium dihydroxymaleate (0.518% or 0.00568M), dihydroxy maleic acid (0.84% or 0.00568M), gave comparatively poor protection. Sodium chloride (2.0%) gave about the same protection as water alone. The antioxidants probably protect the fish against oxidative rancidity by rendering atmospheric oxygen unavailable to the indigenous fats. / Science, Faculty of / Zoology, Department of / Graduate

The thesis deals with the use of a dilatometer in studying some of the physico-chemical phenomena occurring in fresh fish flesh when subjected to freezing at temperatures ranging from 0° C to -30° C. Two different kinds of fish flesh, marine lingcod (Ophiodon elongatus) and fresh water rainbow trout (Salmo gairdnerii) were used for comparison. True freezing point determinations of samples of fresh flesh cut from the above species of fish were made and found to be the same, viz, -1.5°C (29.1°F.). The percentage of water removed as ice at varying temperatures below the initial freezing point were calculated by necessary adjustments of experimentally determined values. A permanent net decrease in volume accompanying freezing and thawing of the samples of flesh was observed and measured. This change in volume is probably due to the denaturation of the protine, and was found to be 0.075%. The coefficient of cubical expansion (∝) of anhydrous fish muscle was measured for the first time and found to have the average value of 0.000118 over a temperature range from -30°C. to +20°C. / Science, Faculty of / Zoology, Department of / Graduate

No description available.

The effect of salt (0, 0.9, 1.7, 2.5%) and pH (range 4 to 10) on surimi gels made from Pacific Whiting (Merluccius productus) was investigated. Gel-forming ability was measured by the torsion test. In general, surimi gels increased in gel strength with increased pH. Breaking shear stress increased to a greater degree than breaking shear strain above pH 7.0. The increase in gel strength was greater at higher pHs for gels made without salt than those made with salt. At neutral pH, the salted surimi showed greater gel forming abilities than the unsalted whiting surimi. Poor gels were formed at low pH (pH 4 to 6) for both the salted and no-salt surimi. These results demonstrated that pH and salt concentration had an interactive effect on the gel-forming ability of the Pacific whiting surimi and that improved gel strength at low salt levels might be obtained by increasing the pH. / Graduation date: 1993

A natural convection solar fish dryer consisting of a flat-plate solar collector, drying chamber, and an auxiliary heater was designed, constructed and tested in the Philippines. The dryer is capable of drying 5 kg of fish in 10 hours. / Water was first heated in a flat-plate solar collector then through thermosyphon effect, heat and mass was moved to the heat exchanger where heat was transferred to the air. Heated air was allowed to flow through the drying chamber where trays of prepared samples of fish were laid. Pre-drying treatment of fish similar to those used in commercial practice, were used for individual drying experiments in order to permit a general evaluation of the system. / Seven drying experiments using different fish samples were conducted and the data generated was used to determine the efficiency of the system in terms of solar energy utilization. Results indicate that the system function efficiently at a minimal water temperature increase of 10$ sp circ$C, and the dryer operates at a system efficiency of 9 per cent which compares well with the findings of Yu Wai Man (1986) which found that natural convection solar dryers operate in the efficiency range between 7 to 14 per cent.

Graduation date: 1981

Graduation date: 2000