No description available.

Microwave and water blanching of carrots and sweet potatoes were evaluated with respect to peroxidase inactivation, texture degradation and color changes for obtaining stable frozen stored products. Carrot slices and french fry style sweet potatoes were blanched in a 700 W domestic microwave oven as well as in boiling water for different treatment times. Blanched and unblanched samples were packaged in retort pouches and frozen stored at $-$20$ sp circ$C, and evaluated for peroxidase activity, texture and color before and after blanching, and after 3.5 and/or 7 months frozen storage. Kinetics of peroxidase activity and texture softening due to blanching was described by semi-logarithmic models. All frozen products, except unblanched samples, were of good quality at the end of 7 months storage. Small quality differences were detected in the blanched frozen samples during storage; samples blanched for intermediate times were superior. / Temperature distribution profiles were determined for model foods consisting of a starch gel with different concentrations of protein and fat, as well as commercial frozen and refrigerated prepared foods. Microwave heating of model foods showed considerable nonuniformity in temperature distribution and alarmingly low center temperatures. Prolonged lower power heating or holding after microwave heating did not always elevate center temperatures to safe levels. Addition of protein to the starch gel reduced temperature uniformity and heating rate, while added fat resulted in an opposite trend. / For the commercial foods, center temperatures reached after heating according to manufacturer's instructions were below 70$ sp circ$C indicating some safety concerns. However, longer heating time at lower power levels improved the temperature uniformity as well as the quality and appearance of these foods.

Thesis (M.S.)--University of Wisconsin--Madison, 1963. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 50-52).

Thesis (M.S.)--University of Wisconsin--Madison, 1963. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 78-79).

A peculiar problem involving cooked turkey products is the appearance of a pink color which consumers often associate with undercooking. Measurements of redness over a period of 4 days of storage were taken on 2 mm thick breast slices from 12 or 18 week old turkeys cooked at selected temperatures of 65, 75, 85 and 95 °C. An analysis of variance indicated that, unlike the age effect, temperature, storage time and their interaction were statistically significant at p<0.01 level. Proper cooking, achieved when an end-point temperature of 85 °C was reached, did not only produce a white to golden-brown color. A tinge of redness was detected by Hunter aL measurement immediately after cooking and disappeared after 3 to 4 days. A simple method developed for the evaluation of pigments in situ, using transmission spectrophotometry, revealed that the residual pink color could be caused by cytochrome c. Visible spectra and electrophoretograms of extracts from cooked breast slices supported the involvement of this pigment. The concentration of cytochrome c in these extracts was 7.9x10⁻² and 5.4x10⁻² mg/g tissue in samples from 12 and 18 week old birds respectively. However the total hemoprotein content in these same breast samples increased from 0.60 to 0.77 mg/g tissue. The method for the evaluation of pigments in situ also was modified in order to investigate the effect of air contact on color immediately after cooking. Additional absorption bands were present when meat slices were kept under anaerobic conditions. The rapid disappearance of these peaks once the meat surface was exposed to air indicated the susceptibility of other hemochromes to oxidation and therefore underlined their relative unimportance in the pinkening phenomenon. Since the above hemoproteins and hemochromes involved in the pinkening phenomenon need to be in a reduced form to give the obtained difference spectra, procedures using ultrafiltration and chromatography were established to search for reducing compounds. The reducing capacity of 1 mL fraction during the first minute of contact with a solution of hemoprotein was called hemoprotein initial reducing activity (IRA). Two groups, one above (higher molecular weight compounds or HMW) and one below (lower molecular weight compounds or LMW) 3000 daltons, were separated. The LMW had a low IRA for both myoglobin and cytochrome c. On the other hand, HMW were produced after heating at 85 °C for 10 min and strongly reduced only cytochrome c. It is postulated that the isolated material may be Maillard reaction products. / Land and Food Systems, Faculty of / Graduate

The relationships between moisture loss and oil uptake and their effects on porosity, pore size distribution and pore structure during deep-fat frying of chicken breast meat were investigated. Chicken meat samples were deep-fat fried in an industrial fryer. The frying oil temperatures were 170, 180 and 190°C and samples were fried for times ranging from 5 to 900 s.

No description available.

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains vii, 90 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 58-59).

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 124-126). Also available via the Internet.

Thesis (M. A.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.