No description available.

Graduation date: 1951

Graduation date: 1933

No description available.

The purpose of this work was to analyze whole kernel corn for such factors as succulence, pericarp content and size of kernels and to check for possible relationships between these values and the subjective tests for tenderness and maturity and flavor. In addition the purpose of this investigation was to accumulate values for succulence, pericarp content and kernel size for sweet corn grown in this area. All varieties were harvested in August 1952, when their moisture content was close to 70 percent. Succulence of this canned corn ranged from 24.7 to 15.2 ml. for 17 varieties; and the six varieties recommended ranged from 24.7 to 22.8 ml. Pericarp content was determined by the standard method, and it was found to be very low when compared with similar data from other sections of the country. Values ranged from 0.6230 to 1.1951 percent, and the six best varieties recommended for all factors together, from 0.6230 to 0.7872 percent. The largest diameters in inches of twenty kernels were measured with a micrometer. Size ranged from 7.0685 to 8.5005 inches for twenty kernels. The same six best varieties ranged from 7.0885 to 7.8730 inches. In addition to these three objective tests a panel of seven members graded this corn for maturity and tenderness on a basis of forty points, and flavor on a basis of twenty points. For maturity and tenderness all varieties lie between 37.1 and 26.4, with the six varieties recommended between 37.1 and 35.7. For flavor the range for all varieties is from 17.6 to 13.3. The same six varieties are from 17.6 to 15.7. Results show that the combination test proposed by Kramer can be applied successfully, and that pericarp content can be omitted in this combination test for corn grown under irrigation in this part of the country. In fact, succulence and kernel size predicted maturity with a multiple correlation of 0.936. / Graduation date: 1953

Thesis (Ph. D.)--Washington State University, May 2007. / Includes bibliographical references.

Thesis (Ph. D.)--University of Tennessee, Knoxville, 2002. / Title from title page screen (viewed Oct. 8, 2002). Thesis advisor: Matthew N. Murray. Document formatted into pages (x, 158 p. : ill. (some col.)). Vita. Includes bibliographical references (p. 151-157).

Thermal processing involves application of heat to destroy pathogenic microorganisms of public heath concern and to reduce the activity of microorganisms and enzymes that spoil the food. However, the technique is associated with considerable degradation of taste, color, texture, flavor and nutritional quality of processed foods. Data on kinetics of changes in quality factors and their temperature dependence, as well as the heat penetration behavior of the food during processing are necessary to predict and optimize the extent of quality retention. The objectives of this study were: (a) to evaluate the kinetics of thermal softening, color degradation and loss of ascorbic acid in potato (Solanum tuberosum) at selected temperatures (70--100°C) and to evaluate their temperature dependence; (b) to evaluate the effect of process variables (temperature, rotational speed, can size and nature of the covering fluid) on heating behavior of canned potatoes and (c) to determine the influence of the above process variables on process time and product quality.

Heat penetration data were obtained for a canned food model (gelatinized waxy maize starch) during processing in an agitating retort under various conditions to evaluate the effect of process variables on the heat penetration parameters (f$ sb{ rm h}$ and j$ sb{ rm ch}$) and resulting process lethality (F$ sb{ rm o}$) and cook value (C$ sb{ rm o}$). Overall heat transfer coefficient (U$ sb{ rm o}$), Hunter L, a and b values were determined. The study indicated that f$ sb{ rm h}$, j$ sb{ rm ch}$, F$ sb{ rm o}$, C$ sb{ rm o}$ and U$ sb{ rm o}$ were influenced (p $<$ 0.05) by all process variables except can headspace. Retention percentage of thiamin, ascorbic acid and chlorophyll at each process condition was estimated using the heat penetration data and documented D and z values for each quality factor. Results confirm better retention of quality factors at higher temperatures and higher rotation speeds. / Rheological changes associated with the starch were evaluated in relation to different factors and were well described by the Power law model. Apparent viscosity of the processed product was related to the cook value of the process. / Fresh vegetables were canned and subjected to end-over-end rotation. Heating times were adjusted to give approximately the same process lethality (F$ sb{ rm o}$ = 10 minutes). Processing under higher temperatures and higher rotation speeds resulted in better retention (p $<$ 0.01) of vegetable texture, while only temperature (higher the better) had a desirable effect on color. / Buffered aqueous mixtures of ascorbic acid and thiamin were sealed in glass vials and cans. At each temperature, rotation speed did not have a significant effect on the retention of either vitamin. Processing at 110$ sp circ$C yielded significantly lower retention (p $<$ 0.01) of both vitamins than at 120$ sp circ$C and 130$ sp circ$C. Estimated ascorbic acid and thiamin retention using experimental time-temperature data and published kinetic parameters showed fairly good agreement with experimental data.

Physical, chemical and sensory attributes were examined on canned green beans (Oregon 1604) of sieve sizes 3 & 4 and 5 & 6 after one and three months of storage at room temperature (RT). The green beans subjected to different pre-blanch conditions in water (T1t1: 160°F - 30 min.; T1t2: 160°F - 90 min.; T2t1: 200°F - 30 min.; T2t2: 200°F - 90 min.) were blanched in a steam exhaust line for 2 min. and 50 sec. at 208-210°F to inactivate the enzymes still active. The control (T3: direct blanch) was significantly different from the others. Heat treatment prior to blanching and the other variables (sieve size and storage) had highly significant effects on all quality attributes of canned green beans. The pH was significantly lowered by pre-blanch and by canned storage. This decrease was considerably faster for sieve 5 & 6 than for sieve 3 & 4. The lowest pH value was obtained for T1t2 and corresponded to the most firm and most green canned green beans. The effects of increasing sieve size, temperature and time of pre-blanch were significant (P ≤ 0.01) on slough. The decrease of sloughing during storage was not found to be significant. The resistance to compression and shear was significantly increased by the lower temperature of pre-blanch (160°F), which activated pectin methylesterase (PME), and also by a longer canned storage time (3 months). Larger green bean sieve size and increasing temperatures, lowered the resistance to compression and shear which was negatively correlated with pH and slough. EDTA-soluble pectins (EDTA-SP) which were significantly higher with lower temperature of pre-blanch and in smaller sieve size were not affected by storage at RT. EDTA-SP, highly positively correlated to resistance to compression and shear, showed a negative relationship with pH and slough. However, water-soluble pectin (WSP) increased with larger sieve size, longer storage and higher temperature, and declined when time of pre-blanch increased. Sensory attributes for texture, appearance, color and flavor had a high degree of correlation with chemical and physical parameters. The judges were more able to distinguish changes introduced by pre-blanch treatments than those related to different stages of storage or different sieve sizes. There was a loss of green color and an increase of yellow and brown color associated with heat treatments. While treatment T1t2 (160°F-90 min.) had the highest retention of green color, the control (T3) displayed the highest loss. Also, firmness and brine clarity of the canned green beans were improved with pre-blanch at the lower temperature (160°F). / Graduation date: 1985