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No description available.

Today's consumers have shown a greater concern in the relationship between dietary fat and human health. The demand for leaner meat is continuously on the rise. The reduction of fat deposits in the abdominal area of ready-to-cook fryers, considered a waste product in the poultry industry, has become a major opportunity for the researcher. Experiments were conducted to evaluate the merit of managerial practices affecting abdominal fat (AF) levels in broiler chickens. Factors studied included seasons of the year, source of the commercial broiler strain crosses, stocking densities, lighting systems, types of housing, dietary salt (NaCl) 1eve1s and feed restriction. Two housing types (open-sided and windowless) and different seasons were utilized to evaluate the influence on broiler performance and AF levels. Raising broilers from the same strain cross in an open-sided building did not affect performance and AF levels. Mean body weight (BW) were highest in fall season (1929 g ) and lowest in summer (1735 g) (p<.05) while highest and lowest % AF revels were observed in spring and winter (2.34, and 1.42 respectively). The comparative effect of feeding regime, (full feed, FF), 95 and 90% FF), dietary salt 1evels (0, 0.25, and 0.5% of the finisher diet), stocking densities (0.06, 0.07, and 0.09 m�� of floor space per bird) and type of housing (battery cages and litter pens) were examined on broiler performance and AF lever. Ninety % FF resulted in significantly lower body weights and AF levers compared to ad libitum feeding. At 49 days of age, mean BW of broilers fed 0.5% salt were higher (P<.05) than the group not provided with salt. Altering stocking densities and rearing in battery cages failed to show any significant improvements performance and % AF. Lighting regime 12 h light (L): 12 h dark (D), recycled during the rearing period resulted in lower (p<.05) mean BW than continuous lighting regime (CL) when applied from 5 days of age. Broilers raised on 16L:8D after 21 days had comparable performance to CL. Lighting regime of 12L:12D, recycled in combination with increasing stocking densities from 0. 06 to 0.8 m�� floor space/broiler and intermittent righting of lL:3D in combination with the addition of 0.5% salt to the diet resulted in improved (P<.05) BW with no corresponding increases in AF levels. Factors such as season of the year, feeding of salt, and manipulation of light (up to 8 h dark) can be used as tools in reducing % AF and overall production costs. / Graduation date: 1993

Polymorphic crystal forms in food fats contribute to physical characteristics of the fats and consequently to their performance in fat based foods. In the present study the phase transitions associated with polymorphism behavior of common food fats were investigated. The polymorphism of butters, margarines, cocoa butter and cocoa butter products were determined and the effects of certain ingredients and conditions of temperature were studied. The following polymorphic forms were detected: sub-alpha, alpha, beta' , beta'3, beta' 2, beta, beta2, and beta1; however, not all forms were observed in all fats. Margarines contained beta' and beta forms depending on their fat constituents, while butter, cocoa butter, and fat blends consisted of alpha, beta' and beta; only the beta' form of butter showed a sharp melting point. Rapeseed oil exhibited alpha, beta1 and beta 2 forms, depending on the degree of hydrogenation. / DSC measurements of fat blends were correlated with viscosity index measurements from Universal Material Testing Machine (UMTM) using a single cycle, back extrusion technique. A correlation of R2 = 0.70 (p = 0.95) was obtained. Viscosity index decreased as temperature increased, suggesting a possible relationship between viscosity index and solid fat fraction. This suggests that viscosity index could be a potential indicator of food fat textural properties which are evaluated by DSC. (Abstract shortened by UMI.)

Knowledge of carcass merit will help the meat duck breeder identify superior stock and accelerate genetic improvement. Selection for leanness will enhance product acceptance by the consumer. Heritability values for carcass traits are in the medium-high range. Feed intake level during rearing is critical for reproduction. The objectives were to evaluate (1) the response of breast muscle thickness of the F1 progeny from parent breeders selected for maximum muscle thickness at market age and (2) the effect of 2 levels of feed restriction during development for subsequent egg production. In a commercial flock, 4842 Pekin ducks (Brome Lake Ducks Ltd.) were individually weighed and measured by ultrasound for breast muscle thickness (MT, mm) at 47 days of age. Three groups of 120 females and 25 males each were selected and allocated to the following groups: (1) control (CT), randomly selected; (2) maximum body weight (BW), and (3) maximum MT. From 7 to 23 wk old, one half of breeders followed a conventional restriction (CR) at 67 g feed/kg body weight daily, the other half were slightly more restricted following a Macdonald restriction (MR) at the same intake as CR but with a weekly skip-a-day feeding. (Abstract shortened by UMI.)

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Deep-fat fried foods have unique characteristics that attract consumers but their high fat contents must be reduced in order to provide healthy foods along with high quality. In the first part of this study, effects of frying temperature and frying pressure on the quality of partially fried breaded cheese sticks were determined. In the second part, far infrared finish cooking methods were compared to traditional deep-fat frying in terms of product quality. Increasing frying temperature significantly (P<0.05) reduced fat and moisture contents of the samples and increased crispness and exterior hardness. Pressure did not affect crust fat content of the samples significantly (P>0.05). However, increasing frying pressure resulted in the samples having higher moisture contents. Crispness and exterior hardness of pressure-fried cheese sticks were lower than traditional deep-fat fried samples. Increasing frying temperature and pressure resulted in darker sample color. Par-fried far-infrared finish cooked cheese sticks had lower fat contents than deep-fat fried cheese sticks had. Moisture contents of far-infrared finish-cooked samples were higher than those of deep-fat fried samples. Far-infrared finish cooking significantly (P<0.05) reduced crispness and exterior hardness of breaded cheese sticks. / Master of Science

Assessment methods are continually updated to adequately measure dietary intakes. Rapid Assessment Methodologies, or RAMs, are being developed to quickly measure specific nutrients. Although no perfect measure of an individual’s diet exists, diet records (DRs) are considered the most accurate assessment technique. The goal of this research was to design a short form using the frequency of consumption to detect clientele with high dietary fat intake. A food frequency questionnaire (FFQ) of 24 foods was developed based on data from national sources and on data on college students. College student FFQ ratings were compared with three-day DRs to determine the foods predicting the fat in their diet. Two RAMs, Fat Factor Short (FF Short) and Fat Factor Long (FF Long) were designed: FF Short (a shortlist of six foods) and FF Long (a longer list of 12 foods). FF Short was the preferred predictor of students consuming a high-fat diet. Short food lists should be useful in predicting dietary fat intake and assist in detecting individuals requiring further educational programs on reducing dietary fat. / Master of Science