Master of Science / Food Science Institute / Elizabeth Boyle / To evaluate the effect of extended post-harvest hanging time on pork sides and the microbial shelf-life of fabricated steaks, aerobic plate count (APC), Enterobacteriaceae (EB), yeast and mold populations, pH, and moisture content of pork sides hung for 21 days at 0±1°C was determined. After hanging, blade steaks fabricated from these sides were vacuum packaged, stored up to 35 days at 0±1°C, and evaluated for APC, EB, yeast and mold populations, and pH. Carcass cooler temperature and percent relative humidity, measured every hour during storage, averaged 0±1°C and 87.3% (66-100%), respectively. Pork carcass surface moisture content declined (P ≤ 0.05) from 65.1% on day 1 to 50.5% on day 21. The carcass pH was similar (P ≥ 0.05) at 5.88 on days 1, 7, and 14; however, by day 21 the pH declined (P ≤ 0.05) to 5.72. The flank, shoulder, and jowl were sampled on pork carcasses. There was no day effect for carcass APC; however, there was a location effect. The jowl had the highest (P ≤ 0.05) APC with 1.21 log CFU/cm². There was no carcass location or day effect for EB or mold populations, but there was a carcass location and day effect for yeast populations. The detection limit (DL) for EB and yeast and mold populations on pork carcass samples (n = 240) was 0.06 and 0.41 log CFU/cm² for the shoulder and flank, and jowl, respectively. For EB and mold populations, 98.8 and 97.9% of carcass samples, respectively, were below the DL. For yeast populations, 37.5, 45.0, and 63.8% were above the DL for flank, shoulder, and jowl, respectively. On days 1, 7, 14, and 21, 60.0, 55.0, 53.3 and 26.6% were above the DL, respectively, for carcass yeast populations; however, none were greater than 2.83 log CFU/cm². The pH of pork steaks was 5.69-5.89. There was a day effect for APC on pork steaks. The initial APC of steaks was 1.61 log CFU/g, increasing (P ≤ 0.05) to 5.06 log CFU/g on day 35. There was a day effect for EB and mold populations; but not for yeast populations. The DL for EB and yeast and mold populations on pork steaks (n = 102) was 0.70 log CFU/g. On days 0, 7, 14, 21, 28, and 35, the percent of EB populations above the DL on pork steaks were 0.0, 0.0, 23.5, 41.2, 94.1, 41.2%, respectively, however, none of the steak samples exceeded 4.40 log CFU/g. For mold populations, 100.0% of steaks were below the DL on days 0, 7, and 14. On days 21, 28, and 35, 18, 24, and 12%, respectively, were above the DL. None of the steak samples exceeded 2.68 log CFU/g for mold populations. For yeast populations, 56.8% of pork steaks samples were above the DL, but none were greater than 3.69 log CFU/g. These results indicate that pork carcasses and vacuum packaged shoulder blade steaks fabricated from these carcasses have acceptable quality for 21 and 35 days, respectively, when stored at 0±1°C after harvest.

Master of Agribusiness / Department of Agricultural Economics / Glynn Tonsor / To remain competitive in an ever changing pork industry, Hormel Foods required careful evaluation of advertising forecast accuracy. This study determines forecasting accuracy for bone-in loins, boneless loins, butts, and ribs pricing within Hormel Foods and determines the relationship between forecast horizon (how many weeks forward in pricing) and forecasting accuracy of these products. The challenge required the data collection of the advertising pricing quotes for the sale price in comparison to the forecasted price. Several different forecasting combinations were examined to determine the ideal combination. The focus of this research was to determine which forecast or combination of forecasts was preferable for Hormel Foods. Findings include that each commodity and weeks out front have a different preferred forecast or combination of forecasts when analyzing root mean square errors. Four forecasts (three forecast companies and the United States Department of Agriculture actual markets at the time of forecasts) were observed with one forecast company rarely utilized in the preferred forecasting combinations and therefore the potential exists for a cost savings that affect the bottom line profitability of the division. In addition, economic models presented in this study explain the errors (both raw and percentage based) in relation to the forecast companies, weeks out front forecasted, and specific commodity differences.

Master of Agribusiness / Department of Agricultural Economics / Allen Featherstone / For the past 25 years, Free Trade Agreements (FTA) in Asia have been increasing. This allows for a potential expansion of exports into Asia for a variety of goods. However usually these agreements have not covered agricultural products. The most recent multilateral agreement currently includes agricultural products and agricultural trade. U.S. pork exports have been on the rise with Asian countries. Trade openness with Asian countries allows U.S. pork companies to gain a market in the region. This thesis estimates the economic impact that FTA’s and multilateral agreements have on pork exports, through the level of open markets measured by Freedom House. Using regression analysis, this research examines the determinants to U.S. pork exports, where trade openness is a major independent variable. Pork is a popular meat preference in East Asia. A regression analysis was estimated to determine the shift along the demand curve of U.S. pork exports to three East Asian countries, China, Japan, and South Korea. Overall all three countries showed their trade openness being weakly associated with the U.S. pork export demand to that particular country during the years of 1995–2013.

Master of Science / Department of Animal Sciences and Industry / John A. Unruh / The objective of our study was to explore relationships between Japanese color score (JCS) and pork-quality attributes and develop equations to predict JCS. Pork carcass traits in population one (n = 781) was used to develop prediction equations and population two (n = 684) was used to test the equations for accuracy. Pearson's correlation coefficients found firmness, ultimate pH, drip loss percentage, L*, a*, b*, hue angle, and chroma were significantly (P < 0.01) correlated to JCS. Correlation loading found 96% of the variation in firmness, pH, drip loss percentage, L*, a*, b*, and hue angle explained 81% of the variation in JCS. Three prediction equations were developed using these traits. Averages for population one traits were used to develop the initial prediction equations. Predicted JCS, which fell within [plus or minus]0.25 of the actual JCS, were retained and multiple linear regression (MLR) was run, resulting in the first prediction equations. Data from population two were then used to evaluate the success of these equations. Equation one using firmness, pH, drip loss percentage, L*, a*, b*, and hue angle was: JCS = 12.698 – (0.00007199 x drip loss) + (0.09008 x pH) – (0.01128 x firmness) – (0.226 x L*) + (0.06923 x a*) – (0.0201 x b*) + (0.02143 x hue angle); r[superscript]2 = 0.916. For the test population, 98.53 and 67.25% of the observations were predicted within [plus or minus]0.50 and 0.25 of the actual JCS, respectively. The second prediction equation, developed utilizing instrumental color measures of L*, b*, and hue angle was: JCS = 15.255 – (0.259 x L*) – (0.213 x b*) + (0.02518 x hue angle); r[superscript]2 = 0.931. For test population, 92.40 and 55.70% of the observations were predicted within [plus or minus]0.50 and 0.25 of the actual JCS, respectively. The third prediction equation developed utilizing L*, a*, and b* was: JCS = 12.920 – (0.219 x L*) + (0.07342 x a*) – (0.02166 x b*); r[superscript]2 = 0.906. For test population, 97.80 and 68.22% of the observations were predicted within [plus or minus]0.50 and 0.25 of the actual JCS, respectively. All prediction equations predicted 92% or more of the JCS observations within [plus or minus]0.50 and would be useful when sorting pork carcasses for export to valuable Asian markets. The second and third prediction equations would be advantageous as they require fewer measurements and could be more rapidly collected.

Please read the abstract in the front section of this document. / Dissertation (M Inst Agrar (Food Production and Processing))--University of Pretoria, 2005. / Food Science / unrestricted

A stratified sample of 420 market hogs representing the seven 10- pound incremental carcass weight classes from 140 lbs. to 210 lbs. , and the nine last rib back fat classes from less than .8 inches to 1.5 inches, or greater, within each weight class were analyzed to determine carcass value and yield of wholesale cuts. Simple correlation coefficients were calculated between each of the carcass measurements. The carcass yield data were manipulated by multiple regression procedures to achieve a series of equations for predicting the weights of the primal cuts. The benefits of being able to predict the weights of the primal cuts were discussed. A procedure for developing a premium/discount matrix was explained . The fo rmulae for developing the matrix were explained. The necessary assumptions were also explored. A procedure for evaluating a premium/discount matrix was developed. The impact of an industry-wide carcass merit program was discussed.

This research focused on studying the sensory quality of low fat bacon when pale, soft and exudative (PSE) pork is used during processing. Low fat bacon is different from normal bacon in that the amount of visible fat in low fat bacon has been reduced. This is as a result of consumer interest in weight control and cholesterol, creating a demand for meat and meat products with reduced fat levels. PSE pork is a condition in which certain muscles are very pale, soft and watery. It is produced when the rate of post-mortem glycolysis is fast and a high level of acidity is reached while the carcass temperature is still high. Different researchers have reported that PSE pork absorbs less brine during curing and this may have a negative effect on the sensory quality and acceptance of both the uncooked and cooked finished products as it is mainly the curing brine that is responsible for the development of the typical colour, flavour, aroma and texture associated with cured meat products. Thirty pig carcasses, 15 PSE and 15 normal pH, suitable for production of low fat bacon, were selected over a period of three weeks at an abattoir in Olifantsfontein to study the effect of PSE meat on the sensory quality of low fat bacon. The carcasses were further processed into low fat bacon at a meat processing plant. Data were collected on the % brine uptake of PSE and normal pH meat after curing; the rating scores on the descriptive sensory attributes of both PSE and normal pH low fat bacon and the % salt concentration and residual nitrite of PSE and normal pH low fat bacon. A consumer test to determine the buying preferences for packaged PSE and normal pH low fat bacon and the eating quality preferences of cooked PSE and normal pH low fat bacon was also conducted. No significant difference (p > 0.05) was found in the % brine uptake between PSE and normal pH meat. There were no significant differences (p > 0.05) in the descriptive sensory attributes of PSE and normal pH low fat bacon. The residual nitrite concentration of normal pH low fat bacon was significantly higher than that of PSE low fat bacon. There was however no significant difference (p > 0.05) in the % salt concentration of PSE and normal pH low fat bacon. Correlation matrices showed significant positive correlations (p ≤ 0.05) between % brine uptake and % salt concentration and between % salt concentration and perceived saltiness of normal pH low fat bacon. For PSE low fat bacon, the correlations between % brine uptake and % salt concentration and between % salt concentration and perceived saltiness was not significant. The correlation between % brine uptake and residual nitrite content was however not significant (p > 0.05) for both the PSE and normal pH low fat bacon. A significantly higher number of consumers indicated that they would prefer to buy samples representing PSE low fat bacon. The pale colour of PSE meat was not masked after curing, which was noticed by the consumers during the evaluation of buying preferences for PSE and normal pH packaged low fat bacon. However, regarded as even more important than colour, the consumers mentioned fat content as the main deciding factor for purchasing low fat bacon. No significant difference (p > 0.05) was found in the preference for the eating quality of cooked PSE and normal pH low fat bacon. It was concluded that PSE meat can successfully be used to produce low fat bacon products of consistent quality. This conclusion is drawn from the analytical sensory test results, where the use of PSE meat did not affect the sensory quality characteristics of low fat bacon. For low fat bacon, fat content is an important factor, regarded as very influential to consumers when making purchases. It is therefore important to produce products with consistent fat content according to specifications. / Dissertation (M Inst Agrar ( Food Production and Processing))--University of Pretoria, 2002. / Food Science / unrestricted

The research is motivated by the significant increase in multiproduct mergers in the meat-protein processing sector, whereby the largest firms now process beef, pork, and chicken. This thesis conducts a theoretical merger analysis, accounting for both within- and across-submarket substitution of demand related goods. The model developed is suitable for analyzing markets in which there are identifiable consumer submarkets within a larger market. The results indicate two primary findings. The first finding is that Bertrand firms have a unilateral incentive to merge. Firms involved in a given merger increase profit, as well as those not included in the merger. Second, it is found that without sufficient realized scope economies by the merged firm, significant anticompetitive price increases are likely. However, as substitutability within and across submarkets tend towards each other in magnitude, the required cost reductions for welfare neutrality increase vastly. Additionally, guidelines for future empirical analysis are discussed.

Sodium lactate and acetic acid derivatives were evaluated for their effects on color retention, microbial growth (TPC), oxidation (TBARS), and sensory attributes of hot-boned pork sausage patties that were stored under retail store display conditions over time. Treatments included: (a) 2.5% sodium lactate 60% solids (L), (b) 2.5% buffered vinegar pH 6.5-8.0 (V), (c) 2.5% sodium lactate and vinegar 52/48% mixture (LV), (d) control with 0.02% BHA/BHT (C), and (e) negative control without additives (NC). Overall acceptability of day 17 LV and L treatments were not different (P>0.05) from day 14 treatments. These results revealed that the L and LV sausage patties retained sensory acceptability and microbial quality from day 14 through day 17 as opposed to other treatments. Additionally, sausage patties with 2.5% LV maintained color (redness) and overall acceptability throughout 17 days of shelf-life when held in retail conditions, when compared to other treatments.

The effects of deionized water and PSE pork percentage on the quality of smoked deli ham and retorted pouched ham with and without non-meat adjuncts were evaluated. Product quality was determined through evaluation of water holding capacity, cooked color, protein-protein bind, and sensory quality. A randomized complete block design with either three or four replications was utilized to test treatment effects in three separate experiments. The retorting process showed the potential to reduce the effect of PSE meat on color that is present in raw material and smoked deli ham. In retorted ham, modified food starch and soy protein concentrate reduced (p<0.05) cook loss and starch improved color. Deionized water can be utilized to improve yields (1 %) in smoked deli hams, and 25 % pale pork can be used without negatively affecting (p>0.05) sensory or instrumental quality in a retorted pouched ham product. Modified food starch can also be utilized to increase yields in a retortable-pouched ham without significantly affecting sensory quality.