Whole muscle cuts and restructured chops were conventionally cooked, microwave cooked, and precooked/ microwave reheated. Whole muscle samples had an additional treatment of blade tenderization. All samples were stored for three storage periods of 2, 15, and 21 days. Precooked samples were evaluated for appearance traits. Blade tenderization did not affect (P>0.05) the traits evaluated with the exception of texture. Precooked products had higher (P<0.05) TBA values than conventionally cooked samples of both whole and restructured chops. Conventionally cooked chops had the lowest (P<0.05) TBA value in both whole muscle and restructured cuts, the lowest (P<0.05) peak force value and the highest (P<0.05) sensory scores in whole muscle samples. TBA values increased (P<0.05) with storage time for up to 21 days. Over 21 days of storage of whole muscle samples, Warner-Bratzler peak force values and overall flavor scores decreased (P<0.05) and juiciness and texture scores improved (P<0.05). Storage did not affect (P>0.05) peak force values and sensory scores of restructured samples. / Master of Science

Consumers are often confused and reluctant to purchase products from fresh retail meat counters that exhibit significant color variations. This hesitation to purchase results in annual profit loss to the pork industry. Processes to minimize color variation remain a major focus of the industry and many meat science programs across the globe. Previously, we found inherent muscle characteristics contribute to variations in pork quality but these characteristics fail to explain the high frequency of two-toning and other pork quality defects routinely occurring in many hog processing facilities. Therefore, we hypothesized harvesting practices, such as scald alter color across muscles of the ham. Scald time was initially investigated using 32 carcasses subjected to either a 4 (n=16) or 8 (n=16) min scald time. Samples were collected before or after scalding and at 24 hrs. A 50% reduction in scald time resulted in (p < 0.0001) lighter muscle color (L*) early postmortem, although the 8 min scald treatment was lighter (p < 0.005) at 24 hrs. Although differences in pH (p < 0.0001) and color were noted, ultimate carcass temperature was not affected. To that end, we moved to validate our hypothesis in an industrial plant setting. Carcasses (n=200) were assigned treatments of 6.5 or 7.5 min scald times, and SM muscle samples were collected at 24 hrs. Surprisingly, the shorter scald time resulted in (p < 0.05) a lighter color, contradicting our first study. To explore this color issue further, we uncoupled scald from the dehairing process. To achieve this goal, carcasses (n=24) were assigned to either an 8 or 16 min time to dehair, with or without scalding. Protracted time to dehair resulted in higher ultimate pH (p < 0.005) and less color variation across the muscle (p < 0.05). Though a color gradient remained, the variation across the muscle was reduced by increasing time to dehair. These data show time to dehair affects pork quality development and suggest that delaying time to physical manipulation of the carcass may improve pork color, thus increasing consumer acceptance. / Master of Science

Once an animal is harvested for meat, skeletal muscle attempts to maintain ATP at or near antemortem levels. To maintain ATP levels postmortem, stored glycogen is catabolized to produce ATP through glycolysis and possibly oxidative metabolism. Hydrolysis of the produced ATP acidifies muscle until an ultimate pH is reached. The ultimate pH of meat directly impacts the quality characteristics of color, texture, and water holding capacity. Therefore, our research intends to describe the contributions glycolysis and oxidative metabolism play in determining ultimate pH and fresh meat quality. Traditionally, glycogen content at death was thought to be responsible for dictating ultimate pH. This was especially true in oxidative muscle with limited glycogen stores. Yet, our research indicated that in the presence of excess glycogen, oxidative muscle maintains a high ultimate pH. Rather, pH inactivation of phosphofructokinase is responsible for terminating postmortem glycolysis and brackets ultimate pH between 5.9 – 5.5. Meat with a pH below this range is uncommon. However, AMPK γ3R200Q mutant pigs produce meat with an ultimate pH near 5.3. Due to lower AMP deaminase abundance in their muscle, AMP levels are elevated late postmortem. Because AMP is a potent activator of phosphofructokinase, the aberrant meat quality from AMPK γ3R200Q mutant pigs is caused by extended postmortem glycolysis. Combined, these data further our understanding of the factors that contribute to the formation of fresh meat quality. We also characterized AMPK γ3R200Q muscle by investigating antemortem skeletal muscle lactate transport. Lactate is transported in or out of tissues by proton-linked iii monocarboxylate transporters (MCTs). Previous reports indicated that acute activation of AMPK increased monocarboxylate transporter expression in skeletal muscle of other species. Yet, it was unknown the impact chronic activation of AMPK will have on MCT1, MCT2, and MCT4 expression in pigs. Compared to wild-type pigs, the longissimus lumborum of AMPK γ3R200Q pigs increased both MCT2 and MCT4 protein expression. Our data suggest glycolytic skeletal muscle from the AMPK γ3R200Q pigs has increased capacity for antemortem lactate export from muscle and possibly increased pyruvate transport into the mitochondria. / Ph. D.

Commercial hams display variation in color uniformity across the cut surface, especially the semimembranosus (SM) muscle. This variation in fresh ham color, or two-toning, persists through further processing and contributes to production of a less desirable end product. In an attempt to understand the underlying source of this color variation, we evaluated the differences in muscle fiber-type composition and glycolytic metabolism in the SM muscle of fresh hams differing in color uniformity. Fifty-eight fresh SM muscles, ranging in color, were selected at 24 h postmortem and each partitioned into four distinct regions and three color classes based on color uniformity in the caudal region. The L* (lightness) values were greatest and a* (redness) values lowest in the most caudal portions of the muscle. The caudal portion also exhibited the lowest ultimate pH (P < 0.0001), lowest myoglobin (P < 0.05), greatest glycolytic potential (GP) (P < 0.0001) and the lowest myosin heavy chain type I isoform (P < 0.0001) abundance of all regions in 'normal' colored hams. After segregating based on L* values, the caudal region had identical pH, GP, LDH, and MyHC-I, despite significant differences in L* (P < 0.0001). These data show the most caudal aspects of the SM are indeed more prone to adverse postmortem metabolism and suggest that inherent differences in muscles of the ham may make some areas of the ham more vulnerable to temperature abuse during harvesting. / Master of Science

Sodium hypophosphite was evaluated for inhibition of growth and toxin production of Clostridium botulinum in a model meat system. Fresh comminuted pork was formulated to contain 0, 1000, or 3000 ppm sodium hypophosphite, with or without 50 ppm sodium nitrite, and 156 ppm sodium nitrite. The test formulations were inoculated with an equal mixture of 9 different strains of C. botulinum spores, vacuum packaged, pasteurized, and incubated for 60 days at 27°C. Packages were removed from incubation as swells developed and were analyzed for botulinal toxin by the mouse bioassay. In the first experiment, first toxic samples occurred at 5, 12, and 60 days of incubation for 0, 1000, and 3000 ppm sodium hypophosphite, respectively. Combinations of 1000 or 3000 ppm hypophosphite with nitrite delayed toxic swells by 17 and 14 days respectively, as compared to 6 days for 50 ppm nitrite alone. An experiment on the effects of sodium chloride on sodium hypophosphite inhibition showed that as the sodium chloride level was increased from O to 1.25 to 2.5%, hypophosphite inhibition was enhanced. For any sodium chloride level tested, increasing the hypophosphite concentration, caused a reduction in the rate of toxic swell formation. A combination of 2.5% salt, 50 ppm nitrite, and 3000 ppm sodium hypophosphite was the most effective combination tested. First toxic swell was delayed to day 24, and subsequent swells to day 33. The effects of various divalent cations on hypophosphite inhibition were studied. Cations produced no effect on sodium hypophosphite inhibition of C. botulinum. All experiments showed sodium hypophosphite to delay swell and toxin formation caused by Clostridium botulinum. / M.S.

An extensive literature examines how distributive (i.e., “pork barrel”) spending is allocated among congressional districts. Much of this research finds evidence that intra-chamber factors like ideology, party, and committee membership are the primary determinants of various forms of distributive spending. However, we know much less about how extra-chamber factors such as district-level demand and the economy impact the distribution of federal outlays. In this study, I find that district-level demand and variation in economic factors, in particular, income and unemployment, significantly predict the distribution of new bureaucratic awards in the 110th Congress. The results support the contention that districts get what they need, and this raises questions about the ability of members of powerful committees to steer awards selectively to their districts. It also provides evidence for the economic “law of increasing state activity,” by which districts with higher income levels receive a larger share of federal assistance.

The focus of this thesis was on the economic feasibility of three food processing projects. They involved freezing of pork loin and fish using cryogenic freezing and stored at $-$18, $-$12 and $-$7$ sp circ$C, and modified atmosphere packaging (MAP) of pork loin using a combination of nitrogen and carbon dioxide gases, chitosan dip and stored at 5, 10, and 15$ sp circ$C. A production plan with similar layout and capacity was adopted for the Montreal area. The benefit-cost analysis (BCA) of each project was carried out assuming that each plant operated approximately 2000 hours per annum at full capacity. Net present value (NPV) and benefit cost ratio (B/C ratio) at 8% discount rate, and internal rate of return (IRR) were determined for each project. The calculations show the NPV of $2.4 million, $1.8 million, and $3.4 million; B/C ratio of 1.09, 1.09, and 1.10; IRR of 15 %, 13 %, and 18 % for frozen pork loin, frozen fish and MAP pork respectively. All IRRs were higher compared to the 1995 return rates of TSE of 9.7 % and the average return of capital of 8.8 % for some food and beverage industries. These economic values are sensitive to changes in working hours, price of raw materials and finished products. It is also found that MAP products could be stored at temperatures up to 15$ sp circ$C. Frozen products could be stored at temperatures of $-$12$ sp circ$C and below only if the length of distribution chain can be reduced. This would decrease electricity costs up to 36% at each level of distribution. It can be concluded that the three projects are economically profitable.

<p>The United States is ranked third for global pork production as well as first in pork exports according to the USDA Economic Research Service in 2019. The majority of the commercial pork production in the United States applies some form of confinement system with environmentally adapted facilities. However, with information and easy media access to the US consumers, news and reports on different farming practices and potential issues in the animal industry have come under the spotlight. Consumers are becoming more interested in knowing what goes on behind the scenes of the commercial animal industry and where and how their food is produced. Whether it is due to personal beliefs, ethical concerns, novelty-seeking, eating experience, or choice of lifestyle, consumers are demanding diversity in their meat purchasing options. Although the commercial pork industry has shifted to fewer and larger farms in the last 40 years, small specialty farms such as heritage breed pork are on the rise to form a niche market. Large Black pig is a pasture-raised heritage breed originating in England, and it remains one of the rarest British pig breeds. Due to differences in husbandry, pasture-raised Large Black pigs consume a relatively high forage diet compared to corn-based diet used in commercial swine production. Although heritage pork has been lauded to have unique and superior quality, enhanced eating experience, and is often sold at a premium price, there are very little data on pork quality of Large Black pig compared to Duroc-sired breeds which are commonly used in commercial pork production. The purpose of this study is to fill the dearth and investigate differences in pork processing characteristics between commercial Duroc-sired and Large Black genetic lines fed high forage or commercial diets.</p><p> The study contained a total of 50 pigs: 25 Duroc-sired (DS) and 25 Large Black sired (LB) pigs. After all the pigs were weighed, the pigs were randomly assigned with heavy and light weights as blocks to two dietary treatments: Fiber (FIB) and Control (CON); and the feeding trial lasted a total of 126 days. There were 14 Large Black pigs fed fiber diet (LB FIB); 11 Large Black pigs fed control diet (LB CON); 14 Duroc-sired pigs fed fiber diet (DS FIB) and 11 Duroc-sired pigs fed control diet (DS CON). Pigs were fed either a control Corn-Soybean Meal-DDGS based diet or a high fiber diet with wheat middlings and dehydrated alfalfa meal replacing corn and soybean meal in the control diet. Diets were fed over six 21 days phases with fibrous ingredient levels increasing from 8.5 to 30 percent of the diet with sequential dietary phase from 1 to 6. Pigs were harvested at a common age with some variations in body weight between genetics (DS 125 ± 2.23 kg, LB 99 ± 2.28 kg; <i>P</i> < 0.001). Individual batches of 80% lean : 20% fat sausage patties with seasoning (136g per patty) were made from the shoulder of each pork carcass. PVC packaging was applied to each batch of sausage patties. Fat smear was noted on day 0 with a fat smear scale of 1 (excessive far smearing) to 8 (clear fat particle definition). Color parameters that include lightness (L*), redness (a*), yellowness (b*), and lipid oxidation (2-Thiobarbituric acid reactive substances, TBARS) due to retail display effect were measured at days 0, 3, and 7 by placing packaged sausage patties under the retail display lighting. Boneless bellies were removed and weighed (fresh weight) from each pig and measurements for belly thickness, length, and firmness were recorded. Fresh bellies were injected to 110% fresh weight, thermally processed (62°C), and cooled (1°C internal temperature). Cooked weight was obtained before slicing. Belly processing yield was calculated as a percentage using (cooked weight / fresh weight) x 100. Adobe Photoshop was used to perform visual image analysis for bacon slice length (SL; cm), slice area (SA; cm²), and slice lean area (LA; %), one 0.64 cm bacon slice was obtained from 25, 50, and 75% distance respectively from the blade end of each cooked bellies for the analysis. RStudio (1.2.1335) was used to analyze data with breed and diet as fixed effects and least square means separated at (<i>P</i> < 0.05).</p><p> Results showed that only diet was significant for patty fat smear (<i>P </i>= 0.0104), CON patties had better particle definition than FIB patties. Difference for patty color L* (<i>P </i>= 0.0051), a* (<i>P </i>< 0.0001) and b* (<i>P </i>< 0.0001) were found for days of retail display. Breed was significant in L* (<i>P </i>< 0.0001) and a* (<i>P </i>< 0.0001) with DS patties being lighter and less red than LB patties. Days under retail display (<i>P </i>< 0.0001) and breed x diet interaction (<i>P </i>= 0.0014) were found in lipid oxidation. DS CON had the least amount of lipid oxidation throughout retail display time. Breed and diet were significant for both belly thickness and length. LB (<i>P </i>= 0.0263) and CON (<i>P </i>< 0.0001) bellies were thicker than DS and FIB bellies respectively. DS (<i>P </i>< 0.0001) and CON (<i>P </i>= 0.0045) bellies were longer than LB and FIB bellies respectively. A breed x diet interaction (<i>P </i>= 0.0527) was observed in belly firmness and LB CON had the firmest bellies. Processing yield was found to be greater in DS bellies (<i>P </i>= 0.0014) than LB bellies. Breed effect had a tendency (<i>P </i>= 0.065) on SL, DS slices were longer. CON had greater SA (<i>P </i>< 0.0048) than FIB slices. DS slices had significantly higher LA (<i>P </i>< 0.0001) than LB slices.</p> The study provided novel insights into the differences in processing characteristics between the DS and LB genetic lines as well as the effect of diet on each breed. Results such as thicker and firmer belly, lower LA in LB were expected since LB is a minor swine breed that has not undergone intense genetic selection for percent lean meat. Overall, each breed had a better product when fed their accustomed diet (FIB for LB, CON for DS) such as less lipid oxidation in sausage patties for DS CON compared to LB CON. Although LB fits into the niche market of heritage breed pork, future studies in management systems, processing methods, and genetic improvement should be considered to improve product quality to better meet modern consumer demands.

<p>In recent years conservation of minor livestock breeds has been faced with numerous challenges attributed to decreasing national herd sizes, as well as differences in reproduction and growth. One such minor swine breed, the Large Black pig (LB), is increasingly attractive to small farmers due to their foraging abilities and carcass characteristics. Therefore, the LB pigs have been used in niche pork production systems which market pasture-raised pork products. The LB breed is critically endangered, maintaining a registered breeding population of less than 400 animals, with increasing prevalence of inbreeding and genetic drift. Therefore, the LB breed could benefit from a genetic importation to increase genetic diversity in a national herd with rapidly decreasing animal numbers. A genetic importation would require frozen semen to be brought in from another country for use in breeding U.S. pigs. Frozen-thawed semen (FTS) presents challenges for swine due to the reduced motile sperm cells which negatively impacts fertility. Therefore, the present study evaluated the utilization of FTS in a genetic importation for the LB pig. </p><p>A genetic importation occurred in 2016 where semen from the United Kingdom was used on various farms in the U.S. but resulted in zero piglets born. Therefore, 16 LB sows were donated to Purdue University for research into improving estrous and ovulation synchronization to facilitate FTS utilization. Four breeding replicates were performed where following 14 days of Matrix feeding, OvuGel® was administered at 144 h following last Matrix feeding (LMF) or 96 h in post-weaned sows and two FTS inseminations occurring at: 30 and 36 h, 17 and 23 h, 24 and 30 h, and 24 and 32 h after OvuGel® for replicates 1-4, respectively. Approximately 2.64±0.3 billion motile sperm cells per insemination were utilized in replicates 1-3 with American LB FTS, with replicate 4 utilizing 0.34±0.03 billion motile sperm cells of imported FTS. Follicle diameter (<i>P</i>=0.260), ovulation within 48 h of OvuGel® (<i>P</i>=0.411), and weight prior to breeding (<i>P</i>=0.681) did not influence conception rate, however expression of estrus was determined to significantly influence conception rate (<i>P</i>=0.043). Seventy-five LB piglets were weaned across the first three breeding replicates, with parity 2 sows observed to have larger litter sizes than parity 1 sows (<i>P</i>=0.066).</p> <p>Large Black and Duroc-sired (DS) crossbred pigs from replicates 1 and 2 farrowing were fed corn and soybean meal based finishing diets supplemented with (FIB) or without alfalfa and wheat middlings (CON). Following 6 dietary phases through finishing, 25 LB and 25 DS pigs were slaughtered at similar ages for digestive organ dissection and carcass measurements. Loin muscles were evaluated for fresh pork quality and instrumental color and tenderness. LB pigs had a reduced ADG (<i>P</i><0.0001) and G:F (<i>P</i><0.0001) compared to DS pigs. Pigs fed FIB resulted in reduced ADG (<i>P</i>=0.020) and reduced G:F (<i>P</i>=0.007). At slaughter LB pigs were 26.4 kg lighter than DS pigs (<i>P</i><0.0001), and pigs that were fed FIB had lighter live weights (<i>P</i>=0.002) than pigs fed CON. LB pigs had 28.5±1.3 cm² smaller longissimus muscle area (<i>P</i><0.0001), yielding 2.0 cm more 10^th rib back fat than DS pigs (<i>P</i><0.0001). CON pigs had heavier HCW (<i>P</i><0.0001) than FIB pigs, however FIB pigs had greater percent lean (<i>P</i>=0.015). LB pigs had significantly reduced percent lean than DS pigs (<i>P</i><0.0001). LB pigs had loins with reduced drip loss (<i>P</i>=0.009) and cooked shear force values (<i>P</i><0.0001). Overall, the growth and carcass composition of the pigs was most affected by genotype, and to a lesser extent than the type of diet fed. </p> <p>In conclusion, the genetic importation of LB semen was successful as ½ blood piglets were created for dispersal into the U.S. LB herd. Improvements in FTS utilization in this heritage breed contributed to the successful creation of live-born pigs. Additionally, growth and carcass information was obtained for LB breeders to use in understanding and marketing of this heritage breed of pigs.</p>

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