Browsing by Author "Graham, Paul P."
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- Biological, Nutritional, and Processing Factors Affecting Breast Meat Quality of BroilersSantiago, Hector Luis (Virginia Tech, 2002-02-07)A series of experiments were conducted to investigate the effects of certain biological, nutritional, and processing factors on breast meat quality of broilers. In the first experiment, the influence of genetic strain, plane of nutrition, and age at slaughter on breast meat quality was evaluated. Breast meat from a high yield line of broilers had lower pH at 24 h postmortem (PM), greater L*, a*, and b* values, lower water holding capacity (WHC), and higher expressible moisture (EM) than those of a line selected for rapid growth. Breast meat from birds processed at 42 d had lower WHC than those processed at 53 d, even though no differences in pH and L* values at 24 h were observed. No significant effects due to plane of nutrition on meat quality traits were observed. In Experiment two, the influence of strain and chilling methods (ice or air chilled) on breast meat quality was studied in broilers. Breast meat quality significantly differed among strains, with one of the strains evaluated having higher muscle pH, lower L* values, and higher WHC than the other strains. Ice-water chilling significantly reduced the rate and extent of PM pH decline, but had significantly lower WHC and higher EM than those from carcasses chilled by air. However, chilling conditions did not influence breast meat color. In Experiment three, the effects of strain and gender on breast muscle quality of broilers was studied. Meat quality traits were evaluated on both sexes of six genetic crosses of commercial strains. No significant differences in breast meat quality traits among strains were observed. However, differences between sexes were highly significant. The P. major muscles of females had lower pH values at all PM times, higher L*, a*, and b* values, and lower WHC than males. The P. minor of females had significantly lower pH, lower WHC, higher EM, but similar color L*, a*, and b* values than males. In Experiment four, the effects of strain, gender, and age at slaughter on breast meat quality were studied. Strain differences were observed in both sexes, but these differences did not show any specific relationship with the strain genotype. Breast muscles from a male pure line had superior meat quality, with higher muscle pH, and WHC, but higher L* values than the other strains. Significant differences in breast meat quality traits due to age at slaughter were also observed. Regardless of gender, breast muscle pH at 24 h PM and WHC decreased linearly with age, while breast muscle temperature and L* values increased in a linear fashion with advancing age at slaughter. No significant strain by age interactions were observed for any of the meat quality traits evaluated. The results of these studies indicate that commercial genotypes differ significantly in PM muscle metabolism and subsequent meat quality. The results also indicate that female broilers and older birds might be more susceptible to meat quality problems.
- Design and Analysis of Defect- and Fault-tolerant Nano-Computing SystemsBhaduri, Debayan (Virginia Tech, 2007-02-19)The steady downscaling of CMOS technology has led to the development of devices with nanometer dimensions. Contemporaneously, maturity in technologies such as chemical self-assembly and DNA scaffolding has influenced the rapid development of non-CMOS nanodevices including vertical carbon nanotube (CNT) transistors and molecular switches. One main problem in manufacturing defect-free nanodevices, both CMOS and non-CMOS, is the inherent variability in nanoscale fabrication processes. Compared to current CMOS devices, nanodevices are also more susceptible to signal noise and thermal perturbations. One approach for developing robust digital systems from such unreliable nanodevices is to introduce defect- and fault-tolerance at the architecture level. Structurally redundant architectures, reconfigurable architectures and architectures that are a hybrid of the previous two have been proposed as potential defect- and fault-tolerant nanoscale architectures. Hence, the design of reliable nanoscale digital systems will require detailed architectural exploration. In this dissertation, we develop probabilistic methodologies and CAD tools to expedite the exploration of defect- and fault-tolerant architectures. These methodologies and tools will provide nanoscale system designers with the capability to carry out trade-off analysis in terms of area, delay, redundancy and reliability. During execution, the next state of a digital system is only dependent on the present state and the digital signals propagate in discrete time. Hence, we have used Markov processes to analyze the reliability of nanoscale digital architectures. Discrete Time Markov Chains (DTMCs) have been used to analyze logic architectures and Markov Decision processes (MDPs) have been used to analyze memory architectures. Since structurally redundant and reconfigurable nanoarchitectures may consist of millions of nanodevices, we have applied state space partitioning techniques and Belief propagation to scale these techniques. We have developed three toolsets based on these Markovian techniques. One of these toolsets has been specifically developed for the architectural exploration of molecular logic systems. The toolset can generate defect maps for isolating defective nanodevices and provide capabilities to organize structurally redundant fault-tolerant architectures with the non-defective devices. Design trade-offs for each of these architectures can be computed in terms of signal delay, area, redundancy and reliability. Another tool called HMAN (Hybrid Memory Analyzer) has been developed for analyzing molecular memory systems. Besides analyzing reliability-redundancy trade-offs using MDPs, HMAN provides a very accurate redundancy-delay trade-off analysis using HSPICE. SETRA (Scalable, Extensible Tool for Reliability Analysis) has been specifically designed for analyzing nanoscale CMOS logic architectures with DTMCs. SETRA also integrates well with current industry-standard CAD tools. It has been shown that multimodal computational models capture the operation of emerging nanoscale devices such as vertical CNT transistors, instead of the bimodal Boolean computational model that has been used to understand the operation of current electronic devices. We have extended an existing multimodal computational model based on Markov Random Fields (MRFs) for analyzing structurally redundant and reconfigurable architectures. Hence, this dissertation develops multiple probabilistic methodologies and tools for performing nanoscale architectural exploration. It also looks at different defect- and fault-tolerant architectures and explores different nanotechnologies.
- Dry Curing Virginia-Style HamGraham, Paul P.; Marriott, Norman G.; Kelly, Robert F. (Virginia Cooperative Extension, 2012-12-18)This publication provides basic steps that can be applied to home curing for do-it-yourselfers who want to cure and age a ham at home.
- Dry-curing Virginia style hamGraham, Paul P.; Kelly, Robert F.; Marriott, Norman G. (Virginia Cooperative Extension, 1998)Virginia ham was one of the first agricultural products exported from North America. The Reverend Mr. Andrew Burnaby enthusiastically reported that Virginia pork was superior in flavor to any in the world. Another early clergyman, the Reverend Mr. John Clayton, wrote the Royal Society in England that Virginia ham was as good as any in Westphalia. Today, after more than three centuries of progress, Virginia ham is still considered a superb product because of its distinctive savory taste. For those who want to "do-it-yourself" cure and age a ham that will recapture the delightful flavor so highly cherished by these early clergymen, certain rules must be followed. This publication provides basic steps that can be applied to home curing or commercial operations.
- Effects of collagen content, fiber alignment, storage and heating on cooking characteristics, dimensional changes and microstructure of restructured beefHsu, Kanghuan M. (Virginia Tech, 1992-09-09)Studies were conducted to determine the effects of collagen level, fiber alignment, frozen storage and oven temperature on cooking characteristics and the dimensional and structural changes of restructured beef steaks. Three replicates of high (HC) and low collagen (LC) raw materials similar in proximate composition, salt content, pH and physical measurements but different in total collagen were manufactured and stored for either 40, 85 or 130 days before cooking by broiling or roasting. HC steaks tended to require less time for heat to penetrate than LC steaks. Collagen levels did not significantly (P>O. 1) affect cooking losses and physical measurements except the width (WI) at he narrow end. Effects of storage were not different for all cooking losses except evaporation losses nor for physical measurements except WI and the longest axis (Ll). Cooking treatments affected all cooking losses and physical measurements except the midpoint thickness of the steak. Random fiber steaks tended to need less time to reach each end-point temperature than aligned steaks. Orientation of fibers had no effect (P>O.l) on cooking losses and physical measurements except Ll and the straight region (L2) on the perimeter of the steak. Broiling yielded higher evaporation and total cooking losses than roasting. Drip losses were not different between heating methods. For both collagen levels and fiber alignments, site 1 (apex of the dome) had higher residual moisture and fat contents than site 3 (no visible change occurred). The possible mechanism for dome formation considers that: 1) complete layers of parallel muscle fibers form heavy barriers; 2) sufficient binding exists between meat pieces to form a dome; 3) excessive protein films (coat) cover meat particles; 4)a dense protein matrix traps moisture and fat components; 5)additional denatured collagen provides strength to support the dome; and 6) "microvoids" exist within the dome with larger voids in the vicinity of the dome. A possible mechanism for channel development is based upon the following observations: 1) sufficient layers of parallel muscle fibers are lacking; 2) insufficient binding exists between meat pieces; 3) insufficient protein films (coat) cover this area; 4) poor protein matrix allows more moisture and fat components to escape into the atmosphere and meat drippings; 5)prominent channels are located between muscle strands connecting the interior and exterior portions of the steak; and 6)voids are located on the steak surface among parallel muscle fibers.
- Food storage guidelines for consumersRoberts, Tim; Graham, Paul P. (Virginia Cooperative Extension, 2004)
- Food storage guidelines for consumersRoberts, Tim; Graham, Paul P. (Virginia Cooperative Extension, 1999)
- How to s-s-s-s-stretch your pork dollarMarriott, Norman G.; Graham, Paul P. (Virginia Cooperative Extension, 2000)
- Marvelous Meat: an Introduction to Meat, Meat Processing, and Meat JudgingDeMarco, Laurie W.; Graham, Paul P. (Virginia Cooperative Extension, 2004)Helper's guide for the 4-H meat project.
- Microbial properties of color-modified turkeyPruett, Wayne P. (Virginia Tech, 1989-06-04)Studies were performed to determine the effect of color modification procedures on the microbial characteristics of turkey thigh meat. Turkey thighs were flaked and then color modified successively with three sodium phosphate buffers (pH 5.8, 7.4, and 8.0). At selected time intervals, flaked unwashed turkey (FUT; control) and color-modified turkey (CMT) stored at 3°C were analyzed for aerobic, psychrotrophic, and coliform bacterial counts. Aerobic and psychrotrophic numbers also were estimated in raw tissues held at -20°C. Cooked FUT and CMT were inoculated with two strain composites of either Salmonella or Listeria monocytogenes and held at 4 and 20OC. Salmonella enteritidis, Salmonella typhimurium, Q. monocytogenes Scott A, and a Q. monocytogenes meat isolate were organisms used in the inoculation studies. Aerobic and psychrotrophic counts were not different (p >0.05) at any sampling interval when numbers in raw EUT were compared to those in raw CMT. Coliform counts in raw FUT did not differ from those in raw CMT (p >0.05) after l day at 3°C. In inoculation studies, numbers of either pathogen generally did not differ (p >0.05) I between cooked FUT and CMT at selected sampling intervals. Salmonella counts declined gradually in cooked samples held at 4°C. By day 3, Salmonella levels increased more than 6 logs in tissues held at 20°C. L. monocytogenes counts increased approximately 5 logs in cooked FUT and CMT held at 4°C for 14 days. Numbers increased more than 5 logs in samples stored at 20°C for 48 hr. Although a significant (p <0.05) factor in some studies, color modification was not considered to have a major effect on microbial growth in altered thigh.
- Nutrient characterization of color modified and unaltered flaked turkey thigh meatPhelps, Steven Kirk (Virginia Tech, 1989-04-15)Flaked, skinless and boneless turkey thighs were successively washed in 0.03M sodium phosphate buffers at pH 5.8, 7.4 and 8.0. Proximate, mineral and riboflavin composition, as well as protein efficiency ratio (PER) and apparent digestibility (AD) using the rat bioassay technique were determined for three replications. The color modified tissue (CMT) had a higher (P=0.0429) moisture content and less (P=0.0527, 0.1240 and 0.0047, respectively) crude protein, fat and ash than flaked thigh (THI). Percentage of iron, magnesium, phosphorous, potassium and manganese decreased (P=0.0187) after color modification, whereas calcium, zinc and copper concentrations did not change (P=0.1184) and sodium increased (P=0.0058). Riboflavin was reduced by 30%. The PER of CMT evaluated was lower (P=0.0318) than THI, but higher (P=0.0001) than either casein or egg albumin diets. AD of CMT was 90.7% which is comparable to other meat products. The overall nutritional evaluation of CMT determined that it has potential as a raw material in further processed foods.
- Optimal utilization of the beef chuckBenito-Delgado, Julian (Virginia Tech, 1992-04-18)The effects of a prerigor CaCl₂ injection and blade tenderization on several sensory and physical characteristics of beef infraspinatus and longissimus muscles were determined. Blade tenderization resulted in increased tenderness (P<0.05) of postrigor infraspinatus muscle as measured by sensory panel, and numerically higher, though insignificant (P>0.05), sensory scores for postrigor longissimus muscle. However, no improvements (P>0.05) in tenderness of prerigor CaCl₂ injected muscles were observed due to blade tenderization. Objective and subjective measurements revealed that prerigor CaCl₂ injected muscles were less tender (P<0.05) than postrigor muscles independent of blade tenderization. Furthermore, steaks from prerigor CaCl₂ injected cuts had lower (P<0.05) texture scores for both muscles and flavor scores for infraspinatus samples, as well as higher microbial counts (P<0.05) than samples from postrigor muscles. Increased aging from 3 days to 7 days resulted in improved (P<0.05) tenderness, but also resulted in decreased (P<0.05) flavor, texture, color, and overall appearance scores, as well as increased (P<0.05) TBA values and microbial load.
- Promoting oxygenation of vacuum packaged fresh pork using soybean leghemoglobinEspinel, Ruth Karina (Virginia Tech, 1992-02-05)Fresh pork loins were cut for three replications and randomly assigned to one of seven treatments: 1) polyvinylchloride (PVC) packaged, 2) vacuum packaged (Vac-pack), 3) 0.2 mL of Tris-Buffer, 4) 0.2 mL of high leghemoglobin high pH (HLbHpH), 5) 0.2 mL of high leghemoglobin low pH (HLbLpH), 6) 0.2 mL of low leghemoglobin high pH (LLbHpH), and 7) 0.2 mL of low leghemoglobin low pH (LLbLpH). Treatments 3 through 7 also were vacuum packaged. Leghemoglobin (Lb) protein treatments improved (P<0.05) the visual color of vacuum packaged pork at the point of purchase. CIE L* values were not affected by HLbHpH, LLbHpH or LLbLpH treatments. However, the HLbLpH treatment was lighter (P<0.05) than the vacuum packaged control treatments on days 3, 4, and 5. High Lb (HLb) treatments had a positive effect (P=0.0116) on the CIE a* values on the day of manufacture. HLbLpH treatment eIE b* values were higher (P<0.05) than Vac-pack and buffer controls from day 0 to day 5. On the day of processing, HLb treatments were higher (P=0.0637) in oxymyoglobin than low Lb treatments. Metmyoglobin of HLb treatments was higher (P<0.05) than the Vac-pack and the buffer treatments on the day of manufacture. pH did not affect (P>0.05) sensory or objective color, pigment state, purge or total psychrotrophic aerobic bacterial counts (TPC) throughout the study. Lb treatments TPC were lower (P<0.0l) than nontreated samples at all assessment times.
- Reduction of Pink Color Development in Cooked,Uncured Ground Turkey Breast by the Addition of Dairy ProteinsSlesinski, Alan J. (Virginia Tech, 1998-10-02)A sporadic pink color development in cooked, uncured turkey products remains a problem within the poultry industry because consumers associate this defect with inadequate cooking. Previous research demonstrated that nonfat dry milk (NFDM) has the ability to reduce pink color. The objective of this research was to determine if other dairy proteins also possess this capability. In particular, sodium caseinate (SC) and whey protein concentrate (WPC) were evaluated and compared to nonfat dry milk and to no dairy protein containing processed turkey. Pink color development was induced in the poultry products to simulate this defect in products by the addition of nicotinamide to produce nicotinamide hemochrome or sodium nitrite or sodium nitrate to produce nitrosylhemochrome. Prior to protein testing, measurement of these two pigment using reflectance spectrophotometric methods was evaluated. The reflectance ratio of %R at 537 nm divided by %R at 553 nm was able to predict (R²=0.99) concentrations of nicotinamide up to 2%, the highest level tested. The ratio of %R at 650 nm divided by %R at 570 nm was able to predict nitrite (R²=0.97) below 20 ppm. To narrow the possible dairy protein choices, three WPC and two SC dairy proteins, along with nonfat dry milk were evaluated for their ability to inhibit nicotinamide and nitrite induced pink color. Results of this prescreening indicated that variations among the different types of proteins existed in both their abilities to reduce the pink color when pink color generating ligands were intentionally added, and when no ligands were added. Some of the dairy proteins actually increased the redness of the control turkey formulation. The WPC (Alacen 882, New Zealand Milk Products, North America, Inc, Santa Rosa, CA) and SC (Alanate 180 New Zealand Milk Products, North America, Inc., Santa Rosa, CA) protein products chosen in the prescreening were evaluated with nonfat dry milk at various levels. A simplex lattice response surface design enabled prediction of these proteins' effects on red color at combinations of up to and including 3.0% added dairy protein. Sodium nitrate did not appear to increase redness of control samples and therefore was not discussed in detail. The WPC and NFDM proteins tested were able to reduce CIE a* values at both 1.5 and 3% and in combination with each other at 1.5% of each protein (P<0.05) regardless of ligand treatment. Of these treatments, SC had the least effect on CIE a*. With the exception of SC, the dairy proteins increased product yield (P<0.05) in all treatment combinations. Using the response surface prediction ability, other combinations of dairy proteins, not specifically tested in this research, were shown to optimize pink color reduction.
- Sensory and dietary quality of fiber-beef blendsKatzir, Irena (Virginia Tech, 1989-08-03)Recently, there has been an increased interest in manufacturing high fiber Foods. Beef patties containing 1% Lupran (sweet lupin bran flour), 2% barley and 3% of both fibers (1% Lu + 2% Ba) and a control all-beef pattie were manufactured and comparatively evaluated by visual and sensory panels. Hypocholesterolemic effects were tested by in vivo studies. Rats were fed diets containing meat or meat-blends as the sole source of protein, fat, fiber and cholesterol. All the diets were isocaloric. At the point of purchase, the meat blends were different (P < 0.05) from the in their apparent amount exudate, fat to lean ratio and integrity. Less significant was the difference in color, both visual and objective, with the beef-barley blend tending to be darker and the beef-lupran product tending to be brighter within 14 days oF storage. The sensory panel scored meat-blends as significantly less beefy, more beany and grainy (P> 0.05). The grainy flavor of barley was especially detectable. Mouthfeel was not significantly altered (P> 0.05) but there was a tendency for the panel to score the barley blend as dryer and tougher than the control. However, these results were not confirmed by objective measurements. Cooking losses and quantity of measured exudate For meat blends were similar to the control. Neither lupran nor barley had a significant antioxidative effect. The meat blend with 3% fiber lowered the LDL fraction in rats relative to that of rats on control diets. However, the amount of added fiber was too low to significantly affect serum or liver cholesterol.
- Survival of Vibrio vulnificus and Escherichia coli in artificially and naturally infected oyster (Crassostrea virginica) tissues during storage in spray- and immersion-type live holding systemsColby, Jhung-Won (Virginia Tech, 1992-04-05)Live holding systems are used as temporary storage facilities for shellfish. The potential for mishandling of shellfish stored in these systems is high. The objective of the project was to examine the effects of storing oysters in a spray and an immersion systems on the survival of Escherichia coli and Vibrio vulnificus within the oysters. The effects of physiological stress imposed on oysters, as a result of interstate shipping, were examined by monitoring the level of E. coli in these oysters during storage in a spray tank. The survival rates of naturally-present E. coli and V. vulnificus in oysters were also observed. The research examined the distribution of artificially- and naturally-present V. vulnificus in oyster tissues during storage in an immersion system. There was no significant difference (p = 0.12) in the artificially-inoculated bacterial population of oysters after 120 hr of storage in a spray live holding tank. The level of E. coli in oysters which were subject to physiological stress did not change significantly (p = 0.30) after 96 hr in the spray tank. Naturally-present E. coli and V. vulnificus in oysters at harvest persisted during the 72 hr storage in the spray tank. V. vulnificus was loosely associated with mucus on the surfaces of the adductor and the mantle tissues in artificially-inoculated oysters. As a result, the bacterial level was reduced on these surfaces during the 72 hr of depuration. V. vulnificus on the gills and the digestive system of artificially-inoculated oysters may become entrapped in cilia and mucus. There was no significant reduction in the bacterial population on the gills (p = 0.11) and on the digestive system (p =0.21). There was no significant difference in the population of V. vulnificus in the adductor muscle (p = 0.37), the mantle (p = 0.16), the gills (p = 0.5), and the digestive system (p = 0.5) of summer oysters naturally-infected with the bacterium. It seems unlikely that depuration of V. vulnificus from oysters naturally harboring the bacterium may be effective.
- Textural and Physical Properties of Fat-Free Turkey-Beef Frankfurters: Effects of Non-Meat Ingredients and End-Point TemperatureInnawong, Bhundit (Virginia Tech, 1998-12-04)The effects of NaCl (1 and 2%), added-water (AW; 30 and 40%), milk protein hydrolysate (MPH; 1, 2 and 3%), and end-point cooking temperature (EPT; 71.1 and 76.7 C) were examined. Regardless of the formulation, all turkey-beef frankfurters contained less than 0.4% fat. As levels of NaCl in the formula increased, the frankfurters had lower (P< 0.05) penetration values (total energy and peak force) but higher shear stress and shear strain. In addition, higher salt levels resulted in lower cooking loss, moisture content, protein content, and darker frankfurters. Increasing AW level reduced (P<0.05) penetration values (total energy and peak force), shear stress, shear modulus, and hardness but increased cohesiveness. Higher levels of AW not only resulted in higher (P<0.05) moisture content but also resulted in higher cooking loss and purge loss. Higher AW products were lighter (P<0.05) in color and less red. Increasing the amount of MPH increased (P<0.05) shear stress and shear modulus but lowered shear strain. Higher MPH reduced cooking loss and produced (P<0.05) darker, more yellow, and less red frankfurters. Higher EPT increased (P<0.05) cooking loss, shear stress, and shear modulus but decreased penetration values (total energy and peak force), shear strain, and cohesiveness. Higher EPT produced lighter (P<0.05) colored frankfurters. There were some two and three-way independent variable interactions (P<0.05) for shear stress, shear strain, and cohesiveness. Of the four independent variables evaluated, AW and EPT most influenced textural properties. By using various combinations of these four independent variables, meat processors would have the ability to improve the quality characteristics of fat-free frankfurters.
- Thermal, oxidative and hydrolytic stability of selected frying shortenings evaluated by new and conventional methodsBati, Nabil A. (Virginia Polytechnic Institute and State University, 1989)The thermal, oxidative, and hydrolytic stability of several frying shortenings were studied via chemical, physical and sensory analyses. Corn, cottonseed and peanut oils, and cottonseed and soybean liquid shortenings were tested under static heating conditions, while peanut oil, and cottonseed and soybean oil liquid shortenings were evaluated under commercial frying conditions. The research had two objectives: to evaluate the relative stability of the various shortenings under both heating condition; and to evaluate new or modified quality assessment methods which would provide early prediction of heat abuse for the fast-food industry. Six of the conducted analyses were conventional or modified: free fatty acids; polar components; gas chromatograph volatile profiles; viscosity; FoodOil-Sensor; and sensory. Three were new: contact angle; high temperature; and high-temperature gas chromatographic analysis of triglyceride; and polar component % as determined by high-performance thin-layer chromatography (HPTLC). Under static heating conditions, varying heating periods or shortening types had significant (P<0.000l) effects on the resulting data of the following tests: free fatty acids; polar component; total volatiles; dielectric constant; viscosity; polar component % measured by HPTLC; contact angle; and sensory analysis; but heating time had no significant effect on triglyceride profiles Under commercial frying conditions of chicken nuggets and filets, heating time had significant effects on changes in the dielectric constant; free fatty acid %; viscosity; contact angle; and sensory rating; also it had a significant effect on the polar component % under chicken nugget frying conditions only. Furthermore, heating time had no significant effect on polar component % under chicken filet frying conditions and on polar component % by HPTLC under both frying conditions Cottonseed oil liquid shortening had sensory scores equal to peanut oil under static and commercial frying conditions even though peanut oil exhibited a greater chemical and physical stability. Soybean oil liquid shortening had an objective quality identical to peanut oil, however, its subjective quality was lower. Cottonseed oil liquid shortening had better flavor but less objective stability than soybean oil liquid shortening The cut-off quality level for the shortenings was not reached, because all the shortenings were discarded after seven days of use which was before the onset of significant-quality deterioration. The best on-site index of shortening stability was the FoodOil-Sensor reading (dielectric constant) which was followed by the free fatty acid test.