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Two experiments were conducted to understand the interrelationship among visual color score, Farnsworth-Munsell values, instrumental meat color measurements, and their impact on beef color evaluation. In experiment 1, L*, a*, and b* values and various reflectance traits of the Farnsworth-Munsell 100-Hue Test tiles were measured.Incremental changes of the tiles were used to predict changes in a* values and other color variables that can be seen by a trained visual panel. Regression analysis suggests that trained panelists that pass the Farnsworth-Munsell Hue Test can discriminate a change of 0.95 in a*, 0.9 in b*, and 2.54 in hue angle values when Illuminant A is used. In experiment 2, ground beef was assigned randomly to one of 36 combinations of 3 storage temperatures, 4 storage times, and 3 display temperatures to create a variety of surface colors. A 10% change in ground beef metmyoglobin content corresponded to 3.2 units of a* (R2=0.95). Of all the instrumental measurements, a* (r=−0.97) and chroma (r=−0.97) best represented the red color intensity that panelists saw on the surface of ground beef. Significant surface discoloration occurred at 37.1% metmyoglobin and an a* value of 25.4 (with Illuminant A). Using a 5-point visual lean color scale,the change required in a* value for a unit change visual color score was 4.6. In conclusion, a* and chroma are highly related to visual color scores and changes in metmyoglobin, and a change in a* of 0.95 can be observed by visual panelists that have passed the Farnsworth-Munsell test.

The effects of extrusion cooking alone or in combination with electron beam radiation (3.5 kGy) on vacuum-packaged beef-based snack sticks containing beef cardiac muscle were investigated. During formulation, Clostridium sporogenes PA 3679 spores were added to achieve a concentration of 4 log CFU/g. Twin-screw extrusion cooking at 72°C reduced aerobic plate counts (APCs) by 3.63 log cycles and C. sporogenes viable cell counts by 2.02 log cycles for the inoculated product. After irradiation (3.5 kGy), APCs were decreased to 1 log CFU/g when compared to 0 kGy counterparts receiving 0 kGy. Spores were not detected in irradiated inoculated samples, which contained C. sporogenes PA 3679 at levels of 3.17 to 3.50 log CFU/g after extrusion cooking.

Five pork carcasses were used to determine the effects of hot boning and various combinations of salt (0, 1.5 or 3.0%) and a phosphate mixture (0 or 0.5%) on microbial, TBA and pH values of preblended pork (preblends). In both HB (hot boned within 2 h postmortem) and CB (conventionally boned at 24 h postmortem) preblends, salt increased (P

Fresh ground beef containing 20 and 25% fat was either treated with 0.01, 0.05 or 0.10% crystalline ascorbic acid or remained as non-treated controls. Samples were displayed in polyvinyl chloride (PVC) film for up to 10 d (24 h/d) at 2 to 3°C under 1076 lux G. E. Natural light. Measures of display life included visual color scores, reflectance measurements, sensory panel scores, thiobarbituric acid (TBA) values and microbial standard plate counts (SPC). At days 1, 3 and 5 of display, average and worst point visual color scores were judged brighter for all ascorbic acid treatments compared to controls. Lower metmyoglobin percentages, higher %R630nm/%R580nm and higher CIE a* readings at days 3, 5 and 10 for the ascorbic acid-treated product supported visual color results. Higher fat (25%) and higher ascorbic acid levels (0.05 and 0.10%) gave brighter visual color responses at 5 d of display than the 20% fat product and that containing 0.01% ascorbic acid. More intense sensory panel beef flavor was associated with the 0.05 and 0.10% ascorbic acid treatments. More off-flavor was found in the higher fat product (25%). TBA values were not different for fat level comparisons, but were lower for the 0.05 and 0.10% ascorbic acid treatments. At day 5 of display, SPC were not affected by ascorbic acid treatment. The 25% fat product had lower SPC at day 5.

Mesophilic and psychrotrophic bacterial counts of hot-boned and conventionally treated cuts from 15 steers were low [Log 0-2 colony forming units (CFU)/cm2] at 0 time; and after 14 days of vacuum-packaged storage (2.2 C), hot-boned cuts had higher counts than conventionally-treated cuts. In the first experiment involving 10 steers, the mesophilic and psychrotrophic counts for hot-boned cuts were Log 5.26 CFU/cm2 and Log 5.15 CFU/cm2, respectively, and for conventionally treated cuts, log 4.64 CFU/cm2 and Log 4.43 CFU/cm2, respectively. In the second experiment involving 5 steers, the mesophilic and psychrotrophic counts were Log 6.62 CFU/cm2 and Log 6.61 CFU/cm2, respectively, for hot-boned cuts; and Log 5.93 CFU/cm2 and Log 4.91 CFU/cm2, respectively, for conventionally treated cuts. Some hot-boned cuts had low levels (Log 0-3 CFU/cm2) of coliforms, fecal coliforms, Clostridium perfringens , coagulase-positive Staphylococcus aureus and fecal streptococci. No Salmonella were recovered from any cuts. Temperature-decline data indicated that hot-boned cuts had longer (several hours) periods of rapid bacterial growth (above 21 C) than conventionally-treated cuts. The longer rapid growth period for hot-boned cuts may have contributed to higher microbial loads and subsequently to more growth of bacteria in cold storage. Slower chilling of hot-boned samples stemmed from vacuum-packaging and boxing soon after cutting. Temperature control of hot-boned meat during the first several hours of chilling is critical, particularly if hot cuts are vacuum-packaged and boxed before chilling. Some temperature decline guidelines, based on bacterial counts, are presented for hot-boned, vacuum-packaged boxed cuts. Most hot-boned cuts processed and stored under our experimental conditions were bacteriologically acceptable.

Microwave ovens are useful in rapid moisture analysis systems and preliminary drying to prepare analytical samples. Because of uneven heat distribution reported previously, we compared effects of 20 sample locations in a microwave oven cavity on moisture percentages of six meat and three milk samples. The same two hot spots (high moisture percentages) were noted for meat and milk samples. Microwave moisture percentages did not differ from standard oven drying results for meat samples but were higher (P < .05) for milk. Placing the sample beaker consistently in the same microwave oven location is advocated.

Twenty Bos taurus (Hereford x Angus crosses) and 20 F1 Bos indicus x Bos taurus heifers of the same age, management and feeding regimen, were harvested and evaluated at 2 days postmortem for carcass and meat traits. Ten muscles were obtained from the right sides and aged until 10 days postmortem. Bos indicus carcasses were lighter, had less fat cover, smaller ribeyes, and less intramuscular lipid (all p≤0.05). Bos taurus longissimus lumborum, gluteus medius, triceps brachii, and semimembranosus muscles cooked as steaks and roasts had a lower Warner-Bratzler shear force (WBSF) (p≤0.05) than those from Bos indicus. Bos taurus deep pectoral and semitendinosus muscles cooked as roasts had a lower WBSF (p

Introduction In semitropical climates in the United States, Bos indicus breeds of cattle, primarily the Brahman breed, are utilized in crossbreeding programs with Bos taurus cattle to improve productivity by increasing disease and insect resistance, heat tolerance, heterosis, and additive genetic variation. About 25% of the U.S. beef population contains some Bos indicus breeding. Numerous published reports show that tenderness of ribeye and strip loin steaks and marbling are significantly reduced in Bos indicus straightbred or crossbred cattle compared to most Bos taurus breeds. One very large study reported that heritability of tenderness and marbling is around 0.4, making it a positive trait to try to improve through selection. Only one published report has compared tenderness differences between Bos indicus and Bos taurus cattle for more than the ribeye and strip loin (longissimus muscle) and that study showed that other muscles were less tender for Bos indicus cattle. The objectives of our study were: (1) to compare carcass traits between Hereford x Angus crossbred cattle with those containing at least 50% Brahman and Sahiwal inheritance, and (2) to validate Warner-Bratzler shear force of steaks and roasts and proximate composition of 10 different muscles from these cattle.

SUMMARY— Data from three experiments suggest that designs for studies using pork loin should consider variations within the loin from the 4th rib to the anterior end of the hip bone.' Of the factors measured on anterior, middle, and posterior sections in the loin, only tenderness and flavor of the LD were similar for all three sections in all three experiments. The middle section lost less weight during cooking, produced the most press fluid, and was the least tender in all experiments. The anterior section required significantly longer total cooking time than middle or posterior sections, whereas there was no factor in which the posterior section usually differed from the other two sections.

Beef neckbones were processed through a traditional Advanced Meat Recovery system (TAMR), a Desinewated Minced Meat machine with/without prior use of Jarvis saw for removal of spinal cord (DMMJ/DMMNJ), or hand boned with/without Jarvis saw (HJ/HNJ). This study investigated the composition of meat recovered by these five methods. Ranking from the most to least total fat percentage was TAMR (22.02%), HNJ (18.37%), HJ (14.69%), DMMNJ (11.14%), and DMMJ (9.76%); higher fat was related to less moisture. Protein was most for HJ (18.32%) and least for TAMR (15.79%). TAMR and HJ were similar ( P > 0.05) in ash content. Calcium was most in DMMJ (79.81 mg); the least was found in the hand boned (HJ, 20.86 mg/100 g and HNJ, 23.66 mg) lean. All samples contained calcium below the required limits set by USDA-FSIS. Total iron was the highest in TAMR (5.28 mg of iron/100 g), followed by DMMJ (3.65 mg), DMMNJ (3.46 mg), HJ (2.77 mg), and HNJ (2.18 mg).

A total of 112 barrows (average weight of 158 lb) were used in a 65-d growth assay to determine the effects of adding beef tallow (a source of saturated fat) into diets with high inclusion of dried distillers grains with solubles (DDGS). The pigs were sorted by ancestry and blocked by weight with seven pigs/pen and four pens/treatment. Treatments were a corn-soybean, meal-based control and diets having 40% DDGS (US Energy Partners, Russell, KS) with none, 2.5, and 5% added tallow. Feed and water were consumed on an ad libitum basis until the pigs were slaughtered (average wt of 287 lb) to allow collection of carcass data and jowl samples. Fatty acid composition of the jowl samples was used to calculate iodine value as an indicator of carcass fat firmness. Overall (d 0 to 65), the corn-soy control supported greater ADG (P 0.35) compared to the DDGS treatments. Increasing fat additions from none to 5% in diets with DDGS did not affect ADG (P>0.76) but improved (linear effect, P

Beef round muscles were injection-enhanced to 6%, packaged in high-oxygen (HiOx) or ultra-low oxygen (LoOx) modified atmospheres, stored 7 d and displayed 2 d (HiOx) or stored 16 d and displayed 1 d (LoOx) at 0 °C, and cooked to 71.1 °C. Raw internal color for steaks in HiOx was lighter, redder, more yellow and saturated, and had more oxymyoglobin and less deoxymyoglobin than steaks in LoOx (P < 0.0001). Cooked internal color of steaks from HiOx appeared prematurely brown and was darker, less red, yellow, and saturated, and had more denatured myoglobin than steaks from LoOx (P < 0.0001). This study presents conclusive evidence that modified-atmosphere packaging influences internal cooked color development of beef steaks.

Fresh ground pork patties from longissimus dorsi muscle were cooked to endpoint temperatures of54.4 °C, 60.0 °C, 65.6 °C, 71.1 °C, 76.7 °C, or 82.2 °C. After cooking, patties were immersed in a solution of sodiumnitrite (125 ppm) and water for 24 h. All patties then were heated again to a final endpoint temperature of 82.2 °Cto allow possible formation of nitrosohemochrome. Instrumental color data, spectrophotometric 650/570 nmreflectance ratio, and visual panelists’ scores on both exterior and interior surfaces revealed greater redness (pinking)at the lower initial cooked temperature endpoints. Most importantly, this study showed that all patties developedpink color on reheating, regardless of initial endpoint cooked temperature.Keywords: pork, color, nitrite, pinking, nitrosohemochrome Introduction M any meat products are formulated by using ingredients thatcontain some form of nitrite. Nitrite allows cured color to befixed while improving flavor and product safety (Cassens and oth-ers 1979; Benedict 1980; Dryden and Birdsall 1980). Nitrite itselfdoes not directly cause the development of cured meat color (Fox1966). Rather, reduction of nitrite to nitric oxide and its subsequentbinding with myoglobin causes the pink cured color to develop,and the color requires heating to become fixed. This cured color isheat stable and does not disappear with further cooking.Pink-cured color is desirable and expected by the consumerwhen purchasing cured products. Conversely, fresh ground prod-ucts are expected to be devoid of any red or pink color when cookedbecause consumers have “learned” to cook product until no redremains (USDA-FSIS 1989). Even though consumers are now in-formed that cooked color is not a reliable indicator of product done-ness (USDA 1997), the belief that a pink product is undercookedprevails, especially for pork, chicken, and ground-meat products.Products retaining pink after cooking have been termed

Meat retailers have reported bone marrow discoloration to be a problem, especially in modified atmosphere packages (MAP). Therefore, it is important to determine the prevalence and cause(s) of bone marrow discoloration in different beef bones and packaging systems. Thirty-six beef humeri, ribs, scapulas, and thoracic vertebrae from USDA Select and Choice carcasses were obtained from a commercial abattoir, cut into 2.54-cm-thick sections at 4 d postmortem, and packaged into 1 of 3 systems: 1) polyvinyl chloride film (PVC) overwrap; 2) high-oxygen (80% O 2, 20% CO 2 ) MAP; and 3) ultra-low-oxygen (70% N 2 , 30% CO 2 ) MAP. Instrumental reflectance and visual color scores were taken on d 0, 2, and 4, and on d 0 to 4 of display, respectively. Bone marrow was extracted from humeri, ribs, and thoracic vertebrae for analysis but not from scapulas. Ribs, scapulas, and thoracic vertebrae packaged in PVC and high-oxygen MAP developed undesirable gray or black discoloration. In ultra-low-oxygen MAP, mean visual color scores were acceptable throughout the entire display period. Discoloration (darkening) was more extensive for ribs, scapulas, and thoracic vertebrae than for humeri, especially for bones packaged in PVC and high-oxygen MAP. Humeri had lower (P < 0.05) a* values (larger positive a* values indicate a redder color) than the other bones. The a* values for ribs, scapulas, and thoracic vertebrae decreased (P < 0.05) over time. Chroma showed that bone marrow discolored during display, but graying was dramatically less for all bones packaged in ultra-low-oxygen MAP and for humeri in PVC and high-oxygen MAP. Humeri marrow had lower (P < 0.05) 2-thiobarbituric acid reactive substances (TBARS) than did ribs and thoracic vertebrae marrow. Ultra-low-oxygen MAP resulted in the least amount of change in TBARS from d 0 to 4, whereas thoracic vertebrae marrow had greater (P < 0.05) TBARS values at d 4 of display than at d 0 in PVC and high-oxygen MAP. Humeri marrow had dramatically less total Fe and hemoglobin than did that of ribs and thoracic vertebrae for all packaging systems. Myoglobin was undetectable in humeri marrow. The much larger amounts of Fe and hemoglobin in ribs and thoracic vertebrae likely contribute to marrow discoloration. Bone marrow discoloration was distinct in ribs, scapulas, and thoracic vertebrae packaged in PVC or high-oxygen MAP. Bones packaged in ultra-low-oxygen MAP had minimal discoloration.

Two experiments were conducted to examine the effects of hot boning, modified atmosphere packaging, and injection enhancement on the oxidative and sensory properties of beef round muscles. The beef knuckle (quadriceps muscles) was partially hot boned within 1.5 h postmortem from one randomly selected side of each beef carcass (n = 14), whereas the quadriceps on the opposite side remained intact throughout a 48-h chilling period. At 5 d postmortem, biceps femoris, semimembranosus, vastus lateralis, and rectus femoris muscles from both hot- and cold-boned sides were injected with an enhancement solution consisting of water, salt, phosphate, and natural flavorings (rosemary) at either 6 (Exp. 1) or 10% (Exp. 2) of fresh muscle weight. Enhanced muscles were then processed into 2.54-cm-thick steaks, which were allotted randomly to high-oxygen (HiOx; 80% O2:20% CO2) or ultra-low oxygen (LoOx; 80% N2:20% CO2) modified atmosphere packaging. Regardless of hot boning or enhancement, steaks packaged in LoOx had lower thiobarbituric acid-reactive substances values (P or = 0.99) and sensory properties (P > or = 0.85). Increasing the level of injection enhancement from 6 to 10% introduced more rosemary and phosphate into the muscles, thereby decreasing the extent of oxidation, but also imparting a nontypical beef flavor. Packaging in LoOx atmosphere offered the optimal result of decreased oxidation and improved tenderness, without detriment to flavor. Injection enhancement (both 6 and 10%) created off-flavors attributable to the enhancement solution; however, the 10% injection seemed to offer more resistance to lipid oxidation.

Meat retailers have reported bone marrow discoloration to be a problem, especially in modified-atmosphere packages (MAP). To evaluate causes of bone marrow discoloration in different beef bones and packaging systems, 36 beef arm bones, ribs, shoulder blades, and thoracic vertebrae from USDA Select and Choice carcasses were obtained from a commercial abattoir, cut into 1-inch-thick sections at 4 days postmortem, and packaged into 1) polyvinyl chloride film (PVC) overwrap; 2) high-oxygen (80% O2, 20% CO2) MAP; or 3) ultra-low-oxygen (70% N2, 30% CO2) MAP. Packages were displayed under continuous fluorescent lighting for 4 days at 35.6 F. Ribs, shoulder blades, and thoracic vertebrae packaged in PVC and high-oxygen MAP developed undesirable gray or black discoloration during display. In ultra-low-oxygen MAP, mean visual-color scores were acceptable throughout display. The a* values (larger values equate to redder color) for ribs, shoulder blades, and thoracic vertebrae decreased (P

This study evaluated the utility of lactate and rosemary in beef enhance-ment solutions for improving strip loin steak color stability during display inmodified atmosphere packages (80% O 2 /20% CO 2 ). Beef longissimus muscleswere injected (6%) with enhancement solutions containing water, salt, phos-phate, and either rosemary, lactate, or a combination of rosemary and lactate.Steaks packaged in high oxygen were stored for 5 days prior to display.Throughout a 7-day display, loins treated with rosemary were lighter red( P < 0.05) than loins treated with lactate or lactate plus rosemary, which weresimilar. However, lactate resulted in a dark-red color rather than a brownmetmyoglobin-like discoloration. Even though steaks from rosemary-enhanced loins were more red ( P < 0.05) on day 0 of display than loinsenhanced with lactate or lactate and rosemary, this bright-red initial colordid not continue throughout display, whereas the lactate-enhanced productswere darker but had a more stable red color.

To evaluate how antioxidants might prevent bone marrow discoloration, beef lumbar vertebrae held at 35.6°F for 6 or 14 days postmortem before packaging were cut into 1inch-thick sections and packaged into 1) PVC overwrap; 2) high-oxygen (80% O2, 20% CO2) modified atmosphere packages (MAP); or 3) ultra-low-oxygen (70% N2, 30% CO2) MAP. Before packaging, bones were treated with: no treatment application (control); 1.25% or 2.5% ascorbic acid; 0.1% or 0.2% rosemary; or a combination treatment of 0.15% OriganoxTM + 0.3% ascorbic acid. Packages were displayed under continuous fluorescent lighting for 4 days at 35.6°F. Untreated lumbar vertebrae and those treated with 0.1 or 0.2% rosemary discolored to gray or grayish-black, as measured by visual color scores and instrumental a* values, in PVC and high-oxygen MAP. The 1.25% ascorbic acid and 0.15% OriganoxTM + 0.3% ascorbic acid were able to maintain desirable color scores through day 2 of display in PVC and highoxygen MAP, but not after 4 days. The 2.5% ascorbic acid treatment was most effective in preventing discoloration and maintaining initial color in both PVC and high-oxygen MAP. In ultra-low-oxygen MAP, the 1.25% ascorbic acid treatment was as effective as the 2.5% ascorbic acid treatment in preventing bone marrow discoloration. In general, discoloration tended to be greater in bones held 14 days postmortem before packaging than in those held 6 days. Ascorbic acid treatments, particularly the 2.5% application, were effective in preventing bone marrow discoloration. Introduction

This project evaluated the internal cooked color changes that occurred during postcooking storage of pork loin chops (m. longissimus thoracis et lumborum, n = 120) from one of six combinations of three endpoint temperatures (71.1, 76.6 and 82.2C) and two pH groups (lower, 5.4–5.5 and higher, 5.6–5.7). Initial internal color (L*a*b*), and 24 and 48 h storage (4C) pink color development were evaluated after cooking. Although pH had no effect (P > 0.05) on initial cooked color, chops with higher pH were more red (P

Beef knuckles were partially hot-boned within 1.5 h postmortem. Biceps femoris (BF), semimembranosus (SM), vastus lateralis (VL), and rectus femoris (RF) muscles were injection enhanced at 6% (experiment 1) or 10% (experiment 2) of non-injected weight and packaged in a high- (HiOx; 80% oxygen and 20% carbon dioxide) or ultra-low oxygen (LoOx; 80% nitrogen and 20% carbon dioxide) modified atmosphere. Hot boning accelerated chilling in all beef round muscles investigated. This resulted in a darker initial beef colour and darker visual colour during display for the BF, RF, and VL, as well as more uniform BF and knuckle steak colour. RF and VL, in experiments 1 and 2, respectively, had the most improved colour and colour stability. Steaks in HiOx MAP had longer colour life in display than steaks that had been in LoOx. Partially removing the beef knuckle early postmortem is a practical process that will improve colour and colour stability of beef round muscles.

— Color and microbiology of steaks and ground beef stored in 0.4% CO, 30% CO2, and 69.6% N2 (but removed from the modified atmosphere before display) were compared with product displayed immediately after packaging in polyvinyl chloride film (only atmospheric oxygen). Storage of ground beef, loineye, inside round, and tenderloin steaks for up to 35 d in 0.4% CO resulted in typical initial bloomed color. Compared with product exposed to only oxygen, storage of ground beef and loineye steaks in 0.4% CO decreased color stability, whereas color life increased for tenderloin and inside semimembranosus muscles. No steaks having acceptable color had spoilage levels of microbes (≥log 7). Thus, carboxymyoglobin formed from 0.4% CO did not mask microbial spoilage.

Alkylcyclobutanones have been recognized as chemical markers of irradiated lipid-containing foods since 1970. They are important because they are produced solely as a result of irradiation and not any other processing method. This study investigated the formation of 2-dodecylcyclobutanone (2-DCB) and 2-tetradec-5'-enylcyclobutanone (2-TDCB) in irradiated ground beef patties from commercial and noncommercial sources. Patties were irradiated using a (60)C source (gamma-irradiation) and electron beam irradiation, at five targeted absorbed doses of 0.5, 1.0, 2.5, 5.0, and 7.0 kGy. Commercially available irradiated patties were also studied. A supercritical fluid extraction (SFE) procedure was optimized and used for the extraction and isolation of the alkylcyclobutanones. Samples can be used for extraction without a prior cleanup step, which makes this procedure rapid and convenient to use. Identification and quantitation of the cyclobutanones were done by gas chromatography-mass spectroscopy. 2-DCB was detected in all of the irradiated samples (including commercial patties), and its concentration increased linearly with the irradiation dose. Electron beam irradiation produced a greater amount of 2-DCB compared to gamma-irradiation at dose levels >2.5 kGy. 2-TDCB was detected only at the two higher irradiation doses, whereas both marker compounds were not detected in the non-irradiated samples.

The relationships of 6 assays for metmyoglobin (Metmb) reducing ability to color stability and the chemical differences between the inside (ISM) and outside (OSM) beef semimembranosus (SM) muscle after 5 or 14 d storage were investigated. The ISM had less (p Le muscle semimembraneux de boeuf est un muscle large et epais. Cette etude compare les dosages de reduction de la metmyoglobine de la portion interne et externe du muscle et determine leur relation avec les caracteristiques chimiques et la stabilite de la couleur du muscle. La portion interne presente une capacite de reduction inferieure a la portion externe, qui peut etre attribuee partiellement a un taux de consommation d'oxygene et des concentrations en NAD inferieurs.

:The effects of several parameters on the development of internal cooked color in ground pork were evaluated. Patties were made from normal or pale, soft, and exudative (PSE) pork and the pigment converted to either oxymyoglobin or deoxymyoglobin. Patties from these 4 treatment combinations were cooked from the frozen or thawed states to 5 endpoint temperatures. PSE patties and those containing oxymyoglobin exhibited premature browning as they appeared cooked and were more (P < 0.05) tan at lower temperatures than normal patties or those with deoxymyoglobin which had a slightly pink internal color at 71 °C. Percentage myoglobin denaturation increased as cooking temperatures increased (P < 0.05) for both types of meat and was greater in patties containing deoxymyoglobin than in those with oxymyoglobin. Patties cooked frozen had lower a* values (P < 0.05) than thawed patties at every endpoint temperature.

Surface roughening during slicing of precooked cured beef Biceps femoris, Semimembranosus, and Semitendinosus roasts was evaluated for its effects on intensity of iridescence and percentage of iridescent area. Using a textured slicing blade surface decreased (P < 0.05) iridescent intensity and the area of iridescence compared to the control (smooth slicing surface). Iridescence intensity and percentage of iridescent area was greatest (P < 0.05) in the Semitendinosus muscle, followed by Semimembranosus and Biceps femoris. Use of a meat-slicing blade with a textured face could reduce the intensity and area of iridescence in sliced meat products.

This study evaluated the combined effects of storage temperature, storage time, display temperature, display time, and fat level on ground beef color. Storage at 32°F minimized discoloration during display compared to storage at 40° and 48°F. Storage up to 12 days at 32°F did not affect ground beef color stability, whereas prolonged storage at 40° and 48°F increased discoloration dramatically. When storage was at 32°F, sales loss was 0.4%, compared to 62% at 48°F. Fat level did not influence discoloration. The use of 32°F during storage and display is essential for maximizing ground beef color life.

Meat product packaging can be as important to consumer acceptance, shelf life, and overall product quality as any endogenous ingredient. With today's convenience-driven consumer, packaging has moved beyond its original function as mere product protection. Packaging today is used to enhance meat products, especially processed meats. This article discusses the different packaging films and types, and how their chemical characteristics allow packages to be used for long-term storage, freezing, and even cookery.

Storage conditions, patty location within packages, and purchase time effects on premature browning (PMB) of ground beef during cooking to 55 C were determined. Packages were purchased twice daily. Patties were formed soon after purchase or after overnight storage (4 °C). Patties from the outer portion of the packages pur- chased in the morning were bright red and had the highest incidence of PMB (62.5%) when cooked. Patties from inner portions of packages purchased in the afternoon and refrigerated overnight were more (P 0.05) purple and had the lowest incidence (25%) of PMB. Premature browning incidence averaged 47%. Consumer handling proce

Chilled (35±3°F) or frozen (0±3°F) allnatural beef and beef-buffalo frankfurters made with or without sodium nitrite (NaNO2) were evaluated. Treatments included frankfurters made with: all-natural beef without NaNO2 and displayed frozen (B0F); all-natural beef and buffalo without NaNO2 and displayed frozen (BU0F); all-natural beef with NaNO2 and displayed frozen (BNF) or chilled (BNC). Batter pH, smokehouse yield, and proximate analysis were determined. No differences (P>.05) were noted in batter pH, smokehouse yield, proximate analysis, or cooking yield. Day of display had no influence (P>.05) on oxidation. However, BU0F had the highest (P .05) during display. Nitrite-free frankfurters can be displayed frozen up to 90 days based on microbial counts, but display life may be limited to 60 days by product color. Inclusion of buffalo did not influence physical or microbiological quality of nitrite-free frozen frankfurters but may accelerate oxidative rancidity.

From 185 to 225 lb BW, no differences in ADG, ADFI, or F/G occurred among pigs fed diets without or with vitamin and trace mineral premixes. Then, from 225 to 266 lb BW, a special premix with megadoses of vitamin E, vitamin C, Mg-proteinate, and Feproteinate was added to the diets of half the pigs given the previous treatments. Growth performance was not different among pigs fed diets without vitamin or with the KSU and special vitamin and mineral premixes. Also, meat quality (color, marbling, and firmness scores; drip, thawing, and cooking losses; shear force; and Hunter L*a*b*) was not affected by inclusion of the KSU and special vitamin and mineral premixes.

Taste panel, Warner-Bratzler shear force (WBS) and cooking loss characteristics of semimembranosus (SM) muscles from thirty electrically stimulated and hot-boned (ESHB) or control young bull sides were evaluated. At 2 hr postmortem, muscles were excised from electrically stimulated sides and chilled in a tray or in a cardboard box. All control sides and ESHB muscles were chilled at 5–7°C until 24 hr postmortem; then 2–4°C for 24 hr. At 48 hr postmortem, steaks were cut, vacuum packaged and aged (2–4°C) for 4 days. Beef flavor was more intense for control steaks than for steaks from either ESHB chilling treatment. No other differences were noted.

The effects of two doses (2.0 and 3.5 kGy) of nonradioactive irradiation on color and oxidative properties were determined and compared to nonirradiated controls for frozen, raw and precooked, ground beef patties with 10 and 22% fat packaged in vacuum and aerobically. Irradiated raw patties were initially darker and less red than controls, but color of control and irradiated samples became more similar during display. Irradiation increased external redness in precooked patties that were vacuum-packaged. Aerobic packaging, in combination with irradiation, increased lipid oxidation and discoloration, whereas vacuum-packaged patties displayed for up to 21 days had minimal changes in color and lipid oxidation. Irradiation versus the controls significantly reduced bacterial counts.

The effects of two doses (2.0 and 3.5 kG'y) of nonradioactive irradiation on color and oxidative properties were determined and compared to nonirradiated controls for frozen and chilled vacuum-packaged boneless beef steaks. The chilled steaks were repackaged in oxygen-permeable film 14 days after irradiation. Irradiation up to 3.5 kGy had minimal effects on color and oxidative rancidity and significantly reduced bacterial counts of frozen and chilled, vacuum-packaged, beef steaks stored and/or displayed for up to 28 days. Irradiated steaks that were rewrapped in permeable film were microbially acceptable at 5 days of display and had more color stabiliry than the controls. Although no differences in TBA numbers between dose levels were observed for chilled steaks rewrapped in permeable film, these steaks had a TBA number of 2.1 after 5 days of retail display compared to 0.2 for vacuum-packaged steaks displayed for 14 days.

Beef strip loins were sprayed with 1.5% (vol/vol) lactic acid before and/or after 14, 28, 56, 84, and 126 days of vacuum-packaged storage at −1.1 or 2°C to assess the effects on bacteria. Five different treatment combinations including a control (no spray treatment) and one treatment with prestorage acid spray followed by poststorage water spray (A/W) were evaluated. Compared to the controls, 97% of all acid-treated loins had lower microbial counts throughout the storage period. Prestorage acid spray (A/0) was more effective than poststorage acid spray (0/A)with the greatest effects (P 0.05). Poststorage washing resulted in a minimal decontaminating effect, irrespective of the washing agent use...

Reduced (7%)- and regular (25%)-fat ground beef were formulated from domestic A- or E-maturity or imported knuckles. Dried Cream Extract (DCE), Hydrolyzed Vegetable Protein (HPV), Natural Prime Beef Bases #224545 and #224546, or no flavoring (C7) were added to reduced-fat formulations for flavor enhancement. Immediately after cooking, A- and E-maturity 25% fat controls (C25) exhibited higher (P

Beef pectoralis muscles were removed at 24 h post mortem from nine steers, and samples were vacuum packaged and exposed to high-intensity ultrasound (20 kHz, 22 W/cm(2)) for 0, 5 or 10 min, then aged for 1, 6 or 10 days before evaluation of purge and cooking losses, instrumental shear and color and sensory traits (Experiment 1). For Experiment 2, unpackaged beef pectoralis muscle samples from eight steers were subjected to ultrasonic cooking, boiling, convection cooking or ultrasound treatment for 5 or 10 min followed by cooking in a convection oven. Neither duration of sonication nor storage of packaged pectoralis muscles affected (p > 0.05) storage purge or cooking losses, shear properties or sensory characteristics (Experiment 1). However, muscles receiving ultrasonic treatment showed tendencies for reduced peak force and total work to shear. Increased length of storage caused pectoralis muscles to become more vivid red-orange colored (p < 0.05), whereas ultrasonic treatment caused muscles to become less vivid, less red and more orange colored (p < 0.05). Ultrasonically cooked pectoralis muscles (Experiment 2) had lower (p < 0.05) cooking losses than muscles cooked by other methods. Both ultrasonic cooking and boiling were faster than convection cooking only and ultrasound exposure followed by convection cooking. Additional studies are needed to verify the ability of ultrasound to promote improved cooking, sensory and shear properties of muscle.

Color and oxidative rancidity were determined for chilled (3 ± 2°C) and frozen (-17 + 3°C) boneless pork chops packaged in vacuum or air and irradiated to an absorbed dose of 0, 1.5 or 2.5 kGy (chilled) or 0, 2.5 or 3.85 kGy (frozen) of electron beam or cobalt 60 irradiation. Irradiation of vacuum-packaged chops produced redder, more stable (color and rancidity) product. More pronounced oxidative rancidity and less stable display color were noted for samples irradiated in aerobic packaging. Irradiation source had varying but limited effects on color and rancidity. Optimum packaging conditions can control color and rancidity changes in boneless chops, thereby enabling irradiation to be a useful intervention technology.

Boneless loins from both sides of 20 pig carcasses were divided into five sections each and assigned equally to five packaging treatments: 100 % CO(2); 50 % CO(2)/50 % N(2); 25 % CO(2)/ 75 % N(2); 25 % CO(2)/65 % N(2)/10 % O(2) and vacuum. Loin sections were packaged in bags of low O(2) permeability, then stored in darkness at 1 °C for up to 22 days. Retail chops were cut from the sections and displayed in oxygen-permeable film under light at 3 °C for 3 additional days. The O(2) concentrations in packages with nominally anoxic atmospheres were 0.1-0.4 %. Sections stored in 25 % CO(2)/65 % N(2)/10 % O(2) had more surface greying and greening, stronger off-odour and psychrotropic counts after storage were more than one log(10) higher compared to sections from the other four treatments. Displayed chops from sections stored in 25 % CO(2)/65 % N(2)/10 % O(2) also had greying/greening at an outer layer of the chops. Off-odour of chops was most pronounced for treatments with 10 % O(2) and vacuum. Drip loss from loin sections was highest for those in 100 % CO(2) (4.2 %) and lowest for those in vacuum (3.2 %). In conclusion, storage in CO(2) or CO (2)N (2) atmospheres benefitted the overall shelf life of pork.

Ground beef patties known to develop a normal (NRM) or premature brown (PMB) color when cooked to 55°C received no treatment or were reduced or oxidized before cooking. Internal raw appearances were red/ purplish-red for NRM, purplish-red/red for reduced, and brown for PMB and oxidized groups. Cooked colors of NRM-no treatment and reduced, and PMB-reduced were more red (P 0.05), and those of NRM-oxidized and PMB-no treatment were similar (P>0.05). Oxidized pigment produced a PMB color, whereas reducing conditions produced NRM cooked color.