Listeria monocytogenes is a pathogen frequently associated with ready-to-eat (RTE) meat and poultry products. Nitrite is a key antimicrobial additive that can offer some degree of protection against L. monocytogenes when included in meat product formulations. The objectives of this study were to determine the potential of nitrite-embedded film to affect the growth of L. monocytogenes following postthermal processing of conventionally-cured and nitrite-free bologna. Two bologna treatment formulations, a conventionally-cured control formulation (CON) and a nitrite-free formulation (UCC), were manufactured, packaged in conventional (CF) or nitrite-embedded (NEF) film, inoculated with 3.5 log CFU/cm2 of a cocktail of L. monocytogenes strains, and stored at 10 ± 1 °C. CON-NEF and UCC-NEF treatments had significantly slower (P < 0.05) growth of L. monocytogenes than CON-CF and UCC-CF, with populations in UCC-CF (which contained no nitrite) increasing by 3.4 logs after 10 d of storage in UCC-CF and 3.6 logs after 50 d in CON-CF (which had formulated nitrite only), while in the NEF-packaged samples, with or without formulated nitrite, they did not exceed the inoculum level until after day 40. Initial (day 0) residual nitrite was significantly greater (P < 0.05) in the control formulation. Packaging in NEF, however, resulted in an increase of 27-28 ppm by day 3, regardless of formulation, after which it decreased rapidly. Results suggest NEF can be used as a post-lethality antimicrobial intervention in food safety intervention strategies, in both cured and uncured processed meat products.

Curing of cooked nitrite-free bologna sausage utilizing nitrite-embedded film (NEF) was investigated. The objectives were to determine the effects of NEF following thermal processing of nitrite-free bologna with and without an added reductant for characteristics important to cured meat, including instrumental color (surface and internal color during lighted and dark storage), surface and sub-surface cured pigment concentration and sub-surface color changes, residual nitrite, and lipid oxidation. Six bologna treatments were produced, with combinations of formulation and package type as follows: a conventionally cured (with sodium nitrite) control formulation packaged in (1) conventional ("CON-CF") and (2) nitrite-embedded ("CON-NEF") film; a nitrite-free formulation packaged in (3) conventional ("UC-CF") and (4) nitrite-embedded ("UC-NEF") film; and a second nitrite-free formulation with an added reductant-cherry powder, a natural source of ascorbic acid-packaged in (5) conventional ("UCC-CF") and (6) nitrite-embedded ("UCC-NEF") film. In- package surface and internal instrumental a* values, residual nitrite, cured pigment concentration, and cured pigment color development from the product surface to the interior were significantly greater (P < 0.05) for UC-NEF and UCC-NEF compared to their conventional film counterparts, UC-CF or UCC-CF, respectively. Lipid oxidation (2-thiobarbituric acid-reactive substances [TBARS] values) was significantly greater (P < 0.05) for UC and UCC formulations but was not different (P> 0.05) over storage time. Purge (%) was significantly lower (P < 0.05) for CF-packaged formulations and increased (P < 0.05) over storage time. The added reductant in the UCC formulation increased the rate of change and degree of difference for color attributes, residual nitrite, pigment concentration, and development of cured color between respective packaging films (NEF or CF). However, the same differences were observed for the nitrite-free formulation (UC) without any added reductant; consequently, the reductant was not required to generate cured meat attributes when packaged in NEF.

The objectives were to determine the effects of post-thermal processing nitrite-embedded film (NEF) packaging on the quality attributes of alternatively-cured (nitrite from celery juice powder (AC)) and nitrite-free bologna. Attributes evaluated included lipid oxidation, instrumental color, pigment concentration, and sensory properties such as cured meat flavor, aroma, and color. Three bologna formulations, each packaged with two packaging films were produced. A conventionally-cured control formulation (with nitrite from sodium nitrite; CON), a nitrite-free formulation (UCC), and an alternatively cured formulation (nitrite from cultured celery juice powder; AC) were packaged in conventional (CF) or nitrite-embedded (NEF) film. Instrumental a* values (measured during both light and dark storage at intervals of 7 or 14 days over 126 days of storage) and cured pigment concentration (measured at 14-day intervals over 84 days of storage) were significantly greater (P < 0.05) for the UCC-NEF treatment compared to its conventional film counterpart, UCC-CF. No significant differences (P > 0.05) for lipid oxidation (TBARS values) were observed with NEF. Trained sensory panelists, who evaluated samples at 14-day intervals over 70 days of storage, found significantly greater (P < 0.05) cured aroma, cured flavor, pink color and less off-flavor for uncured bologna packaged in NEF compared to conventional film. For the uncured bologna formulation, NEF packaging provided cured meat attributes comparable to the control formulation that included nitrite. This is the first time that cured aroma and flavor have been observed when nitrite from packaging film is added to a cooked meat product under anaerobic conditions.

The objective of this study was to evaluate biochemical factors affecting Warner-Bratzler shear force (WBSF) and East Asian consumers’ eating preferences of 6 different beef shank cuts cooked by moist heat. Six different beef shank muscles were collected from 12 USDA Choice beef carcasses (N = 72). Shank cuts from the left sides were cooked with moist heat and used for East Asian consumer sensory evaluation and WBSF, and shank cuts from the right sides were left uncooked and used for biochemical analysis and visual panels utilizing the same group of consumers. A correlation analysis was conducted to determine the driving factors that contributed to WBSF and East Asian consumers’ overall liking for beef shanks. Biceps brachii and flexor digitorum superficialis-pelvic received the greatest sensory overall liking, with deep digital flexor from the foreshank having the lowest scores (P < 0.01). Deep digital flexor from the foreshank had the greatest WBSF value, most cooked collagen content, and greatest insoluble collagen percentage as well as the greatest raw and cooked pyridinoline (PYD) densities among all the beef shank cuts (P < 0.05). For visual overall liking, shank cuts at approximately 700–750 g such as biceps brachii and extensor carpi radialis received the highest ratings (P < 0.01), and consumers indicated that there was no visual difference in surface color among the shank cuts (P > 0.10). Correlation analysis showed that cooked collagen content and insoluble collagen percentage as well as raw PYD densities had positive correlations with WBSF (P < 0.05) and negative correlations with consumer overall liking (P < 0.01). Surprisingly, collagen content from uncooked shank cuts did not have a direct relationship with consumers’ overall liking nor with WBSF. The results demonstrated that raw PYD density may be a great indicator for cooked beef tenderness in beef cuts with a high concentration of connective tissue prepared with moist heat cookery.

The quality attributes of beef longissimus lumborum during 15 d of retail display were assessed using surface bioelectrical impedance analysis (S-BIA) and internal bioelectrical impedance analysis (I-BIA). Beef loins (N = 18) were obtained from 3 commercial processors with 3 postmortem (PM) ages (27, 34, and 37 d). Loins were fabricated into twelve 2.54-cm-thick steaks, subdivided into 6 consecutively cut pairs, and randomly assigned to one of 6 display days (DD): 0, 3, 6, 9, 12, or 15. Steaks were assessed for S-BIA and I-BIA. Three locations were analyzed within each steak: top, middle, and bottom. Microbiological analysis, BIA, pH, instrumental color, proximate composition, and lipid oxidation were measured. There was a location × PM day × DD interaction (P < 0.05) for longissimus lumborum steaks for S-BIA. Among all 3 locations, steaks aged 27 d had higher (P < 0.05) S-BIA values on day 9 and 12 than steaks aged 34 and 37 d. There were no location × PM day × DD or two-way interactions (P > 0.05) for I-BIA. Display day affected (P < 0.05) all instrumental color data regardless of PM aging times. Among all PM aging times, steaks aged 27 d were 13% and 7% higher for a* and b* , respectively, compared with 34 and 37 d PM. There was a PM day × DD interaction (P < 0.05) for aerobic plate counts (APC). From day 0 and 9 of display, APC of steaks aged 27 d PM were 1 to 2.0 log colony-forming units/cm 2 lower than steaks aged 34 and 37 d. Quality attributes, including a*, b* , APC, and thiobarbituric acid reactive substances, were correlated (r = 0.70, − 0.64, − 0.56, and 0.69, respectively) with S-BIA. Overall, BIA values increased on aerobically packaged longissimus lumborum steaks and were correlated with various freshness quality parameters.

The objective of this study was to determine effects of extended aging and intramuscular location on Warner-Bratzler shear force (WBSF), muscle fiber cross-sectional area (CSA), and protein degradation of semitendinosus (ST) and longissimus lumborum (LL) steaks. Left ST and LL were removed from 40 carcasses at 6 d postmortem. The ST was fabricated into five locations (LOC), with LOC 1 being most proximal and LOC 5 being most distal. The posterior LL was fabricated into 3 LOC, with LOC 1 being most anterior. Vacuum sealed ST steaks were aged 7, 14, 28, 56, or 112 d postmortem, while LL steaks were aged 7, 28, or 112 d postmortem at 2 ± 1 °C. A steak from each LOC was assigned to WBSF or laboratory analyses. There were no Day of Aging (DOA) × LOC interactions for all dependent variables (P > 0.06). There were DOA effects for ST and LL WBSF values and degraded 38-kDa desmin (DES; P < 0.01). Day-7 ST-steak WBSF value was greater than all other days (P < 0.01) and day-14 steaks had greater WBSF value than remaining days (P < 0.05). Day-28 ST-steak WBSF values were greater than day 56 and 112 (P < 0.01), which did not differ (P = 0.53). In the LL, day-7 steaks had greater WBSF values than the other two timepoints (P < 0.01) and day-28 steaks had greater (P < 0.01) WBSF values than day-112 steaks. Degraded ST 38-kDa DES content was less on day 7 and 14 compared to all other days (P < 0.03), but did not differ (P = 0.79) from each other. Days 28 and 56 38-kDa DES content was less than day 112 (P < 0.01), but did not differ (P = 0.34) from each other. Degraded LL 38-kDa DES content was less on day 7 than day 28 and 112 (P < 0.02), which did not differ (P = 0.67). There were LOC effects for only ST WBSF and muscle fiber CSA (P < 0.05). Semitendinosus steak LOC 1 and 2 had greater WBSF values than all other locations (P < 0.01), but did not differ (P = 0.32) from each other. Semitendinosus steak LOC 3 and 5 had greater WBSF values than LOC 4 (P < 0.01), but did not differ (P = 0.85) from each other. The CSA of all ST fiber types were largest in LOC 1 compared to all other fiber types (P < 0.01). The CSA of all LOC 2 and 3 fiber types was greater than LOC 4 and 5 (P < 0.01), but were not different from each other (P > 0.81), and LOC 4 had greater CSA than LOC 5 (P < 0.01). Steak aging WBSF value improvements seemed proteolysis catalyzed, while the ST intramuscular tenderness gradient was more likely due to muscle fiber CSA.

The objective of this study was to collect and interpret three-axis acceleration, temperature, and relative humidity data from six locations within commercial transport trailers shipping market-weight pigs. Transport was observed in Kansas (n = 15) and North Carolina (n = 20). Prior to loading, three-axis accelerometers were affixed to six locations on the trailers: top fore (TF), top center (TC), top aft (TA), bottom fore (BF), bottom center (BC), and bottom aft (BA) compartments. Data were post-processed to calculate root-mean-square (RMS) accelerations and vibration dose values (VDV) in the vertical direction and the horizontal plane. These values were compared with exposure action values (EAV) and exposure limit values (ELV), vibration levels deemed uncomfortable and potentially dangerous to humans. Additionally, RMS and VDV were compared among the trailer compartments. The vertical RMS accelerations for all compartments exceeded the EAV for loads measured in Kansas, and for the majority of the compartments measured in North Carolina. Many compartments, specifically the BA compartment from all trips, exceeded the vertical ELV. Regardless of where the data were collected, fewer compartments exceeded the EAV in the horizontal orientation. Only BA compartments exceeded the ELV in the horizontal orientation. There were Area × Level interactions for vertical and horizontal RMS and VDV (P < 0.01). The BF compartment had a greater vertical RMS value than the TF, TC, and BC (P < 0.02) compartments, but did not differ (P = 0.06) from the TA compartment. The vertical RMS of the TA compartment did not differ from the TF, TC, and BC compartments (P > 0.13). The BF compartment had a greater (P = 0.02) vertical VDV value than the TC location, but did not differ from the other locations (P > 0.16). All other locations did not differ in vertical VDV (P > 0.12). The BF compartment had greater horizontal RMS than the TC and TA compartments (P < 0.01), but did not differ from TF and BC compartments (P > 0.12). All other compartments did not differ in horizontal RMS (P > 0.34). All compartments, aside from the BA compartment, did not differ in horizontal VDV (P > 0.19). Vibration analyses indicated the BA compartment had the greatest vertical and horizontal vibrations and a large percentage of the compartments exceed the EAV and ELV, which indicated pigs may have experienced uncomfortable trips that could cause discomfort or fatigue.

The objective of this study was to measure and examine 3-axis acceleration data from 6 locations within commercial transport trailers shipping market pigs. Over winter months (December through February) of 2018 to 2019 and 2019 to 2020, 16 pot-belly and 14 straight-deck trailer loads of market pigs were measured from 2 producers located in Kansas and North Carolina, respectively. Six accelerometers were placed in protective cases and affixed to the underside of the floor in the approximate center of the front compartment, middle of the trailer, and back compartment of the top and bottom decks. Data were post-processed to calculate power spectral density (PSD) functions and corresponding root mean square (RMS) accelerations. The PSDs lend insight into the vibrational frequency content of the trailers, while the RMS values indicate the severity of the vibration over the duration of each trip. With the exception of the lower aft portion of the trailer where levels are significantly higher, RMS values were consistent across trips and largely similar between sensor location and axis. Accelerations ranged between 0.06 and 0.18 g and varied in time, indicating data were non-stationarity. The PSD results reveal a largely broadband frequency response of the loaded trailers between 0 and 50 Hz, especially for sensors on the lower deck. Preliminary analysis of the data indicates the severity of vibrations experienced by pigs during transport would be considered uncomfortable by humans.

Abstract The objective of this study was to determine the effects of four microalgae and antioxidant feeding regimens on beef longissimus lumborum color stability and palatability. Steers were blocked by weight and randomly assigned to one of four dietary treatments fed during a 45-d feeding period. Treatments (n = 10 per treatment) consisted of a control diet (CON) and control diet plus 100 g∙steer−1∙d−1 microalgae (ALGAE), ALGAE plus antioxidants (103 IU/d vitamin E and Sel-Plex) fed throughout feeding (AOX), and AOX fed for the final 10 d of finishing (LATE). The longissimus lumborum muscle was removed, aged for 14 d, and fabricated into steaks for objective and subjective color and palatability analyses. There were treatment × day of display interactions for a* value and steak surface metmyoglobin percentage (P < 0.01). There were no treatment differences through day 4 of display for a* value (P > 0.16) and day 5 of display for surface metmyoglobin (P > 0.10). By day 10 of display, ALGAE steaks had a smaller a* value than all other treatments (P < 0.01). Steaks from AOX steers had a greater (P < 0.01) a* value than CON steaks, whereas both a* values did not differ from LATE steaks (P > 0.19). By the end of display, ALGAE steaks had more metmyoglobin than the other treatments (P < 0.01). Steaks from AOX steers had less metmyoglobin than CON and LATE steaks (P < 0.04), which did not differ (P > 0.25). Treatment did not affect trained panel ratings (P > 0.15); however, treatment did affect (P < 0.01) off-flavor intensity. Steaks from ALGAE and AOX steers had greater off-flavor ratings than CON steaks (P < 0.03), but did not differ (P = 0.10). Steaks from LATE steers did not differ in off-flavor ratings from the other treatments (P > 0.07). Use of antioxidants improved color stability of steaks from microalgae fed steers; however, panelists still detected off-flavors.

Prescribed fire is required to maintain the native tallgrass prairie ecosystem.Typically, ranchers apply annual spring fire from mid-March through late April to suppress woody vegetation and to stimulate cattle performance.It has been recently documented that shifting prescribed fire from spring to late summer or early fall provides comprehensive control of the noxious weed sericea lespedeza (Lespedeza cuneata).In spite of those findings, Flint Hills ranchers have voiced reluctance to consider using late-summer or early-fall prescribed burning as a routine sericea lespedeza control measure on grazing lands because of concerns about unintended harm to beef cattle growth performance or a perceived protracted weakening of native warm-season grass populations.In year one of a six-year study, 18 pastures were grouped by watershed and assigned to one of three burn treatments: spring (April), mid-summer (August), or early fall (October).All fire treatments were applied before grazing began.Yearling heifers (n = 360) were grazed for 90 days beginning May 1. Plant composition, forage biomass, and root carbohydrate concentration in key native plants in the tallgrass prairie were evaluated during late June and early July.Heifers grazing spring-burned pastures had greater total body weight gain and greater average daily gain (P = 0.02) than heifers grazing summer-or fallburned pastures.Pre-treatment forage biomass was not different (P = 0.12) between treatments.One year following fire application, forage biomass was greatest (P ≤ 0.01) in the summer-burn treatment, intermediate in the spring-burn treatment, and least in the fall-burn treatment.Total grass and forb basal cover did not differ (P ≥ 0.13) between treatments.Conversely, spring and summer fires were associated with greater (P = 0.03) native grass basal cover compared with fall fire.Furthermore, summer fire resulted in lesser (P = 0.02) basal cover of introduced grass species compared to the fall fire.Root starch and water-soluble carbohydrate levels in three key warm-season forage grasses and one key native legume did not differ (P ≥ 0.32) among treatments.These preliminary findings were interpreted to indicate that prescribed fire timing influenced stocker cattle performance, plant composition, and forage biomass accumulation.In contrast, root carbohydrate reserves were not affected by season of fire.Beef producers are encouraged to compare potential revenue loss associated with the declines in yearling growth performance reported here with the cost of alternative methods of sericea lespedeza control.

To evaluate the effect of extended post-harvest hanging time on pork carcass sides (n = 20), aerobic plate count (APC), Enterobacteriaceae, yeast and mold populations, pH, and moisture content were determined. Pork carcasses were sampled on d 1, 7, 14, and 21 to determine their microbial quality from the lean tissue of 3 anatomical locations, the flank, shoulder, and jowl. After the 21-d extended hanging time, pork shoulder butts (n = 17) (Institutional Meat Purchase Specifications #406; USDA Agricultural Marketing Service, 2014) were fabricated from these carcasses into 2.54-cm pork blade steaks. Pork blade steaks were vacuum packaged, stored up to 35 d at 0°C ± 1°C, and evaluated for APC, Enterobacteriaceae, yeast and mold populations, and pH on d 0, 7, 14, 21, 28, and 35. Pork carcass surface moisture content declined (P < 0.01) from 65.1% on d 1 to 50.5% on d 21. The carcass pH was similar (P > 0.42) at 5.88 on d 1, 7, and 14; however, the pH declined (P < 0.05) to 5.72 at d 21. Pork carcass APC populations remained relatively low during the extended hanging time; however, the jowl had the highest (P < 0.05) APC populations among all anatomical locations. In addition, the proportion of yeast populations above the detection limit for the jowl was found to be greatest (P < 0.05) compared to the flank and the shoulder. Pork blade steak APC population was 5.06 log colony-forming units/g (CFU/g) on d 35; however, these counts were below 108 log CFU/g, which is when meat is considered spoiled. There was a day effect for Enterobacteriaceae and mold populations (P < 0.05). These results indicate that pork carcasses and vacuum-packaged steaks fabricated from pork carcasses have acceptable microbial quality when they undergo an extended hanging time.

The objective of this study was to determine the impact of quality grade and steak location on color stability of semitendinosus (ST) steaks during a 9-d refrigerated study. Twenty-one ST muscles (12 Choice and 9 Select) were purchased from a commercial beef packing plant and fabricated into twelve 2.54-cm thick steaks per muscle. Steaks 1, 6, and 12 were designated for immunohistochemistry while remaining steak locations of proximal (steaks 2 to 4), middle (5 to 8), and distal (9 to 11) were randomly assigned to 0, 4, or 9 d of simulated retail display. Surface color attributes of day-9 steaks were recorded daily by a visual color panel and spectrophotometer. On days 0, 4, and 9 of display, steaks were analyzed for metmyoglobin reducing ability (MRA) and oxygen consumption (OC). Grade × day of display (DOD) interactions were detected for L*, a*, surface oxymyoglobin (OMb) and metmyoglobin (MMb) percentages, and visual panel surface redness and discoloration scores (P ≤ 0.02); however, no Grade × DOD interactions were observed for MRA or OC (P > 0.17). There were location main effect (LOC) × DOD interactions for L*, a*, surface MMb, visual panel surface redness and discoloration, and MRA (P ≤ 0.02). Distal steaks had lower L* values compared with the other locations (P < 0.01), which coincided with steaks being rated visually darker red (P < 0.01). Proximal steaks had greater a* values and had less surface discoloration than middle steaks (P < 0.05), which had an increased percentage of surface MMb (P ≤ 0.04). Distal and proximal steaks had increased MRA compared with middle steaks on days 0 and 4 (P < 0.05), and distal steaks had greater OC than the other locations throughout display (P < 0.01). There were fewer type I fibers at the proximal end with a greater percentage located at the middle and distal ends, and an increased percentage of type IIX fibers at the middle and proximal locations (P ≤ 0.01). Less type IIA fibers were detected at the middle LOC compared with the other two locations (P < 0.10). Larger type I, IIA, and IIX fibers were located at the proximal and middle locations compared with the distal LOC (P < 0.01). ST color and color-stability characteristics were influenced by DOD and LOC, which may partially be explained by differences in fiber types among locations.

Objective: To use external bioelectrical impedance analysis to assess postmortem chemical changes in normal- and high-pH beef longissimus lumborum steaks during simulated retail display.

The effects of surface application of amino acids on the formation of heterocyclic amines (HCAs) and meat quality properties were evaluated in pan-fried beef patties (230 °C/15 min). Tryptophan, lysine, leucine, and proline at three concentrations, 0.05%, 0.20%, and 0.50% (w/w), were tested. The meat crusts were analyzed for HCA content using liquid chromatography-tandem mass spectrometry. Results showed that surface application of all tested amino acids significantly reduced total HCA content (P < 0.05), and the interaction of amino acid type and concentration significantly affected (P < 0.05) both individual and total HCA formation. Tryptophan at 0.50% reduced total HCAs the most (0.92 ng/g, 93% inhibition), followed by 0.50% lysine (1.94 ng/g, 84% inhibition), while leucine (3.95 ng/g, 64% inhibition) and proline (4.71 ng/g, 56% inhibition) were less effective at 0.50%. In addition, applying amino acids to meat surface significantly influenced (P < 0.05) pH and surface color change of beef crusts; particularly, lysine at 0.20% and 0.50% increased pH and a* (redness) but reduced b* (yellowness), while tryptophan and leucine at 0.50% increased L* (whiteness). No significant effect was observed on cooking loss. Adding amino acids at 0.50% affected (P < 0.05) formation of aldehydes and pyrazines (as the key flavor compounds of fried beef). Overall, the results of this study suggested that adding amino acids to ground beef patties could effectively mitigate mutagenic HCA formation during cooking.

Abstract The objective of this pilot study was to examine the effect of oral supplementation of nicotinamide riboside chloride (NR) on pork loin chop color stability. Seven days prior to the beginning of the experiment, 10 finishing barrows (initial BW 111.9±1.6 kg) were assigned to individual pens that allowed ad libitum access to food and water. Barrows were randomly assigned to 1 of 2 NR treatments, 0 or 30 mg/kg daily of NR (ChromaDex, Irvine, CA) mixed in Karo syrup and administered by oral gavage. Barrows were administered their assigned treatment for 10 d, after which they were harvested under USDA inspection. Twenty-four hours postmortem, whole-boneless loins were fabricated, vacuum packaged, and aged for 10 d. Loins were cut into 3 chops immediately posterior to the spinalis dorsi, with chop 1 being used for day-0 metmyoglobin reducing ability (MRA) analysis, chop 2 being used for day-4 MRA and oxygen consumption rate (OCR) analyses, and chop 3 for 8-day objective/subjective color evaluation and MRA and OCR analyses. There were no Treatment × Day interactions for all objective and subjective color measurements (P > 0.77). Day of display affected all measures consistent with the discoloration of meat (P < 0.02), except L* value which was not affected (P = 0.14). Objective measures indicated NR chops had greater a*, greater surface oxymyoglobin, and less surface metmyoglobin formation over the 8-day display period (P < 0.01). Panelists indicated NR chops had less discoloration form over the entire 8-day display period (P < 0.01), but treatment did not affect OCR and MRA (P > 0.19). Feeding NR at the end of the finishing period may enhance visual pork loin chop color during simulated retail display; however, a larger study is needed to confirm this finding.

Objective: The objective of this study was to determine the effect of quality grade and time after cooking on the instrumental color of steaks cooked to varying degrees of doneness. Study Description: Beef strip loins (n = 24) from 12 animals representing five quality treatments [Prime, Top Choice, Low Choice, Select, Select Enhanced (108%)] were collected. Each steak was cooked to a peak internal temperature of very-rare (130°F), rare (140°F), medium-rare (145°F), medium (160°F), welldone (170°F), or very well-done (180°F). Each cooked steak was cut in half, perpendicular to the long axis of the steak, and lightness (L*), redness (a*), and yellowness (b*) was evaluated on the internal face of the medial side at 0, 1, 2, 3, 6, 9, and 12 minutes post-cutting using a Hunter Lab Miniscan spectrophotometer. The Bottom Line: The impact of time on internal cooked color was dependent on degree of doneness, with steaks cooked to lower degrees of doneness becoming lighter and more red in color with time and steaks cooked to higher degrees of doneness becoming darker. Additionally, quality treatment had no impact on cooked color measures of non-enhanced steaks. These results provide insight into cooked beef color changes related to time and how this might impact degree of doneness perceptions by consumers.

ObjectivesThe objective of this study was to assess if visual degrees of doneness (DOD) are in-line with current published cooking temperatures and to assess differences in perceptions between consumers and chefs.Materials and MethodsTwenty-four paired beef strip loins (IMPS #180) representing four quality grades [Prime, Top Choice, Low Choice, Select] and an additional 12 enhanced Select strip loins were fabricated into 2.54 cm thick steaks and used in the study. Steaks were randomly assigned to one of six DOD: very rare (55°C), rare (60°C), medium-rare (63°C), medium (71°C), well done (77°C), or very well done (82°C). Following cooking, a photograph of the cut steak surface was taken immediately using a digital camera (Canon PowerShot SX620 HS). A digital survey for chefs and consumers was created for the electronic evaluation of the pictures of the internal surface of the cooked steaks. Chefs (n = 83) and consumers (n = 1134) were asked to assess the DOD of digital steak pictures representing multiple DOD and quality grades. Participants were also asked several questions related to how they determine DOD when cooking steaks, about their use of thermometers, and the temperatures they associate with each DOD.ResultsThere were no quality treatment effects (P > 0.05) for any DOD for the images evaluated. Between 14 to 44% of chefs categorized the steak images as the DOD to which it was cooked. For all DOD, 9 to 48% of chefs classified the steak images as 2 or more DOD from the DOD to which the steak was cooked. Of the 1134 consumers, 27 to 35% of consumers categorized steaks as the appropriate DOD. For all DOD, 16 to 36% of consumers identified steaks as 2 or more DOD higher or lower than the DOD that the steak was cooked. When chefs were asked how they determined DOD when cooking beef steaks, 66% of chefs reported using feel or firmness, whereas 28% stated they use a thermometer. Within the chefs that reported use of thermometers, 15% indicated the specific temperature they used was pull-off the heat temperature and 13% used carry-over cooking temperature. To assess DOD when cooking beef at home, 54% of consumers reported they used color, 16% used feel or firmness, and 10% used time. Additionally, 3% of consumers responded that they do not determine DOD. Only 16% of consumers reported using temperature or food thermometer for determining the correct DOD when cooking beef. Consumers that answered to using a food thermometer were then prompted to state the temperature they utilize, being either pull off the heat temperature (69%) or temperature following the post-cooking temperature rise (31%). However, 48 to 61% of consumers that stated they use a thermometer then reported they did not know the temperatures that correspond with each DOD. Additionally, only 14 to 32% of consumers that utilized peak temperatures matched the NCBA temperatures.ConclusionAlthough consumers do not have a good understanding of beef cooking temperatures, they are able to identify DOD of steaks cooked to specified endpoint temperatures. Additionally, chefs do not consistently use the same method when determining DOD and are unable to accurately identify DOD of steaks cooked to specified endpoint temperatures. This lack of uniformity between chefs and consumers on DOD determination can create challenges for foodservice establishments to successfully meet consumer DOD expectations.

The objective of this study was to determine the effects of the LIPEX finishing diet regimen on pork chop n-3 polyunsaturated fatty acid (PUFA) content and fresh meat quality. Twenty-eight finishing pigs (PIC 359 × F1 Hermitage/NGT; initial BW 81.5 ± 2.55 kg) were subjected to a 49-d feeding trial. Treatments consisted of a 2 × 2 factorial design with Sex (n = 14 barrows and gilts each) and Diet as main effects. Dietary treatments consisted of a 2-phase standard finishing diet regimen or a 2-phase LIPEX finishing diet regimen (EXL Milling, Lloydminster, SK, Canada). The LIPEX diet regimen added the EXL LIPEX.FA369 additive during phase 1 and the EXL LIPEX.FA369 and XFE Omega-3 Finishing Touch during phase 2. Five-days postmortem, whole boneless pork loins were transported to the Kansas State University Meats Laboratory, aged 14 d, and halved immediately behind the spinalis dorsi. After blooming for 30 min, chops were evaluated for Japanese color score and National Pork Producers Council (NPPC) color and marbling scores. A 2.54-cm chop was taken immediately anterior to the loin cut and was used for fatty acid and proximate composition analyses. Four 2.54-cm chops were cut from the posterior portion of the loin and were utilized for a 7-d simulated retail display analyses, Warner-Bratzler shear force (WBSF), and trained sensory panel. There were no Sex × Diet interactions for all variables measured in the study (P > 0.10). The LIPEX finishing regimen increased chop C18:3n-3, C20:5, and C22:5, which decreased the n-6:n-3 ratio (P < 0.01). There were no Diet effects on pH, Japanese and NPPC color and marbling scores, and proximate composition (P > 0.23). Diet did not affect cook loss, WBSF, and trained sensory panel scores (P > 0.012). There were no 2- or 3-way interactions between Diet, Sex, and Day, or Diet and Sex main effects for L*a* values, surface oxy- and metmyoglobin percentages, or visual panel chop redness and surface discoloration scores (P > 0.14). Feeding the LIPEX finishing diet regimen increased chop n-3 PUFA content without negatively impacting fresh chop palatability or color stability.

Objective : The objective of this study was to assess consumers’ degree of doneness practices in addition to their ability to identify beef steak degrees of doneness. Study Description : Beef strip loins (n = 24) from 12 animals representing five quality treatments [Prime, Top Choice, Low Choice, Select, and Select Enhanced (108%)] were collected. Steaks were cooked to an end-point temperature of very-rare (130°F), rare (140°F), medium-rare (145°F), medium (160°F), well-done (170°F), or very well-done (180°F). Cooked steaks were cut in half, perpendicular to the long axis of the steak, and photographs were taken immediately on the internal face of the lateral side. A digital survey for consumers was developed for electronic evaluation of the cooked steak images. Consumers (n = 1,134) answered a demographics questionnaire, followed by questions pertaining to temperature and determining degree of doneness. Next, 10 steak images depicting varying degrees of doneness were randomly selected by Qualtrics Software for each consumer to identify the degree of doneness of the steak pictured. The Bottom Line : Consumers do not have a good understanding of beef degrees of doneness, and are unable to consistently and accurately identify degrees of doneness of steaks cooked to specified end-point temperatures. This can create challenges when consumers communicate their degree of doneness preferences at foodservice establishments. Abstract The objective of this study was to assess consumers’ degree of doneness practices in addition to their ability to identify beef steak degrees of doneness. Beef strip loins (n = 24) were collected from 12 animals representing five quality treatments [Prime, Top Choice, Low Choice, Select, and Select Enhanced (108%)]. Steaks were cooked to an end-point temperature of very-rare (130°F), rare (140°F), medium-rare (145°F), medium (160°F), well-done (170°F), or very well-done (180°F). Each cooked steak was cut in half, perpendicular to the long axis of the steak, and photographs were taken immediately of the internal face of the lateral side. A digital survey was developed for consumers to evaluate the cooked steak images. Of the 1,134 respondents, 27.3 to 35.1% of consumers correctly categorized steaks for the appropriate degree of doneness. Medium-rare was reported by 41% of consumers as their preferred degree of doneness and only 16% of consumers reported using temperature or a food thermometer for determining degree of doneness when cooking beef. Consumers do not have a good understanding of beef degrees of doneness, and are unable to consistently and accurately identify degrees of doneness of steaks cooked to specified end-point temperatures.

The objective of this study was to evaluate the chemical composition, consumer liking, and consumer acceptability of ground beef with 2 finishing diets. Three ground beef treatments were used in this study and included grass-fed, grain-fed Angus, and grain-fed commodity beef. Ground beef samples were evaluated for consumer sensory response, pH, proximate composition, and fatty acid composition. Grain-fed samples were rated higher (P < 0.01) for overall liking compared to grass-fed samples. Consumers found tenderness and juiciness similar (P > 0.05) for all 3 types of ground beef. Consumers preferred (P < 0.05) Angus over grass-fed ground beef with a flavor acceptability of 83.3 and 73.9%, respectively; and 94.9 and 82.5%, respectively, for overall acceptability. Commodity ground beef had a similar (P > 0.05) flavor acceptability and overall acceptability to Angus and grass-fed ground beef. Grass-fed, Angus, and commodity ground beef were similar (P > 0.05) for moisture, fat, and protein content. Commodity ground beef had a higher pH (P < 0.05) than Angus and grass-fed ground beef. Samples of ground beef from the 2 grain-fed treatments had greater (P < 0.05) total saturated fatty acids (SFA) than grass-fed samples; however, ground beef from grass-fed cattle had higher monounsaturated fatty acids (MUFA; P < 0.01) than the grain-fed treatments. Total polyunsaturated fatty acids (PUFA) was similar (P > 0.01) across all treatments. Omega-3 fatty acids were found in the greatest (P < 0.05) proportions in samples from grass-fed beef. Additionally, the omega-6:omega-3 ratio for grass-fed ground beef was lower (P < 0.05) than grain-fed source. Angus and commodity ground beef were more palatable, and there was no evidence of higher PUFA in grass-fed ground beef.