Simulated Retail Display Research Articles

The Impact of Antioxidant Supplementation and Heat Stress on Carcass Characteristics, Muscle Nutritional Profile and Functionality of Lamb Meat.

The impact of antioxidant supplementation and short-term heat stress on lamb body weight gain, meat nutritional profile and functionality (storage stability of lipids and colour) of lamb meat was investigated. A total of 48 crossbred ((Merino × Border Leicester) × Dorset) lambs (42 ± 2 kg body weight, 7 mo age) were randomly allocated to three dietary treatments (n = 16) by liveweight (LW) that differed in dosage of vitamin E and selenium (Se) in the diet. Vitamin E and Se levels in the control (CON), moderate (MOD) and supranutritional (SUP) dietary treatments were 28, 130 and 228 mg/kg DM as α-tocopherol acetate and 0.16, 0.66 and 1.16 mg Se as SelPlex™/kg DM, respectively. After four weeks of feeding in individual pens, including one week of adaptation, lambs were exposed to two heat treatments. Animals were moved to metabolism cages for one week and subjected to heat treatments: thermoneutral (TN; 18-21 °C and 40-50% relative humidity) and heat stress (HS; 28-40 °C and 30-40% relative humidity) conditions, respectively. Final LW and hot carcass weight were influenced by dietary treatments with higher final live weight (FLW) (p = 0.05; 46.8 vs. 44.4 and 43.8 kg, respectively) and hot carcass weight (HCW) (p = 0.01; 22.5 vs. 21.3 and 21.0 kg, respectively) recorded in lambs fed the SUP as opposed to the CON and MOD diets. Vitamin E concentration in the longissimus lumborum (LL) muscle tended to be higher in lambs fed MOD or SUP diets than the CON group. Lipid oxidation of aged meat at 72 h of simulated retail display was reduced by antioxidant supplementation. Short-term (one week) heat stress treatment significantly increased muscle linoleic acid and total omega-6 concentrations compared with the CON group. The results demonstrate that four-week antioxidant supplementation at the SUP level improved animal productivity by increasing LW and carcass weight and the functionality of meat exhibited by reduced lipid oxidation. An increase in muscle omega-6 fatty acid concentration from short-term heat stress may induce oxidative stress via proinflammatory action.

Impact of myoglobin oxygenation state prior to frozen storage on color stability of thawed beef steaks through retail display

Consumers consider beef color to be an indicator of freshness and therefore it is a major factor when purchasing beef. The ideal conditions for maintaining color throughout retail display following frozen storage have yet to be well established. Therefore, the objective of this study was to determine the effects of myoglobin oxygenation levels (especially high oxygenation) during freezing on color stability of thawed steaks during retail display (RD) and to determine the impact that frozen storage duration, aging, and packaging films have on meat color after thawing under RD conditions. USDA Choice strip loins (n = 36) were aged for 4 or 20 d. Steaks were randomly assigned to a myoglobin oxygenation level [deoxymyoglobin (DeOxy; packaged within 3 min), oxygenation (Oxy; oxygenated in air for 30 min), or high oxygenation (HiOxy; packaged for 24 h in 80% O2)]. Steaks were then vacuum packaged in oxygen permeable or impermeable film and immediately frozen (−10 °C). Following either 0, 2, 4, or 6 months of frozen storage at -5 °C, steaks were removed from the packaging and immediately placed under simulated RD conditions for 7 d. During RD, instrumental color and subjective color were measured every day after the initial 24 h thaw period. Steaks were analyzed for instrumental color (L*, a*, b*), a*:b* ratio, percentage oxymyoglobin, metmyoglobin, and deoxymyoglobin, delta E, redness ratio, subjective discoloration, and lipid oxidation. For all days of RD, steaks that were frozen for 0 months had higher a* values (greater redness) than steaks frozen for 6 months which typically had the lowest a* values (P < .0001). HiOxy steaks frozen for 6 months had the lowest amounts of percentage oxymyoglobin than all other frozen storage periods and myoglobin oxygenation levels on days 4–7 of RD (P < .05). The HiOxy steaks frozen for 4 and 6 months had higher percentage metmyoglobin than DeOxy and Oxy, regardless of packaging (P < .05). Delta E, discoloration, and lipid oxidation were greatest for HiOxy steaks compared to Oxy and DeOxy (P < .05). Extended storage brought about detrimental color effects for all differing levels of myoglobin oxygenation. The HiOxy steaks through the first few days of RD and frozen for under 6 months provided had bright cherry red color, similar to that of DeOxy and Oxy. However, with extended frozen storage and RD, HiOxy steaks had worse color characteristics (more discoloration) than the other myoglobin oxygenation levels.

Use of lucerne hay in ruminant feeds to improve animal productivity, meat nutritional value and meat preservation under a more variable climate

This study investigated the effect of low energy (LE) and high energy (HE) diets fed to Crossbred and Merino sheep on carcass weight, meat nutritional value (essential fatty acids) and preservative (shelf life) aspects. Animals were slaughtered after seven weeks of feeding and the longissimus lumborum (LL) and rectus femoris (RF) muscles collected for measurement of fatty acid concentration and retail colour. Liveweight and carcass weight at slaughter were not affected by dietary treatments. Adding lucerne hay as an ingredient to LE diet increased (P < .001) omega-3 fatty acids concentrations and lowered (P < .001) the omega-6: omega-3 ratio in meat. The redness of meat for LL and RF muscles at simulated retail display was higher (P < .05) for lambs fed LE than lambs fed HE diet. Results indicate that adding lucerne hay as an ingredient in ruminant diets has potential for maintaining liveweight (wellbeing) of animals as well as nutritional value and preservative aspects of meat.

Effects of quality grade and intramuscular location on beef semitendinosus muscle fiber characteristics, NADH content, and color stability.

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.

The effects of graded levels of concentrate supplementation on colour and lipid stability of beef from pasture finished late-maturing bulls

Finishing late-maturing bulls on grass may alter the antioxidant/prooxidant balance leading to beef with higher susceptibility to lipid oxidation and a lower colour stability compared to bulls finished on cereal concentrates. In this context, lipid oxidation and colour stability of beef from late-maturing bulls finished on pasture, with or without concentrate supplements, or indoors on concentrate was assessed. Charolais or Limousin sired bulls (n = 48) were assigned to four production systems: (1) pasture only (P), (2) pasture plus 25% dietary DM intake as barley-based concentrate (PC25), (3) pasture plus 50% dietary DM intake as barley-based concentrate (PC50) or (4) a barley-based concentrate ration (C). Following slaughter and postmortem ageing, M. Longissimus thoracis et lumborum was subjected to simulated retail display (4°C, 1000 lux for 12 h out of 24 h) for 3, 7, 10 and 14 days in modified atmosphere packs (O2 : CO2; 80 : 20). Lipid oxidation was determined using the 2-thiobarbituric acid-reactive substances assay; α-tocopherol was determined by HPLC; fatty acid methyl esters were determined using Gas Chromatography. Using a randomised complete block design, treatment means were compared by either ANOVA or repeated measures ANOVA using the MIXED procedure of SAS. Total polyunsaturated fatty acid (PUFA) concentrations were not affected by treatment, n-3 PUFAs were higher (P < 0.001) and the ratio of n-6 to n-3 PUFAs was lower (P < 0.001) in muscle from P, PC25 and PC50 compared to C. α-Tocopherol concentration was higher in muscle from P compared to PC50 and C bulls (P = 0.001) and decreased (P < 0.001) in all samples by day 14. Lipid oxidation was higher in muscle from C compared to P bulls on day 10 and day 14 of storage (P < 0.01). Finishing on pasture without supplementation did not affect beef colour stability and led to lower lipid oxidation, possibly due to the higher α-tocopherol concentration compared to concentrate finished beef.

PSXIV-2 Late-Breaking: The effect of nicotinamide riboside on pork loin chop color stability – a pilot study

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 &amp;gt; 0.77). Day of display affected all measures consistent with the discoloration of meat (P &amp;lt; 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 &amp;lt; 0.01). Panelists indicated NR chops had less discoloration form over the entire 8-day display period (P &amp;lt; 0.01), but treatment did not affect OCR and MRA (P &amp;gt; 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.

Correlation Among Ground Beef Lipid Content, Color, and Lipid Oxidation Over a 7-Day Simulated Retail Display Period

ObjectivesGround beef is more susceptible to lipid oxidation compared to whole muscle beef cuts. This is due to its smaller particle size and greater surface area, which makes the meat products more prone to be exposed to various environmental factors during production. The objective of this study was to determine the relationships among ground beef lipid content, instrumental color, visual discoloration, and lipid oxidation over a 7d simulated retail display period.Materials and MethodsBeef inside rounds (IMPS #168) from the right sides of steer carcasses (n = 63) were collected from a commercial processing facility and delivered to the U of Guelph Meat Science Laboratory for further analyses. Each inside round was trimmed of all subcutaneous fat and connective tissue, and then fabricated into ground beef patties (113 g/patty) at two targeted fat addition levels (no added fat and 25%). Lean ground beef (no added fat) was made by grinding cubes of inside round muscle through a Sirman Master 90 Y12 meat grinder (Sirman USA, Franklin Park, IL). Regular ground beef (25% added fat) was made by grinding cubed round muscle with an additional 25% subcutaneous fat that originated from the rib primal of the same carcass. For the simulated retail shelf life study, 2 crust frozen patties (crust frozen for 1 h to improve packaging ability) were placed on a Styrofoam meat tray with a soaker pad and overwrapped with PVC film. In total, there were 4 trays of patties per ID (2 trays/targeted fat level). Trays were placed under two LED lights (52 W, 1850 lumens, color temperature of 4000K, 1612.5 to 2152 lux) at 4°C and the locations on shelves were changed every 24 h. Minolta L*, a*, b* color and subjective surface discoloration were evaluated every 24 h for 7 d. Lipid peroxidation of patties before and after the retail display was estimated using thiobarbituric reactive substances (TBARS; mg MDA/g fat). Lipid content of patties was quantified using Soxhlet extraction with petroleum ether. Summary statistics and Pearson correlation coefficients were determined using the PROC CORR procedure of SAS. Correlations were regarded as weak at r &lt; |0.35|, moderate at |0.36| ≤ r ≤ |0.67|, and strong at r ≥ |0.68|.ResultsLipid content in the 126 ground beef samples evaluated in this study ranged from 3.47% to 30.43% (16.30% ± 6.18%). A moderate and significant correlation was observed between lipid content and change in TBARS values (r = –0.59, P &lt; 0.0001). Similarly, an increase in lipid content is moderately correlated with a decrease in a* values (r = –0.58, P &lt; 0.0001) and an increase in surface discoloration after a 7d display period (r = 0.53, P &lt; 0.0001). Δ TBARS values was weakly correlated with Δ L* (r = 0.24, P &lt; 0.01), Δ a* (r = 0.11, P = 0.25), and visual discoloration (r = –0.16, P = 0.09). Finally, Δ a* was strongly correlated with surface discoloration values at d7 (r = –0.76, P &lt; 0.0001).ConclusionAn increase of lipid content in ground beef had a moderate association with decreased redness, greater surface discoloration, and less change in lipid oxidation over a 7d simulated retail display period. Color values were not great predictors of lipid oxidation values and trained technicians often equated visual discoloration in beef to a deviation from the desired cherry red color.

Alternative Merchandising Strategy of the Beef Top Round

ObjectivesThe study objectives were to compare the deep (D) vs. superficial (S) portions of the beef top round (NAMI #169A PSO1), semimembranosus (SM) muscle, for tenderness, lipid oxidation, and color.Materials and MethodsTo simulate the retail setting, USDA Choice top rounds (n = 12) were purchased from a commercial food distributer and delivered to the University of Idaho Meat Science Laboratory under refrigeration. Top rounds were aged for 21 to 24 d from their pack date prior to removing the SM for subsequent analysis. Four steaks were cut from each SM proximally to distally. To account for steak location, steaks were systematically assigned to one of the following analyses; Warner-Bratzler Shear Force (WBSF) measurement, lipid oxidation using the Thiobarbituric Acid Reactive Substances (TBARS) method, subjective and objective color analysis on the whole steak to calculate color uniformity (two-toning), and subjective and objective color of a steak separated into D and S portions. The separating cut was made approximately two inches from the superficial edge of the steak. After cutting, WBSF steaks were cooked on clamshell grills to an internal temperature of 71°C. Steaks were then chilled overnight before 6 cores were sheared perpendicular to the muscle fiber direction on a WBSF machine. Steaks were sampled and evaluated for TBARS on Days 0 and 4 of retail display, while color was evaluated subjectively and objectively on Days 0, 1, 2, 3, and 4 of retail display. Steaks used for TBARS and color analysis were placed on white Styrofoam trays, overwrapped with an oxygen permeable PVC film, and displayed in a glass-fronted retail display case at 3°C for 4 d to simulate retail display. Data were analyzed using the mixed models procedure of the Statistical Analysis System (SAS Institute, Inc., Cary, NC) and significance was determined at P &lt; 0.05.ResultsMean Warner-Bratzler shear force values were lower (P = 0.0012) in the S (4.2 kg) than the D (5.2 kg) portion of the SM. On Day 0, D and S portions had similar TBARS values (0.172 vs. 0.118 mg MDA/kg Meat); yet, by Day 4, the D portion had substantially greater TBARS values than the S portion (0.497 vs. 0.194 mg MDA/kg Meat; treatment × day of retail display interaction, P &lt; 0.0001). The D portion was lighter (higher L*; P &lt; 0.0001) colored than the S portion. Furthermore, the D portion became less red compared to the S portion during simulated retail display (treatment × day of retail display interaction; P &lt; 0.0001). The whole steak had greater levels of two-toning initially, as well as throughout the 4 d of retail display, compared to the D and S portions (treatment × day of retail display interaction; P &lt; 0.0001). Therefore, cutting top round steaks into a D and S portion would result in the steaks being more uniform in color. Additionally, the S portion has longer shelf-life as well as improved tenderness compared to the D portion.ConclusionIn conclusion, the S portion may be able to generate a premium compared to the whole steak at the retail level because of its superiority in color to the D portion and more uniform color compared to the whole steak.

Effects of Pyruvic Acid, Succinic Acid, and Oregano Essential Oil on Salmonella, Natural Microflora, and Quality of Raw Ground Chicken

ObjectivesThe growing stringency of regulations related to pathogens in raw poultry and increasing consumer demand for more natural food ingredients makes it imperative to explore alternative antimicrobial agents. The aim of this study was to assess the anti-Salmonella effect of combinations of succinate or pyruvic acid with oregano essential oil in raw ground chicken. Additionally, their effect on natural microflora and quality of ground chicken over simulated retail display was evaluated.Materials and MethodsNalidixic acid (NA) adapted Salmonella Typhimurium was inoculated on skin-on broiler breast meat pieces. The antimicrobial treatments given to meat were 2 and 3% pyruvic acid (PA) or monosodium succinate (SA) in combination with 0.5% essential oil (EO). Agar at the concentration of 0.05% was added to water used to prepare antimicrobial solutions to disperse the essential oil. Mode of antimicrobial treatment was 30 s dip. The meat was then ground and evaluated for pathogen reduction. Data were analyzed using 1-way ANOVA. Surviving Salmonella were recovered on XLT-4 with 50 ppm NA. Non-inoculated meat was similarly treated with antimicrobial dip and ground. Ground chicken was packaged in foam trays with PVC overwrap, and evaluated for mesophilic aerobic plate count (APC), psychrotrophic count (PC), pH, instrumental color (CIE L*, a*, and b*), and expressible moisture over 8 d of simulated retail display.A factorial design was assigned to the experiment with antimicrobial treatments and display days as the fixed effect factors. Data were analyzed using a mixed general linear model that considered replicates as a random effect in addition to the mentioned fixed effects. All trials were conducted in three replicates.ResultsMaximum reduction obtained in Salmonella counts from ground chicken was 1.52 log CFU/g and 0.98 log CFU/g, resulting from 3% SA + 0.5% EO, and 3% PA + 0.5% EO, respectively. Three percent SA + 0.5% EO treatment resulted in ground chicken with approximately 1.2 log CFU/g lower APC on Day 8 that was significantly lower (P &lt; 0.05) than all other treatments. This treatment also resulted in less pH variation over the entire shelf life duration and lighter color of ground meat on Day 8.ConclusionThese results indicate that combination of monosodium succinate and oregano essential oil provides effective reduction of Salmonella and improved raw quality of ground chicken. This antimicrobial combination can be employed as a clean label ingredient for raw chicken applications.

Effects of Divergently Selected Broiler Lines for Meat Color on Pseudomonas Growth Under Simulated Retail Display

ObjectivesSelection of broilers based on L* values have affected the meat pH of broiler breast meat. The objective is to determine if the selection of L* values have affected Pseudomonas ssp. growth under simulated retail display.Materials and MethodsBroilers from the 13th generation of three different lines (n = 30/line) selected for high L* (HMC), low L* (LMC) and a random bred control (RBC) were harvested at 7 wk of age. Carcasses were weighed and deboned after a 4 h postmortem (PM) chill. Parts were weighed to determine parts yield based on chilled carcass weight. Meat pH was determined 24 h PM and 24 h drip loss was determined. Split breasts were weighed, packaged, displayed under simulated retail conditions, and sampled on display Days 0, 1, 2, and 3 for instrumental color and microbial count of Pseudomonas ssp.ResultsChilled carcass weight was greater (P &lt; 0.05) in the HMC and RBC lines than the LMC line. Percent yield of breast, wing, leg and rack were not different (P &gt; 0.05) among the three lines. The LMC and RBC lines had greater (P &lt; 0.05) tenderloin yield compared to the HMC line. The LMC line had greater (P &lt; 0.05) meat pH followed by the RBC line and then the HMC line. The HMC line had greater (P &lt; 0.05) L*, b* and hue values followed by RBC line and then LMC line. The LMC line had greater (P &lt; 0.05) a* values and oxymyoglobin ratio followed by RBC line and then LMC line. There was no difference (P &gt; 0.05) in chroma among the three lines. After 24 h PM, the HMC line had more (P &lt; 0.05) percent drip loss than the LMC and RBC lines but there was no difference (P &gt; 0.05) in package drip loss from the start of simulated display to end of simulated display among the three lines. On each display day, the LMC line had increased counts of Pseudomonas ssp. compared to the RBC and LMC lines. Counts of Pseudomonas ssp. was similar between RBC and LMC lines on display Days 0, 2, and 3 with RBC line having increased counts on display Day 1 compared to the HMC line. There was a weak correlation (r = 0.12) between meat pH and counts of Pseudomonas ssp.ConclusionSelection for L* affected chilled carcass weights and percent yield of tenderloins, but not any other part yields. The growth of Pseudomonas ssp. is affected by the lines selected for L* but the relationship of meat pH and the growth of Pseudomonas ssp. is weak.

Using a Potato By-Product to Replace Phosphate in Enhanced Whole-Muscle Turkey Breast

ObjectivesThe objective of the study was to determine the functionality of potato starch by-product (PS) as a phosphate replacement in cooked turkey breasts for cook yield, subjective color, objective color, and consumer acceptability.Materials and MethodsFour inclusion levels of PS (0.2%, 0.5%, 0.7%, and 1%) were tested along with a negative control (no phosphate; NEG) and a positive control (sodium phosphate; POS). Frozen turkey breasts (NAMI #P2015; n = 36) were delivered to the University of Idaho Meat Science Laboratory, thawed for 10 d at 2°C, pumped with their respective treatment solutions to 110% of green weight, and placed in individual vacuum sealed cook-in bags. Turkey breasts were tumbled for 30 min, cooked to an internal temperature of 73.9°C, and chilled overnight at 2°C. On d 0, external color was measured on all turkey breasts, and a single breast from each treatment was randomly selected for initial internal color, cook loss, and consumer sensory panel. The remaining turkey breasts were displayed in a glass-fronted retail display case at 3°C for 21 d to simulate retail display. On d 21, the same analysis was conducted as 0 d. Continuous data were analyzed using MIXED procedure of the Statistical Analysis System (SAS Institute, Inc., Cary, NC) whereas binomial data were analyzed using the GLIMMIX procedure; significance was determined at P &lt; 0.05.ResultsThe model was not significant (P = 0.19) with regard to cook yield percentage and therefore no mean comparisons were able to be made. External color on d 0 was not different (P &gt; 0.05) between treatments. Internal yellowness was greater (P &lt; 0.01) in breasts formulated with 1% PS than all other treatments, whereas redness was greater in POS and 0.7% PS breasts than all other treatments. Subjective color analysis indicated the greatest amount (P &lt; 0.01) of two-toning on the cut surface was the 1% PS followed by the 0.7% PS with NEG and 0.2% PS having the least amount of two-toning. Consumer taste panel evaluations were not different between treatment for mean overall acceptance, juiciness, or tenderness. There were significant off-flavors observed between treatments (P &lt; 0.001). The 0.7% PS had the most detectable off-flavor and was greater than all other treatments (P &lt; 0.05). The NEG treatment had the least frequency of detectable off-flavors (P &lt; 0.05). The 0.7% PS had the most frequency of detectable off-flavors with nearly 35% of the respondents reporting.ConclusionIn conclusion, PS could be an acceptable replacement for POS in cooked turkey breasts if used at levels that do not impart an off-flavor.

The Use of Bioelectrical Impedance to Assess Shelf-Life of Beef Longissimus Dorsi

ObjectivesTo evaluate quality attributes of beef longissimus dorsi (LD) during 15 d of simulated retail display using surface and internal bioelectrical impedance analysis (BIA) measurement techniques.Materials and MethodsThe experiment was designed as a split-plot with loin as the whole-plot and pairekd steaks as the sub-plot. Display day (DD) was treated as the sub-plot treatment. Postmortem age time (PM) and DD were treated as fixed effects. Beef strip loins (N = 18; IMPS #180), obtained from 3 commercial processors (PM = 27, 34, or 37 d), were fabricated into 12 2.54-cm thick steaks (N = 216). Steaks were subdivided into 6 consecutively cut pairs and pairs were randomly assigned to one of 6 display days: 0, 3, 6, 9, 12, and 15. For all pairs, one steak was allocated to microbiological analysis and pH and the paired steak for BIA, objective color assessment, proximate composition, and TBARS. Surface BIA (S-BIA) and internal BIA (I-BIA) assessment were compared. Steaks were packaged on styrofoam trays with a moisture absorbent pad, overwrapped with polyvinyl chloride film, and displayed under fluorescent lighting at 0–4°C in coffin-style retail cases.ResultsThere was a PM × DD interaction (P &lt; 0.05) for S-BIA values. From d 0 to 12 of display, steaks aged 27 d had higher (P &lt; 0.05) S-BIA values than steaks aged 34 and 37 d; however, on d 15 of display, steaks aged 34 d had 22% higher (P &lt; 0.05) S-BIA values than steaks aged 37 d, but had similar (P &gt; 0.05) values compared to steaks aged 27 d. There was no PM × DD interaction (P &lt; 0.05) for I-BIA values; however, an effect on PM and DD was found (P &lt; 0.05). Steaks aged 27 d were 17% higher for I-BIA values (P &lt; 0.05) than 37 d, but similar (P &gt; 0.05) to steaks aged 34 d. For all PM aging times, d 0 had the lowest (P &lt; 0.05) I-BIA values among all display days with 81.44. D 3 was the second lowest (P &lt; 0.05) and 8% higher than d 0 for I-BIA values. D 6 was 16% higher (P &lt; 0.05) than d 3 but similar (P &gt; 0.05) to d 9 and d 12. D 12 and D 15 were similar (P &gt; 0.05). There was a DD × BIA method interaction (P &lt; 0.05). On d 0, 3, and 6, BIA values were different (P &lt; 0.05); however, after d 6 onward, BIA values were similar (P &gt; 0.05). Covariance component was smaller in I-BIA than S-BIA. There were no PM × DD interactions (P &gt; 0.05) for a* and b* values; however, there was an interaction for L* values. Postmortem aging had no effect (P &gt; 0.05) on L*; however, an effect on a* and b* was found (P &lt; 0.05). For APC populations, there was a PM × DD interaction (P &lt; 0.05). No PM × DD interaction or PM effect (P &gt; 0.05) were found for TBARS; however, there was a DD effect (P &lt; 0.05). There was no PM day × DD interaction (P &gt; 0.05) or PM day (P &gt; 0.05) for moisture content. Display day (P &lt; 0.05) had an effect on moisture content. Moderate negative correlations occurred between S-BIA values and a*, b*, and moisture content with –0.48, –0.46, and –0.46, respectively; and –0.51, –0.48, and –0.43, respectively, for I-BIA. Conversely, moderate positive correlation was found between S-BIA values and APC and TBARS with 0.34 and 0.53, respectively; and 0.29 and 0.51, respectively, for I-BIA.ConclusionI-BIA has potential for use to assess shelf-life of retail steaks and it was more precise than S-BIA; however, I-BIA may translocate bacteria into the muscle. Protein degradation and WHC should be evaluated to better understand BIA changes over time.

The Effect of Breadfruit (Artocarpus altilis) Flour on Color of Comminuted Beef Compared with Other Flour Sources

ObjectivesNovel, non-allergenic ingredients with properties that improve the quality of processed meat products are needed for the meat industry. The objectives of this study were to investigate the effect of breadfruit (Artocarpus altilis) flour on color of comminuted beef compared with other flour sources.Materials and MethodsFlour sources included breadfruit, corn, soy, tapioca, and wheat. All flours were obtained commercially and were unmodified. Lean beef (from the same commercially sourced batch targeted to 90% lean and 10% fat), 10% ice, 1.5% salt, and flour sources at two inclusion levels (2.5% and 5%) were mixed using a bowl chopper to prepare beef patties for evaluation. The ground beef was manufactured into 115 g patties that were placed on a retail display shelf under continuous LED lighting at 4°C for 7 d. Lighting was measured periodically during the study and LUX was ensured to be between 1612.5 lux and 2152.0 lux. Objective CIE L* (lightness), a* (redness), and b* (yellowness), chroma, and hue scores were collected with a Minolta CR-400 Chroma meter (Konica Minolta Sensing, Inc., Osaka, Japan) utilizing a D65 light source and a 0° observer with an aperture size of 8 mm on each day of the simulated retail display. This study was conducted in three independent replicates for each treatment. Statistical analyses for parameters (L*, a*, b*, chroma, and hue) were conducted using the MIXED procedure of SAS with fixed effects of flour source*inclusion level, day, and their interaction. Least square means were separated using the PDIFF option with a Tukey-Kramer adjustment. Differences were considered statistically different at P &lt; 0.05.ResultsThe interaction of storage day and treatment significantly (P ≤ 0.001) affected a*, b*, chroma, and hue. There was not an interaction of storage day and treatment for L*. Both the main effect of storage day and the main effect of treatment significantly (P &lt; 0.01) affected all the attributes measured in this study. Mean L* over the display period of beef patties prepared with 2.5% breadfruit flour were not different (P = 0.95) compared with control samples. There was no significant difference between the mean hue over the 7-d display period of the beef patties prepared with 2.5% breadfruit flour compared with control samples. a* decreased at different rates for each treatment throughout the display period. Beef patties prepared with 2.5% and 5% breadfruit flour were redder (greater a*; (P &lt; 0.05)) compared with other treatments and control samples over the 7-d display period. To the contrary, a* values of beef patties prepared with soy flour were less than (P &lt; 0.05) other treatments and the control samples on Day 0 and Day 1 and remained constant at lower values as the display period increased.ConclusionBreadfruit flour improved the redness of comminuted beef products immediately and prevented discoloration for a longer period. The results indicate that breadfruit flour can effectively improve initial color and stability of color in processed beef products. More research is warranted to further investigate the mechanism of action of breadfruit flour in governing the color properties of comminuted beef products.

The effects of the LIPEX finishing diet regimen on pork quality, fatty acid profile, palatability, and color stability.

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.

77 Improving lean muscle color of atypical dark- cutting beef by antioxidant-enhancement and modified atmospheric packaging

Abstract Any deviation from the bright-red color of beef leads to discounted price or consumer rejection. Atypical dark-cutting beef represents darker color of lean around a pH 5.6 – 5.8. However, limited studies have determined the postharvest practices to improve the lean color of atypical dark-cutting beef. Therefore, the objective was to evaluate the effects of rosemary-enhancement and modified atmospheric packaging on atypical dark-cutting beef. Atypical dark-cutting beef strip loins (n = 13, pH=5.70 ± 0.09; ADC) and USDA Choice beef strip loins (n = 6, pH=5.57 ± 0.1; CH) were selected within 72 h of harvest. Atypical dark-cutting strip loins were divided into 2 sections, and randomly assigned to one of the following enhancement treatments: control non-enhanced (ADC), or a 1.1% rosemary-enhanced treatment (ADCE). After enhancement, 2.54 cm steaks were cut from CH, ADC, and ADCE strip loins and assigned to 1 of 3 packaging treatments: polyvinyl chloride overwrap (PVC), carbon monoxide modified atmosphere packaging (CO-MAP; 0.4% CO, 69.6% N, and 30% CO2), and high-oxygen modified atmospheric packaging (HiOx-MAP; 80% O2 and 20% CO2). A HunterLab MiniScan was used to determine color during the 6 d simulated retail display. Visual color measurement for muscle darkening (MD), muscle color (MC), and surface discoloration (SD) were recorded on d 2, 4, and 6 of retail display. There was a significant enhancement x packaging interaction for instrumental and visual color measurements. For all packaging types, ADCE steaks possessed greater L* values than DC steaks. In addition, ADCE steaks packaged in HiOx-MAP or CO-MAP had brighter-red color than ADC steaks. Furthermore, ADCE and C steaks had less muscle darkening compared with ADC steaks for MD and MC attributes. The results suggest that enhancement and modified atmospheric packaging have the potential to improve the surface color of atypical dark-cutting beef.

35 Applying GGP-F250 genotypes to elucidate the biochemical basis for animal variation in meat quality attributes

Abstract Understanding the biological factors regulating animal variation in meat quality traits continues to challenge meat scientists. Meat scientists have studied the impacts of numerous intrinsic and extrinsic variables on meat quality traits. Often, component traits, known to directly contribute to the trait of interest, have been utilized to determine the mechanisms by which these impacts are made. However, only a limited amount of the variation in these traits is explained by component traits, indicating that a significant knowledge gap exists. The rise of genotyping assays for functional alleles provides an opportunity to further understanding of the biological basis of meat quality traits. For example, lean color is the primary factor utilized by consumers in making purchasing decisions. Cuts from some carcasses discolor rapidly and must be discounted or discarded. Component traits (reducing ability and oxygen consumption) generally explains a total 30 to 40% of the variation in lean color stability. A genome-wide association study (GWAS) was conducted using GGP-F250 genotypes from 2,476 steers representing crosses of 18 beef breeds that had been phenotyped for lean color change during simulated retail display. The GWAS identified 417 single nucleotide polymorphisms (SNP) explaining the heritable variation (0.45). Identified genes included genes coding for reductases and cytochromes as well as mitochondrial genes, which are consistent with conventional wisdom regarding lean color stability. However, other genes identified are related to muscle contraction, action potential mediation, calcium binding, actin binding, stress response, and apotosis. In addition, gene ontology analysis indicates 128 genes contributing to metabolic processes, with 74 being associated with nucleobase containing compound metabolic processes. Thus, these results suggest novel mechanisms, which have not been previously studied in detail in relation to lean color stability. This approach provides a means to increase understanding of the biological regulation of meat quality traits.

356 Young Scholar Presentation: An applied approach to studying heat stress: Effects of cyclic heat and zinc supplementation on body temperature, gut health, and pork quality

Abstract Heat stress (HS) has depletory effects on intestinal morphology, induces metabolic changes, and disposes pigs to oxidative stress. Zinc has roles in gut health, nutrient and insulin mediated metabolism. To better understand the effects of cyclic heat and dietary Zn supplementation on gut integrity, carcass composition, and pork quality, commercial crossbred mixed-sex pigs (n = 400; initially 72.2 kg) were housed under either thermoneutral (TN; 18.9–16.7°C) or cycling HS conditions simulating chronic summer heat (30°C/26.7°C for 12h:12h on days 24–65) with acute heat periods of 32-33°C/29-30°C for 12h:12h on days 21–24, 42–45, and 63–65. Treatments were arranged in a 2×2×2 factorial with main effects of environment (HS vs. TN), added Zn level (50 vs. 130 mg/kg available Zn), and added Zn source (inorganic from ZnO vs. organic from Availa®Zn; Zinpro Corp, Eden Prairie, MN). Relative to TN, HS elevated (P &lt; 0.050) body temperatures during the growing period. Heat stress was correlated with ileal villus height (r=-0.51, P = 0.015) and HSP-70 expression (r=0.46, P = 0.041). Growth was reduced such that carcasses from HS pigs were lighter (P = 0.011) and exhibited improved carcass quality with higher (P = 0.001) 24-hour loin pH, decreased (P = 0.034) drip loss, and greater (P &lt; 0.050) subjective color and firmness scores compared to TN carcasses. Relative to TN, loin chops and sausage patties manufactured from the HS carcasses had similar oxidative stability (CIE L*a*b* color, 2-thiobarbituric acid reactive substances) throughout a 10-day simulated retail display. The HS induced fatty acid profile differences in the pork product but were not sufficient to shift IV (P &gt; 0.10). Belly firmness and slice lean were also unaffected (P &gt; 0.10) by HS. Zinc supplementation had minimal impact on the carcass quality characteristics studied. Further research is necessary to better understand the impact of HS duration, combination with additional stressors, and refine the ability to utilize thermal monitoring to manage negative impacts of HS.

Genetic variation in colour stability traits of lamb cuts under two packaging systems

Data from samples of longissmus lumborum (LL) and semimembranosus (SM) muscles from 391 lamb carcasses, which had been packaged in overwrap (OW) or high oxygen modified atmosphere packaging (MAPO2) systems and then subjected to simulated retail display, were used to estimate genetic variation for colour stability traits of lamb meat as a step in identifying a trait for genetic evaluation. Traits included the ratio of the reflectance of light at wavelengths of 630 nm and 580 nm (oxy/met) measured at a single time point at the end of the display period (day 3 under OW; day 8 under MAPO2) and the predicted time for oxy/met to reach a benchmark value. Under OW and MAPO2, the measures of meat colour stability of the LL tended to be of moderate heritability (0.09–0.29), but for the SM were of low heritability (0–0.10). Improving retail colour stability of lamb loins through selection of genetically superior animals may be better based on measurement of oxy/met.

Potassium carbonate improves fresh pork quality characteristics

Meat enhancement strategies like sodium tripolyphosphate (STP) are used to improve fresh meat quality attributes like color, water-holding capacity, and tenderness. However, alternatives are necessary because of reduced consumer acceptance of STP. One alternative is potassium carbonate (K2CO3). A study was conducted to evaluate K2CO3's impact on fresh, boneless, center-cut pork loins enhanced with one of five treatments: a negative control, positive control (0.3% STP), and three concentrations of K2CO3 (0.1, 0.3, and 0.5%). Loins were cut into chops, stored under simulated retail display, and analyzed for color (L*, a*, b*), pH, cook loss, and tenderness. For each quality characteristic measured, the 0.3% and 0.5% K2CO3 maintained redness (a*), decreased yellowness (b*), reduced cooking loss, and maintained tenderness compared to STP. SDS-PAGE analysis further determined that both K2CO3 and STP extracted myosin heavy chain. Combined, these data suggest that K2CO3 may function as an alternative to STP in the fresh pork industry provided microbial safety and shelf-life are appropriately controlled.

The impact of ultrasound and vacuum pack on quality properties of beef after modified atmosphere on display

AbstractBeef steaks (L. lumborum and Semitendinosus) were randomly assigned to one of three treatments: 1) No‐ultrasonicated; 2) 16 W/cm2 or 3) 28 W/cm2 ultrasonicated in vacuum bags (VAC). Later, steaks were also randomly packed in either VAC or modified atmosphere (MAP, 25–75%, CO2‐O2). After simulated retail display (SRD, 3°C, 12 h light) for 6 d, High‐intensity Ultrasound (HIU) increased redness and saturation on VAC meat (p &lt; 0.05) and produced an increase on L. lumborum (p &lt; 0.05) but not on Semitendinosus (p &gt; 0.05) shear force. High concentrations of O2 in MAP increased loss of redness (2.83 vs. 2.13 MAP vs. VAC, respectively) and saturation (2.64 vs. 1.99, respectively) during SRD. MAP also increased L. lumborum shear force (4.4 vs. 3.2 kgf, respectively p &lt; 0.001) and lipid oxidation (p &lt; 0.001). HIU may be consider as a strategy to improve beef color on VAC. Moreover, high O2 concentrations on MAP should be used with caution for beef, because of a possible negative impact on oxidative stability and tenderness.Practical applicationsHigh intensity ultrasound on bovine Longissimus lumborum and Semitendinosus appears to be a promising method among the recent techniques for improving color of vacuum packed beef without a negative effect on pH and water holding capacity when applied to fresh meat. Hence, ultrasonication may be considered as a strategy to positively influence the acceptance of vacuum packed beef by final consumers.