Discoloration Scores Research Articles

Determination of Consumer Color and Discoloration Thresholds for Purchase of Representative Retail Ground Beef

The objective of this study was to identify the threshold for color and discoloration for consumers to purchase ground beef and to determine the best objective measurement to predict consumer purchase intent. This study was designed in 2 phases, with Phase 1 requiring consumers to evaluate ground beef samples of multiple days of display simultaneously, and Phase 2 having consumers evaluate samples of only a single day of display. Ground beef packages (80% lean) were evaluated for overall appearance liking and purchase intent (yes/no) by consumers (n=216 and 318). Additionally, packages were evaluated for L*, a*, b*, calculated percentage of metmyoglobin, oxymyoglobin, chroma, hue angle, and trained sensory panel redness and discoloration scores. Models showed that each of the objective measures evaluated were predictors (P<0.05) of consumer purchasing intent. All logistic regression equations (P<0.01) had high R2 values of 0.48 to 0.86 (Phase 1) and 0.26 to 0.65 (Phase 2) and correctly classified 78.1% to 90.1% (Phase 1) and 70.5% to 84.0% (Phase 2) of samples as would/would not purchase. Linear regression equations predicting consumer overall appearance ratings with objective measures also resulted in significant (P<0.01) models, with R2 values of 0.57 to 0.93 and 0.35 to 0.54. The a* values of 21.6, 24.6, 28.3, and 30.5 (Phase 1) and 20.7, 26.2, 31.7, and 35.4 (Phase 2) correspond with consumers being 50%, 75%, 90%, and 95% likely to purchase the product at full price. However, if the product was discounted, the a* values were reduced to 17.9, 21.4, 25.0, and 27.4 (Phase 1) and 17.7, 22.7, 27.7, and 31.1 (Phase 2). The models generated from this study provide the ability to predict consumer willingness to purchase ground beef and provide ground beef processors an indication of potential consumer purchasing behaviors based upon objective values that are easy to measure.

Characterization of Pork Loin Chop Color Stability Using Loin Quality Traits and Instrumental Discoloration Measures

The objective of this study was to characterize the color stability of pork loin chops using fresh quality traits and instrumental measures of discoloration. Boneless pork loins (N=484) were evaluated for quality traits at 11 or 14 d post-mortem. One chop was cut from each loin near the 10th rib for retail display, overwrapped, and displayed under constant fluorescent lighting for 7 d. Objective color, myoglobin redox forms, and subjective visual discoloration traits were evaluated daily. After retail display, chops were categorized based on final visual discoloration (Day 7) as Very Color Stable (VCS; 0% to 5% discoloration), Color Stable (CS; 5% to 10% discoloration), Neutral (10% to 25% discoloration), Color Labile (CL; 25% to 30% discoloration), or Very Color Labile (VCL; >30% discoloration). Quality and color traits were analyzed using the GLIMMIX (visual discoloration) or MIXED (all other measures) procedure of SAS. Retail display data were analyzed as repeated measures. Chops ultimately classified as CS or VCS were darker, redder, and had lesser surface metmyoglobin (P<0.01) than CL and VCL chops at both Day 1 of retail display and throughout display. Stable chops also had generally increased R630/580 values as well as decreased visual discoloration scores and yellowness during display. A group×day interaction was observed for all traits measured during retail display (P<0.0001). No differences in aged loin ventral surface redness were observed between color stability groups (P≥0.16). Overall, chops ultimately classified as CS came from aged loins that were generally darker, redder, and less yellow, with greater pH values, greater marbling scores,and decreased purge loss.

Principal component analysis of lipid and protein oxidation products and their impact on color stability in bison longissimus lumborum and psoas major muscles

The study aims were to compare lipid (malondialdehyde [MDA], 4-hydroxy-2-nonenal [HNE]) and protein (carbonyl content [CAR]) oxidation products between two bison muscles (longissimus lumborum [LL] and psoas major [PM]) at different aging and retail display time and determine their influence on muscle color stability. Regardless of the aging and retail display time, LL showed greater redness (a* value; P = 0.04) and lower surface discoloration (P < 0.01) than PM as well as LL exhibited lower MDA, HNE, and CAR content compared to PM (P < 0.05). In both muscles, MDA showed the highest correlation to a* (r = −0.78; P < 0.01) and discoloration (rs = 0.82; P < 0.01) scores, particularly in PM muscle compared to LL muscle. In conclusion, the principal component analysis revealed 4 distinct color deterioration clusters within steaks displayed at d 4 according to the muscle and aging time, and MDA critically influences color deterioration patterns in bison muscles.

Color Stability of Flowable Composites in Different Viscosities

Objective: This in vitro study was aimed to evaluate the color stability of resin-based composite materials in different viscosities immersed in various colorant solutions.Methods: 250 composite samples of A2 shades were prepared using two high-viscosity flowable composites (G-aenial Injectable, GC, Tokyo, Japan; Estelite Super Low Flow, Tokuyama Dental, Japan A2 shade), a bulk-fill flowable composite (Filtek Bulk-Fill, 3M, USA), a low-viscosity flowable composite (Filtek Ultimate Flowable, 3M, USA), and a packable composite (Filtek Ultimate, 3M, USA). Samples were polymerized and polished from both sides with a LED curing unit (Valo Grand, Ultradent, Switzerland) and polishing discs (SofLex, 3M, USA). Then divided by test groups (n=10 for each) regarding colorant solutions; coke (CocaCola Company, USA), tea (Yellow Label, Lipton, Rize, Turkey), coffee (Nescafe Classic; Nestle, Switzerland), red wine (Doluca, Öküzgözü, Doluca, İstanbul, Turkey), and physiologic saline as the control solution. Samples were discolored for 144 hours with solutions in an incubator at 37°C, and repolished after discoloration. Color measurements were performed using a clinical spectrophotometer (EasyShade IV, Vita, Germany) and a colorimeter (ShadeStar, Dentsply Sirona, USA). Two-way Anova test and Tukey HSD test were used for statistical analyses.Results: Composite material and colorant solution were considered effective factors for influencing the color change, regarding after discoloration scores (p&amp;lt;0.001, p&amp;lt;0.001, respectively). In addition, colorant solution was found more effective than the type of composite. Filtek Ultimate Flowable presented significantly the highest level of color change among others (p&amp;lt;0.001), for both ‘after discoloration (5,34 ± 3,78b)’ and ‘after repolishing (3,93 ± 2,23b)’ periods. No significant difference in color change was found between Gaenial Injectable, Estelite Super Low Flow, Filtek Bulk Fill Flowable, and Filtek Ultimate, and all showed imperceptible color changes (∆E*&amp;lt;3.7). Red wine solution showed significantly the highest level of color change (8,00 ± 2,08d) among other colorant solutions (p&amp;lt;0.001), and followed by coffee (4,59 ± 1,52c), tea (3,38 ± 1,21b), and coke (1,58 ± 0,99a), respectively. A strong relation was found between the spectrophotometer and colorimeter measurements.Conclusion: Viscosity was considered an effective factor for discoloration of RBCs. Color stability of high viscosity flowable composite materials were found to be good and similar to packable composite. Samples immersed in red wine showed the greatest level of discoloration and followed by coffee, tea, and coke. The repolishing procedure was considered effective for reversing back the surface discoloration of composite materials.

Ultimate pH effects on dry-aged beef quality

This study aimed to evaluate pH effects on moisture loss and meat quality characteristics of dry-aged beef. Strip loins from six normal pH carcasses (pH = 5.47 ± 0.02) and dark cutting (DC) strip loins from six high pH carcasses (pH = 6.69 ± 0.09) were obtained. One strip loin from each carcass was dry aged and one was wet aged, giving four treatments: DRY, DRY-DC, WET, and WET-DC. Loins were aged for 42 d. Ultimate pH did not affect the rate or amount of moisture loss, trim loss, yield, or tenderness in dry-aged beef (P > 0.05). In general, DC steaks had the lowest lightness (L*), redness (a*), and yellowness (b*) values, regardless of aging method (P < 0.05). Discoloration scores and TBARS values for DC steaks remained low throughout retail display. Dry aging significantly reduced bacterial counts mitigating the microbial damages associated with DC. Flavor characteristics of DC were not improved by dry aging when compared to dry-aged loins from carcasses with normal pH.

Analysis of chemical deposits on tooth enamel exposed to total particulate matter from cigarette smoke and tobacco heating system 2.2 aerosol by novel GC–MS deconvolution procedures

Tobacco smoking contributes to tooth discoloration. Pigmented compounds in the smoke generated by combustion of tobacco can cause discoloration of dental hard tissues. However, aerosols from heated tobacco products cause less discoloration than cigarette smoke (CS) in vitro. The objective of the present study was to optimize a method for extracting the colored chemical compounds deposited on tooth enamel following exposure to total particulate matter (TPM) from CS or a heated tobacco product (Tobacco Heating System [THS] 2.2), analyze the extracts by gas chromatography coupled to time-of-flight mass spectrometry, and identify the key chemicals associated with tooth discoloration. Sixty bovine enamel blocks were exposed for 2 weeks to TPM from CS or THS 2.2 aerosol or to artificial saliva as a control. Brushing without toothpaste and color measurements were performed each week. Noticeable discoloration of enamel was observed following exposure to CS TPM. The discoloration following exposure to THS 2.2 aerosol TPM or artificial saliva was not distinguishable to the eye (ΔE < 3.3). Carbon disulfide was used to extract surface-deposited chemicals. Untargeted analyses were followed by partial least squares correlation against discoloration scores (R2 = 0.96). Eleven compounds had variable importance in projection scores greater than 2. Discriminant autocorrelation matrix calculation of their mass spectral information identified eight of the eleven compounds as terpenoids. None of the compounds were related to nicotine. Several of these compounds were also detected in THS 2.2 aerosol TPM-exposed enamel, but at lower levels, in line with our findings showing less discoloration. Compared with CS TPM exposure, THS 2.2 aerosol TPM exposure resulted in lower deposition of color-related compounds on enamel surface, consistent with minimal discoloration of dental enamel.

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.

Comparison of Lipid and Protein Oxidation Products and their Impact on Colour Stability in Bison Longissimus Lumborum and Psoas Major Muscles

ObjectivesTo compare lipid (malondialdehyde [MDA], 4-hydroxy-2-nonenal [HNE]) and protein (carbonyl content [CAR]) oxidation products and determine their influence on color stability in two bison muscles (longissimus lumborum [LL; color stable] and psoas major [PM; color labile]).Materials and MethodsA total of 10 longissimus lumborun (LL) and 10 psoas major (PM) from five A1 grade bison carcasses were obtained from a commercial slaughter plant within 48 h post-mortem. From each muscle, a 10-cm thick piece was removed and subsampled for evaluation of pH, MDA (by thiobarbituric acid assay), HNE (by ELISA) and CAR (by 2,4-dinitrophenylhydrazine). These measurements allowed the establishment of a baseline for the different oxidation products. The remainder of the muscles were cut into two equal portions, and each portion was vacuum-packaged and assigned to an ageing period of 7 and 14 d at 2°C. At the end of each ageing period, each muscle portion was removed from their packages, pH measured, and steaks obtained for sensory (muscle and discoloration scores) and instrumental color measurements (L*, a* and b*) over 5 d of retail display, and for estimation of MDA, HNE and CAR. After 5 d in retail display and following color and pH measurements the steaks were removed and collected for MDA, HNE and CAR determination. Data were analyzed as a completely randomized design with a split-split plot arrangement. Additionally, correlation and regression analysis were performed to identify the influence of the measured attributes on color.ResultsRegardless of the ageing time, LL showed greater redness and lower surface discoloration by instrumental (a* value; P = 0.04) and sensory (P &lt; 0.01) color evaluation than PM at the end of the retail display. Furthermore, LL exhibited lower MDA, HNE and CAR content compared to PM (P &lt; 0.05). A three-way interaction (muscle × ageing time × retail day display) was detected on MDA content, where PM presented a higher level of MDA with increasing ageing time and retail display than LL (P = 0.02). The pH was not different between LL and PM (P &gt; 0.05) steaks.In both muscles, Pearson (r) and Spearman (rs) correlation coefficients indicated that MDA was the oxidation compound showing the highest correlation to a* (r = –0.78; P &lt; 0.01) and discoloration (rs = 0.81; P &lt; 0.01) scores, followed by a moderate correlation with HNE and CAR (r or rs &lt; 0.7; P &lt; 0.01). The pH did not exhibit correlation with color traits, except for lightness, in both muscles. For the stepwise regression analysis, the main variable entered into the equation for predicting a*, color and discoloration score in PM muscle was MDA with an R2 of 0.72, 0.75 and 0.78, respectively, while for LL muscle, MDA presented an R2 of 0.62, 0.68 and 0.66;, respectively. The pH, HNE and CAR only explained an additional 2% of the variation in those attributes.ConclusionThe results of color attributes corroborated that bison LL is a color-stable muscle due to the lower level of protein and lipid oxidation products developed during storage and retail display compared to PM muscle, which is considered color-labile muscle. The MDA seemed to have remarkable importance in the color deterioration than HNE and CAR, particularly in bison PM muscle.

Color and Lipid Stability of Dry Aged Beef During Retail Display

ObjectivesThere has been an increased interest in merchandising dry-aged steaks at the retail level. Further understanding of the influence of the dry aging process on meat color and lipid stability is needed to ensure dry-aged beef products can be merchandised without adverse impacts on retail display life. Therefore, this study aimed to determine color and lipid stability of steaks from dry-aged beef loins over 7 d (d) of retail display.Materials and MethodsSixteen USDA low Choice boneless strip loins were assigned to one of four aging treatments: vacuum (Wet), dry-aging at 50% relative humidity (RH) (RH50), dry-aging at 70% RH (RH70), or dry-aging at 85% RH (RH85). Dry-aged loins were placed in each assigned dry aging chamber, while wet aged counterparts were aged in vacuum bags in the same cooler. Loins were aged for 42 d at 1°C. After aging, loins were trimmed of dehydrated lean/fat and fabricated into steaks. Steaks were trimmed of subcutaneous fat, and placed on foam trays, overwrapped with oxygen permeable film and placed under retail display (RD) conditions for 7 d at 2°C. Objective color measurements were taken once daily from d 0 to 7 of RD. Trained visual color panelists (n = 6) evaluated surface discoloration from d 0 to 7 of RD once daily. Lipid oxidation was measured via thiobarbituric acid reactive substance assay (TBARS) at 0, 4, and 7 d of RD. Color data were analyzed as a split-plot repeated measures design with treatment as the whole-plot and RD time as the repeated measures. TBARS data were analyzed as a split-plot design with aging treatment as the whole-plot, and RD time as the split-plot. In this study, chamber (loin) was considered the experimental unit. Data were analyzed using the PROC GLIMMIX procedure of SAS with α = 0.05.ResultsFor all three-color scales, a RD effect was found (P &lt; 0.001). In general, L*, a* and b* values decreased as RD time increased, regardless of the aging treatment. Wet-aged steaks had higher L* (P &lt; 0.05), a* (P &lt; 0.05), and b* values (P &lt; 0.001) than any other dry-aged treatment. No differences in L*, a*, and b* values among dry aging treatments were found (P &lt; 0.05). A 2-way interaction between treatment and RD for discoloration was observed (P &lt; 0.05). No differences were found among treatments over the first 2 d of RD (P &gt; 0.05). Samples began to diverge on Day 3 of RD. Dry-aged steaks had greater discoloration scores (P &lt; 0.05) than wet-aged steaks at 4, 5, 6, and 7 d of RD. However, no differences in discoloration scores among RH treatments were found. There was a RD effect on TBARS values (P &lt; 0.001). Greater TBARS values were found as RD progressed from d 0 to d 4 and d 7, regardless of the aging treatment. A treatment effect was observed for lipid oxidation (P &lt; 0.05). Dry-aged steaks had higher TBARS values than wet-aged steaks. No differences in TBARS values among dry aging treatments were found.ConclusionDry aging of beef resulted in decreased lightness and redness values and increased lipid oxidation compared to wet aging. Results suggest that with prolonged RD dry aging of beef has the potential to reduce color and lipid stability compared to wet-aging and thus reduce display life. Dry-aged steaks met the 20% discoloration threshold and overcame the acceptability threshold of 2.28 mg of malonaldehyde/kg at d 4 of RD, indicating that dry-aged steaks can be merchandised in the retail level for 3 d without detrimental effects on color and lipid oxidation.

Dry Aging of High Ultimate pH Beef

ObjectivesDry aging is a process in which water is removed from the meat by evaporation. As meat loses water, the flavor compounds are concentrated, resulting in stronger flavor. Meat pH may be important when dry aging as it relates to the ability of muscle to bind water. Therefore, this study aimed to evaluate pH effects on water loss when dry aging and the effects on meat quality characteristics. Dry aging of dark cutting (DC) beef may improve flavor and increase yield.Materials and MethodsSix USDA low Choice and six dark cutting (DC) carcasses with the same degree of marbling were selected and boneless strip loins from both sides were obtained. Longissimus muscle pH was measured, and carcasses were classified as DC (pH = 6.69), or control (pH = 5.47). Then, strip loins from each animal were assigned to 2 aging methods (wet or dry). The 4 treatments included 2 dry aging (DRY and DRY-DC) and 2 wet-aging treatments (WET and WET-DC). Dry aging occurred in individual dry-aging chambers at 50% relative humidity and 2200 RPM fan speed. The chambers (86 cm Length × 48 cm Width × 35 cm Height) have built-in weighing scales that can continuously monitor weight loss (± 5 g). Wet and dry-aged loins were aged in the same cooler for 45 d at 1°C.After aging, loins were fabricated into steaks and evaluated for trim loss, yield, tenderness (WBSF), color, discoloration, lipid oxidation, and sensory analysis (flavor) via triangle test (n = 32). Steaks assigned for color and lipid oxidation were placed under retail display (RD) at 2°C for 7 d. Rate of moisture loss and color data were analyzed as a split plot design with repeated measures. The TBARS data were analyzed as a split-plot design. All the other data were analyzed as a completely randomized design. Chamber (loin) was considered the experimental unit. Data were analyzed using the PROC GLIMMIX procedure of SAS with α = 0.05.ResultsWet-aged treatments had lower moisture loss, trim loss and higher yield than dry-aged treatments (P &lt; 0.05). However, no differences in rate of moisture loss (P = 0.51), total moisture loss (P = 0.96), trim loss (P = 0.69), or yield (P = 0.75) between DRY-DC and DRY were found. There were no differences among treatments for WBSF (P = 0.67). In general, DRY-DC and WET-DC steaks had the lowest lightness (L*) values, redness (a*) values (Fig. 3a), and yellowness (b*) values over the first 5 d of RD (P &lt; 0.05). Discoloration scores for DC steaks remained low throughout the RD period (Fig. 3b). DRY steaks had greater TBARS values than any other treatment at 0 d RD. At 4 and 7 d of RD, DRY-DC and WET-DC steaks had the lowest TBARS values, DRY steaks had the highest, while WET was intermediate (P &lt; 0.001). Results from the triangle test indicated a detectable difference between DRY-DC versus DRY (P = 0.01), DRY-DC versus WET-DC (P = 0.01), DRY-DC versus WET (P = 0.01), and WET-DC versus WET (P &lt; 0.01). Panelists frequently made unsolicited comments which suggested inferior eating satisfaction associated with DC flavor (wet or dry), although they were not asked questions regarding preference.ConclusionUltimate pH did not affect the rate and total moisture loss in dry aged beef. Results suggest that neither yield nor flavor were positively affected by dry aging of DC beef.Figure 3.a) Effect of ultimate pH (Dark cutters [DC] vs. Normal) and aging method (Wet vs. Dry) on objective redness (a*) values of strip loins steaks aged for 45 d through 7 d of retail display. b) Effect of ultimate pH (Dark cutters [DC] vs. Normal) and aging method (Wet vs. Dry) on discoloration (%) of strip loins steaks aged for 45 d through 7 d of retail display. a-c Means within a day with different superscripts are different (P &lt; 0.005).

Does Treating Beef Subprimals with UV-Light Reduce Pathogens and Impact Quality?

ObjectivesTo evaluate reduction of pathogens and impact on quality parameters of beef strip loins treated with pulsed-UV light.Materials and MethodsInoculum was prepared as a cocktail of three non-pathogenic, rifampicin-resistant E. coli Biotype I surrogates. Strip loins were halved, inoculated, individually vacuum packaged, and assigned to one of three pulsed-light UV treatments: (1) light height 5 cm, belt speed 15 Hz; (2) light height 28 cm, belt speed 15 Hz; and (3) light height 28 cm, belt speed 25 Hz. Microbiological samples were obtained and enumerated pre- and post-treatment (n = 90; 3 UV treatments × 5 strip loin halves per treatment × 2 sampling times (pre/post treatment) × 3 replications).To evaluate quality parameters, a control group was added to the three UV treatments. Uninoculated strip loin halves (n = 48) were fabricated, packaged, and assigned (n = 12 strip loins halves per treatment) to one of the four treatment groups. Within each group, n = 3 strip loin halves were assigned a storage time (0, 7, 14, or 21 d). After treatment, three steaks from each strip loin half (approximately 2.54-cm thick; n = 192 total steaks) were cut and individually packaged for analyses: (1) trained aroma and color panel, (2) steak surface pH, purge pH, purge quantification, and objective color, and (3) aerobic plate counts.Data were analyzed using JMP Pro (SAS Institute Inc., Cary, NC). The fit model function was used for analysis of variance, and least squares means comparisons were conducted when appropriate using Student’s t test with an α-level 0.05.ResultsNo differences were seen (P &gt; 0.05) in reductions of E. coli surrogates among the three UV treatments, with all reductions less than 1-log. No differences (P &gt; 0.05) in aroma scores among treatment groups were noted, although differences in aroma attribute scores occurred between aging times. Panelists scored samples highest (P &lt; 0.001) for bloody/serumy on d 0 than any other aging time. Conversely, sour dairy and spoiled intensified over time with d 21 samples receiving the highest scores (P &lt; 0.001). Although trained panelists’ responses for lean color score did not differ (P = 0.277) among UV treatments, scores for percent discoloration did (P = 0.014). Notably, percent discoloration scores for d 0 were statistically higher than other aging times, meaning that discoloration diminished as aging continued. No statistical differences were identified for L*, a*, or b* values across UV treatments. Between aging times, differences were seen (P &lt; 0.001) for a* and b* values, with d 0 having the lowest values for both. For purge and pH, the surface pH of steaks was higher on Days 0 and 7 and began to decrease, showing statistical similarities on Days 14 and 21. The amount of purge (g) steadily increased as steaks aged. APC counts were not found to differ due to UV treatment but generally tended to increase as storage times lengthened.ConclusionPulsed-UV light on chilled subprimals resulted in low microbial reductions, however, this technology could be beneficial if used in addition to other antimicrobial interventions. Initial discoloration was identified but improved as steaks aged. While APCs tended to increase over the course of storage, as did purge, no differences due to UV treatments were seen. Further research is warranted to determine if different treatment parameters would result in greater microbial reductions.

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.

A randomized controlled 10 years follow up of a glass ionomer restorative material in class I and class II cavities

ObjectiveTo evaluate the durability of a glass ionomer restorative material in Class I and Class II cavities during 10 years compared with a micro filled composite resin. MethodsFifty-nine participants (mean age 24 years) received 140 (80 Class I and 60 Class II) glass ionomer (GI) or composite resin (CR) restorations. Evaluation was performed with slightly modified USPHS criteria at baseline, and yearly during the 10 years. Data were analyzed with Cohran's Q and McNemar's tests. ResultsFifty-one patients and 124 restorations (61 GI / 38 Class I - 23 Class II, 63 CR / 38 Class I, 25 Class II) were evaluated after 10 years. The recall rate was 86.4%. The overall clinical recall rate of restorations was 88.6%. The success rate of Class I and II restorations were calculated as 100% for both materials. The cumulative failure rate (CRF) of all Cl I and Cl II GI restorations was 3.17% in total, but CFR was 8 % for Cl II GI restorations. A significant difference was observed between the marginal discoloration scores of restorations at 10 years (p = 0.022). No significant difference was seen between two restorative materials in terms of marginal adaptation (p > 0.05). A significant change was seen in color match of GI restorations at 10 years (p < 0.05). No significant change was found for the anatomical form, secondary caries, postoperative sensitivity, surface texture, and retention for either restorative material (p > 0.05). ConclusionsBoth tested restorative materials showed an acceptable success rate in the restoration of Class I and Class II cavities during the 10-year follow up.

Evaluation of clinical performance and success of Fuji II and Fuji IX in restoring occlusal caries of primary molars over a one year follow up: A Randomized Clinical Trial

Introduction: Dental practitioners frequently face a notable challenge in selecting an ideal restorative material. Glass ionomer cement (GIC) has been a frequently used material as a substitute to amalgam in restoring primary dentition. Aim of the study: To clinically evaluate GC Fuji II LC (Light-Cured, Resin-Reinforced Glass Ionomer Restorative) and GC Fuji IX GP EXTRA (Packable Glass Ionomer) when used to restore occlusal caries in lower second primary molars. Materials and Methods: Seventy-six molars in 38 children were included in this study. Inclusion criteria included patients; (1) Free from any medical conditions. (2) Aged 5-7 years old. (3) Reported with bilateral restorable decayed second primary molars with simple occlusal decay. (4) Clinically; no signs of irreversible pulpitis. Split-mouth technique was used and a single operator performed all restorations. Examined restorative materials were randomly allocated to either side of the mouth. Cavities were prepared in the utmost conservative manner. Both Fuji II and Fuji IX were prepared according to manufacturers’ instructions. Clinical assessment was performed after 3, 6, 9 and 12 months according to United States Public Health Services (USPHS) evaluation criteria and rating system. Statistical Analyses included Wilcoxon signed-rank test as well as Friedman’s test followed by Dunn’s test. Results: Among the treated 38 subjects; there were18 boys (47.4%) and 20 girls (52.6%). Mean ± standard deviation values for age were 5.7 ± 0.8 years old with a minimum of 5 and a maximum of 7 years old. After 12 months, a statistically significant difference was noted between marginal adaptation, anatomic form, secondary caries and marginal discoloration scores in the two materials. Conclusions: Fuji II and Fuji IX showed comparable marginal adaptation. Fuji II restorations showed better results regarding anatomic form, secondary caries and marginal discoloration when compared to Fuji IX.

Comparison of Lipid and Protein Oxidation Products and their Impact on Colour Stability in Bison Longissimus Lumborum and Psoas Major Muscles

ObjectivesTo compare lipid (malondialdehyde [MDA], 4-hydroxy-2-nonenal [HNE]) and protein (carbonyl content [CAR]) oxidation products and determine their influence on color stability in two bison muscles (longissimus lumborum [LL; color stable] and psoas major [PM; color labile]).Materials and MethodsA total of 10 longissimus lumborun (LL) and 10 psoas major (PM) from five A1 grade bison carcasses were obtained from a commercial slaughter plant within 48 h post-mortem. From each muscle, a 10-cm thick piece was removed and subsampled for evaluation of pH, MDA (by thiobarbituric acid assay), HNE (by ELISA) and CAR (by 2,4-dinitrophenylhydrazine). These measurements allowed the establishment of a baseline for the different oxidation products. The remainder of the muscles were cut into two equal portions, and each portion was vacuum-packaged and assigned to an ageing period of 7 and 14 d at 2°C. At the end of each ageing period, each muscle portion was removed from their packages, pH measured, and steaks obtained for sensory (muscle and discoloration scores) and instrumental color measurements (L*, a* and b*) over 5 d of retail display, and for estimation of MDA, HNE and CAR. After 5 d in retail display and following color and pH measurements the steaks were removed and collected for MDA, HNE and CAR determination. Data were analyzed as a completely randomized design with a split-split plot arrangement. Additionally, correlation and regression analysis were performed to identify the influence of the measured attributes on color.ResultsRegardless of the ageing time, LL showed greater redness and lower surface discoloration by instrumental (a* value; P = 0.04) and sensory (P < 0.01) color evaluation than PM at the end of the retail display. Furthermore, LL exhibited lower MDA, HNE and CAR content compared to PM (P < 0.05). A three-way interaction (muscle × ageing time × retail day display) was detected on MDA content, where PM presented a higher level of MDA with increasing ageing time and retail display than LL (P = 0.02). The pH was not different between LL and PM (P > 0.05) steaks.In both muscles, Pearson (r) and Spearman (rs) correlation coefficients indicated that MDA was the oxidation compound showing the highest correlation to a* (r = –0.78; P < 0.01) and discoloration (rs = 0.81; P < 0.01) scores, followed by a moderate correlation with HNE and CAR (r or rs < 0.7; P < 0.01). The pH did not exhibit correlation with color traits, except for lightness, in both muscles. For the stepwise regression analysis, the main variable entered into the equation for predicting a*, color and discoloration score in PM muscle was MDA with an R2 of 0.72, 0.75 and 0.78, respectively, while for LL muscle, MDA presented an R2 of 0.62, 0.68 and 0.66;, respectively. The pH, HNE and CAR only explained an additional 2% of the variation in those attributes.ConclusionThe results of color attributes corroborated that bison LL is a color-stable muscle due to the lower level of protein and lipid oxidation products developed during storage and retail display compared to PM muscle, which is considered color-labile muscle. The MDA seemed to have remarkable importance in the color deterioration than HNE and CAR, particularly in bison PM muscle.

Color and Lipid Stability of Dry Aged Beef During Retail Display

ObjectivesThere has been an increased interest in merchandising dry-aged steaks at the retail level. Further understanding of the influence of the dry aging process on meat color and lipid stability is needed to ensure dry-aged beef products can be merchandised without adverse impacts on retail display life. Therefore, this study aimed to determine color and lipid stability of steaks from dry-aged beef loins over 7 d (d) of retail display.Materials and MethodsSixteen USDA low Choice boneless strip loins were assigned to one of four aging treatments: vacuum (Wet), dry-aging at 50% relative humidity (RH) (RH50), dry-aging at 70% RH (RH70), or dry-aging at 85% RH (RH85). Dry-aged loins were placed in each assigned dry aging chamber, while wet aged counterparts were aged in vacuum bags in the same cooler. Loins were aged for 42 d at 1°C. After aging, loins were trimmed of dehydrated lean/fat and fabricated into steaks. Steaks were trimmed of subcutaneous fat, and placed on foam trays, overwrapped with oxygen permeable film and placed under retail display (RD) conditions for 7 d at 2°C. Objective color measurements were taken once daily from d 0 to 7 of RD. Trained visual color panelists (n = 6) evaluated surface discoloration from d 0 to 7 of RD once daily. Lipid oxidation was measured via thiobarbituric acid reactive substance assay (TBARS) at 0, 4, and 7 d of RD. Color data were analyzed as a split-plot repeated measures design with treatment as the whole-plot and RD time as the repeated measures. TBARS data were analyzed as a split-plot design with aging treatment as the whole-plot, and RD time as the split-plot. In this study, chamber (loin) was considered the experimental unit. Data were analyzed using the PROC GLIMMIX procedure of SAS with α = 0.05.ResultsFor all three-color scales, a RD effect was found (P < 0.001). In general, L*, a* and b* values decreased as RD time increased, regardless of the aging treatment. Wet-aged steaks had higher L* (P < 0.05), a* (P < 0.05), and b* values (P < 0.001) than any other dry-aged treatment. No differences in L*, a*, and b* values among dry aging treatments were found (P < 0.05). A 2-way interaction between treatment and RD for discoloration was observed (P < 0.05). No differences were found among treatments over the first 2 d of RD (P > 0.05). Samples began to diverge on Day 3 of RD. Dry-aged steaks had greater discoloration scores (P < 0.05) than wet-aged steaks at 4, 5, 6, and 7 d of RD. However, no differences in discoloration scores among RH treatments were found. There was a RD effect on TBARS values (P < 0.001). Greater TBARS values were found as RD progressed from d 0 to d 4 and d 7, regardless of the aging treatment. A treatment effect was observed for lipid oxidation (P < 0.05). Dry-aged steaks had higher TBARS values than wet-aged steaks. No differences in TBARS values among dry aging treatments were found.ConclusionDry aging of beef resulted in decreased lightness and redness values and increased lipid oxidation compared to wet aging. Results suggest that with prolonged RD dry aging of beef has the potential to reduce color and lipid stability compared to wet-aging and thus reduce display life. Dry-aged steaks met the 20% discoloration threshold and overcame the acceptability threshold of 2.28 mg of malonaldehyde/kg at d 4 of RD, indicating that dry-aged steaks can be merchandised in the retail level for 3 d without detrimental effects on color and lipid oxidation.

Effects of dietary fat source on beef strip loin steak display life

The effects of feeding different dietary fat sources with modified distillers grains plus solubles (MDGS) on beef display life were evaluated. Steers (n = 256) were fed for 134 d on either a corn, 40% full-fat MDGS, 40% de-oiled MDGS, or 38% de-oiled MDGS plus 2% corn oil diet. Twenty-four United States Department of Agriculture Choice carcasses (3 head/pen) were randomly selected within each dietary treatment and strip loins were collected and aged for 2, 9, 16, or 23 d. Steaks from each aging period were placed under retail display (RD) conditions for 0, 4, and 7 d. Stearic acid was predominant (C18:0; P = 0.03) in beef from the de-oiled MDGS plus oil treatment in comparison with all other dietary treatments. Feeding MDGS increased linoleic acid (C18:2; P < 0.01) and polyunsaturated fatty acids (PUFA; P = 0.01) in comparison to the corn diet. The de-oiled MDGS plus oil group had greater C18:3 content (P = 0.03) when compared to corn, but no differences were observed between all other diets. There were no differences among dietary treatments for L* (P = 0.74) and b* (P = 0.25) values. The de-oiled MDGS group had lower a* values than all other treatments (P < 0.01) at day 5 of RD. The corn treatment had greater a* values (P ≤ 0.05) than de-oiled MDGS and de-oiled MDGS plus oil at day 6 and 7 of RD. Strip loin steaks from cattle fed full-fat MDGS tended to have lower a* values (P = 0.10) than steaks from cattle fed corn at day 7 of RD. Feeding de-oiled MDGS resulted in greater discoloration (P ≤ 0.05) at days 5, 6, and 7 of RD when compared to corn. Steaks from the de-oiled MDGS plus oil and full-fat MDGS groups had greater discoloration scores at day 7 of RD in comparison to corn (P ≤ 0.05). Strip loin steaks from cattle fed corn tended to have lower thiobarbituric acid reactive substance (TBARS) values (P ≤ 0.10) in comparison to de-oiled MDGS and de-oiled MDGS plus oil at day 7 of RD. Results suggest that feeding MDGS to cattle reduces color and lipid stability in addition to increasing C18:2 and PUFA content of beef. Addition of corn oil to de-oiled MDGS decreased redness and increased discoloration and lipid oxidation in comparison to corn diets.

Will a chlorhexidine‐fluoride mouthwash reduce plaque and gingivitis?

What is the efficacy of a chlorhexidine (CHX) mouthwash (MW) containing sodium fluoride (NaF) compared to a CHX-MW alone on the parameters of plaque, gingivitis and discoloration? MEDLINE-PubMed, Cochrane-CENTRAL, and EMBASE were searched for papers from inception to December 2017. The inclusion criteria were (randomized) controlled clinical trials conducted in human subjects with good general health and without removable prosthesis. Papers evaluating the effect of a MW containing CHX+NaF compared to a CHX alone were included. From the eligible studies, data were extracted, a descriptive analysis was performed and a meta-analysis when feasible. Independent screening of 412 unique papers resulted in 9 eligible publications presenting 10 clinical trials comparing the effect of CHX+NaF to CHX-MW and provided 13 comparisons. Five evaluated the MW as an adjunct to brushing and 8 were non-brushing comparisons of which 4 used an experimental gingivitis model. No significant difference was observed for plaque score reduction in the brushing studies the end scores (diffM; -0.04, P=.36; 95%CI: [-0.13, 0.05]) nor the differences (diffM; 0.11, P=.33; 95%CI: [-0.12, 0.24]). In the descriptive analysis, none of the experiments demonstrated a statistical significant difference regarding Gingival Index (GI), Bleeding Score and Discoloration Scores. For the GI, a meta-analysis of the difference of Means was not significant when included experimental gingivitis model studies end scores (0.01, P=.78; 95%CI: [-0.08, 0.11]) and the difference (0.01, P=.81; 9 5%CI: [-0.08, 0.10]) either for the end scores of brushing studies (diffM; -0.01, P=.82; 95%CI: [-0.10, 0.08]). From this study, it can be concluded that NaF and CHX may be present in the same MW without reducing CHX efficacy with respect to plaque and gingivitis scores. Moreover, no difference in the development of tooth discoloration was observed.

Effects of Cattle Backgrounding Diets on Carcass Characteristics and Beef Quality

ObjectivesTo determine how backgrounding cattle will affect carcass characteristics and fresh beef quality. It was hypothesized that backgrounding cattle will result in an increased hot carcass weight, without impacting fresh beef quality.Materials and MethodsThe impact of utilizing a moderate energy backgrounding diet was evaluated using 95 crossbred steers (initial body weight: 352 ± 30 kg) that were randomly assigned to 1 of 15 pens. Each pen was randomly assigned 1 of 2 dietary treatments. Dietary treatments included a traditional high energy (HigE) finishing diet (n = 7) or a moderate energy (ModE) backgrounding diet (n = 8). Cattle on HigE were fed a high energy finishing diet for all 193 d; those fed ModE were fed the moderate energy diet for 63 d followed by feeding the HigE diet for the last 130 d. All steers received Revalor-XS on d 1. Two steers were randomly chosen from each pen for further evaluation. Hot carcass weight (HCW), 12th rib backfat (BF), ribeye area (REA), marbling score, USDA yield grade, and percent kidney, pelvic, and heart fat (KPH) were collected 48 h postmortem. Strip loins (IMPS #180) were retrieved and evaluated for vacuum purge loss and objective backfat color. The strip loins were fabricated into 2.54 cm steaks for drip loss, Warner-Bratzler shear force (WBSF), sensory evaluation, and subjective and objective color score evaluation. Data were analyzed using the mixed procedure of SAS (SAS Inst. Inc., Cary, NC) with treatment as a fixed effect and pen as a random effect. Pen was the experimental unit. Significance was determined at p ≤ 0.05, while trends were determined at p ≤ 0.10.ResultsThere was a tendency for HCW to be heavier for ModE cattle (P = 0.06). There was no treatment effect for BF (P = 0.43), REA (P = 0.96), Marbling (P = 0.16), YG (P = 0.76), or KPH (P = 0.22). No moisture loss attributes differed between treatments: Purge loss (P = 0.40) and drip loss (P = 0.41). Backfat a* (P = 0.43) and b* (P = 0.18) values were not statistically significant between treatments, however, L* (P = 0.06) tended to be higher for HigE cattle. Warner-Bratzler shear force values did not differ between treatments (P = 0.72). There were no treatment effects for any of the steak subjective sensory attributes evaluated: Overall liking (P = 0.80), flavor liking (P = 0.75), texture liking (P = 0.44), toughness (P = 0.31), juiciness (P = 0.65), and off-flavor (P = 0.21). Objective color score did not differ between the 2 treatments: L* (P = 0.39), a* (P = 0.55), and b* (P = 0.68). Subjective color (P = 0.11) and discoloration (P = 0.21) scores also showed no differences between treatments. Subjective sensory analysis showed that steaks from the HigE treatment tended to be more desirable (P = 0.10).ConclusionFeeding a backgrounding diet before finishing led to similar carcass characteristics with a lower reliance on concentrate feed ingredients. Backgrounded cattle also had similar fresh beef qualities but could be compromised at the retail display case with subjective desirability scores tending to be lower.

Improving the lean muscle color of dark-cutting beef by aging, antioxidant-enhancement, and modified atmospheric packaging.

The objective was to evaluate the effects of wet-aging, rosemary-enhancement, and modified atmospheric packaging on the color of dark-cutting beef during simulated retail display. No-roll dark-cutting strip loins ( = 12; pH > 6.0) were selected from a commercial packing plant within 3 d postharvest. Using a balanced incomplete block design, dark-cutting loins were sectioned in half, and assigned to 1 of 3 aging periods: 7, 14, or 21 d. After respective aging, each aged section was divided into 3 equal parts, and randomly assigned to 1 of 3 enhancement treatments: nonenhanced dark-cutting, dark-cutter enhanced with 0.1% rosemary, and dark-cutter enhanced with 0.2% rosemary. Following enhancement, steaks were randomly assigned to 1 of 3 packaging treatments: high-oxygen modified atmospheric packaging (HiOx-MAP; 80% O and 20% CO), carbon monoxide modified atmospheric packaging (CO-MAP; 0.4% CO, 69.6% N, and 30% CO), and polyvinyl chloride overwrap (PVC; 20% O). Instrumental and visual color measurements were recorded during 5 d simulated retail display. Lipid oxidation was determined utilizing the thiobarbituric acid reactive substances (TBARS) method. There was a significant packaging × enhancement × display time interaction for values and chroma ( 0.001). On d 0 of display, dark-cutting steaks enhanced with 0.1% and 0.2% rosemary and packaged in HiOx-MAP had greater ( 0.001) values and chroma than other dark-cutting packaging/enhancement treatments. A significant packaging × enhancement × display time interaction resulted for values ( 0.001). Dark-cutting steaks enhanced with 0.2% rosemary and packaged in HiOx-MAP was lighter ( 0.001; greater values) than other dark-cutting treatments on d 5 of display. There were no differences ( 0.34) in discoloration scores on d 5 among different dark-cutting treatments when steaks were packaged in HiOx- and CO-MAP. There was an aging period × enhancement × packaging interaction ( < 0.0033) for lipid oxidation. On d 0 of display, there were no differences ( 0.54) in TBARS values between different aging periods and enhancement treatments. Dark-cutting steaks enhanced with 0.2% rosemary had lower ( 0.001) TBARS values than 0.1% rosemary on d 5 when aged for 21 d and in HiOx-MAP. The results suggest that rosemary enhancement with CO- or HiOx-MAP has the potential to improve the surface color of dark-cutting beef.