Simulated Retail Display Research Articles

Performance and meat quality of native and continental cross steers grazing improved upland pasture or semi-natural rough grazing

There is growing interest in the environmental benefits of grazing by cattle, yet little information is available regarding the levels of production that might be achieved on semi-natural rough grazing (SNRG). The overall aim of this research was to assess the performance of native and ‘improved’ breeds of cattle when grazing grass/clover swards and SNRG in order to explore potential genotype × nutritional environment interactions. This paper reports the findings of three experiments conducted over three years. The first experiment assessed the performance of autumn-born Welsh Black (WB) and Charolais cross (CX) cattle aged approximately 9 months when grazing ryegrass/white clover-dominated improved permanent pasture (PP) and Molinia caerulea-dominated SNRG. Both genotype and pasture type had significant effects on liveweight gain, with growth rates higher for WB steers than CX steers ( P < 0.001) and higher on the improved pasture than on the SNRG ( P < 0.001). The second experiment was conducted the following summer when the steers were 20 months old and evaluated the effects of breed and pasture type on subsequent finishing performance, carcass composition, meat quality, flavour and fatty acid composition. Genotype had no effect on liveweight gain during the grazing period, but pasture type again had a highly significant effect on growth rate ( P < 0.001). Carcass conformation was good and similar for both breeds. Pasture type had a greater effect on fatty acid composition of the meat than did breed. Likewise, genotype had no effect on meat colour or stability, whereas pasture type affected both. Loin steaks from the SNRG-grazed animals had significantly more vitamin E than those from PP-grazed animals ( P < 0.001) and this was reflected in lower lipid oxidation (TBARS) after simulated retail display ( P < 0.001). The third experiment assessed the performance of spring-born Welsh Black and Limousin cross steers aged 14 months when grazing PP and SNRG. Again only pasture type had a highly significant effect on growth rate ( P < 0.001). Measurements made during the first two experiments using automatic behaviour recorders indicated that pasture type influenced grazing behaviour to a greater degree than breed, and sward measurements found no between-breed differences in utilisation of M. caerulea. Overall the results indicate that the type of sward grazed has a greater influence on animal performance and meat quality than breed type when beef cattle are produced in Less Favoured Areas.

Interactive effect of ractopamine and dietary fat source on pork quality characteristics of fresh pork chops during simulated retail display1

Crossbred pigs (n = 216) were used to test the interactive effect, if any, of ractopamine (RAC) and dietary fat source on the performance of finishing pigs, pork carcass characteristics, and quality of LM chops during 5 d of simulated retail display (2.6 degrees C and 1,600 lx warm-white fluorescent lighting). Pigs were blocked by BW and allotted randomly to pens (6 pigs/pen), and, after receiving a common diet devoid of RAC for 2 wk, pens within blocks were assigned randomly to 1 of 4 diets in a 2 x 2 factorial arrangement, with 5% fat [beef tallow (BT) vs. soybean oil (SBO)] and RAC (0 vs. 10 mg/kg). Diets were formulated to contain 3.1 g of lysine/Mcal of ME and 3.48 Mcal/kg of ME. Across the entire 35-d trial, pigs fed RAC had greater (P < 0.01) ADG and G:F, but RAC did not affect (P = 0.09) ADFI; however, performance was not affected (P >or= 0.07) by dietary fat source. Carcass weight, LM depth, and lean muscle yield were increased (P < 0.01), whereas fat depth was decreased (P = 0.01), in carcasses from RAC-fed pigs; however, carcass composition measures were similar (P >or= 0.27) between fat sources. Feeding 10 mg/kg of RAC reduced (P <or= 0.04) the proportions of SFA and MUFA and increased (P < 0.01) the proportion of PUFA and the iodine value, in pork backfat. Conversely, backfat from carcasses of BT-fed pigs had greater (P < 0.01) percentages of SFA and MUFA, and lower (P < 0.01) percentages of PUFA, than backfat from SBO-fed pigs. Moreover, the PUFA:SFA and iodine value were considerably reduced (P < 0.01) by including BT in swine finishing diets. The LM from pigs fed RAC had greater pH values (P = 0.03) and received greater (P <or= 0.01) American and Japanese color scores during retail display. The LM from RAC-fed pigs had lower (P <or= 0.02) L*, a*, and b* values, whereas the LM of SBO-fed pigs received greater (P < 0.01) subjective color scores and b* values, as well as lower L* values, than the LM of BT-fed pigs. Across the 5-d display period, oxidative rancidity was not affected by dietary RAC (P = 0.58) or fat source (P = 0.47). Neither RAC nor fat source altered LM cooking losses and shear force values. Feeding 10 mg/kg of RAC will improve rate and efficiency of gain, carcass composition, and LM quality. And, even though fatty acid composition of backfat samples was altered by dietary fat source, performance and carcass composition, as well as quality during 5 d of retail display, were similar when pigs were fed diets formulated with BT or SBO.

Effects of dark storage and retail display on beef chuck and round muscles enhanced with ammonium hydroxide, salt, and carbon monoxide1,2

The objective of this study was to determine the retail shelf stability of beef chuck and round muscles enhanced with ammonium hydroxide, salt, and carbon monoxide. A split plot design was used for each of 3 muscles [triceps brachii (TB), biceps femoris (BF), and rectus femoris (RF)] with 2 treatments (0 and 20% pump), 3 dark storage periods (1, 2, and 3 wk), and 3 replications in the whole plot and retail display period as the split plot. There were a total of 12 subprimals per treatment per dark storage period (n = 72 each). Individual steaks were cut to a thickness of 2.54 cm and packaged in a modified-atmosphere package (MAP). The TB was packaged in a high-oxygen MAP (80% oxygen, 20% carbon dioxide). The BF and RF were packaged in a low-oxygen MAP (100% carbon dioxide). At the completion of each dark storage period, steaks were subjected to 7 d of simulated retail display. Steaks were used for objective and subjective color measurements, total plate counts, and determination of retail purge and oxidation. For all muscles, total plate counts were always numerically greater in injected steaks. Triceps brachii steaks held in dark storage for 3 wk and displayed at retail for 4 or more days all exceeded 10(7) log of cfu/cm(2) for aerobic plate count. Biceps femoris and RF steaks packaged in a low-oxygen MAP had much lower bacterial counts, with levels below 4.2 log of cfu/cm(2), even after 7 d of retail display. Oxidation values for the TB were extremely high (ranging from 12.3 to 26.6), whereas the BF and RF had values that were much lower (< or =1.0 mg of malonaldehyde/kg of muscle), likely due to the oxidation occurring in a high-oxygen MAP for the TB. Enhanced TB steaks proved to have greater color stability (less discoloration) than nonenhanced TB steaks. In addition, the BF and RF (low-oxygen MAP) steaks had better color stability (more stable redness values) than TB (high-oxygen MAP) steaks, although TB steaks initially exhibited a brighter red color. Retail display life was enhanced by packaging in 100% carbon dioxide, and enhanced steaks exhibited greater color stability in retail display than control steaks.

Improving ground beef safety and stabilizing color during irradiation using antioxidants, reductants or TSP

The objective of this research was to extend ground beef retail display life using antioxidants, reductants, and/or TSP treatments combined with electron beam irradiation. Ground beef was produced with added butylated hydroxyanisole (BHA) plus butylated hydroxytoluene (BHT) with the following combinations; (1) ascorbate; (2) trisodium phosphate(buffer); (3) erythorbate; (1) and (2); (1) and (3); (1), (2), and (3); and an untreated control, C. Half of the treated samples were irradiated (I) at 2.0 kGy-absorbed dose under a nitrogen atmosphere, half remained non-irradiated (N). Samples were displayed under atmospheric oxygen and evaluated for total aerobic plate count (TPC), thiobarbituric acid reactive substances (TBARS) and instrumental color during 9 d of simulated retail display (SRD). Controls had the highest ( P < 0.05) TBARS value and the lowest ( P < 0.05) redness (CIE a∗), proportion of oxymyoglobin and vividness. Treated irradiated samples were just as red and vivid on SRD day 9 as the non-irradiated untreated control at day 0. Treatments stabilized color and lipids of ground beef after irradiation and during SRD.

Genotype and age at slaughter influence the retail shelf-life of the loin and knuckle from sheep carcasses

This study was conducted to determine the effect of genotype and age at slaughter (8, 14 and 22 months) on the retail display life of lamb chops [boneless loin (M. longissimus thoracis) and boneless leg steaks from the knuckle (M. rectus femoris)]. The genotypes represented were Poll Dorset × Border Leicester Merino, Poll Dorset × Merino, Merino × Merino (M × M) and Border Leicester × Merino. The colour and retail shelf-life of lamb cuts were assessed objectively, using a HunterLab Miniscan, at 24 h postslaughter and at 0, 2 (midpoint of commercial retail display life) and 4 (endpoint of commercial retail display life) days for overwrapped product in a simulated retail display. M × M had a higher ultimate pH (pHu) in the knuckle, but not the loin, at 8, 14 and 22 months of age relative to the other three genotypes. Generally, at 1 day postslaughter and over the 4 days of retail display, the loin from the M × M genotype was lighter, less red and more brown with a lower oxymyoglobin : metmyoglobin (oxy : met) ratio, a faster time to discolouration and a higher percentage change in the oxy : met ratio during retail display. Conversely for the knuckle, the M × M genotype was generally less brown (more red) and less yellow with a higher oxy : met ratio, a slower time to discolouration and a lower percentage change in the oxy : met ratio. There were few differences between the other genotypes in surface meat colour either at 1 day postslaughter or during retail display for either muscle. At 14 and 22 months of age, the loin was darker, redder and yellower with a higher oxy : met ratio relative to the previous age than meat from the 8- and 14-month-old sheep, respectively. In conclusion, the loin from Merinos was most susceptible to discolouration in retail display and thus would be least acceptable to the consumer. In spite of the higher pHu in the knuckle of the Merino genotype, the meat was less susceptible to discolouration during retail display compared with the other genotypes.

한우 노산암소에 대한 발정억제제 및 항산화제의 급여가 증체와 도체성적에 미치는 영향

Twenty four Hanwoo cull cows were assigned to 2 groups, control and melengerol acetate(MGA) + selenium supplement containing vitamin E(SeE), based on the parity(6.5 ± 1.7 birth) and body weight (493.17 ± 55.61 kg), and the experiment was conducted to establish the reasonable fattening method of cull cows for 240 days. Average daily body gains during 240 days were 0.51 kg and 0.63 kg in control and MGA + SeE, respectively(P<0.10). DDMI/ADG of MGA + SeE group improved compared to control group(P<0.05). Therefore, supplementation of MGA + SeE in concentrates may accelerate both of the growth rate and feed efficiency in Hanwoo cull cows. MQI from MGA + SeE was more developed based on the larger rib-eye area and thinner backfat thickness in carcass than that from control. Marbling score for MGA + SeE tended to increase compared to control. Dietary Se supplementation significantly affected muscle Se concentration in longissimus dorsi meat of MGA + SeE group(P<0.05). Similar results to Se were obtained from α-Tocoperol concentration. During 7 days of simulated retail display, accumulations of thiobarbituric acid reactive substances(TBARS) concentration in beef was greater(P<0.05) in control than in supplemented cows. These results supported the hypothesis that supplementation of MGA + SeE improve the growth performance and carcass grade both by the growth stimulating effect of MGA + SeE and by preventing the oxidation of the longissimus dorsi muscle in Hanwoo cull cows.

Effects of enhancement with differing phosphate types, concentrations, and pump rates, without sodium chloride, on beef biceps femoris instrumental color characteristics

Enhancement of beef biceps femoris muscles ( n = 45) with solutions comprising sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), or tetrasodium pyrophosphate (TSPP) at either 0.2% or 0.4% of product weight, with the exclusion of sodium chloride, was performed to observe the independent phosphate effects on instrumental color during simulated retail display. All solutions were injected into muscle samples at either 112% (12% pump) or 118% (18% pump) of raw product weight. All three phosphate types maintained higher ( P < 0.05) L* values than untreated steaks (CNT) through 5 days-of-display, and SHMP had higher ( P < 0.05) L* values than STPP and TSPP through 7 days-of-display. Additionally, steaks with 0.2% phosphate inclusion were lighter ( L*; P < 0.05) than CNT throughout display, and were lighter ( P < 0.05) than steaks enhanced with 0.4% phosphates through 7 days of display. Steaks enhanced with TSPP had higher ( P < 0.05) a* values than CNT on days 5 and 7 of display, whereas SHMP- or STPP-enhanced steaks generally had similar ( P > 0.05) a* values as CNT after 3 d of display. Direct comparison of phosphate concentrations revealed no differences ( P > 0.05) in a* values. Only steaks enhanced with TSPP were more vivid ( P < 0.05) and had higher ( P < 0.05) proportions of oxymyoglobin than CNT on days 5 and 7 of display. However, direct comparison of phosphate types indicated that TSPP- and STPP-enhanced steaks had similar ( P > 0.05) oxymyoglobin proportions during display. Phosphate inclusion at 0.4% maintained higher ( P < 0.05) oxymyoglobin proportions than 0.2% phosphate inclusion through 5 days-of-display. These results indicate that while 0.2% phosphate concentrations maintain lighter color, 0.4% concentrations can more effectively retain oxymyoglobin during display. Additionally, only steaks enhanced with TSPP were redder, more vivid, and had higher oxymyoglobin proportions than untreated steaks during the latter stages of display.

Retail Shelf‐Life of Pork Dipped in Organic Acid before Modified Atmosphere or Vacuum Packaging

ABSTRACTModified atmosphere packaging (MAP) is increasingly popular for meat, but raw, chilled pork in vacuum or anoxic environments has a purple color. The retail shelf‐life of pork chops dipped in 500 ppm ascorbic acid, 250 ppm citric acid, or no acid dip and stored at 1 °C before simulated retail display in MAP with gas exchange or air‐permeable packaging after vacuum pouch storage was determined. The 80% N2:20% CO2 in MAP was exchanged with 80% O2:20% CO2, and chops were removed from vacuum packages and overwrapped with permeable film (VP‐PVC) on the 7th day before simulated retail display at 4 °C. Shelf‐life traits were determined at 1, 7, 8, 10, 12, and 14 d postpackaging. The pH values changed with time, but returned to post‐dipped, prepackaged levels at the end of simulated retail storage. Weight loss of chops increased (P &lt; 0.05) in VP‐PVC compared with MAP. The a* values increased (P &lt; 0.05) and L* and b* values decreased during simulated retail display, with higher L*, a*, and b* color values for chops in MAP than VP‐PVC. Log numbers of psychrotrophic microorganisms were higher (P &lt; 0.05) on VP‐PVC samples than for chops in MAP on days 12 and 14. Psychrotrophic counts on ascorbic acid‐treated samples were decreased compared with citric acid or no dipping on pork during simulated retail display. Pork chops in MAP with gas exchange had lighter and redder color, increased weight retention, decreased psychrotrophic counts, and increased lipid oxidation compared with conventional vacuum and overwrap packaging systems.

Effects of enhancement with varying phosphate types and concentrations, at two different pump rates on beef biceps femoris instrumental color characteristics

The effect of enhancing beef biceps femoris muscles ( n = 45) with solutions comprising 2.0% sodium chloride and either sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), or tetrasodium pyrophosphate (TSPP) at either 0.2% or 0.4% of product weight on instrumental color during simulated retail display was investigated. All solutions were injected into muscle samples at either 112% (12% pump) or 118% (18% pump) of raw product weight. Muscles treated with all three phosphate types had lower ( P < 0.05) L* and b* values compared to untreated muscles (CNT). Steaks enhanced with STPP had similar ( P > 0.05) a* values as CNT, whereas SHMP- and TSPP-treated steaks generally had lower a* values than CNT. Across phosphate type, excluding day 3 of display, steaks treated with phosphate at 0.4% had similar ( P > 0.05) a* values as CNT, whereas those with 0.2% phosphate addition had lower ( P < 0.05) a* values than CNT. Across five days of display, STPP maintained higher ( P < 0.05) a* values than steaks treated only with sodium chloride, whereas SHMP did not differ ( P > 0.05) from sodium chloride-treated steaks. While STPP maintained a similar ( P > 0.05) saturation index as CNT, SHMP and TSPP generally had decreased ( P < 0.05) vividness during display. Additionally, excluding day 3 of display, phosphate concentration at 0.4% maintained similar vividness as CNT, whereas 0.2% phosphate concentration caused decreased ( P < 0.05) vividness, compared to CNT. The 630/580 nm ratio results indicated that SHMP had less ( P < 0.05) oxymyoglobin than CNT throughout display. Disregarding day 3 of display, both STPP and TSPP had similar ( P > 0.05) oxymyoglobin proportions as CNT. These results indicate that STPP was the most effective phosphate type for maintaining color. Additionally, 0.4% phosphate concentrations can maintain color better than 0.2% phosphate concentrations. However, none of the phosphate/salt combinations produced superior color, compared to untreated steaks.

Effect of endophyte type on carcass traits, meat quality, and fatty acid composition of beef cattle grazing tall fescue

Fourteen Hereford steers were used to compare carcass traits, meat quality, and fatty acid composition of beef from cattle grazing tall fescue infected with either wild-type (E+; n = 6) or novel, nil ergot alkaloid (AR542; n = 8) endophyte for 209 d. Average daily gain, live weight, and HCW were greater (P < 0.05) for AR542 cattle than for E+. No differences in LM color or pH were observed between AR542 and E+. Steaks from E+ cattle tended (P = 0.10) to have higher L* and b* than those from AR542 cattle at 0 d of display. Ground beef from E+ cattle also had higher (P < 0.05) L* than AR542 cattle, with no differences in a* or b* at 0 d of display. Color changes during display did not differ for both steaks and ground beef from E+ and AR542. Lipid oxidation levels increased (P < 0.05) during simulated retail display, but they did not differ between endophyte treatments. Adipose tissues from E+ cattle had a higher (P < 0.05) percentage of SFA, and a lower (P < 0.05) percentage of MUFA than adipose from AR542 cattle. Ground beef and i.m. fat had higher (P < 0.05) concentrations of SFA, MUFA, and cis-9, trans-11 isomer of conjugated linoleic acid, and lower (P < 0.05) concentrations of PUFA and PUFA:SFA ratio than s.c. fat. The n-6:n-3 fatty acid ratio did not differ among fat depots. Ergot-alkaloids were detected in s.c. adipose tissues, and alkaloid concentration was greater (P < 0.05) for E+ than AR542. Warner-Bratzler shear force values did not differ between endophyte types, but it decreased (P < 0.01) across the postmortem aging period. Conversely, sensory panel evaluation detected greater (P < 0.01) chewiness and lower (P < 0.05) juiciness for AR542 than for E+ steaks aged for 14 d. Although grazing cattle on tall fescue pastures infected with nil ergot alkaloid endophyte improved cattle performance, these results suggest that endophyte type has minor effects on carcass traits and meat quality of pasture-fed beef. Moreover, finishing cattle on tall fescue pastures showed the potential to enhance the fatty acid profile of beef from a human health perspective. Alkaloid concentration was greater (P < 0.05) in s.c. fat from E+ than AR542 (2.81 vs. 0.92 ppb; fresh-tissue basis). This is the first published report demonstrating the presence of alkaloids in beef tissues.

Dietary conjugated linoleic acid improves carcass leanness without altering meat quality in the growing pig

One constraint facing the pig industry is that ad libitum feeding can often result in high levels of body fat and technologies which can reduce the ratio of lean to fat deposition in the pig are continually being explored. Conjugated linoleic acids have been shown to decrease body fat content in pigs. Therefore, the aim of this study was to determine whether dietary conjugated linoleic acids supplementation has any effect on meat quality and carcass characteristics in finisher pigs. Sixty female crossbred (Large White × Landrace) pigs (average initial weight 56.6 ± 1.9 kg and average initial P2 backfat 11.4 ± 1.3 mm) were used in the present study. Pigs were individually housed and randomly allocated to 1 of 6 dietary treatments: 0, 0.125, 0.25, 0.50, 0.75 or 1.0% (w/w) of conjugated linoleic acids-55. The wheat-based diets were formulated to contain 14.3 MJ DE and 9.3 g available lysine per kg and were fed ad libitum for 8 weeks. Pigs were slaughtered and meat quality was determined on the longissimus thoracis using standard techniques. Dietary conjugated linoleic acids reduced subcutaneous back fat in a linear manner with effects being most pronounced in the middle back fat layer. There was also a linear (P&lt;0.001) decrease in intramuscular fat with increasing dietary conjugated linoleic acids supplementation. However, there was no effect of conjugated linoleic acids on subjective measures of marbling of the loin. Also, loin muscle ultimate pH (P = 0.94), lightness values (P = 0.46) subjective colour scores (P = 0.79), cooking loss (P = 0.71), drip loss (P = 0.40), shear force (P = 0.61) and subjective measures of wetness/firmness (P = 0.19) were unaffected. Dietary conjugated linoleic acids did not alter oxidation, as measured by the level of TBARs at day 1 post-slaughter (P = 0.38) or after 9 days of simulated retail display (P = 0.35). These data confirm that dietary conjugated linoleic acids can improve carcass quality by decreasing back fat depths without having any detrimental effects on meat quality.

Influence of different gas compositions on the short-term storage stability of mother-packaged retail-ready lamb packs

Longissmus dorsi muscles were removed from Suffolk cross-breed lambs (aged 4–9 months) and cut into steaks. Lamb steaks were over-wrapped on trays and placed in vacuum pack bags. Bags were divided into 3 groups and flushed with gas mixtures containing 100:0, 90:10 or 80:20/CO 2:N 2. Mother packed lamb bags were stored for 4 days (T2) and 7 days (T3), respectively, in darkness at 4 °C, prior to retail display. The effect of aerobic packaging alone on lamb meat quality was used as the control (T1). Under retail display, all over-wrapped trays were held under refrigerated conditions (4 °C, 616 lx) for up to 8 days. Steaks were assessed for microbial growth, oxidative and colour stability as well as pH every 2 days. Mother-packing in 100:0/CO 2:N 2 was the most effective way of extending the storage life of retail ready lamb prior to display, particularly over longer storage periods. TVCs for T3 lamb meat using all gas compositions remained below 2.0 × 10 6 CFUs/g meat up until day 6 compared to day 4 in both T1 and T2 lamb. Lipid oxidation in lamb mother-packed for 7 days occurred at a faster comparative rate than discolouration and microbial growth and was the major determinant of shelf-life. However, under simulated retail display in aerobic packages, TBARS values did not increase significantly. There was no significant difference between Hunter ‘ a’ values for T3 lamb meat and the control, but T3 meat mother-packed in 100:0/CO 2:N 2 had higher ‘ a’ values than those of the control and T3 meat packed in other gas compositions. Lamb steaks in T3 previously mother-packed in 100:0/CO 2:N 2 were also significantly ( p < 0.05) higher than those of T2 on day 0. T3 meat also maintained initial colour values over those of the control.

Effects of vitamin C supplementation on plasma ascorbic acid and oxalate concentrations and meat quality in swine.

Two experiments were conducted to determine the effects of vitamin C supplementation 48 h before slaughter on plasma ascorbic acid and oxalate concentrations and its effect on pork quality. In Exp. 1, 16 pigs (87.8+/-2.13 kg BW) were blocked by sex and weight and assigned randomly within block to one of three vitamin C treatments: 1) control; 2) 1,000 mg/L; or 3) 2,000 mg/L supplemented in the drinking water for a 48-h period. This was then followed by an additional 48-h period without supplemental vitamin C. Vitamin C increased plasma ascorbic acid concentrations (11.6, 19.5, and 23.4 microg/mL for 0, 1,000, and 2,000 mg/L of vitamin C; P < 0.05) within 6 h of supplementation. Plasma ascorbic acid concentrations from treated pigs decreased and did not differ from those of control pigs (13.7, 18.2, and 18.6 microg/mL for 0, 1,000, and 2,000 mg/L of vitamin C; P = 0.30) within 2 h of ending supplementation. No differences in plasma ascorbic acid concentrations were found between the two levels of supplementation. Vitamin C did not affect plasma oxalate or cortisol; however, cortisol tended to increase quadratically (P = 0.077) with vitamin C after 96 h. In Exp. 2, 30 pigs (107.5+/-0.54 kg BW) were blocked by sex and weight and assigned randomly within block to one of three vitamin C treatments: 1) control; 2) 500 mg/L; or 3) 1,000 mg/L supplemented in the drinking water 48 h before slaughter. Pigs were slaughtered 4 to 5 h after vitamin C supplementation ended, and loin samples were collected for meat quality measurements. At the time of slaughter, no differences in plasma ascorbic acid or cortisol were observed, but oxalate tended (P = 0.074) to increase quadratically with increasing vitamin C. Muscle ascorbic acid at slaughter and lactic acid in muscle at 0 and 1.5 h after slaughter were not different; however, lactic acid increased (P = 0.048) quadratically at 24 h after slaughter. Vitamin C did not affect initial or ultimate pH. Initial fluid loss (P = 0.041), and fluid loss on d 4 (P = 0.014) and 8 (P = 0.076) of simulated retail display; L* on d 0 (P = 0.038), 4 (P = 0.010), and 8 (P = 0.051); a* on d 0 (P = 0.021); and b* on d 0 (P = 0.006), 4 (P = 0.035), and 8 (P = 0.017) were negatively affected in a quadratic manner when vitamin C was supplemented. Vitamin C tended (P = 0.086) to increase oxidation in chops on d 0, but not d 4 or 8. Results indicate that on-farm supplementation of vitamin C was generally not effective in improving pork quality, which may be related to timing relative to slaughter.

Prerigor infusion of lamb with sodium chloride, phosphate, and dextrose solutions to improve tenderness

Combinations of sodium chloride, phosphate, and dextrose solutions were infused prerigor into lamb carcasses to evaluate effects on tenderness, palatability, color change and microbiological growth during simulated retail display. Each carcass ( n=48) was randomly assigned to one of the following: (1) deionized water (dH 2O), (2) 2% NaCl (S), (3) 3% dextrose (D), (4) 0.5% tri-polyphosphate (P), (5) 2% NaCl and 3% dextrose (SD), (6) 2% NaCl and 0.5% tri-polyphosphate (SP), (7) 0.5% tri-polyphosphate and 3% dextrose (PD), and (8) 2% NaCl, 0.5% tri-polyphosphate, and 3% dextrose (SPD). The right side was pumped to 120% its original green weight and the corresponding left side served as the paired control in a nested design. The SD, SP and SPD solutions improved ( P<0.05) Warner-Bratzler shear force values (WBS), sensory panel evaluations for tenderness, decreased cook loss, and increased ultimate pH when compared with their corresponding controls. In addition, no adverse affects on color or microbiological growth were observed for any of the treatments.

QUALITY OF STRAWBERRIES AS AFFECTED BY TEMPERATURE ABUSE DURING GROUND, IN-FLIGHT AND RETAIL HANDLING OPERATIONS

QUALITY OF STRAWBERRIES AS AFFECTED BY TEMPERATURE ABUSE DURING GROUND, IN-FLIGHT AND RETAIL HANDLING OPERATIONS

Effects of chlorine dioxide, cetylpyridinium chloride, lactic acid and trisodium phosphate on physical, chemical and sensory properties of ground beef

The impact of beef trimmings treated with either 0.5% cetylpyridinium chloride (CPC), 200-ppm chlorine dioxide (CLO), 2% lactic acid (LA) or 10% trisodium phosphate (TSP) and an untreated control (C) prior to grinding, on instrumental color, sensory characteristics, TBARS values, pH and Lee-Kramer shear under simulated retail display were evaluated. Trimmings were ground, pattied and sampled at 0, 1, 2, 3 and 7 days of display. Patties from LA, CPC and CLO treatments were lighter ( L*; P<0.05) and TSP patties were redder ( a*; P<0.05) than C. Panelists found TSP and CPC patties were similar or superior in beef and off odor to C on days 3 and 7 of display. Therefore, treatment of beef trimmings before grinding with TSP, CPC, CLO or LA may not only improve ground beef safety, but maintain or enhance patty shelf life.

Lipid, instrumental color and sensory characteristics of ground beef produced using trisodium phosphate, cetylpypiridinium chloride, chlorine dioxide or lactic acid as multiple antimicrobial interventions

Beef trimmings were treated with 0.5% cetylpyridinium chloride followed by 10% trisodium phosphate (CT), 200-ppm chlorine dioxide followed by 0.5% cetylpyridinium chloride (CLC), 200-ppm chlorine dioxide followed by 10% trisodium phosphate (CLT), or 2% lactic acid followed by 0.5% cetylpyridinium chloride (LC). The trimmings were ground, packaged and sampled at 0, 1, 2, 3 and 7 days of simulated retail display and compared with an untreated control (C) for instrumental color, sensory color and odor and TBARS (Thiobarbituric acid reactive substances) characteristics. Ground beef from the LC and CLC treatments were lighter ( P <0.05; L*) than C. The LC and CT ground beef samples were similar ( P > 0.05) in vividness to C. On day 3, CT was scored redder ( P <0.05) than C. Therefore, the use of CT, CLT, CLC and LC had little impact on ground beef color and CT improved ground beef color shelf life.

Effects of implant regimens (trenbolone acetate-estradiol administered alone or in combination with zeranol) and vitamin D3 on fresh beef color and quality.

In the first oftwo experiments, 123 calf-fed steers were used over a 2-yr period to evaluate the effects of trenbolone acetate (TBA)-based implants administered alone or in combination with zeranol implants on fresh beef muscle quality, color, and physiological maturity of the carcass. Implant treatments decreased (P < 0.05) a* values (d 0 and d 3 of retail display) and b* values (d 0, d 1, and d 3 of retail display) after 14 d of aging. Carcasses from cattle initially implanted with Revalor-S and reimplanted with Revalor-S on d 60 of the finishing period showed increased lean and bone maturity scores and ash content of the 9th to 11th thoracic buttons and Warner-Bratzler shear force values (WBS) compared to those initially implanted with Ralgro and subsequently reimplanted with Revalor-S or control cattle. In addition, implants decreased (P < 0.05) marbling, percentage of the carcasses grading Choice, and kidney, pelvic, and heart fat (KPH). Implant treatments increased (P < 0.05) ADG, hot carcass weights, and longissimus muscle (LM) area. In the second experiment over a 2-yr period, 166 steers fed as yearlings were allotted to one of two implant treatments and one of two vitamin D3 preharvest supplementation treatments. Implanted steers had heavier (P < 0.05) final body weights and higher (P < 0.05) ADG, less (P < 0.05) KPH fat, and larger (P < 0.05) LM. Also, implanted steers had more (P < 0.05) advanced bone maturity scores, higher (P < 0.05) ash content of the 9th to 11th thoracic buttons, and higher (P < 0.05) WBS values on 5-d postmortem loin steaks. Vitamin D3 feeding decreased (P < 0.05) final live weight, ADG (P < 0.05), and LM (P < 0.05), but did not significantly improve WBS values. In Experiment 2, neither implant treatment nor vitamin D3 supplementation had significant effects on L*, a*, or b* values of muscles in steaks before or during simulated retail display.

Effects of hot water and lactic acid treatment of beef trimmings prior to grinding on microbial, instrumental color and sensory properties of ground beef during display

The impact of 82°C hot water (HW) or 5% lactic acid (LA) applied aerobically or by vacuum to beef trimmings prior to grinding on Salmonella Typhimurium (ATCC 1769NR; ST), Escherichia coli (ATCC 11775; EC), coliform (CO), aerobic plate count (APC), instrumental color and sensory characteristics of ground beef through simulated retail display was investigated. For this, beef trimmings were inoculated with a mixture (7 log CFU/ml each) of ST and EC, and treated either aerobically or under vacuum in a tumbler with HW or LA antimicrobials. Trimmings were ground, packaged and sampled on days 0, 1, 2, 3 and 7 of display for ST, EC, CO, APC, sensory and instrumental color characteristics. Vacuum HW or LA application had no additive effect ( P>0.05) when compared with aerobic application for reducing EC, ST, CO or APC. However, lactic acid was effective for reducing ( P<0.05) EC, CO and APC, but reduced ground beef redness.

The effects of acetic acid, gluconic acid and trisodium citrate treatment of beef trimmings on microbial, color and odor characteristics of ground beef through simulated retail display

Antimicrobial effects of selected acidulants in a ground beef production system were studied. Lean beef trimmings were inoculated with Escherichia coli (EC) and Salmonella Typhimurium (ST) then treated with either 5% acetic acid, 5% gluconic acid (GA) or 5% trisodium citrate and then compared with an untreated control (C). Trimmings were ground, packaged and sampled at 0, 1, 2, 3 and 7 days of display for EC, ST, coliforms, aerobic plate counts (APC), sensory color and odor as well as instrumental color traits. Acetic acid reduced ( P<0.05) all bacterial types evaluated, but caused changes ( P<0.05) in ground beef color ( L*, a* and b* values) and odor characteristics. Conversely, although GA reduced ( P<0.05) EC and APC, it had little effect on color or odor characteristics as compared with C. Trisodium citrate did not affect ( P>0.05) microbial populations, color or odor characteristics of ground beef.