The Effects of Different Zilpaterol Hydrochloride Feed Supplements and Extended Aging Periods on the Meat Quality of Feedlot Bulls

This study researched the effects of two commercially available zilpaterol hydrochloride (ZH) β-adrenergic agonists, denoted as ZH-A and ZH-B, on the meat quality characteristics of typical South African feedlot bulls (taurine × indicus composites), over extended aging periods of up to 120 days. The effects of ZH were studied to address concerns about the possible adverse effects of ZH on beef quality following extended aging, which typically occurs during the exportation of beef by boat. The completely randomized control study consisted of 3 homogenous experimental groups, with 3 replicates per treatment and 50 bulls per replicate = 450 animals. Treatments were a negative control (CT) with no ZH supplementation added to the basal diet or a basal diet supplemented with either zilpaterol hydrochloride A (ZH-A) or zilpaterol hydrochloride B (ZH-B), both at 105 g ZH/ton, fed from the first day of the finishing period (D0) for 30 days. Subsamples were collected from 38 random carcasses from each treatment for proximate analysis and meat quality analysis using Longissimus dorsi samples. ZH supplementation decreased meat tenderness (Warner-Bratzler shear force values (WBSF)) of bulls fed ZH-A or ZH-B, compared to those fed the CT diet (p < 0.05; η2 = 0.24). The WBSF values of both ZH treatments were about 0.5-0.8 kg higher during the aging periods compared to the CT, but ZH did not affect post-mortem meat aging or meat quality characteristics differently compared to the CT. Post-mortem aging per se influenced all meat quality characteristics investigated (p < 0.001; η2 > 0.30), showing improvements in WBSF, a decrease in meat colour and an increase in drip and cooking losses. L*-values increased from 3 to 56 days of aging and then decreased to day 120 (p < 0.001; η2 = 032). Chroma values decreased from day 3 to day 120 (p < 0.001; η2 = 0.50). Hue° decreased from day 3 to day 7 and stabilized until day 120 (p < 0.001; η2 = 0.40). Moisture and cooking loss (CL) increased to 56 days and then decreased to 120 days.

Evaluation of citrus fiber as a natural alternative to sodium tripolyphosphate in marinated boneless broiler chicken breast and inside beef skirt (transversus abdominis)

OBJECTIVE

This research was conducted to evaluate the effects of citrus fiber (CF) as a natural alternative to sodium tripolyphosphate (STPP) in marinated broiler boneless chicken breast and inside beef skirt on overall retention rate, shear force, and consumer sensory attributes.

METHODS

Five different marinade formulations were targeted to include 0.9% salt, either 0.25% or 0.50% STPP or CF and water on a finished product basis. Water and salt only were considered the negative control (CON). Chicken breasts (n = 14) and inside beef skirt (n = 14) were randomly assigned to a treatment, raw weights recorded and then placed in a vacuum tumbler. Marinated weights were recorded, individually packed, and randomly assigned to either retail display for 10-day retention rate, shear force analysis, cook loss, or consumer sensory panel.

RESULTS

Pickup percentage, and overall retention was similar among treatments for chicken breast and inside beef skirt. Citrus fiber treatments resulted in higher cooking loss compared to the CON in chicken breast; though, CF050 resulted in similar cooking loss compared to STPP025 in inside beef skirt. No differences were found in sensory attributes for chicken breast, however, WBSF data showed CF025 was tougher than CF050, STPP050, and CON. Inside beef skirt with CF050 were least liked overall by the consumer panel.

CONCLUSION

Citrus fiber included in marinades at a lower percentage rate can produce similar texture characteristics, and sensory properties compared with those marinated with STPP.

47 Effects of Sous Vide Cooking on the Tenderness of Beef Loins from Different USDA Quality Grades

The objective of this study was to determine the effects of sous vide cooking on the tenderness of beef loins from different USDA quality grades. Certified Angus Beef (CAB, n = 6), consisting of Motest0-Moderate100 marbling scores, USDA Low Choice (CH, n = 6), and USDA Select (SEL, n = 6) beef loins were purchased from a local meat purveyor and aged for 20 d with pack date set as d 0. Following aging, loins were cut into 2.54-cm-thick steaks, and every alternating steak was assigned to tenderness evaluation. Steaks were randomly assigned 1 of 3 treatments: sous vide 1 h (SV1), sous vide 2 h (SV2), and grilled (GR). Following sous vide cooking at 57°C, all treatments were grilled using the flat surface of a clamshell grill to an internal temperature of 71°C. Instrumental measurements for external cooked color (L*, a*, and b*) were recorded at 3 different locations on each steak following cooking using the HunterlLab Miniscan EX Plus spectrophotometer. Beef tenderness was evaluated using TA.XTPlus Warner-Bratzler shear (WBS) force machine after steaks chilled at 4°C for 12 – 18 h. There was no significant (P &gt; 0.05) treatment by quality grade interactions for WBS force. GR steaks had a higher (P &lt; 0.05) WBS force compared with SV1 and SV2 indicating a less tender product. SEL also had a higher WBS force value (P &lt; 0.05) than CAB. Additionally, there was an increase (P &lt; 0.05) in L* between GR, SV1, and SV2 indicating GR steaks were whiter, followed by SV1, then SV2 being the darkest. SV2 had a higher (P &lt; 0.05) cook loss than SV1. In conclusion, there was no difference between the interactions of WBS force and treatments. Therefore, sous vide has an impact on tenderness that overpowers the quality grade differences, providing a more tender product compared to grilling.

Effects of Pork Quality Types, Packaging, and Degree of Doneness on Trained Sensory and Instrumental Tenderness, Color, and Consumer Perception

The objective of this study was to evaluate the palatability and retail display differences of 3 types of pork loins. Enhanced (n = 10), nonenhanced (n = 10), and high-quality (n = 10) pork loins were selected from a commercial food distribution company. Loins were cut into 2.54-cm-thick chops and randomly assigned to retail display, sensory, or Warner-Bratzler shear force analyses. For retail display, chops were randomly assigned to 1 of 3 packaging treatments: polyvinyl chloride overwrap, carbon monoxide-modified atmosphere packaging, and high-oxygen modified atmospheric packaging. Instrumental and visual color measurements were taken during 5 d of retail display. For trained sensory panel and Warner-Bratzler shear force analyses, chops were evaluated at 3 different degrees of doneness (63°C, 68°C, and 74°C). Consumer sensory panelists (N = 50) evaluated the overall liking, flavor, juiciness, and tenderness of chops cooked to 68°C. A treatment × packaging interaction (P &lt; 0.05) occurred for L* and a* values. High-quality chops packaged in polyvinyl chloride overwrap were lighter in color (P &lt; 0.05) compared with other treatment and packaging types. However, high- quality chops had lower (P &lt; 0.05) a* values than other treatment and packaging types during retail display. Trained panelists reported no difference (P &gt; 0.05) in tenderness for enhanced chops when cooked at 3 different degrees of doneness. Consumer panelists preferred the enhanced chops for overall liking, tenderness, and juiciness (P &lt; 0.05) compared with high-quality and nonenhanced chops. The results suggest that enhanced, nonenhanced, and high-quality pork loins avail- able in the market vary in color and marbling. Both pork loin type and packaging can influence display color and palatability.

147 Tenderness and Retail Display Evaluation of Non-Enhanced, Enhanced and High-Quality Pork Chops

Quality variation within the pork industry is commonly associated with intramuscular fat and muscle color. The objective of this study was to determine the effects of packaging, pork quality types, and cooking temperature on color and shear force. Normal, non-enhanced (N, n = 10), Enhanced with salt and phosphate (E, n = 10) and Highly Marbled (H, n = 10) pork loins from a local food distributor. Loins were cut into 2.54-cm-thick chops and assigned to retail display or tenderness evaluation. Retail display chops were assigned to 1 of 3 packaging treatments: polyvinyl chloride overwrap (PVC), carbon monoxide modified atmosphere packaging (CO-MAP) and high-oxygen modified atmospheric packaging (HiOx-MAP). Visual color measurement for muscle color (MC), fat color (FC), surface discoloration (SD), and surface color uniformity (SCU) was recorded on d 0, 2, and 4 of retail display. Pork tenderness was evaluated at 3 different degrees of doneness (63, 68, & 74°C) using Warner-Bratzler shear (WBS) force. There were significant treatment and packaging interactions for muscle color. For muscle color score, E pork loins had a significantly lower (P &lt; 0.05) muscle color score compared with N and H loins indicative of a brighter, more pale pink color. In addition, CO- and HiOx-MAP packaged chops were significantly brighter (P &lt; 0.05) compared to PVC chops. There were treatment and degree of doneness main effects (P &lt; 0.05) for WBS force values. Enhanced pork loins were more tender (P &lt; 0.05) than N pork loins. Furthermore, pork chops cooked to 63 °C were more tender than chops cooked to 68 and 73°C. In conclusion, enhanced chops packaged in CO- or HiOx-MAP result in a brighter color of lean compared non-enhanced and high-quality. Additionally, the results suggest that enhanced, non-enhanced, and high-quality pork products available in market have different quality parameters.

110 Metmyoglobin reducing activity and oxygen consumption properties of atypical dark-cutting beef

Deviation from characteristic bright-red color during grading leads to discounted carcass price and value. Dark-cutting carcasses are examples of color deviation due to high-pH. However, atypical dark-cutters are not discounted at grading but have a dark color compared to normal-pH beef. Limited knowledge is currently available on the biochemical properties of atypical dark cutting beef compared with normal-pH beef. Therefore, the objective of the study was to determine metmyoglobin reducing activity and oxygen consumption of atypical dark-cutting beef. Strip loins from atypical dark-cutting (ADC; selected based on HunterLab L* values and pH less than 5.8 and not discounted by grader) and USDA Low Choice (C) carcasses were selected from a commercial beef processing plant and transported to the Food and Agricultural Products Center in Stillwater, Oklahoma. pH, color, oxygen consumption, and metmyoglobin reducing activity of atypical dark cutters and normal pH loins were determined on d3 postmortem. The surface color was determined using a HunterLab Miniscan spectrophotometer. Reflectance-based methods using K/S ratios were utilized to determine oxygen consumption and metmyoglobin reducing activity. The data were analyzed using the Mixed Procedure of SAS and the experiment was replicated 10 times (n = 10). There were no differences in initial pH (C = 5.46 and ADC = 5.6 atypical dark-cutter; P = 0.05) between normal-pH and atypical dark cutters. However, atypical dark cutters had lower lightness (L* values; C = 44.2 and ADC = 38.4), redness (a* values; C = 28.6 and ADC = 25.2), and red intensity (chroma; C = 40.2 and ADC = 36.4) compared with normal-pH. Further, atypical dark cutters had greater (P &lt; 0.05) oxygen consumption and metmyoglobin reducing activity than normal-pH. The results suggest that atypical dark cutters and normal-pH beef have different biochemical properties.

Effects of Enhancement and Modified Atmosphere Packaging on Flavor and Tenderness of Dark-Cutting Beef

The objective of this study was to evaluate the effects of rosemary/beef flavor enhancement and modified atmosphere packaging (MAP) on retail display color and palatability of beef longissimus lumborum muscle. Dark-cutting beef strip loins (n = 8; pH &gt; 6.0) and USDA Low Choice beef strip loins (n = 5) were selected from a commercial packing plant within 72 h of harvest. Dark-cutting strip loins were divided into 2 equal sections and randomly assigned to either nonenhanced or rosemary/beef flavor–enhanced treatments. Dark-cutting enhanced loins were injected to 110% of their green weight with a rosemary/beef flavor enhancement to attain 0.1% rosemary, 0.5% salt, and 0.55% beef flavor in the final product. Six 2.54-cm-thick steaks were cut from nonenhanced USDA Choice, nonenhanced dark-cutting, and enhanced dark-cutting strip loins and randomly assigned to one of 3 packaging treatments: vacuum packaging, carbon monoxide MAP (0.4% CO, 69.6% N, and 30% CO2), and high-oxygen MAP (80% O2 and 20% CO2). Following 3-d retail display, instrumental color measurements were recorded, and one steak from each packaging type was evaluated by a trained sensory taste panel and another used to measure Warner-Bratzler shear force. Enhanced dark-cutting steaks packaged in high-oxygen MAP and carbon monoxide MAP had greater a* values (P &lt; 0.0001) than dark-cutting steaks in vacuum packaging. Enhanced dark-cutting steaks were lighter (P &lt; 0.0001, greater L* values) than nonenhanced dark-cutting steaks. Nonenhanced dark-cutting steaks exhibited a lower (P = 0.03) overall juiciness compared to enhanced dark-cutting steaks. Enhanced and nonenhanced dark-cutting steaks were more tender (P = 0.002) than the USDA Choice steaks. Enhanced dark-cutting steaks had higher (P = 0.006) sour flavor in vacuum packaging than other packaging types. The results suggest that rosemary/beef flavor enhancement has the potential to improve the surface color of dark-cutting beef while improving or maintaining palatability.

Effects of adding liquid lactose or molasses to pelleted swine diets on pellet quality and pig performance

Two experiments were conducted to evaluate the effects of including liquid lactose (LL) and molasses (M) in swine diets on pellet quality and pig performance. In experiment 1, a total of 194 nursery pigs (DNA 241 × 600, initially 6.7 ± 0.4 kg at 27 d of age) were used in a 33-d experiment evaluating the effects of LL (SweetLac 63; Westway Feed Products, Tomball, TX) or cane molasses on nursery pig performance and pellet quality. Pelleted experimental diets were fed from d 0 to 21, and a common pelleted diet fed from d 21 to 33. Dietary treatments consisted of a control diet containing 19.1% total sugars from whey powder and whey permeate and experimental diets with a percentage of whey permeate replaced by either 5% or 10% LL or 9.4% cane molasses (5 LL, 10 LL, and 9.4 M, respectively). Hot pellet temperature and production rate decreased (P < 0.05) from the control to 9.4 M treatments with 5 LL and 10 LL having intermediate effects. Pellet durability index (PDI) increased (P < 0.05) in 5 LL, 10 LL, and 9.4 M, respectively. From d 0 to 7, pigs fed the 10 LL and 9.4 M treatment had the best G:F followed by the control and 5 LL treatments. From d 0 to 21, ADFI had a marginally significant improvement (P < 0.10) in pigs fed up to 10 LL in the diet. Fecal consistency scores at d 7 were also firmer (P < 0.05) in pigs fed 9.4 M compared with pigs fed the control or 5 LL treatments with pigs fed the 10 LL treatment being intermediate. There was no evidence for differences in fecal consistency scores for d 14. In experiment 2, a total of 289 finishing pigs (DNA 241 × 600; initially 53.5 ± 0.5 kg BW) were used in a 53-d experiment evaluating the effects of LL on pellet quality and finishing pig performance. Experimental diets were fed in pelleted form from d 0 to 53 divided into three phases. Dietary treatments were a corn-soybean meal control diet with 0%, 2.5%, 5%, and 7.5% LL added in the place of corn. PDI improved (linear, P < 0.01) with increasing inclusion of LL. There were no differences in ADG, ADFI, final BW, or carcass characteristics. Pigs fed diets with increasing levels of LL tended to have improved (quadratic, P = 0.070) G:F.

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

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.