Beef Loin Steaks Research Articles

Using untargeted metabolomics and volatile aroma compounds to predict expert sensory descriptors and consumer liking of beef loin steaks varying in quality grade, aging time, and degree of doneness

Precursors to flavor are important to its development, yet little is known about the intrinsic products of metabolism that influence flavor. Our objective was to use untargeted metabolomics and volatile aroma compounds to predict expert and consumer sensory traits. USDA Select and upper 2/3 Choice beef strip loins were wet aged for 10 or 20 d and then cut into steaks, vacuum-packaged, and frozen. Steaks were cooked to 63 °C, 71 °C, or 80 °C end-point internal steak temperature. USDA Choice steaks had more intense beef flavor identity, brown, roasted, fat-like, salty, sweet, sour, umami, buttery, and overall sweet flavors compared to USDA Select steaks (P < 0.05). Steaks cooked to 80 °C had more intense beef identity, brown, roasted, and umami flavors than steaks cooked to a lower degree of doneness. Steaks cooked to either 63 °C or 71 °C had more intense bloody, metallic, and sour flavors and were juicier, more tender, and had less connective tissue than steaks cooked to a higher degree of doneness. Volatile aroma compounds increased (P < 0.05) in Choice steaks aged for 20 d, while cooking steaks to 80 increased aldehydes, ketones, and pyrazines. Raw steaks had 69 small-molecule metabolomic compounds shared across all four quality grade x aging combinations, and discriminant analysis correctly categorized (P < 0.05) these metabolites. Metabolites and volatiles can be used to predict (r2 > 0.85) expert and consumer sensory panel descriptors and liking.

Pulsed UV-C radiation of beef loin steaks: Effects on microbial inactivation, quality attributes and volatile compounds

The aim of this study was to investigate the effect of pulsed light treatment at fluences of 0.525, 1.05, 2.1 and 4.2 J/cm2 on the chemical composition, microbiological quality and volatile compounds of beef loin steaks. Pulsed light treatment did not affect total moisture, total protein, total lipid and ash content of samples significantly (P > 0.05). The a* and b* values of the pulsed light treated samples significantly decreased compared to control samples with maximum difference of 2.11 and 1.33 unit, respectively (P < 0.05). The highest reduction (3.49 ± 0.67 log CFU/g) in total aerobic mesophilic bacterial counts (compared to naturally occuring microbiota in control group) was achieved for samples treated with 4.2 J/cm2 of UV-C fluence level. A total of 14 volatiles, mainly aldehydes, alcohols, ketones and terpen compounds were identified in the raw samples and pulsed light treatment caused an increase in the amounts of some volatile compounds, including hexanal (from 33.41 μg/kg to 69.67 μg/kg), 2-heptenal (from 0.60 μg/kg to 1.52 μg/kg), 2-octenal (from 0.39 μg/kg to 1.58 μg/kg), 2,4-nonadienal (from 0.05 μg/kg to 0.24 μg/kg), 2,4-decadienal (from 0.04 μg/kg to 0.26 μg/kg), 3-octen-2-one (from 0.37 μg/kg to 2.53 μg/kg), limonene (from 2.06 μg/kg to 18.42 μg/kg). Otherwise, pulsed light decreased the levels of some compounds coming from microbial metabolism such as 1-heptanol (from 0.57 μg/kg to 0.39 μg/kg), 1-octen-3-ol (from 1.83 μg/kg to 1.12 μg/kg), 2-octen-1-ol (from 0.28 μg/kg to 0.09 μg/kg). In conclusion, pulsed light treatment can enhance the microbial safety of meat and has potential for use in the meat industry.

Consumer Assessment of New Zealand Forage Finished Beef Compared to US Grain Fed Beef

Consumer sensory analysis was conducted to determine differences in beef palatability between three process-verified feeding programs (New Zealand fodder beet, New Zealand grass/non-fodder beet, US grain). Beef strip loins were selected to represent low or high expected eating quality (based on eligibility for the company’s branded program, which focuses on carcass attributes of marbling, ossification, pH, 12th rib fat, and HCW), resulting in 6 treatments: fodder beet low quality (FBL), fodder beet high quality (FBH), non-fodder beet low quality (NFBL), and non-fodder beet high quality (NFBH), Select (SEL) and Top Choice (TCH). Samples were aged until 21 or 35 d postmortem. Extending postmortem aging positively influenced (P &lt; 0.05) New Zealand non-fodder beet samples, but largely had no effect (P &gt; 0.05) on New Zealand fodder beet samples, with the exception that tenderness was improved (P &lt; 0.05). Postmortem aging had a negative impact (P &lt; 0.05) on SEL juiciness and TC flavor and overall liking and no impact (P &gt; 0.05) on all remaining traits of US grain fed beef loin steaks. When focusing on the high eating quality samples, consumers did not discriminate between finishing systems when samples were aged 35 d, scoring TCH, FBH, and NFBH similarly (P &gt; 0.05) for all palatability traits. The FBL and NFBL were normally scored similarly (P &gt; 0.05) or with a slight advantage over SEL, regardless of aging period. Ultimately, finishing beef cattle using fodder beet in New Zealand can be a viable option to supply high quality beef during winter months, while maintaining the eating quality expectations associated with “grass-fed” beef according to US consumers from the Lubbock, TX area.

Comparing Honduran and United States Consumers’ Sensory Perceptions of Honduran and U.S. Beef Loin Steaks

The objective of this study was to compare the eating quality characteristics of beef from the United States and Honduras and to assess the willingness of Honduran and U.S. consumers to pay for these products. All U.S. sourced strip loins from grain-finished cattle, aged 21 d, were selected to equally represent USDA Select (SEL; n = 6) and upper 2/3 (Top) Choice (TC; n = 6) quality grades. Additionally, strip loins (n = 6) from Honduran grass-finished (HGRASS) cattle and grain-finished (HGRAIN) cattle (n = 6) were collected from a commercial abattoir in Siguatepeque, Honduras and aged 21 d. Samples were evaluated on 8-point hedonic scales for flavor, tenderness, juiciness, and overall liking by 240 consumers in each country. Consumers indicated if each trait was acceptable, and willingness to pay for each sample was rated in U.S. dollars (or the Honduran Lempiras equivalent): $0, 3, 6, and 10 per 0.45 kg. Chemical composition and Warner-Bratzler shear force (WBSF) were also determined. The TC had greater (P &lt; 0.05) fat percentage than SEL and HGRASS, but did not differ (P &gt; 0.05) from HGRAIN. The HGRAIN had greater WBSF values than TC and SEL, which did not differ (P &gt; 0.05); however, HGRASS was similar (P &gt; 0.05) to all other treatments. The TC had greater tenderness and flavor liking scores (P &lt; 0.05) than all other treatments, followed by SEL, HGRASS, and HGRAIN, with a significant difference between each treatment. Honduran consumers assigned greater ratings for tenderness and flavor liking when compared to U.S. consumers. The lowest rated treatment in both countries was Honduran grain-finished followed by Honduran grass-finished. Consumers in Honduras were willing to pay more for samples when compared to U.S. consumers. Consumers were also willing to pay a premium for products with greater palatability, regardless of the country of origin.

Comparing Honduran and United States Consumers’ Sensory Perceptions of Honduran and U.S. Beef Loin Steaks

The objective of this study was to compare the eating quality characteristics of beef from the United States and Honduras and to assess the willingness of Honduran and U.S. consumers to pay for these products. All U.S. sourced strip loins from grain-finished cattle, aged 21 d, were selected to equally represent USDA Select (SEL; n = 6) and upper 2/3 (Top) Choice (TC; n = 6) quality grades. Additionally, strip loins (n = 6) from Honduran grass-finished (HGRASS) cattle and grain-finished (HGRAIN) cattle (n = 6) were collected from a commercial abattoir in Siguatepeque, Honduras and aged 21 d. Samples were evaluated on 8-point hedonic scales for flavor, tenderness, juiciness, and overall liking by 240 consumers in each country. Consumers indicated if each trait was acceptable, and willingness to pay for each sample was rated in U.S. dollars (or the Honduran Lempiras equivalent): $0, 3, 6, and 10 per 0.45 kg. Chemical composition and Warner-Bratzler shear force (WBSF) were also determined. The TC had greater (P 0.05) from HGRAIN. The HGRAIN had greater WBSF values than TC and SEL, which did not differ (P > 0.05); however, HGRASS was similar (P > 0.05) to all other treatments. The TC had greater tenderness and flavor liking scores (P < 0.05) than all other treatments, followed by SEL, HGRASS, and HGRAIN, with a significant difference between each treatment. Honduran consumers assigned greater ratings for tenderness and flavor liking when compared to U.S. consumers. The lowest rated treatment in both countries was Honduran grain-finished followed by Honduran grass-finished. Consumers in Honduras were willing to pay more for samples when compared to U.S. consumers. Consumers were also willing to pay a premium for products with greater palatability, regardless of the country of origin.

Effects of Dry-Aging on Color and Oxidation Stabilities of Beef Loins

ObjectivesDry-aging is a traditional process to store whole carcasses or unpackaged primals/sub-primals under a controlled environment. Due to its known positive impacts on palatability attributes, dry-aging has been typically practiced in local meat processors or small meat purveyors for upscale butcher shops and/or gourmet restaurants. While there is an increasing demand from local consumers to purchase dry-aged beef from a retail market, there is little information on how dry-aging affects color and oxidation stabilities of beef muscles. Therefore, the objective of this study was to evaluate the effect of dry-aging on color and oxidation stabilities of beef loins. To measure the objectives, the conventional dry-aging (DA) of sub-primal loins was compared with two other aging methods– vacuum packaged wet-aging (WA) and dry-aging in a high water permeable bag (DAW).Materials and MethodsPaired beef loins (M. longissimus lumborum) from 9 beef carcasses were obtained at 7 d postmortem, cut into two sections, and assigned to three different aging methods (DA, WA, or DAW) for 28 d at 2°C and 78% relative humidity. After aging, initial trimming of dried surface was made. Then, one steak (2.54 cm thick) was cut from each aged section, overwrapped with PVC film, and displayed for 7 d under a simulated display condition. Instrumental and visual color evaluations were performed during 7 d of display. The 2-thiobarbituric acid reactive substances (TBARS) and heme/non-heme iron contents were measured for 0 and 7 d of samples. The experimental design was a balanced incomplete block design with three aging methods allocated to the loin sections from 9 beef carcasses in a saturated arrangement (n = 12; 9 carcasses × 2 loins × 2 sections = 36 sections for 3 treatments). All data were analyzed using the PROC MIXED procedure of SAS (SAS Inst. Inc., Cary, NC), and least squares means for all traits were separated (F test, P < 0.05) by using least significant differences generated by the PDIFF option.ResultsDAW beef loin steaks exhibited the most rapid decreases in CIE a* (redness) and visual lean color scores, and sharp increases in hue angle and visual discoloration scores during 7 d of retail display. Conversely, beef steaks from WA and DA treatments showed similar hue angle values during display (P > 0.05), although a slightly higher visual discoloration was observed in DA steaks compared to WA at d 7 (P < 0.05). The TBARS values were affected by different aging types (P < 0.05), where DAW showed the highest accumulation of lipid oxidation followed by DA and WA at the end of display. The heme and non-heme iron contents were not affected by either aging types or display time (P > 0.05).ConclusionThe results from this current study found that dry-aging in a high water permeable bag resulted in the most rapid discoloration and accelerated lipid oxidation during retail display. Steaks from the conventionally dry-aged beef loins seem to have similar color and lipid oxidation stabilities compared to the wet-aged beef counterpart at least up to 5 d of retail display. This observation indicates that steaks from dry-aged beef loins can be likely merchandised in the retail consumer level, once the proper initial trimmings are made. Further studies determining pro-oxidant factors of DAW causing more lipid oxidation and discoloration compared to DA and WA should be warranted.

The effect of feeding native warm season grasses in the stocker phase on the carcass quality, meat quality, and sensory attributes of beef loin steaks from grain-finished steers

The objective of this study was to evaluate the effect of feeding native warm season grass (NWSG) to beef cattle during the stocker phase (110days) on carcass and meat quality. Treatments included Bermudagrass (BER), Indiangrass monoculture (IND), and a mixture of NWSG including Big Bluestem, Little Bluestem, and Indiangrass (MIX). Cattle were finished on grain (180days) in a commercial feedlot and carcass data were collected after harvest. The percentages of ‘choice’ carcasses were 100, 95.8, and 87 within MIX, BER, and IND treatments, respectively. Steaks from BER had greater (P<0.05) fat content, and lower (P<0.05) protein and moisture percentages when compared to steaks from IND and MIX treatments. However, steaks from the MIX and IND treatments had less (P<0.05) lipid oxidation than steaks from BER after 6days of refrigerated storage. Results indicate that NWSG could be effectively incorporated into forage systems for stocker cattle without compromising carcass and meat quality.

Tenderness assessments of top loin steaks from retail markets in four U.S. cities.

The purpose of this study was to evaluate the tenderness of beef loin steaks from retail markets in 4 U.S. cities. Beef top loin steaks ( = 1,613) were obtained for Warner-Bratzler shear force (WBSF), slice shear force (SSF), and consumer sensory determinations. Personnel at 4 universities (California Polytechnic State University, Colorado State University, University of Missouri, and Texas A&M University) conducted the study over a 12-mo period. Enhanced/blade-tenderized top loin steaks had the lowest ( < 0.05) WBSF and SSF values, whereas nonenhanced top loin, bone-in steaks had the highest ( < 0.05) WBSF and SSF values. Enhanced/blade-tenderized top loin steaks received the highest ( < 0.05) ratings by consumers for palatability scores, whereas nonenhanced top loin, bone-in steaks had the lowest ( < 0.05) consumer panelist ratings. The USDA quality grade did have an effect ( < 0.05) on the tenderness of nonenhanced steaks but did not affect ( > 0.05) steaks that were enhanced/blade tenderized. The WBSF values and consumer sensory values for top loin steaks were comparable to the 2010 National Beef Tenderness Survey, signifying that no drastic changes in tenderness have occurred due to changes in antemortem or postmortem conditions.

Effect of electrohydraulic shockwave treatment on tenderness, muscle cathepsin and peptidase activities and microstructure of beef loin steaks from Holstein young bulls

Hydrodynamic pressure processing (HDP) or shockwave treatment improved tenderness (18% reduction in Warner–Bratzler shear force (WBSF) of beef loin steaks. Endogenous muscle proteolyic activities (cathepsins and peptidases) and protein fragmentation of sarcoplasmic and myofibrillar proteins detected by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) were not influenced by HDP. However, microstructure changes were clearly detected using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Specifically a disruption of the structure at the muscle fiber bundles and an increased endomysium space were observed. The present paper supports the evidence of physical disruption of the muscle fibers as a cause behind the tenderness improvement. The paper discusses the possible mechanisms responsible for the meat tenderisation induced by HDP treatment.

Effects of food ingredients and oxygen exposure on premature browning in cooked beef

Premature browning (PMB) in the centre of cooked hamburgers and beef loin (M. longissimus dorsi) steaks was assessed visually and instrumentally. Rosemary extract, ascorbic acid, sodium lactate, polyphosphate or lingonberry juice were added to freshly ground beef with predominant oxymyoglobin, and hamburgers were cooked to 62°C. In general, the tested ingredients did not reduce the extent of PMB in hamburgers, but polyphosphate tended to reduce PMB due to increased pH. Control burgers made of vacuum packaged meat with deoxymyoglobin were cooked to 62, 69 and 75°C, and did not express PMB. Beef loins were injected with a solution of sodium lactate, polyphosphate and sodium chloride. Loin steaks were stored under 75% O2/25% CO2 for 5days and also cooked to 62°C. Injected steaks had less PMB than non-injected controls, but of a low magnitude unlikely to influence the perception of doneness. The study demonstrated that anaerobic packaging is the most efficient measure to avoid PMB in beef.

Retail Display Evaluation of Steaks from Select Beef Strip Loins Injected with a Brine Containing 1% Ammonium Hydroxide. Part 2: Cook Yield, Tenderness, and Sensory Attributes

The impact of 2 different brines on the palatability and tenderness of select beef strip loin steaks was evaluated. Brines were differentiated by the type of alkaline agent, 4.5% sodium-based phosphate (control brine; CON) or 1% ammonium hydroxide (ammonium hydroxide treatment; AHT), incorporated into the formula. Injected steaks were placed in high oxygen (80% O(2)/20% CO(2)) MAP, stored 4 d at 4 °C in dark storage to simulate transportation, and then placed in retail display. Steaks were selected randomly on day 0, 7, and 14 retail display to measure pH, cook loss, shear force, and sensory characteristics. The pH for AHT steaks (pH 5.96) was slightly higher than CON steaks (pH 5.86; P < 0.05). Cook loss was lower (21%) for CON than AHT steaks (23%). There was neither a treatment nor day effect on tenderness as measured by Warner-Braztler shear force (P > 0.05). Sensory evaluation indicated that on day 0, retail display the initial juiciness, sustained juiciness, tenderness 1st impression, tenderness overall impression, and connective tissue in AHT steaks was not different from CON steaks (P > 0.05). A day effect (decrease) for those sensory parameters was observed only for sustained juiciness (P < 0.05). AHT steaks were rated higher in cooked beef flavor while CON steaks were higher in peppery and salty flavor. There was no difference in soapy and ammonia intensity between treatments. Results indicated that despite lower performance in cook loss the replacement of 4.5% sodium-based phosphate in a meat injection brine with 1% ammonium hydroxide produced a beef loin steak with comparable tenderness and palatability. Practical Application: The research in this study compares steaks that have been injected with a commercial brine formulated with sodium phosphates to steaks that have been injected with a brine where the sodium phosphate in the formulation was replaced with 1% ammonium hydroxide. Ammonium hydroxide is an USDA-FSIS approved ingredient in brines injected into fresh meats. Successful replacement of sodium phosphate with ammonium hydroxide would allow processors to significantly reduce the sodium content of injected fresh meat.

Effects of zilpaterol hydrochloride feeding duration on beef and calf-fed Holstein strip loin steak color

Two studies using beef and calf-fed Holstein cattle were conducted to determine the effect of zilpaterol hydrochloride (ZH) supplementation on the color of strip loin steaks packaged in traditional and modified-atmosphere packaging. Select (USDA) strip loins were obtained from the carcasses of beef (n = 118) or calf-fed Holstein (n = 132) cattle fed ZH (6.8 g/ton on a 90% DM basis) for the last 0, 20, 30, or 40 d of feeding. One portion of the strip loin was moisture enhanced, cut into steaks, and packaged in an atmosphere containing 80% oxygen and 20% carbon dioxide. The remaining portion of the strip loin was vacuum-packaged until further processing. At 14 d postmortem, the vacuum-packaged loins were portioned and packaged in traditional retail packaging. Traditionally packaged and modified-atmosphere-packaged steaks were then placed in retail cases at -1 to 3 degrees C for 5 d and evaluated by both trained and consumer panelists. Instrumental color values and purge loss were also recorded. Zilpaterol hydrochloride duration had no effect on the color and purchase intention scores of consumer panelists for beef and calf-fed Holstein strip loin steaks. Zilpaterol hydrochloride feeding duration had no effect on the color or discoloration scores of trained panelists for enhanced, modified-atmosphere-packaged beef strip steaks. Traditionally packaged beef steaks from cattle treated with ZH for 20 d had more desirable (P < 0.05) lean color scores than steaks from cattle not treated with ZH on d 2, 3, and 4 of display and had similar discoloration scores on d 1, 2, and 3 of display. The color scores of trained panelists for enhanced calf-fed Holstein steaks were more desirable (P < 0.05) for steaks from cattle not treated with ZH than for steaks from cattle treated with ZH for 20 d on d 1, 2, 3, and 4 of display. However, the discoloration scores of trained panelists for enhanced and modified-atmosphere-packaged calf-fed Holstein steaks were similar for steaks from cattle treated with ZH for 0 and 20 d on d 1, 2, and 3 of display. The scores of trained panelists indicated that traditionally packaged steaks from calf-fed Holsteins treated with ZH for 0 d had a darker lean color (P < 0.05) than steaks from ZH-treated cattle on d 1 of display, whereas the lean color scores for ZH treatments of all durations were similar on d 4 of display. The scores of trained panelists indicated that ZH treatment had no effect on the discoloration of traditionally packaged, nonenhanced strip steaks from calf-fed Holsteins. Therefore, feeding ZH to beef or calf-fed Holstein steers had no detrimental effect on the lean color or color stability of strip loin steaks subjected to enhancement, packaged in modified-atmosphere or traditional packaging, and displayed under simulated retail conditions.

Consumer acceptance of calcium chloride-marinated top loin steaks.

In this study, a multi-city, retail consumer survey was used to determine whether marinating in calcium chloride at 72 h postmortem improves consumer and trained sensory panel evaluations of beef loin steaks, Warner-Bratzler shear force (WBSF) values, and the value of CaCl2 marinades to improve tenderness in a national consumer market. Boneless strip loin subprimals (n = 8) were obtained from eight, not electrically stimulated, USDA Standard-grade carcasses, halved, and alternating ends were marinated with 200 mM CaCl2 at 5% (wt/wt) or not injected (controls). Strip loins were then aged for 7 d in vacuum packages at 2 degrees C before WBSF, trained or consumer evaluations. Four trained research teams traveled on the same 7-d period to collect the consumer data. Consumers (n = 393; minimum of 10 consumers/panel, three panels/store, three stores/city, and four cities) varying widely in income level, education, and gender evaluated the steaks for tenderness, beef flavor, juiciness, and overall quality in each of three supermarkets in major cities (Los Angeles, CA; Baltimore, MD; Chicago, IL; and Dallas, TX). The average improvement (P < 0.05) in WBSF for steaks marinated with CaCl2 was 1.39 kg. Trained panelists scored marinated steaks higher (P < 0.05) than control steaks in sustained juiciness (6.00 vs. 5.09), beef flavor (6.31 vs. 5.64), and overall mouth-feel (5.98 vs. 4.93). Consumers also rated marinated steaks higher (P < 0.05) than control steaks in juiciness (5.98 vs. 5.45), beef flavor (6.70 vs. 6.05), tenderness (6.75 vs. 5.89), and overall quality (6.68 vs. 6.20). Consumers in this study would pay dollar 0.95/kg more for steaks marinated with CaCl2, adding dollar 21.64 to the value of a loin from tough carcasses. These results indicate that consumers can differentiate tenderness levels and are willing to pay a premium for calcium chloride marinating to effectively improve the quality of beef loin steaks.

Feeding 25-hydroxyvitamin D3 to improve beef tenderness.

The objective of this trial was to determine if a single oral bolus of 25-hydroxyvitamin D3 (25-OH D3) given at various times before slaughter would enhance the tenderness of beef loin steaks. One hundred eight crossbred steers were allotted to 18 pens so that the mean weight of the cattle in each pen was similar. Treatments (25-OH D3 dose [62.5 or 125 mg]) and time of administration of the single oral bolus (4, 7, 21, or 35 d before slaughter) were assigned randomly to each pen of steers. Serial plasma samples were collected at each bolus administration time for control animals. For steers assigned to a treatment group, a baseline blood sample was collected before bolus administration and at each subsequent administration when other treatment groups received their bolus. Plasma samples were assayed for 25-OH D3 and calcium concentrations. Troponin-T degradation and Warner-Bratzler shear force were measured as indicators of tenderness for loin steaks collected at slaughter and aged for 6 or 14 d postmortem. Muscle samples, collected concurrently, were assayed for 25-OH D3 and calcium concentrations. A single oral bolus of 25-OH D3 was sufficient to increase plasma 25-OH D3 concentrations (P < 0.001) through slaughter, regardless of dose or time of bolus administration. The single oral bolus of 25-OH D3, however, did not increase plasma calcium concentrations (P > 0.05). As a result, neither troponin-T degradation nor Warner-Bratzler shear force was improved (P > 0.05) by treatment. Muscle 25-OH D3 concentrations were increased (P > 0.001) by treatment with 25-OH D3. Although sustained plasma 25-OH D3 concentrations did not increase plasma or muscle calcium at slaughter nor influence tenderness, the use of 25-OH D3 as a nutritional means of improving beef tenderness is in its infancy, and more research to delineate an effective dose and the potential interaction of seasonal exposure to ultraviolet light is warranted.

Warner‐Bratzler Shear Force Repeatability in Beef Longissimus Steaks Cooked With a Convection Oven, Broiler, or Clam‐shell Grill

ABSTRACT: Repeatability of Warner‐Bratzler shear (WBS) force in beef loin strip steaks was determined using a small kitchen clam‐shell grill (GRILL), oven roasting (OVEN), or oven broiling (BROIL). Cooking time for the GRILL method (7.0 min) was shorter, and the OVEN method (22.8 min) was longer compared with the BROIL cooking method (17.5 min, P&lt; 0.001). WBS values across all cooking methods ranged from 1.5 to 7.5 kg. Repeatability of WBS was relatively high for BROIL (r = 0.83), GRILL (r = 0.88), and OVEN (r = 0.88) cooking methods. Grilling beef loin steaks with an inexpensive clam‐shell grill is an acceptable method for cooking steaks for research purposes.

Effects of injection marination with various calcium sources and molar concentrations on display color life, tenderness, and microbial inhibition of beef loin steaks (2002)

Beef strip loins were assigned to one of 11 treatments that included injection marination (10% by weight) with three calcium salts at three molar concentrations, a distilled water control, and a non-marinated control. The effects of calcium salt and concentration were tested for retail display color life, tenderness and sensory traits, and microbial growth. Calcium lactate marinated steaks had longer color life and less microbial growth than those treated with calcium chloride or calcium ascorbate. Increasing molar concentration (.1M to .2M to .3M) caused faster color deterioration, and did not significantly improve microbial inhibition. All calcium treatments improved tenderness; however, calcium chloride treatments induced off-flavors. Considering a whole system approach that accounts for color life, microbial inhibition, shear force, and sensory traits, we recommend injecting beef longissimus with 10% of a .1M solution of calcium lactate, and do not recommend other calcium salts or concentrations.

The storage life of beef and pork packaged in an atmosphere with low carbon monoxide and high carbon dioxide

Ground beef, beef loin steaks and pork chops were packaged in modified atmospheres of 0.4% CO/60% CO 2/40% N 2 and 70% O 2/30% CO 2. In addition ground beef was packaged in clipped chub packs, beef loin steaks were vacuum packaged, and pork chops were packaged in an atmosphere of 60% CO 2/40% N 2 with each pack containing an O 2 absorber. The packs were stored in the dark at 4 or 8°C for up to 21 days. Meat in 0.4% CO/60% CO 2/40% N 2 had a stable bright red colour that lasted beyond the time of spoilage. The storage lives in this gas mixture at 4°C, as limited by off-odours, were 11, 14 and 21 days for ground beef, beef loin steaks and pork chops, respectively. The 70% O 2/30% CO 2 atmosphere resulted in an initially bright red to red colour of the meat, but the colour was unstable and off-odours developed rapidly. The off-odours probably were caused by Brochothrix thermosphacta, which grew in all meat types, or by pseudomonads in ground beef. Meat stored in chub packs, vacuum packs or 60% CO 2/40% N 2 with an O 2 absorber developed off-odours and microflora similar to those of meat in 0.4% CO/60% CO 2/40% N 2, but with less acceptable appearances. These results show that a low CO/high CO 2 atmosphere is effective for preserving retail-ready meat. ©

An audit of retail beef loin steak tenderness conducted in eight U.S. cities.

An audit of supermarkets in eight U.S. cities was conducted to characterize retail beef loin steaks with respect to grade, postfabrication aging, and tenderness and to provide an interim measure of progress in industry efforts to improve retail beef tenderness. Top sirloin steaks (n = 819) and strip loin steaks (n = 827 paired steaks) were purchased at retail markets in Atlanta, Chicago, Denver, Houston, Philadelphia, Phoenix, San Francisco, and Seattle and shipped to Colorado State University for measurement of shear force (both cut types) and evaluation by a trained sensory panel (strip loins only). Approximately 80% of the steaks originated from beef plants in Kansas, Texas, Nebraska, and Colorado. Postfabrication aging periods ranged from 2 to 87 d (mean = 20.8 d) for top sirloin steaks and from 2 to 91 d (mean = 19.2 d) for strip loin steaks, although most top sirloin (85%) and strip loin (91%) steaks were available for purchase 7 to 35 d after fabrication. The mix of quality grades was similar for both cuts: 60% Select, 31% "commodity" Choice, 6 to 7% "Certified" Choice, and 2 to 3% Prime. Shear force averaged 3.46 kg (SD = .74) for top sirloins and 3.05 kg (SD = .95) for strip loins; 75% of both steak types had shear force values between 2 and 4 kg. Postfabrication periods shorter than 7 d were associated with reduced (P < .05) tenderness, especially for top sirloin steaks. Higher quality grades were associated with greater (P < .05) tenderness (Prime > Choice > Select) for both cuts. Based on panel tenderness ratings, the approximate odds of obtaining a "slightly tough" or tougher strip loin steak at a retail supermarket were: 0 for Prime, 1 in 10 for "Certified" Choice, 1 in 5 for "commodity" Choice, and 1 in 4 for Select. Audit results suggest that tenderness characteristics of loin steaks have not changed materially since the National Beef Tenderness Survey was conducted in 1991 and that two primary focal points of the beef industry's efforts to improve tenderness should be 1) to prevent short-aged (< 7 d postfabrication) product from reaching consumers and 2) to identify methods for enhancing tenderness of Select and "commodity" Choice beef.

DYNAMIC GAIN MATRIX APPROACH TO MODELING OF DYNAMIC MODIFIED ATMOSPHERE PACKAGING SYSTEMS4

ABSTRACTVariations in food and biological systems create nonlinear interactions that increase complexity of mathematical models. A multivariable correlative mathematical modeling strategy, dynamic gain matrix (DGM) method, was derived using advanced process control concepts and it was applied to describe quality changes in beef loin steaks with postmortem fabrication time and modified atmosphere packaging (MAP) conditions altered by dynamic gas exchange. DGM was used for modeling of dynamic MAP to satisfy the special modeling requirements of relationships between the processing and packaging variables and quality parameters through consideration of multivariable interacting deterioration mechanism in mathematical terms. A normalization method was also developed and applied to eliminate initial condition effects arising from meat source differences. A total of 960 data points were analyzed, and the model is reported as a series of first order differential equations with respect to retail display time to describe changes in color, pH and microbial population as functions of postmortem fabrication time, distribution gas composition, gas exchange time and retail gas composition. The model was optimized to minimize prediction sum of residual errors, and a pairing and control strategy was proposed to be used for optimum control of quality parameters for a chosen display time by manipulation of processing and packaging variables. The strategy developed has specific use for prediction and design of dynamic gas exchange MAP systems as well as potential use in similar biological engineering systems.

Dietary vitamin E supplementation shifted weight loss from drip to cooking loss in fresh beef longissimus during display2

Effects of dietary vitamin E supplementation on drip loss, cooking loss, and muscle fiber disruption in fresh beef loin steaks from Holstein and crossbred beef steers were studied. Nine Holstein steers and nine beef steers were fed a control diet and nine Holstein steers and eight beef steers were supplemented daily with 298 IU of vitamin E/kg of diet for 211, 232, or 252 d. Drip loss, cooking loss, cooking yield, and shear value were measured in each longissimus lumborum sample displayed in PVC film for 2, 6, 10, or 14 d. Dietary vitamin E supplementation produced meat that had smaller (P < .001) increases in drip loss during 14 d of display but higher (P < .01) cooking losses. Cooking yield was reduced (P < .05) by vitamin E supplementation. Vitamin E supplementation reduced (P < .01) muscle cell disruption in beef steak displayed for 14 d. These results indicated that dietary vitamin E treatment stabilized cell integrity and enhanced the ability of beef steak to hold sarcoplasmic components during display, although subsequent losses due to cooking were greater.