Investigation of the effects of commercial carcass suspension (24 and 48 h) on meat quality in high oxygen modified atmosphere packed beef steaks during chill storage

Hanging for 24 or 48 hours (h) of intact carcasses in the chill store cooler prior to further processing occurs periodically at processor level due to demand for product. The aim of the study was to investigate the effects of commercial carcass suspension (24 and 48 h) on meat tenderness attributes in modified atmosphere packed beef steaks during chill storage. A secondary objective was to investigate protein oxidation reactions occurring and the subsequent meat tenderness consequences. Carcasses were hung for 24 or 48 h in order to reproduce commercial short term storage of meat at processor level. Experimental gas atmospheres used in packs consisted of; 40%, 50%, 60%, 70% and 80% oxygen, with all packs containing 20% CO₂ and the remainder being provided by the filler gas N₂. Steaks from the 24 h suspended carcasses were tougher than those from 48 h suspended muscle. Additionally, packaging systems with high oxygen had a negative influence on tenderness (instrumental) and consumer determined juiciness in cooked beef steaks. The carbonyl content and TBARS numbers increased to the greatest extent in high oxygen packed samples. Protein oxidation was directionally and significantly correlated (P < 0.01) to the higher O₂ treatments. Protein and lipid oxidation also occurred to a greater extent in the samples from the 48 h treatment, possibly due to physical matrix differences in the meat compared to the 24 h treatment. Meat from the 48 h treatment appeared less red than meat from the 24 h treatment.     

Consumer acceptance and steak cutting yields of beef top sirloin and knuckle subprimals

Beef knuckles (n = 150) and center-cut top sirloin butts (n = 150) were used to determine portion-controlled steak cutting yields, palatability characteristics, and consumer acceptance of rectus femoris (RF), vastus lateralis (VL), and gluteus medius (GM) steaks. Steak yields were higher (P < 0.05) for top sirloins than knuckles. Trained sensory panel ratings for overall tenderness, juiciness, and flavor were similar between RF and GM. Consumer panel ratings for tenderness and juiciness were higher (P < 0.05) for GM than RF; however, consumer perceptions of overall like and flavor were similar for GM and RF. Vastus lateralis received lower (P < 0.05) trained panel and consumer ratings for all traits than either RF or GM. Palatability of VL will need improvement to be a viable foodservice offering. Yet, these data suggest that RF would amply substitute for GM in foodservice settings, and that knuckle steak yields would be adequate for foodservice applications.     

Consumer Assessment of Beef Tenderloin Steaks from Various USDA Quality Grades at 3 Degrees of Doneness

A consumer study was conducted to determine palatability ratings of beef tenderloin steaks from USDA Choice, USDA Select, and USDA Select with marbling scores from Slight 50 to 100 (USDA High Select) cooked to various degrees of doneness. Steaks were randomly assigned to 1 of 3 degree of doneness categories: very‐rare, medium‐rare, or well‐done. Consumers (N = 315) were screened for preference of degree of doneness and fed 4 samples of their preferred doneness (a warm‐up and one from each USDA quality grade treatment in a random order). Consumers evaluated steaks on an 8‐point verbally anchored hedonic scale for tenderness, juiciness, flavor, and overall like as well as rated steaks as acceptable or unacceptable for all palatability traits. Quality grade had no effect (P > 0.05) on consumer ratings for tenderness, juiciness, flavor, and overall like scores, with all traits averaging above a 7 (“like very much”) on the 8‐point scale. In addition, no differences (P > 0.05) were found in the percentage of samples rated as acceptable for all palatability traits, with more than 94% of samples rated acceptable for each trait in all quality grades evaluated. Steaks cooked to well‐done had lower (P < 0.05) juiciness scores than steaks cooked to very‐rare or medium‐rare and were rated lower for tenderness (P < 0.05) than steaks cooked to a very‐rare degree of doneness. Results indicate consumers were not able to detect differences in tenderness, juiciness, flavor, or overall like among beef tenderloin steaks from USDA Choice and Select quality grades.     

Effects of fibre orientation, myoglobin redox form, and postmortem storage on NIR tissue oximeter measurements of beef longissimus muscle

To determine near-infrared tissue oximeter responses to muscle fibre orientation, display time, and surface colour differences of beef longissimus lumborum steaks, beef loins were cut into steaks either perpendicular or parallel to the muscle fibre orientation. Surface colour differences were created by packaging steaks in vacuum (VAC), 80% O₂ and 20% CO₂ modified atmosphere packaging (HiOx MAP), polyvinyl chloride film overwrap (PVC), and HiOx MAP converted to PVC (HiOx-PVC) after 2 days. Changes in surface colour and subsurface pigments during display (0, 2, 4, 10, and 15 days at 2 °C) were characterized by using a reflectance-spectrophotometer and a near-infrared tissue oximeter, respectively. Fibre orientation, storage, and packaging affected (P < 0.05) colour, total pigment, deoxymyoglobin, and oxymyoglobin content. Tissue oximetry measurements appear to have potential for real-time monitoring of myoglobin redox forms and oxygen status of packaged meat, but fibre orientation needs to be controlled.     

Effect of lactate-enhancement, modified atmosphere packaging, and muscle source on the internal cooked colour of beef steaks

Earlier studies on lactate-mediated colour stability in beef did not address the possible influence on cooked colour. Our objective was to examine the effect of lactate-enhancement, muscle source, and modified atmosphere packaging (MAP) on the internal cooked colour of beef steaks. Longissimus lumborum (LL) and Psoas major (PM) muscles from 16 (n = 16) beef carcasses (USDA Select) were randomly assigned to 4 enhancement treatments (non-injected control, distilled water-enhanced control, 1.25% and 2.5% lactate), and fabricated into 2.54-cm steaks. Steaks were individually packaged in either vacuum (VP), high-oxygen MAP (HIOX; 80% O₂ + 20% CO₂), or carbon monoxide MAP (CO; 0.4% CO + 19.6% CO₂ + 80% N₂), and stored for 0, 5, or 9 days at 1 °C. At the end of storage, surface and internal colour (visual and instrumental) was measured on raw steaks. Steaks were cooked to an internal temperature of 71 °C, and internal cooked colour (visual and instrumental) was evaluated. Lactate-enhancement at 2.5% level resulted in darker (P < 0.05) cooked interiors than other treatments. Interior cooked redness decreased (P < 0.05) during storage for steaks in VP and HIOX, whereas it was stable for steaks in CO. Our findings indicated that the beef industry could utilise a combination of lactate-enhancement and CO MAP to minimise premature browning in whole-muscle beef steaks.     

Effect of O2 scavenger on the shelf‐life of catfish (Pangasius sutchi) steaks during chilled storage

BACKGROUND: Active packaging for preserving meat products, including seafoods, has been gaining importance in recent times. The present study was undertaken to assess the effectiveness of O₂ scavenger, the most widely used active packaging technology, on the shelf‐life of catfish steaks in chilled storage conditions. RESULTS: O₂ scavenger was effective in reducing the oxygen concentration inside the packaging to as low as 0.42% within 24 h. This reduction in oxygen in O₂ scavenger packages showed positive effects on quality parameters compared to control air packs. Total volatile base nitrogen (TVB‐N), thiobarbituric acid value and peroxide value of catfish steaks packed in O₂ scavenger was significantly different (P < 0.05) compared to air‐packed samples. Based on the sensory, microbiological and TVB‐N values, the control samples were acceptable only up to 10 days, compared to 20 days in O₂ scavenger‐packed samples, extending the shelf‐life by 10 days. CONCLUSION: O₂ scavenger reduced the oxygen concentration inside the package significantly within 24 h compared to control air packs. By using this technique, the use of a vacuum packing machine can be avoided. Further, O₂ scavenger extended the product's shelf‐life up to 20 days, compared to 10 days in control packs. Copyright © 2007 Society of Chemical Industry     

Nucleotide breakdown products of seer fish (Scomberomorus commerson) steaks stored in O2 scavenger packs during chilled storage

Freshness of seer fish (Scomberomorus commerson) steaks packed with and without O₂ scavenger was assessed by sensory and chemical methods. O₂ scavenger used in the present study reduced the O₂ level in the pack to less than 0.01% within 24 h. Samples in air packs were sensorily acceptable only up to 12 days compared to 20 days in O₂ scavenger packs. TVB-N levels were 37 and 34 mg N₂/100 g and TMA-N levels were 16.4 and 15.2 mg N₂/100 g on the day of sensory rejection for air and O₂ scavenger packs, respectively. IMP decrease and Hx increase was significantly (P < 0.05) faster in air packed samples compared to O₂ scavenger packs. On sensory rejection day, the average K, Ki, P and H values were 63–65%, Fr value was 34% and G value was 178% for O₂ scavenger packed samples compared to 81%, 18% and 443% for air packed samples, respectively.Industrial relevanceThe O₂ scavenger is an innovative active packaging technique, which is highly effective in reducing the O₂ present inside the pack. This can be used in place of traditional vacuum packaging for extending the shelf life of fish products, which reduces the use of vacuum packaging equipments thereby making the process cost effective.     

Palatability of beef steaks marinated with solutions of calcium chloride, phosphate, and (or) beef-flavoring

This study evaluated the efficacy of marination for increasing consumer acceptability of beef. Top-sirloin steaks from 28 USDA select steers were randomly assigned to one of six marination treatments: control (CT), 150 mM calcium chloride (CA), 10% solution of beef-flavoring/seasoning mixture (FL), CA and FL (CF), 2.5% sodium phosphate and FL (PF), and tap water (TW). Steaks were marinated in vacuum pouches, aged for 7 days, cooked to 70°C and evaluated by a trained sensory panel. Marination with CA did not affect tenderness ratings, but increased (P<0.05) bitter and metallic flavors compared to CT or TW treatments. Use of FL, alone or in conjunction with CA or sodium phosphate, increased (P<0.05) tenderness and juiciness ratings and reduced (P<0.05) bitterness and metallic flavors compared to CT, CA and TW marinades. Marination of beef, in vacuum pouches, is an effective method for increasing consumer acceptability and value beef.     

CONSUMER RESPONSE TO RESTRUCTURED BEEF STEAKS PROCESSED TO HAVE VARYING LEVELS OF CONNECTIVE TISSUE

Restructured beef steaks were manufactured to have either extra high (EH), high (H) or low (L) levels of connective tissue. Steaks were subjected to consumer response studies involving 300 consumers (six test groups of 50 consumers each). Sex and age of consumers did not greatly influence responses. In direct comparisons of EH with L steak, 82 % of the consumers felt EH had more gristle than L steaks, however, only 44% of the consumers found more gristle in H vs L steaks. Over 50% of the consumers tested felt the amount of gristle in EH steaks to be excessive compared to only 14% for consumers evaluating L steaks. In addition to excessive gristle, consumers found texture and toughness to be undesirable characteristics of EH steaks. For all six test groups, consumer acceptability was highest for L steaks followed by H steaks with the lowest acceptability assigned to EH steaks.     

Carbon dioxide flavour taint in modified atmosphere packed beef steaks

The objective of this study was to investigate the effects of carbon dioxide (CO₂) concentration (100mlCO₂/100 ml pack gas, 50mlO₂:20mlCO₂:30mlN₂/100 ml pack gas, 70mlO₂:30mlCO₂/100 ml pack gas and 80mlO₂:20mlCO₂/100 ml pack gas) on the sensory quality of modified atmosphere packed (MAP) beef steaks (M. longissimus thorasis). Steaks were stored at 4 °C for 15 days and tested for CO₂ off flavour, lipid oxidation flavour, juiciness and tenderness (up to day 12) of the resulting cooked meat as well as pH, colour, drip loss, and cooking loss. One steak from each of the experimental treatments was taken immediately from the respective MA packs and cooked before serving straight to panellists. A second steak from each of the pack was treated similarly, but left in ambient air for 30 min to let dissolved CO₂ dissipate from the meat prior to cooking and serving. The 50mlO₂:20mlCO₂:30mlN₂/100 ml pack gas treatment displayed a significantly (P ≤ 0.05) and negative correlation to CO₂ flavour which was even more pronounced for samples where the CO₂ was allowed to dissipate (Dis, P ≤ 0.001). Thus this packaging gas combination could be used to optimise the sensory quality of MAP steak. Additionally opening retail MAP packs up to 30 min prior to cooking has a benefit towards the perceived sensory quality of the cooked product.     

CONSUMER EVALUATION OF THE PALATABILITY OF USDA SELECT,USDA CHOICE AND CERTIFIED ANGUS BEEF STRIP LOIN STEAKS FROM RETAIL MARKETS IN LUBBOCK,TEXAS, U.S.A.

ABSTRACT

Select, Choice and Certified Angus Beef (CAB) strip loin steaks were sold in Lubbock, TX to determine consumer acceptability. A home survey was attached to each package of steaks (return = 191 steak evaluations). Consumers did not detect differences in tenderness or flavor, but rated CAB steaks juicier (P < 0.05) than Select or Choice. However, 68% of CAB consumers rated steaks as extremely or very tender, but less than half rated Choice and Select steaks the same way. Consumer tenderness and flavor scores for Select steaks were more variable, but consumer satisfaction and tenderness acceptability did not differ (P > 0.05) between grades. Trained sensory panelists rated CAB steaks higher (P < 0.05) than Choice or Select for all palatability traits except flavor intensity. Shear force decreased (P < 0.05) by quality grade as CAB steaks sheared with the least resistance. These results showed marbling influenced objective palatability measures and decreased the variation in both objective and consumer measures of palatability.

PRACTICAL APPLICATIONS

Quality grades were established to predict beef palatability, but marbling can be an unreliable predictor of tenderness. Branded beef programs, such as Certified Angus Beef (CAB), have been developed to distinguish higher palatability products and provide more consistent products for consumers. Consumers can distinguish between levels beef tenderness and are willing to pay a premium for tender beef. Moreover, consumers find product consistency is moderately important when purchasing fresh beef. Therefore, the purpose of this study was to determine consumer acceptability based on in‐home evaluations of strip loin steaks from United States Department of Agriculture Select and Choice grades and CAB purchased from a retail supermarket environment.

     

Prevention of Transient Discoloration of Beef

Oxygen absorbent technology in conjunction with controlled atmosphere packaging(CAP) was used to prevent transient discoloration in master‐packaged beef steaks. Two types of commercial O₂ scavengers were used in the study. The master packs were stored at 1± 0.5 °C. The steaks from master packs were presented in a display‐case for visual evaluation. Reflectance spectra from each steak‐surface were obtained to estimate metmyoglobin content. Steaks packaged without O₂ scavengers showed more discoloration, and had significantly higher proportions of metmyoglobin when compared to steaks with O₂ scavengers, after most storage intervals (p < 0.05). Prevention of metmyoglobin formation was influenced by the number but not the type of O₂ scavenger employed (p > 0.05). Keywords: oxygen scavengers, centralized meat operations, transient discoloration     

Establishing tenderness thresholds of Venezuelan beef steaks using consumer and trained sensory panels

The tenderness thresholds for ribeye steaks at 2 d postmortem were found by using sensory trained (n = 734 steaks) and consumers panel data (55 ribeye steaks and 296 consumers). Also, consumers’ perceptions of sensory attributes of beef steaks were assessed to establish their relationships and to determine acceptability levels. The tenderness threshold obtained by regression analysis from trained panelists was 37.98 N (3.87 kg). Customer satisfaction of 81% was obtained when beef steaks had Warner-Bratzler shear force values (WBSF) less than 40.13 N (4.09 kg), suggesting that 40.13 N could be considered as a tenderness threshold to segregate tough from tender steaks, for Venezuelan beef consumers. According to correlation and regression analyses, consumers focused on flavor to assign their overall liking score. Results suggest that consumers are able to detect changes in tenderness of steaks with different WBSF and that flavor drives customer satisfaction when the beef tenderness is acceptable.     

Effect of reduced oxygen atmosphere and sodium acetate treatment on the microbial quality changes of seer fish (Scomberomorus commerson) steaks stored in ice

The effect of reduced oxygen atmosphere and sodium acetate treatment on the microbial quality of seer fish (Scomberomorus commerson) steaks was determined during chilled storage (1–2 °C). The O₂ absorber reduced the oxygen content in the pack to less than 0.01% corresponding to 99.96% reduction within 24 h. The use of O₂ absorber with sodium acetate dip treatment (2% w/v) extended the sensory shelf life up to 25 days compared to only 12 days for control air packs and 20 days for untreated samples with O₂ absorber. A prominent lag phase was observed for many bacterium studied, particularly for the sodium acetate treated samples with O₂ absorber. On the day of sensory rejection, both the total mesophilic and psychrotrophic counts reached 7.7–8.1 and 7.1–7.9 log cfu/g, respectively. The sodium acetate treatment and reduced O₂ atmosphere affected the type of major spoilers. In air packed samples, H₂S-producers predominated followed by Brochothrix thermosphacta, Pseudomonas spp., where as in the untreated samples with O₂ absorber, H₂S-producers predominated the microbial flora followed by Lactobacillus spp. For treated samples with O₂ absorber, B. thermosphacta formed the major micro-flora followed by Lactobacillus spp. The use of O₂ absorber inhibited the growth of Pseudomonas spp., and total Enterobacteriaceae.     

Fresh and cooked color of dark-cutting beef can be altered by post-rigor enhancement with lactic acid

Fresh and cooked color of dark-cutting (DC) beef strip loins (mean pH = 6.56) enhanced with 0.25, 0.50, 0.75 or 1.00% lactic acid (LA) were compared to non-enhanced DC and normal pH (NpH; mean pH = 5.43) strip loins. Even though NpH steaks received the most (P < 0.05) desirable fresh color scores, color scores for steaks from DC sections enhanced with 0.25% LA approached those of NpH steaks after the first day of retail display. Discoloration scores were also similar (P > 0.05) among NpH and 0.25% LA-enhanced DC steaks throughout the 5 d of display. Fresh steaks from NpH strip loins were redder, as evidenced by greater (P < 0.05) a^* values and lower (P < 0.05) hue angles, than DC steaks and DC steaks enhanced with LA, regardless of concentration. However, cooked color scores and proportions of denatured myoglobin were similar (P > 0.05) between untreated NpH steaks and DC steaks enhanced with 0.25% LA. Results from this study indicate that enhancing DC beef with LA may lead to the brightening of the fresh color and prevention of the persistent red cooked color, approaching that of NpH beef.     

Changes in fatty acids and polar material of restructured low-fat or walnut-added steaks pan-fried in olive oil

The study aims to determine the influence of pan-frying on the fatty acid composition and fat content and alteration of functional restructured beef steaks. Low-fat (L, 2% fat), 20% walnut-added (W, 13% fat) and medium fat (M, 13% fat) steaks were prepared and fried in extra virgin olive oil. Pan-frying increased fat in L and W steaks and decreased it in M ones. Raw L and M steaks showed similar fatty acid profiles while W ones contained a lower percentage of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) but a higher percentage of polyunsaturated fatty acids (PUFA). The fatty acid profile of fried steaks was between that of the raw steaks and olive oil. Several fatty acids (g fatty acid/100 g edible steaks) were affected (p < 0.001) by the frying × meat-formulation interaction. Linoleic and linolenic acid contents did not decrease in fried W steaks, but decreased (p < 0.05) when data were expressed on a dry matter basis.Frying increased SFA, MUFA and ω-6 PUFA contents in L samples while it decreased SFA and increased ω-6 PUFA in M steaks. Before and after frying, W steaks had atherogenic and thrombogenic indexes at least three times lower than their counterparts. Both indexes decreased in fried L samples while only the AI in M ones. Polar material content (PM) increased only in L samples. No relevant differences were found between PM of the fried steaks and that of their corresponding used oils. Results suggest that pan-frying improves the fatty acid composition of L and M steaks with minor changes in PM. The high retention of lipids observed in the W samples permits consumption of ω-3 PUFA- and ω-6 PUFA-enriched meat with a very low content of alteration compounds.     

Solution Enhancement and Post-enhancement Storage Effects on the Quality, Sensory, and Retail Display Characteristics of Beef Triceps Brachii Muscles

Beef triceps brachii muscles (6 d postmortem; n= 15; muscle sections n= 45) were sectioned into 3rds and allocated to 1 of 3 treatments. The treatments were untreated (CNT), or injected at a 12% pump rate with either tap water‐only (H₂O) or a solution comprising tetrasodium pyrophosphate and sodium chloride (TSPP/ NaCl) at 0.4% and 1.0% target final product weight concentrations, respectively. Each muscle (comprising all 3 treatments) was then allocated to 2, 14, or 28 d of vacuum‐packaged 1°C storage. Purge losses during storage were greatest (P < 0.05) for H₂O muscles and least (P < 0.05) for TSPP/NaCl muscles. Purge losses also increased (P < 0.05) from 2 d to 14 d of storage. Steaks enhanced with TSPP/NaCl had less (P < 0.05) free water and lower (P < 0.05) cooking losses than either CNT or H₂O steaks. Storage duration did not affect (P > 0.05) Warner‐Bratzler shear force (WBS) or sensory tenderness, but juiciness decreased (P < 0.05) with increased storage duration. While storage duration did not impact (P > 0.05) instrumental color characteristics, aerobic plate counts generally increased during storage. The TSPP/NaCl steaks had lower (P < 0.05) WBS values and improved (P < 0.05) sensory tenderness and juiciness characteristics compared with CNT or H₂O steaks. While CNT steaks had greater (P < 0.05) L* values (lightness) than TSPP/NaCl steaks, TSPP/NaCl steaks had similar (P > 0.05) oxymyoglobin proportions (630/580 nm) and a* values (redness) as CNT steaks. These results suggest enhancement with TSPP/NaCl can improve triceps brachii yield and palatability characteristics. Increased post‐enhancement storage did not impact or worsened palatability while increasing purge losses, suggesting general deleterious effects of increased postmortem storage for this muscle.     

Scandinavian consumer preference for beef steaks packed with or without oxygen

Beef steaks retail-packed with (80% O₂, 20% CO₂) or without oxygen (either skin-packed or gas-packed (69.6% N₂, 30% CO₂, 0.04% CO or 70% N₂, 30% CO₂)) were compared by consumers in Denmark (n = 382), Norway (n = 316) and Sweden (n = 374). Two pairs of two steaks – one steak packed in a high oxygen atmosphere and one packed without oxygen – were given to the consumers. They were instructed to prepare the steaks at home on two consecutive days, and two persons had to taste each steak. In Denmark, the oxygen-free packing was either gas packing with CO (69.6% N₂, 30% CO₂, 0.04% CO) or without CO (70% N₂, 30% CO₂), in Norway it was either gas packing with CO (69.6% N₂, 30% CO₂, 0.04% CO) or skin packing, and in Sweden it was either skin packing or gas packing without CO (70% N₂, 30% CO₂). The meat represented animals that were between 17 and 80 months old (Denmark) and young bulls (Norway and Sweden).