Processing, Microbial and Sensory Characteristics of Cooler and Freezer Stored Hot-Boned Beef

Weiners were prepared from preblended hot-boned (prerigor) beef raw materials stored up to 21 days at 2°C and up to 28 days at -10°C. The addition of salt was necessary for maintenance of desirable sausage-making characteristics of hot-boned beef stored at 2°C for 7 days. The addition of salt for the maintenance of desirable functional properties does not appear to be necessary, if the prerigor materials are stored at freezer temperatures (-10°C). Flavor problems may develop in products from preblended raw materials stored at -10°C beyond 14 days postmortem.     

Stability of Precured Beef Blends

Preblends of lean beef were prepared using 20% water, 75 ppm nitrite, 3 or 6% salt (based on raw meat wt.) and stored at – 10, 0 and 15°C for 3 days. The nitrite levels in preblends were drastically reduced at 15°C storage temperature; but, after the initial loss following nitrite addition, the residual nitrite remained almost unchanged for products stored at 0 and – 10°C. Samples stored at 15°C increased in microbial numbers during storage and neither 3% nor 6% salt prevented this increase. Samples at both salt levels stored at 0°C or – 10°C did not show a significant change in bacterial numbers during storage. Salt and storage temperature had a significant effect on TBA values, with 6% salt resulting in higher TBA values than 3% salt and storage at 15°C resulting in higher TBA values than storage at 0 or ?10°C.     

Oxidative Stability and Sensory Attributes of Prerigor Cooked Beef Steak

Beef sirloin tip steaks from 12 steer carcasses were cooked prerigor and postrigor using three heating methods and stored at 4 °C or ‐20 °C. Prerigor cooked steak had lower cook loss, higher pH, higher shear force, and sensory hardness than postrigor cooked steak. Conventional oven cooking produced the lowest cook loss for prerigor steak. Prerigor cooked steak had lower thiobarbituric acid value than postrigor cooked samples after 2 wks at 4 °C or 3 mo at ‐20 °C. Sensory warmed‐over flavor intensity scores were low and showed no differences between prerigor and postrigor cooked steaks for refrigerated or frozen samples.     

Oxidative Stability of Batter-Breaded Restructured Nuggets Processed from Prerigor Pork

Restructured pork slices made with either prerigor or postrigor meat, with or without 1.5% of defatted glandless cottonseed flour (GCF). were batter-breaded with or without GCF in predust and batter-mix: Prerigor products had less cooking losses than postrigor products; GCF in the meat or coating reduced cooking losses. Prefried prerigor products were more susceptible to lipid oxidation and warmed-over flavor development than prefried postrigor products. GCF in the meat or coating markedly reduced the oxidative deterioration in nuggets stored at 4°C or ?20°C regardless of the rigor state of meat used for restructuring. Little lipid oxidation occurred in vacuum-packaged raw nuggets stored at ?20°C.     

Sensory Properties and Lipid Oxidation in Prerigor Processed Fresh Pork Sausage

Fresh pork sausage prepared from prerigor ground and salted meat had higher pH, lower cooking losses, higher juiciness scores, and less easily fragmented cooked patties than that prepared from post-rigor ground and salted meat. Sausage from prerigor ground-post-rigor salted meat was intermediate in these properties to prerigor ground and salted and postrigor ground and salted products. Prerigor grinding and salting reduced the rate of autoxidation (TBA number) during storage at 0°C contrasted to oxidation in sausage that was salted postrigor after either prerigor or postrigor grinding.     

Effects of Salt Levels in Prerigor Blends and Cooked Sausages on Water Binding, Released Fat and pH

Prerigor pork was used to make preblends of 0, 1, 2, 3 or 4% salt and 125 ppm sodium nitrite. Sausages formulated with 1.5 or 2.0% salt were made from all preblends; sausages formulated with 1.0% salt were made from preblends of 0, 1, 2 and 3% salt. Sausages made with nonsalted preblends had less water binding capacity (WBC) and more released fat (RF) than sausages made with preblends of 2, 3, or 4% salt (P < 0.05). Levels of salt in preblends did not affect (P > 0.05) WBC when salt contents of sausages were reduced from 2.0 to 1.5%; however, these WBC values were lowered somewhat when preblends with 0 or 1.0% salt were used. Water binding capacity decreased (P < 0.05) when salt contents of sausages were reduced from 1.5 to 1.0%, and when these sausages were made with preblends containing 2.0 or 3.0% salt. Data suggest that salting of prerigor pork is beneficial for optimizing WBC in sausages made with low salt contents.     

Effects of Rigor-State, Levels of Salt and Sodium Tripolyphosphate on Physical, Chemical and Sensory Properties of Frankfurter-Type Sausages

Preblends of prerigor or postrigor pork with 2 or 4% salt were used to make sausages with finished product salt contents of 2.5 or 1.5% and with or without sodium tripolyphosphate. pH values increased (P > 0.001) when sausages were made with preblends of 4% salt or when phosphate was used. Reducing salt contents from 2.5 to 1.5% did not (P < 0.05) affect physical, chemical or sensory properties except for saltiness and Instron force of rupture values. Firmness of sausages increased (P < 0.05) when sodium tripolyphosphate or preblends with 4% salt were used. Data suggest that salt levels could be reduced 50% without detrimentally affecting physical, chemical or sensory properties of these frankfurter-type sausages.     

Psychrotrophic Bacteria in Prerigor Ground Pork

The numbers of psychrotrophic bacteria in prerigor ground pork were slightly greater than in postrigor ground pork throughout an 11-day storage period at 2°C. Freezing both types of samples and subsequent thawing before storage at 2°C reduced the initial psychrotrophic counts but the freezing effects did not persist beyond 8 days of storage. Differences in psychrotrophic counts between prerigor and postrigor ground pork were not sufficiently great in any comparison to limit the use of prerigor grinding of pork.     

Effects of Electrical Stimulation and Hot-Boning on Physical Changes, Cooking Time and Losses, and Tenderness of Beet Roasts

Beef semimembranosus and semitendinosus muscles were removed prerigor (1 hr postmortem) and postrigor (7 days postmortem) after one-half of the left and right sides were electrically stimulated. The influence of electrical stimulation and hot-boning upon physical changes; cooking losses; shear force; taste panel evaluation; and time required to heat product to an internal temperature of 63°C was studied. There was no consistent influence of electrical stimulation upon physical changes of prerigor muscles or upon tenderness of pre– or postrigor roasts. Hot-boned and precooked roasts were less tender than cold-boned counterparts. Cooking yields were not altered by electrical stimulation. Prerigor roasts had 9% higher yields than postrigor roasts. Prerigor roasts from electrically stimulated sides required a longer time to cook to 63°C than roasts from the control sides. Hot-boning reduced the length of time of cooking (95 min/kg to 72 mm/kg of raw weight).     

Use of Cryoprotectants to Stabilize Functional Properties of Prerigor Salted Beef During Frozen Storage

Changes in functional properties (gelforming ability, water-holding capacity, and protein solubility) of salted prerigor beef and postrigor beef were measured over 6 months frozen storage at ?28°C, as affected by addition of 5.6% cryoprotectants [Polydextrose® or a mixture (1:1) of sucrose and sorbitol]. Addition of NaCl to comminuted muscle prior to freezing accelerated destabilization of muscle proteins with respect to functional properties. This effect was reduced by cryoprotectants; most effectively by sucrose/sorbitol and only slightly less effectively by polydextrose. As evidenced by the parameters investigated, quality of prerigor salted muscle treated with cryoprotectants and stored 6 months was approximately equal to that of untreated postrigor meat prior to freezing.     

Evaluation of Prerigor Freeze-Dried Beef in the Manufacture of Dry Fermented Sausage

Experiments were designed to determine the acceptability of prerigor freeze-dried beef in the manufacture of dry fermented sausage. Several chemical and physical variables were measured on dry fermented sausages prepared using (1) prerigor salted, freeze-dried, (2) prerigor unsalted, freeze-dried, (3) postrigor salted, freeze-dried, and (4) postrigor frozen beef as ingredients. Results showed that fat and moisture content, total shrinkage, Instron firmness and panel scores for juiciness, texture, and flavor were not affected to a large degree by treatment or rigor state of the beef ingredient. Generally, freezedried beef was found to be equal to conventional beef for dry sausage production regardless of when the freeze-dried beef was salted.     

Effect of sodium chloride concentration on pH, water-holding capacity and extractable protein of prerigor and postrigor ground beef

Fifteen beef cattle of similar age and management history were randomly allotted by slaughter days into three groups. Paired sternomandibularis were removed immediately following bleeding and trimmed of visible fat and connective tissue. They were randomly labelled as prerigor and postrigor and assigned to a 0, 0·5, 1·0, 2·0 or 4·0% NcCl treatment. Water-holding capacity (WHC), pH, the ratio of absorbance at 250 nm over the absorbance at 260 nm (R-values), and 1·0m NaCl extractable protein (EP) were monitored over treatment times. The 0 h samples were defined as when the NaCl was incorporated with the muscle. R-values verified that 0 h samples were in the prerigor or postrigor state. Ultimate pH remained higher (P < 0·05) in prerigor homogenates with increasing NaCl concentration. EP and WHC were higher (P < 0·05) in prerigor than in postrigor homogenates with 2 and 4% NaCl at all time periods. Prerigor homogenates containing 0·5 and 1·0% NaCl had higher (P < 0·05) WHC at 12, 24, 24, 48 and 96h than similarly treated postrigor homogenates and as high or higher WHC than any postrigor treatment. Results of this study indicate an advantage to using low NaCl concentrations in prerigor salted beef.     

Accelerated Postmortem Aging of Beef Utilizing Electronbeam Irradiation and Modified Atmosphere Packaging

The combined effects of electron-beam irradiation and modified atmosphere packaging (MAP) with 25% CO₂ and 75% N₂ were examined. Steaks from prerigor beef longissimus (lumborum and thoracis) were prepared, placed in MAP, irradiated with 2 kGy, and stored at 15°C or 30°C. Postrigor longissimus steaks from the other half of each carcass were vacuum-packaged and stored at 2°C. Analysis for tenderness, lipid oxidation, color, and microbial growth were conducted over 2 wk. Aging irradiated prerigor beef at 30°C for 2 days with MAP resulted in similar Warner-Bratzler shear values as conventional wet aging at 2°C for 7 or 14 days, and steaks did not show discoloration, lipid oxidation, or microbial spoilage.     

A modified hot processing strategy for beef: functionality of electrically-stimulated and hot-boned meat preblended with different NaCl concentrations

Chucks from 20 electrically-stimulated hot-boned (HB) and cold-boned (CB) beef carcasses were preblended with different concentrations of NaCl (0, 0·5, 1·0, 1·5 and 2·0% w/w). Preblends were analysed for pH, 2-thiobarbituric acid (TBA) values, protein extraction and emulsifying capacities. Bologna (with and without added sodium tripolyphosphate) and ground meat patties prepared from these preblends were also evaluated for cooking yield, color and texture parameters. Ultimate pH values of HB preblends increased with increasing NaCl concentration. At 1% NaCl, HB had higher ultimate pH than CB preblends (P ≤ 0·05) but preblending HB meat with 2% NaCl reduced TBA values (P ≤ 0·05) because the pH was maintained above 6·0. Higher amounts of protein were extracted from HB than from CB preblends (P ≤ 0·01), but boning and salting treatments did not affect their emulsifying capacities (P > 0·05). Two percent NaCl was required to fully achieve the prerigor salting effect. At this concentration, cooking yields of bologna prepared from HB preblends and phosphate containing bologna prepared from CB preblends were not different (P > 0·05) and were higher than those of bologna without added phosphate made from CB preblends (P ≤ 0·05). No meaningful effects were observed on color and texture parameters. Cooking losses were lower in patties made from HB than CB preblends (P ≤ 0·05) independent of NaCl concentration, but boning and salting treatments had no further effects on color or textural parameters (P > 0·05). Therefore, the superior functional properties of electrically stimulated prerigor meat can be maintained by the addition of 2% NaCl up to 2 h post-mortem.     

Processing, Sensory and Chemical Properties of Wieners prepared from CO2, Brine and Conventionally Chilled Beef Raw Materials

Wieners were prepared from CO₂-chilled hot-boned beef, brine-chilled hot-boned beef, and conventionally chilled beef raw materials after 0, 7, 14, and 21 days of storage (2°C) in chub packages. Chilling method had little influence on the extractability and emulsifying capacity of salt-soluble proteins. Processing yields and sensory ratings for the wieners prepared from hot-boned beef were either equal to or superior to those prepared from cold-boned beef. Sensory panel ratings indicated that weiners may be processed from pre-rigor beef without a loss in palatability. Results from this study indicate that chilling hot-boned beef with CO₂ or with brine does not significantly alter its functional properties as a sausage raw material.     

Use of carbon monoxide combined with carbon dioxide for modified atmosphere packaging of pre- and postrigor fresh pork sausage to improve shelf life

Fresh pre- and postrigor pork sausage patties were manufactured in the Iowa State University Meat Laboratory and packaged either in modified atmosphere (MAP) with 0.4% carbon monoxide (CO) and 99.6% carbon dioxide (CO2) or on foam trays overwrapped with oxygen-permeable film (OW). Packages were stored at 2 to 40C under fluorescent lights for up to 31 days. Aerobic, anaerobic, and psychrotrophic plate counts, raw and cooked color, purge, and lipid oxidation were measured during storage. Results indicated that both pork sausage products in MAP had lower aerobic and psychrotrophic counts and less lipid oxidation throughout storage (P < 0.05). Raw color of both products in MAP was redder than the OW patties (P < 0.05), but the prerigor pork sausage in MAP benefited more from the CO atmosphere in terms of raw color than the postrigor pork sausage in MAP. Cooked color of the prerigor pork sausage in MAP was significantly redder than cooked color of the postrigor pork sausage. Both pork sausage products in MAP were also lighter (L* value) than the OW patties for raw and cooked color. Therefore, the combination of CO and CO2 in MAP was beneficial in extending the shelf life of pre-and postrigor fresh pork sausage by reducing aerobic and psychrotrophic microbial growth and improving oxidative stability and color, compared to conventional OW packaging. However, increased purge, increased anaerobic growth, and changes in cooking behavior were also observed for the products in MAP during storage (P < 0.05).     

ACCELERATED RESTRUCTURING OF BEEF

Restructured steaks manufactured by two comminution methods from prerigor electrically stimulated (PES) beef, nonstimulated counterparts (NES) and postrigor non-electrically stimulated (C) samples were compared. After frozen storage for 0,14, and 42 days, samples were subjectively evaluated for appearance and palatability traits. Objective measurements included Hunter Color, TBA, Kramer, and Instron values. Electrical stimulation reduced peak force but did not consistently improve sensory panel scores. Comminution method did not consistently affect any traits. Results suggested that subjective appearance was affected more by storage time than other treatments and that prerigor beef may be effectively utilized in restructured beef without affecting palatability traits.     

Effect of Muscle pH and Calcium Content on Quality of Pre-and Postrigor Chicken Breast Muscle

Effects of calcium chloride and [ethylene-bis (oxymethylene-nitrile)] tetraacetic acid (EGTA) marination at pH 5.0 and 7.5 on quality of pre- and postrigor chicken muscles were determined. Marinade absorption was lower and shear resistance was higher for prerigor compared with postrigor muscles at both pH levels. Shear resistance of EGTA-pH 5.0 treated prerigor muscles was greater than those of all other prerigor muscles but that of EGTA-pH 7.5 treated prerigor muscles was similar to that of the controls. Calcium content and pH were related factors affecting muscle quality.     

Effect of Salt Reduction on Growth of Listeria monocytogenes in Meat and Poultry Systems

Abstract: Reducing sodium in food could have an effect on food safety. The objective was to determine differences in growth of Listeria monocytogenes in meat and poultry systems with salt substitutes. For phase 1, fresh ground beef, pork, and turkey with NaCl, KCl, CaCl₂, MgCl₂, sea salt, or replacement salt added at 2.0% were inoculated with L. monocytogenes to determine growth/survival during 5 d at 4 °C to simulate a pre‐blend process. L. monocytogenes populations significantly decreased (0.41 log CFU/g) during the storage time in beef, but no differences (P > 0.05) were observed over time in pork or turkey. Salt type did not affect (P > 0.05) L. monocytogenes populations during pre‐blend storage. MgCl₂ and NaCl allowed significant growth of aerobic populations during storage. For phase 2, emulsified beef and pork products were processed with 2% NaCl, KCl, sea salt, or a NaCl/KCl blend and post‐process surface‐inoculated with L. monocytogenes to determine growth/survival at 4 °C for 28 d. Pork products showed significantly greater L. monocytogenes population growth at all sampling times (0, 7, 14, 21, and 28 d) than beef products, but salt type had no effect on L. monocytogenes populations with sampling times pooled for data analysis. Although salt types had no impact on L. monocytogenes populations in preblend and emulsified meat products, pork and turkey preblends and emulsified pork had greater L. monocytogenes populations compared with beef products. These studies demonstrate that sodium may not affect the safety of preblends and emulsified meat and poultry products. Practical Application: odium reduction in food is an important topic because of sodium's unfavorable health effects. This research shows that reducing sodium in pre‐blends and emulsified meat and poultry products would have no effect on Listeria monocytogenes populations, but replacement of NaCl with MgCl₂ may affect growth of aerobic populations.     

Hot Processed Raw Materials and Fat Level Affect Physical and Sensory Characteristics of Ground Beef

Sixteen treatment combinations of ground beef were evaluated (two lean types, four fat types, and two fat levels) to determine the characteristics of ground beef produced from hot fat and prerigor lean (HL). Half of each batch was immediately made into patties and the remaining chub pack stored (2°C). Fat type had no (P>0.05) effect on appearance or sensory characteristics of patties; however, all prerigor fat treatments and HL reduced (P<0.05) cooking loss. Fat smearing was greater (P<0.05) in HL patties, but no (P>0.05) difference was detected after chub pack storing (2°C). The HL improved (P<0.05) tenderness in stored ground beef.