F.W. Pohlman

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

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

Reduction of E. coli, Salmonella typhimurium, coliforms, aerobic bacteria, and improvement of ground beef color using trisodium phosphate or cetylpyridinium chloride before grinding

The impact of 10% trisodium phosphate (TSP) or 0.5% cetylpyridinium chloride (CPC) applied to beef trimmings either aerobically or under vacuum before grinding on Salmonella typhimurium (ST), Escherichia coli (EC), coliform (CO), aerobic plate count (APC), color and sensory attributes of ground beef through display was studied. For this, beef trimmings were inoculated with ST and EC then treated with either TSP or CPC in vacuum or aerobic conditions. Trimmings were ground, packaged, displayed under simulated retail conditions and sampled on days 0, 1, 2, 3 and 7 for microbial, instrumental color, and sensory color and odor characteristics. Aerobic and vacuum antimicrobial application methods were equally effective (P>0.05) for reducing microorganisms in ground beef. Trisodium phosphate and CPC reduced (P<0.05) all bacterial types monitored. In addition, TSP and CPC improved (P>0.05) ground beef redness (a*), oxymyoglobin stability (630 nm/580 nm) and sensory overall color throughout display without adversely affecting odor characteristics.

Effects of sodium chloride, phosphate type and concentration, and pump rate on beef biceps femoris quality and sensory characteristics

Beef biceps femoris muscles (n=45) were used to evaluate the effect of enhancement with solutions comprising 2.0% sodium chloride and either sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), or tetrasodium pyrophosphate (TSPP) at either 0.2% or 0.4% of product weight. All solutions were injected into muscle samples at either 112% (12% pump) or 118% (18% pump) of raw product weight. Muscles treated with all three phosphate types had decreased (P<0.05) free water compared to untreated muscles (CNT), and while TSPP-treated muscles were able to bind greater (P<0.05) additional water than CNT, STPP- and SHMP-treated muscles did not differ (P>0.05) from CNT. Disregarding phosphate type, steaks with 0.4% phosphate inclusion bound more (P<0.05) water than those with 0.2% phosphate inclusion. Steaks treated with STPP or TSPP had decreased (P<0.05) cooking losses than CNT, while SHMP-treated steaks did not differ (P>0.05) from CNT. Steaks injected at 18% pump had greater (P<0.05) percent moisture, and did not differ (P>0.05) in free water, water binding, or cooking losses from steaks injected at 12% pump. Although there were no differences (P>0.05) in Warner-Bratzler shear force in this study, steaks with SHMP, STPP, and TSPP all were rated more tender, and juicier (P<0.05) by sensory panelists than CNT steaks or steaks enhanced only with sodium chloride. Regardless of phosphate type, steaks enhanced with 0.4% phosphate and those steaks at 18% pump received improved (P<0.05) sensory tenderness ratings compared to 0.2% phosphate and 12% pump, respectively. These results suggest that enhancing biceps femoris muscles with STPP or TSPP can improve water retention, yield, and palatability characteristics. Additionally, enhancement with a phosphate/salt solution at an 18% pump rate, compared to a 12% pump rate, can allow for improved sensory tenderness perceptions without decreasing product yields.

Effects of dietary magnesium and duration of refrigerated storage on the quality of vacuum-packaged, boneless pork loins.

Quality data were initially collected on 78 pork loins from crossbred pigs fed diets containing 0, 1.25 or 2.5% magnesium mica (MM). Loins were then vacuum-packaged, and randomly assigned to either 4 or 8 weeks of storage at 2°C. Dietary MM had no (P > 0.05) effect on moisture loss/retention or subjective and objective color measurements. Purge volume increased (P<0.05) and drip loss decreased (P<0.05) as storage time increased. Moreover, longissimus thoracis et lumborum (LM) chops became lighter (P<0.05), redder (P<0.05), and more yellow (P<0.05) during 8 weeks of storage. Although TBARS values increased linearly (P<0.001) during extended storage, LM chops from pigs fed 2.5% MM tended to have lower (P<0.07) TBARS values after 4 weeks of storage than chops from pigs fed 0 and 1.25% MM. After 8 weeks of storage, however, there was a tendency for TBARS values of chops from pigs fed 1.25% MM to be lower (P<0.07) than chops from pigs fed 2.5% MM. Even though feeding swine diets containing MM did not affect color and water-holding capacity of pork loins during storage, the data indicated inclusion of MM in swine diets may retard onset of oxidative rancidity in vacuum-packaged pork loins.

Microbial, instrumental color and sensory color and odor characteristics of ground beef produced from beef trimmings treated with ozone or chlorine dioxide.

The effects of beef trimming decontamination with ozone and chlorine dioxide on ground beef microbial, color and odor characteristics were studied. Beef trimmings were inoculated with Escherichia coli (EC) and Salmonella Typhimurium (ST), then treated with either 1% ozonated water for 7 min (7O) or 15 min (15O), or with 200 ppm chlorine dioxide (CLO) and compared with a control (C). Trimmings were ground, packaged and sampled at 0, 1, 2, 3 and 7 days of display for EC, ST, coliforms (CO), aerobic plate counts (APC), instrumental color, as well as sensory color and odor characteristics. The 15O and CLO treatments reduced (P<0.05) all bacterial types evaluated, whereas the 7O treatment reduced (P<0.05) APC and ST. All treatments caused ground beef to become lighter (L*) in color (P<0.05); however, the 15O treatment was similar (P>0.05) in redness (a*), percentage discoloration, beef odor and off odor intensities when compared to C.

The pre- and post-grinding application of rosemary and its effects on lipid oxidation and color during storage of ground beef.

The timing of the application of rosemary extract was evaluated as one-way of minimizing myoglobin and lipid oxidation in ground beef. In experiment 1, rosemary extract was added to beef at four different stages namely trim, cube, coarse, and fine ground beef. The beef was evaluated for color and TBARS values during 144h of storage (4°C). Results showed that when rosemary was added to the pre-grinding treatments of trim and cube, ground beef had the highest a(∗) values (redness), oxymyoglobin content, and lowest TBARS values at 144h. In experiment 2, the effect of rosemary extract was evaluated on the color quality of case ready ground beef inoculated with 10(7)CFU/g Escherichia coli. Microbial counts, color, and TBARS values were measured during 144h of simulated storage. The results showed that both the rosemary treated samples that were inoculated and uninoculated remained redder longer and had lower TBARS values than the untreated inoculated and uninoculated controls. There was no significant inhibition of E. coli by the rosemary extract.

Impact of muscle type and sodium chloride concentration on the quality, sensory, and instrumental color characteristics of solution enhanced whole-muscle beef.

Beef biceps femoris (n=10; muscle sections, n=20; BF), infraspinatus (n=10; muscle sections, n=20; IS), and longissimus (n=10; muscle sections, n=20; LM) muscles were utilized to evaluate the effect of enhancement with phosphate and varying levels of sodium chloride in beef muscles differing in composition and palatability. Muscles were untreated or solution enhanced to 112% of raw product weight with sodium tripolyphosphate at 0.4% of product weight (STPP), or STPP and sodium chloride (NaCl) at 0.5%, 1.0% or 1.5% of product weight. There was a quadratic relationship (P=0.04) for percent free water to decrease and a linear relationship (P<0.01) for cook yield to increase as the level of NaCl increased. The IS steaks required less (P<0.05) shear force than either the BF or LM, with the BF and LM having similar (P>0.05) shear force values. There was a linear relationship (P<0.01) for shear force values to decrease with increasing salt concentration. Steaks from all four enhancement treatments had lower (P<0.05) shear force values than untreated steaks. Sensory overall tenderness ratings revealed that the IS and LM were similar (P>0.05) and superior (P<0.05) to the BF in tenderness. Steaks enhanced with STPP and 0.5%, 1.0%, or 1.5% NaCl all were rated more tender (P<0.05) than untreated or STPP-only treated steaks. The BF exhibited the lowest (P<0.05) L* (lightness) and a* (redness) values, as well as decreased (P<0.05) vividness. The LM generally exhibited superior color to the other two muscle types. There was a linear relationship (P<0.01) for L*, a*, b* (yellowness) values, and vividness to decline with increasing salt concentration, but steaks enhanced with STPP and 0.5% NaCl were similar (P>0.05) in a* values and vividness to untreated steaks. These results suggest that across three different muscles varying in composition and palatability, enhancement with 0.4% STPP and 0.5% NaCl allowed for improvements in palatability while minimizing the color deterioration associated with phosphate/salt enhancement.

The effects of ozone, chlorine dioxide, cetylpyridinium chloride and trisodium phosphate as multiple antimicrobial interventions on microbiological, instrumental color, and sensory color and odor characteristics of ground beef

The impact of multiple antimicrobial interventions on ground beef microbial, color and sensory characteristics was studied. For this, beef trimmings were inoculated with Escherichia coli (EC) and Salmonella typhimurium (ST) then treated with either (1) 1% ozonated water followed by 5% acetic acid (OA), (2) 1% ozonated water followed by 0.5% cetylpyridinium chloride (OC), (3) 200 ppm chlorine dioxide followed by 10% trisodium phosphate (CT) or (4) control (C). Trimmings were ground, packaged and sampled at 0, 1, 2, 3 and 7 days of display for EC, ST, coliforms (CO), aerobic plate count (APC), instrumental color and sensory color and odor characteristics. The OA and OC treatments reduced (P<0.05) all bacterial types evaluated, while CT reduced (P<0.05) EC, CO and APC. The CT treatment was redder (P<0.05) in overall color than C, and there was no difference (P>0.05) in beef odor or off odor between OC, CT or C treatments.

Reduction of microorganisms in ground beef using multiple intervention technology

The effectiveness of multiple antimicrobial interventions on ground beef microbial, instrumental color and sensory characteristics through display was studied. Beef trimmings were inoculated with Escherichia coli (EC) and Salmonella typhimurium (ST) then treated with either: (1) 5% acetic acid followed by 0.5% cetylpyridinium chloride (AC); (2) 200 ppm chlorine dioxide followed by 0.5% cetylpyridinium chloride (CC); (3) 0.5% cetylpyridinium chloride followed by 10% trisodium phosphate (CT); or (4) control (C). Trimmings were ground, packaged and sampled through display for EC, ST, coliforms (CO), aerobic plate count (APC), and sensory color and odor characteristics. All treatments reduced (P<0.05) all bacterial types monitored through display. Ground beef from the CC treatment was similar (P>0.05) in redness (a*) to C. The CT treatment remained (P<0.05) redder (a*) in color, contained more (P<0.05) oxymyoglobin and had less (P<0.05) overall, worst point and percentage discoloration than C by day 7 of display.

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

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