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Least squares means for traits of beef steaks and ground beef stored at 4°C

 
Traits Control FreshCase1 SEM P-value
Beef steaks2
Lean L* 34.64 34.03 0.22 0.052
Lean b* 8.94b 9.35a 0.10 0.005
Fat L* 51.04 50.61 0.38 0.428
Fat a* 3.52b 5.76a 0.19 <0.0001
Fat b* 14.40a 13.90b 0.14 0.016
APB 5.48a 5.32b 0.05 0.037
LAB 6.01 5.95 0.04 0.309
pH 5.47 5.48 0.00 0.697
Ground beef
L* 39.93 39.97 0.31 0.937
APB 6.59 6.50 0.06 0.354
LAB 5.97 5.93 0.05 0.808
pH 5.61a 5.58b 0.01 0.008
a,bLeast squares means (112 samples/treatment for beef steaks and 42 samples/treatment for ground beef) within a row with different superscripts differ (P < 0.05).
1Bemis Company, Inc., Oshkosh, WI.
2L* reflects the lightness of meat color, a* reflects the redness, and b* reflects the yellowness. APB = aerobic psychrotrophic bacteria; LAB = lactic acid bacteria.



View Full Table | Close Full ViewTable 2.

Least squares means of objective color (CIE L*, a*, and b*)1 affected by storage time (day) of beef steaks for lean and fat meat stored at 4°C

 
Lean
Fat
Day L* b* L* A* b*
0 33.56c 8.04g 51.14bcde −0.01g 10.51h
5 33.91bc 9.00ef 52.23bc 2.44f 13.06g
10 37.40a 10.60ab 57.28a 5.54abc 16.43a
13 34.18bc 8.72fg 51.89bc 3.81def 13.54efg
14 34.77bc 10.67a 57.18a 4.55cde 15.68ab
15 34.49bc 8.59fg 49.34cdef 5.80abc 15.21bc
16 33.11c 9.62cde 48.14ef 5.50abc 13.89defg
17 33.46c 9.83bcd 47.82f 6.63a 14.77bcd
18 34.49bc 9.98abc 47.94f 6.31ab 15.02bcd
19 33.35c 9.12def 48.44def 5.28abcd 14.67bcde
20 34.65bc 8.33fg 52.49b 3.89def 14.07defg
26 34.07bc 8.93ef 51.10bcde 4.85bcde 14.31cdef
31 34.40bc 8.49fg 51.21bcd 3.64ef 13.25fg
36 35.53b 8.88ef 50.54bcdef 5.28abcd 14.28cdef
41 34.49bc 9.02ef 48.39def 4.75cde 13.52fg
47 33.52c 8.47fg 48.14ef 6.01abc 14.20cdef
SEM 0.62 0.29 1.08 0.55 0.41
a–gLeast squares means (7 samples per treatment per day) within a column with different superscripts differ (P < 0.05).
1CIE L* (lightness), a* (redness), and b* (yellowness).



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Least squares means of bacterial counts (log cfu/g) for beef steaks stored in different packaging types during storage time (day) at 4°C

 
APB1
LAB1
Day Control FreshCase2 Average3 Control FreshCase Average3
0 2.51 2.54 2.52h 1.78 1.72 1.75j
5 2.68 2.71 2.69h 2.98 3.14 3.06i
10 4.37 4.31 4.34g 5.55 5.19 5.37h
13 4.98 4.31 4.65fg 5.96 5.32 5.64gh
14 5.10 4.78 4.94ef 5.71 5.79 5.75g
15 5.39 5.14 5.27de 6.32 6.03 6.17f
16 5.39 5.13 5.26de 6.10 5.77 5.93fg
17 5.80 5.74 5.77c 6.47 6.66 6.57de
18 5.82 5.45 5.64cd 6.50 6.03 6.27ef
19 5.68 5.68 5.68c 6.29 6.17 6.23ef
20 5.82 5.77 5.79c 6.60 6.77 6.69cd
26 6.41 6.44 6.43b 6.91 7.27 7.09b
31 6.78 6.73 6.75ab 6.93 7.09 7.01bc
36 6.80 6.68 6.74ab 7.15 7.29 7.22ab
41 7.10 7.06 7.08a 7.49 7.47 7.48a
47 7.07 6.80 6.93a 7.49 7.46 7.47a
SE 0.18 0.22 0.14 0.17 0.26 0.12
a–jLeast squares means (7 samples per treatment per day) within a column with different superscripts differ (P < 0.05).
1Aerobic psychrotrophic bacteria (APB) grew on tryptic soy agar plates that were incubated at 7°C for 10 d; lactic acid bacteria (LAB) grew on de Man, Rogosa, and Sharpe agar plates that were incubated at 25°C for 5 d.
2Bemis Company, Inc., Oshkosh, WI.
3Because there was no interactive effect between storage time and packaging type, only day effect on the average counts of bacteria from samples stored in Control and FreshCase packages is reported in this table.



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Least squares means (SE) of odor panel scores (cm)1 by storage time (phase)2 effect for raw and cooked beef steaks stored at 4°C

 
Raw
Cooked
Phase Putrid Acid Sour Rancid Meaty Putrid Sour Rancid
Phase 1 0.01c (0.22) 0.05b (0.12) 0.22c (0.22) 0.16c (0.3) 3.42a (0.19) 0.02b (0.1) 0.05c (0.12) 0.12b (0.31)
Phase 2 0.70b (0.10) 0.11b (0.05) 1.19b (0.10) 2.36b (0.13) 2.77b (0.08) 0.20ab (0.04) 0.33b (0.05) 2.29a (0.14)
Phase 3 1.38a (0.16) 1.32a (0.08) 2.64a (0.15) 3.46a (0.21) 2.23c (0.13) 0.28a (0.07) 0.81a (0.08) 2.86a (0.22)
a–cLeast squares means within a column with different superscripts differ (P < 0.05).
1A 15-cm scale continuous line was used to evaluated the intensity of off-odor and meaty odor for ground beef samples. Extreme left indicated absence of odor and extreme right indicated a very strong presence of the odor. An odor panel score was expressed as the distance of a vertical line marked by a panelist from the extreme left end of the 15-cm scale.
2Phases are grouped by aerobic psychrotrophic bacterial counts from tryptic soy agar plate cutoff (log cfu/g). Phase 1: Day 0 through 5 (<3 log), 28 samples; Phase 2: Day 10 through 20 (4 log – 6 log), 77 samples; Phase 3: Day 26 through 47 (>6 log), 21 samples.



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Least squares means of thiobarbituric acid reactive substances values (mg malonaldehyde/kg) affected by the interaction of package and storage time (day) for beef steaks stored at 4°C1

 
Day
Treatment 0 5 10 15 20 26 31 36 41
Control 0.44a 0.26bcde 0.28bcd 0.07g 0.11fg 0.33ab 0.34ab 0.23bcde 0.31bc
FreshCase2 0.18defg 0.29bcd 0.20cdef 0.15efg 0.15efg 0.20cdef 0.29bcd 0.32ab 0.18defg
a–gLeast squares means (4 samples per treatment per day) within columns and rows with different superscripts differ (P < 0.05).
1The SEM is 0.06.
2Bemis Company, Inc., Oshkosh, WI.



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Least squares means of bacterial counts (log cfu/g) for ground beef stored in different packaging types during storage time (day) at 4°C

 
APB1
LAB1
Day Control FreshCase2 Average3 Control FreshCase Average3
0 4.14 4.10 4.12e 3.09 3.03 3.06e
5 5.31 5.13 5.21d 4.82 4.91 4.87d
10 6.82 6.71 6.76c 6.54 6.30 6.42c
12 7.37 7.36 7.37b 7.15 6.98 7.07ab
13 7.86 7.89 7.88a 7.25 7.36 7.31a
14 8.03 7.85 7.94a 6.99 6.97 6.98b
SEM 0.15 0.15 0.1 0.15 0.14 0.1
a–eLeast squares means (7 samples per treatment per day) within a column with different superscripts differ (P < 0.05).
1Aerobic psychrotrophic bacteria (APB) grew on tryptic soy agar plates that were incubated at 7°C for 10 d; lactic acid bacteria (LAB) grew on de Man, Rogosa, and Sharpe agar plates that were incubated at 25°C for 5 d.
2Bemis Company, Inc., Oshkosh, WI.
3Because there was no interactive effect between storage time and packaging type, only day effect on the average counts of bacteria from samples stored in Control and FreshCase packages is reported in this table.



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Least squares means of odor panel scores (cm)1 by package effect for ground beef stored at 4°C.

 
Sensory traits Control FreshCase2 SEM P-value
Raw
Putrid 0.38 0.39 0.12 0.97
Acid 0.06 0.09 0.04 0.56
Sour 0.54 0.42 0.10 0.21
Rancid 1.08 0.98 0.15 0.51
Meaty 3.13 3.12 0.11 0.91
Cooked
Putrid 0.21 0.19 0.06 0.71
Sour 0.73a 0.32b 0.13 0.004
Rancid 1.32a 0.8b 0.14 0.001
Meaty 8.23 8.17 0.15 0.71
a,bLeast squares means (21 samples/treatment) within a row with different superscripts differ (P < 0.05).
1A 15-cm scale continuous line was used to evaluated the intensity of off-odor and meaty odor for ground beef samples. Extreme left indicated absence of odor and extreme right indicated a very strong presence of the odor. An odor panel score was expressed as the distance of a vertical line marked by a panelist from the extreme left end of the 15-cm scale.
2Bemis Company, Inc., Oshkosh, WI.



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Least squares means of odor panel scores (cm)1 by storage time (day) for raw and cooked ground beef stored at 4°C

 
Raw
Cooked
Day Putrid Acid Sour Rancid Meaty Putrid Sour Rancid Meaty
0 0.33ab 0.05b 0.02d 0.23d 2.50c 0.03d 0.11b 0.21c 8.46a
5 0.10b 0.02b 0.12d 0.16d 3.33ab 0.31ab 0.10b 0.58bc 8.22a
10 0.05b 0.10ab 0.33cd 1.03bc 3.21ab 0.13bcd 0.07b 0.80b 6.94b
12 0.67a 0.24a 0.75ab 0.8c 3.03b 0.1cd 0.15b 0.68bc 8.52a
13 0.41ab 0.01b 0.64bc 1.34b 3.49a 0.28abc 0.19a 1.90a 8.66a
14 0.75a 0.03b 1.04a 2.65a 3.22ab 0.39a 0.06b 2.34a 8.39a
SEM 0.15 0.05 0.12 0.19 0.13 0.07 0.16 0.17 0.18
a–dLeast squares means with a column with different superscripts differ (P < 0.05).
1A 15-cm scale continuous line was used to evaluated the intensity of off-odor and meaty odor for ground beef samples. Extreme left indicated absence of odor and extreme right indicated a very strong presence of the odor. An odor panel score was expressed as the distance of a vertical line marked by a panelist from the extreme left end of the 15-cm scale.



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The interactive effect of package and storage time on the least squares means of thiobarbituric acid reactive substances (TBARS) values1 for ground beef stored at 4°C

 
Day
Sample 0 5 10 12 13 14
Control 0.29d 0.75bc 0.95b 0.78bc 0.95b 1.19a
FreshCase2 0.25d 0.75bc 0.74c 0.76bc 0.82bc 0.41d
a–dLeast squares means for columns and rows with different superscripts differ (P < 0.05).
1TBARS values (4) were expressed as milligrams malonaldehyde/kilogram and the SEM was 0.07.
2Bemis Company, Inc., Oshkosh, WI.