Ohio State University Extension Bulletin

Research and Reviews: Meat

Special Circular 172-99


Functional and Sensory Attributes of Normal pH Values in Sm Bull Muscles Depending on Time of Cutting and Aging

H. W. Ockerman1* and T. Lesiow
The Ohio State University Department of Animal Sciences

Abstract

No influence was found for cutting time (24 and 48 hours post mortem [p.m.]) of the Semimembranosus (Sm) bulls’ muscles and aging time (up 96 hours post mortem) on pH, cooking losses, dominant wavelength, color purity, firmness, and tenderness. Considering higher lightness after 48 hours p.m. and lower shear force after 48 and 72 hours p.m. for Semimembranosus muscles cut 24 hours p.m. than for those cut 72 hours p.m., it appears that muscles cut 24 hours p.m. should be directed to the retail trade. In further processing, it is necessary to take into account that the Semimembranosus muscle had the highest water-holding capacity after 48 hours, when cut 24 hours p.m., and after 72 and 96 hours p.m., when cut 48 hours p.m., which suggests a longer aging period for further processed product.

Introduction

The Longissimus dorsi muscle (Ld) is the most frequently used muscle for estimating meat quality attributes. The Ld and Semimembranosus (Sm) muscle differ with regard to muscle metabolism (O’Halloran et al., 1997) and sensory properties (Carmack et al., 1995; McKeith et al., 1985). Only a few studies have focused on the physical and sensory properties of the Sm muscle of bulls. Some studies have included hot-boned and vacuum-packaging storage up to 15 days (Hertzman et al., 1993; Olsson et al., 1994), or cut from carcasses 7 days (Hostetler et al., 1975) post mortem or cut 48 hours p.m. and then vacuum stored up to 14 days (Fjelkner-Modig and Ruderus, 1983).

It is common practice in meat processing to cut muscles from carcasses as early as possible. Polish legislation (8) requires that beef parts or cuts be aged no longer than 60 hours after excision at 24 hours p.m. and should be maintained at a temperature of 0 to 4°C and a relative humidity of 90%.

This research examined the influence of cutting time (24 and 48 hours p.m.) and aging time (up to 96 hours p.m.) on functional and sensory attributes of normal pH (pH < 5.8) Sm muscle of bulls.

Materials and Methods

Investigation was made on Sm muscles taken from young bulls 24 hours and 48 hours p.m. after commercial slaughter and rapidly cooled in a Wroclaw, Poland, meat factory. At different periods, the Sm muscles with a pH < 5.8 were excised from the hindquarter from six different bulls. Each time the Sm muscles were wrapped in polythene bags and transported in a cooler to the laboratory and then stored at 2 to 4°C for up to 96 hours p.m. After 24, 48, and 72 hours p.m., three 2.5 cm thick steaks were cut, and after 96 hours p.m., one steak was cut from the Sm muscles cut 24 hours p.m. From Sm muscles cut 48 hours p.m., after 48, 72, and 96 hours p.m., three 2.5 cm thick steaks were cut. From the medium side of each steak, five to eight cores of 2 cm diameter and 1cm thick were obtained. The cores were then covered by oxygen-permeable polyvinyl-chloride film and allowed to bloom for 60 minutes at 2 to 4°C and utilized for lean-color analysis. The lean-color attributes:

Dominant wavelength:
lambdad (nm) = 11.01 X [(R640/R540) - 1] + 596.41

Color purity:
Pe(-) = 0.105 X {0.1101 [(R640/R540-1)2 + 0.5641[(R640/R540) -1] + 1} + 0.293

Lightness:
Y(%) = 1.029 X R540 + 9.421

were estimated by measuring reflectance at 540 and 640 nm wavelengths with a Spectrophotometer (Specol) equipped with R 45/0 attachment according to the Tyszkiewicz (Tyszkiewicz, 1964) method. The remaining meat was ground through a 3 mm plate. The pH was measured with a meter by electrodes inserted into the ground meat. Water-holding capacity (WHC) was expressed as percent of bound water (Wierbicki et al., 1962). A meat homogenate was obtained by homogenization of 15 g of ground meat with 60 ml of 0.67 M NaCl at pH 6.5 for 1 min at 4,000 rpm. It was used for determination of viscosity (Pa x s) at a shear rate of Dr 16.2 (s-1) with a Rotatory viscometer "Rheotest-2" with attachment H.

The two remaining steaks in separate plastic bags were cooked in a water-bath at 80°C for 90 minutes, cooled for 40 minutes, and weight loss was reported as percent cooking loss. After refrigeration for 18 hours, the steaks were cut into six sections (2 cm2) for sensory evaluation and into six to eight slices (3 x 2 x 2 cm length x width x depth) for Warner-Bratzler peak shear force (kg). Samples were evaluated by six trained judges based on a 7-point scale for flavor, 1 = extremely strong, 7 = extremely weak; juiciness, 1 = extremely juicy, 7 = extremely dry; firmness, 1 = extremely weak (soft), 7 = extremely firm; and tenderness, 1 = extremely tender, 7 = extremely tough.

For each of six animals studied, multiple determinations were obtained and analysis of variance (ANOVA) and Duncan’s method were used to test differences (11).

Results

Sm muscles cut 24 and 48 hours p.m. which had an ultimate pH lower than 5.8 were treated as normal meat. The pH of Sm muscles cut both at 24 and 48 hours p.m. did not change significantly during the aging time (Table 1). A lack of pH change during aging was not reflected in WHC. Muscles cut 24 hours p.m. and after 48 and 96 hours p.m. storage had the highest WHC and were significantly different from minimal WHC after 72 hours p.m. For the Sm muscle cut 48 hours p.m., WHC significantly increased after 72 hours p.m., and a further increase of WHC was not significantly different from the value of the WHC after 72 hours p.m. WHC of Sm muscles cut 48 hours p.m. in relation to the WHC of Sm muscles cut 24 hours p.m. and after 72 hours was significantly higher by 4.57%. No significant difference in cooking losses from Sm muscles cut 24 and 48 hours p.m. during aging were found despite significant changes in WHC of these muscles (Table 1).

Table 1. Means and Standard Deviations (sd) for Functional Properties and Color Parameters of Semimembranosus (Sm) Muscles Cut 25 Hours Post Mortem(p.m.) and 48 Hours p.m. from Bull Carcasses and After Thermal Treatment for Shear Force and Sensory Characteristics of Steaks During Cold Aging Up to 96 Hours p.m.1

Parameter Aging Time (Hours Post Mortem)
  Sm Muscles
Cut 24 Hours p.m.
Sm Muscles
Cut 48 Hours p.m.
  24 48 72 96 48 72 96
pH 5.40
(0.4)
5.45
(0.05)
5.48
(0.01)
5.47
(0.01)
5.45
(0.05)
5.50
(0.05)
5.51
(0.04)
WHC2 5.96abc
(1.72)
8.25bcd
(0.97)
4.25a
(1.36)
7.96bcd
(0.81)
5.30ab
(1.89)
8.82cd
(3.69)
9.49d
(1.65)
Viscosity of meat homog.,
Pa x s
255.88ab
(39.93)
270.27a
(51.59)
223.94b
(36.53)
231.08ab
(18.06)
95.12c
(16.20)
51.60d
(17.27)
62.30d
(17.52)
Cooking losses,
%
42.07
(0.4)
42.32
(0.05)
42.50
(0.01)
--
--
41.95
(0.94)
41.11
(1.28)
41.33
(0.61)
Dominant wavelength (lambda d),
nm
635.71
(3.17)
635.52
(3.66)
639.19
(2.54)
636.53
(2.42)
637.88
(3.72)
639.79
(2.46)
637.00
(2.92)
Color Purity (Pe),
--
0.761
(0.057)
0.756
(0.047)
0.804
(0.034)
0.768
(0.031)
0.784
(0.050)
0.812
(0.034)
0.777
(0.039)
Lightness (Y),
%
16.14ab
(1.30)
17.04a
(1.45)
16.34ab
(0.85)
16.95a
(0.54)
15.62b
(0.93)
16.16ab
(1.24)
17.50a
(0.65)
Flavor 3.85ab
(0.63)
3.75abc
(0.68)
4.35a
(0.41)
--
--
3.14c
(0.69)
3.55bc
(0.73)
4.17ab
(0.75)
Juiciness 4.35ac
(0.82)
3.90c
(0.84)
4.55abc
(0.69)
--
--
5.36b
(0.85)
4.80ab
(0.92)
4.75abc
(0.76)
Firmness 5.72
(0.57)
5.40
(0.52)
5.36
(0.67)
--
--
5.42
(0.67)
5.38
(0.52)
5.00
(0.00)
Tenderness 4.83
(1.25)
4.46
(1.08)
4.05
(0.44)
--
--
5.14
(0.6)
5.21
(0.62)
4.75
(0.99)
Shear Force (SF) 9.09ab
(2.45)
8.42b
(2.25)
7.49b
(1.47)
--
--
10.98a
(2.27)
10.51a
(2.02)
10.78a
(1.50)
1 Means with different superscript in the same row are significantly different (P < 0.05)
2 WHC = Water-holding capacity.

The lowest meat homogenate viscosity for Sm muscle cut after 24 and 48 hours p.m. was found after 72 hours p.m. of storage (Table 1). Viscosity of Sm muscles cut 24 hours p.m. compared to the viscosity of Sm muscles cut 48 hours p.m. was significantly higher (2.84 to 4.31 times) at the corresponding storage times. Based on the Borderias et al. (Borderias et al., 1985) hypothesis, the changes in viscosity can be explained by different actomyosin solubility. The lower meat homogenate viscosity for Sm muscles cut 48 hours p.m. than for Sm muscles cut 24 hours p.m. can be explained by lower amounts of extractable actomyosin from these muscles.

The color parameters (dominant wavelength and color purity) for Sm muscles cut 24 and 48 hours p.m. did not change significantly during aging and were comparable for corresponding storage times (Table 1). However, lightness of Sm muscles cut 48 hours p.m. increased during aging and after 96 hours p.m. the value was significantly higher than after cutting 48 hours p.m. Moreover, lightness of the Sm muscles cut 24 hours p.m. and after 48 hours p.m. was higher by 1.42% than for the Sm muscles after cutting 24 hours p.m. and after 48 hours p.m.

Within each muscle group up to 72 hours p.m. when cut 24 hours p.m., and up to 96 hours p.m. when cut 48 hours p.m., there were no significant differences in sensory attributes with only one exception (Table 1). The flavor intensity of steaks from Sm muscles cut 48 hours p.m. decreased during storage and after 96 hours p.m. was significantly different than after cutting 48 hours p.m. Moreover, the steaks from Sm muscles after cutting 48 hours p.m. were estimated as having significantly higher flavor intensity than samples from the Sm muscles after cutting 24 hours p.m. and after aging for 72 hours p.m. The same relationship was found when comparing flavor after 72 hours p.m. of storage for the Sm muscle cut 24 and 48 hours p.m. respectively.

On the other hand, steaks from the Sm muscles after cutting 48 hours p.m. were estimated as being less juicy than steaks from the Sm muscles after cutting 24 hours p.m. and after aging 48 hours p.m. These differences in juiciness evaluation of steaks did not correspond with the WHC values, which, for corresponding periods, were not significantly different.

The shear force (SF), which was lower within all examined periods for steaks from the Sm muscles cut 24 hours p.m. than for steaks from the Sm muscles cut 48 hours p.m., was not reflected by sensory estimation of the Sm steaks’ tenderness, which was not significantly different for both cutting and aging times.

Discussion

The lower lightness of Sm muscles after cutting 48 hours p.m. than after aging up to 96 hours p.m. (Table 1) is consistent with results of Griffin et al. (Griffin et al., 1982) who found that the Sm of beef muscles after cutting three days p.m. had less brighter lean color than after nine days of muscle slices vacuum stored.

The flavor intensity decrease found in steaks from the Sm muscles cut 48 hours p.m. (Table 1) during storage is not in agreement with findings of Fjelkner-Modig and Ruderus (1983) who found that steaks from the Sm bull muscles cut 48 hours p.m. and in slices vacuum stored were estimated as having more intense flavor after five and 14 days. Although some authors found that flavor of steaks from the Sm beef muscles, hot boned, sliced, and placed in vacuum storage, was optimal after four days and after that was less intense (Spanier et al., 1997), the Sm steer muscles were more desirable when muscles were cut from aged carcasses after four rather than after seven days p.m. (Parrish et al., 1969), but these results were not obtained from bulls.

Some authors have shown a lack of significant differences in juiciness (Carmack et al., 1995) and SF of (Hostetler et al., 1975; Fjelkner-Modig and Ruderus, 1983; Parrish et al., 1969) steaks from bulls’ or steers’ muscles after cutting and/or additional aging which agrees with results for juiciness and SF presented in Table 1. However, the others found more desirable juiciness of steaks from the Sm steer muscles after four rather than after seven days of carcass aging (Parrish et al., 1969) and decrease of SF in steaks from the Sm bull muscles hot boned during vacuum storage up to 15 days (Hertzman et al., 1993; Olsson et al., 1994) or from Sm beef muscles after 11 days of aging wholesale cuts (Smith et al., 1978).

Insignificant changes in tenderness of steaks from the Sm muscles cut both 24 and 48 hours p.m. during aging (Table 1) are not consistent with results of Fjelkner-Modig and Ruderus (1983) who found an improvement in tenderness of steaks from the Sm bull muscles cut 48 hours p.m. during vacuum aging and results of Parrish et al. (1969) who found that tenderness of steaks from the Sm steer muscles were more desirable after four rather than after seven days of carcass aging.

Conclusions

No influence was found for cutting time (24 and 48 hours p.m.) of the Sm bull muscles and aging time (up 96 hours p.m.) on pH, cooking losses, dominant wavelength, color purity, firmness, and tenderness. Considering higher lightness after 48 hours p.m. and lower SF after 48 and 72 hours p.m. for Sm muscles cut 24 hours p.m. than for those cut 72 hours p.m., it appears that muscles cut 24 hours p.m. should be directed to the retail trade. In further processing, it is necessary to take into account that the Sm muscle had the highest WHC after 48 hours, when cut 24 hours p.m., and after 72 and 96 hours p.m., when cut 48 hours p.m.

References

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Carmack, C. F., Kastner, C. L., Dikeman, M. E., Schwenke, J. R., and Garcia Zepeda, C. M. 1995. Meat Science 39:143—147.

Fjelkner-Modig, S. and Ruderus, H. 1983. Meat Science 8:203—220.

Griffin, D. B., Savell, J. W., Smith, G. C., Lind, K. D., and Galloway, D. E. 1982. J. Food Sci. 47:1746—1748.

Hertzman, C., Olsson, U., and Tornberg, E. 1993. Meat Science 35:119—141.

Hostetler, R. L., Carpenter, Z. L., Smith, G. C., and Dutson, T. R. 1975. J. Food Sci. 40: 223—226.

Mc Keith, F. K., De Vol, D. L., Miles, R. S., Bechtel, P. J., and Carr, T. R. 1985. J. Food Sci. 50:869—872

O’Halloran, G. R., Troy, D. J. and Buckley, D. J. 1997. Meat Science 45:239—251.

Oktaba, Elementy statystyki matematycznej I metodyka doswiadczalnictwa. 1980. Ed. by Warszawa, P. W. E .

Olsson, U., Hertzman, C., and E. Tornberg, 1994. Meat Science 37:115—131.

Parrish Jr., F. C., Rust, R. E., Popenhagen, G. R., and Miner, B. E. 1969. J. Animal Sci. 29:398—403.

Polska Norma. 1988. PN-88/A—82003.

Smith, G. C., Culp, G. R., and Carpenter, Z. L. 1978. J. Food Sci. 43:823—826.

Spanier, A. M., Flores, M., McMillin, K. W., and T. D. Bidner. 1997. Food Chemistry 59:531—538.

Tyszkiewicz, St. 1964. Roczniki IPMiT 1:51—77.

Wierbicki, E., Tiede, M.G., and Burrell, R. C. 1962. Fleischwirtschaft 10:948—951.


* Collaborative research with the Agricultural University of Wroclaw, Poland.
1
For more information, contact at: The Ohio State University 15 Animal Science, 2029 Fyffe Road, Columbus, OH 43210, (614) 292-4317, Fax (614) 292-2929; email:ockerman.2@osu.edu


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