Influence of the season of the year on some technological. parameters and ultrastructure of PSE, normal and DFD chicken

Transcription

1 Influence of the season of the year on some technological parameters and ultrastructure of PSE, normal and DFD chicken breast muscles Lesiow Tomasz*, Szmanko Tadeusz, Korzeniowska Ma gorzata, Bobak ukasz, Oziemb owski Maciej *Department of Quality Analysis, University of Economics in Wroclaw, 118/120 Komandorska St., Wroclaw, Poland Department of Animal Products Technology and Quality Management, Wroclaw University of Environmental and Life Sciences, 25 Norwida St., Wroclaw; Poland Correspondence: Abbreviated title: Ultrastructure of PSE and DFD chicken muscles Summary The purpose of the present study was to investigate the variations in some textural and technological parameters and ultrastructure of PSE, normal and DFD chicken breast muscles, selected 3 h p.m., in autumn-winter period. The samples were classified based on muscle ph and color lightness (L * ). Shear force, cooking loss and hardness of muscles were measured and ultrastructure was evaluated using scanning microscopy. PSE and normal muscles had comparable shear force and cooking loss values in autumn and winter and they were higher than for DFD muscles. Differently, in autumn, hardness of PSE and DFD muscles had similar but higher in comparison with normal muscles values and in winter differences between muscles were not found. Both shear force and cooking loss values for all kinds of muscles were lower in autumn than that in winter with one exception, i.e. DFD muscles had higher cooking loss in autumn than in winter. Additionally, all types of muscles in autumn were favored by higher hardness when compared with that in winter. Changes in PSE muscles resulted in looseness of structure whereas DFD muscles were characterized by tighten structure. The comparable structural changes in PSE and DFD muscles were observed in both periods. 1

2 Keywords: PSE and DFD, chicken breast muscle, microstructure, WHC, hardness, breaking force, cooking loss, autumn-winter Introduction The occurrence of PSE and DFD meat is caused by genetic, biochemical, metabolic and environmental factors (Barbut et al., 2008, Lesiow and Kijowski, 2003). It is important to minimize the occurrence of this phenomenon by better knowledge of conditions affecting their incidence. The influence of genotype, season, transportation, holding conditions before slaughter on quality of breast chicken broiler muscles is well documented, however the problem of PSE and DFD meat is all time opened and brings new remarks (Bianchi et al. 2006, 2007, Swatland, 2008). The aim of the present study was to estimate the effect of autumn-winter period on some textural and technological parameters and ultrastructure of PSE, normal and DFD chicken breast muscles selected 3 h p.m. Materials and methods Experimental design Birds from Cobb 500 lineage from different farms were slaughtered in industrial conditions during autumn-winter months. In four separate experiments color parameters (L*,a*,b*) and ph of 50 randomly chosen muscles were measured after 3 h p.m. Color parameters (L*,a*,b*) were measured three times along the longitudinal axis of each muscle by colorimeter Minolta CR-400. The ph was determined in duplicate using ph-meter Testo 230 by inserting electrode into the each examined muscle. The color of each muscle was estimated subjectively by 4-5 plant workers. On the basis of lightness (L*), ph and color subjective assessment from each 50 muscles were chosen 4 muscles within three groups: lighter than normal (L*>53; ph<5.7), normal (48<L*<53; 5.7<pH<6.1), and darker than normal (L*<48; ph>6.1) for subsequent analysis. Then vacuum packed muscles were transported in cooler to University laboratory. 2

3 Methods Histometrical measurements were performed under the light microscope. For staining of tissue sections Delafield s hematoxylin and eosin were used. Muscle fiber diameter and interfiber spaces were measured. Muscles were put into polyethylene bags and sealed with air evacuation, then thermally treated in water bath at 74ºC to final internal temperature of 72 o C then chilled for 12 hours at 4 C. Samples for rheological analysis were cut from chilled meat. Texture profile analysis (TPA) was performed on cylindrical samples (25 mm in diameter and 15 mm high) using double compression test with 70% of deformation on Zwick Roel equipment. Additionally, shearing force F max was measured using Warner-Bratzler cutting edge. Cooking loss of muscle was evaluated as percentage of initial sample weight. All the results were analyzed statistically using Statistica 8.0 program with one-way analysis of variance at the significance level of P<0.05. Results and discussion The influence of autumn-winter season on some textural and technological properties of broiler chicken breast muscles is presented in Table 1. PSE and normal (N) muscles had comparable shear force (F max ) and cooking loss (CL) values in autumn and winter, and CL of PSE and N muscles for winter was significantly higher than that for DFD muscles. Differently, in autumn, PSE and DFD muscles had similar hardness (Ha) which was significantly higher in comparison with normal muscles and in winter differences between muscles in Ha were not found. The results are not in accordance with Zhang and Barbut (2005) who found the lowest Ha in PSE muscles and comparable Ha for N and DFD muscles. Both shear force and cooking loss values for all kinds of muscles were lower in autumn than that in winter with one exception, i.e. DFD muscles had higher cooking loss in autumn than in winter. Additionally, all types of muscles in autumn were favored by higher Ha when compared with corresponding values in winter. Changes in PSE muscles resulted in looseness of structure whereas DFD muscles were characterized by tighten structure (Figure 1-6) what is in accordance with Barbut et. al. (2005). The comparable structural changes in PSE and DFD muscles were observed in both periods. In winter period when compared with autumn muscles were characterized by significantly lower interfiber spaces, i.e. PSE 7.6±0.07 and 9.2±0.12; normal 4.6±0.08 and 5.0±0.09; and DFD 4.2±0.07 and 4.4± (Figure 1-6). The structural changes were in accordance with muscles fiber diameter. The muscle fiber diameter of N muscles was significantly lower (35 µm) than defective muscles, i.e. PSE (38 µm) and DFD (36.8 µm). 3

4 Irrespective of described structural changes the chicken breast N, PSE and DFD muscles had well preserved architecture with distinguished endomysium. The lower Ha of chicken breast muscles in winter can be explained by more advanced collagen thermohydrolysis which could result from higher muscle water holding capacity what is supported by smaller interfiber muscle spaces in winter than in autumn (Huff-Lonergan and Lonergan, 2005). Trends for higher chicken breast muscles shear force (F max ) in winter than in autumn can be a consequence of higher muscle fiber concentration on muscle section unit resulted also from lower interfiber muscle spaces. Conclusion The chicken normal (N), PSE and DFD broiler breast muscles in autumn had higher Ha and lower CL than that in winter. It was not found significant differences in SF between all groups muscles in autumn winter period. Lower Ha of N muscles than that for PSE and DFD muscles as well as lower SF of DFD muscles than that for N and PSE muscles can be related to interfiber space differences (increase in N and PSE muscles and decrease in DFD muscles when compared autumn and winter period). Acknowledgements Research was financed by Polish Ministy of Science and Higher Education grant no N /2206,

5 References BARBUT, S., SOSNICKI, A.A., LONERGAN, S.M., KNAPP, T., CIOBANU, D.C., GATCLIFFE, L.J., HUFF-LONERGAN, E. and WILSON, E.W. (2008) Progress in reducing the pale, soft and exudative (PSE) problem in pork and poultry meat. Meat Science, 79: BARBUT, S., ZHANG, L. and MARCONE, M. (2005) Effects of pale, normal, and dark chicken breast meat on microstructure, extractable proteins, and cooking of marinated fillets. Poultry Science, 84: BIANCHI, M., PETRACCI, M. and CAVANI, C. (2006) The influence of genotype, market live weight, transportation, and holding conditions prior to slaughter on broiler breast meat color. Poultry Science, 85: BIANCHI, M., PETRACCI, M., SIRRI, F., FOLEGATTI, E., FRANCHINI, A. and MELUZZI, A. (2007) The influence of the season and market class of broiler chickens on breast meat quality traits. Poultry Science, 86: HUFF-LONERGAN, E. and LONERGAN, S.M. (2005) Mechanisms of water-holding capacity of meat: The role of postmortem biochemical and structural changes. Meat Science, 71: LESIOW, T. and KIJOWSKI, J. (2003) Impact of PSE and DFD on poultry processing a review. Polish Journal of Food and Nutrition Science, 53: 3-8. SWATLAND, A.J. (2008) How ph causes paleness and darkness in chicken breast meat. Meat Science, 80: ZHANG, L. and BARBUT, S. (2005) Rheological characteristics of fresh and frozen PSE, normal and DFD chicken breast meat. 5

6 Table 1. Influence of the autumn-winter period (n=12) on Hardness (Ha, N), shear force (F max, N) and cooking loss (CL, %) of breast chicken broiler normal (N), PSE and DFD muscles Period/Parameter Type of muscle PSE normal (N) DFD Autumn/Ha C ± B ± C ±5.80 Winter/Ha A ± A ± A ±5.12 Autumn/F max AB ± AB ± A ±10.81 Winter/F max AB ± B ± AB ±9.59 Autumn/CL A ± A ± A ±1.21 Winter/CL B ± B ± C ±0.17 A-B Means in the same row and column having the same superscript are not significantly different (P<0.05), separately for Ha, F max and CL. 6

7 Fig. 1. Structure of breast chicken broiler normal muscle for autumn period, magnification 300x Fig. 4. Structure of breast chicken broiler normal muscle for winter period, magnification 300x Fig. 2. Structure of breast chicken broiler PSE muscle for autumn period, magnification 300x Fig.5. Structure of breast chicken broiler PSE muscle for winter period, magnification 300x Fig. 3. Structure of breast chicken broiler DFD muscle for autumn period, magnification 300x 7 Fig. 6. Structure of breast chicken broiler DFD muscle for winter period, magnification 300x

8 8