Impact of season on the composition and quality of male and female blesbok (Damaliscus pygargus phillipsi) muscles

[摘要] ENGLISH ABSTRACT:The objective of this study was to investigate the impact of season on the composition and qualityof male and female blesbok (Damaliscus pygargus phillipsi) muscles (Longissimus dorsi, Bicepsfemoris, Semimembranosus, Semitendinosus, Infraspinatus and Supraspinatus). The latter wasquantified on the chemical composition (moisture, protein, fat and ash contents), fatty acid profile,mineral composition and physical attributes (pH, colour, drip and cooking loss, water holdingcapacity and tenderness) of the selected muscles.All of the blesbok muscles had higher (p<0.01) mean protein contents (20.6 g.100 g-1 to23.1 g.100 g-1) when the plane of nutrition was believed to be higher (spring of 2009). A strongnegative correlation (r = – 0.82; p<0.01) existed between the moisture and protein contents of theblesbok muscles. The Longissimus dorsi muscle had the highest (p<0.01) mean intramuscular fatcontent (3.4 g.100 g-1) when the plane of nutrition was higher. The chemical composition of theLongissimus dorsi, Biceps femoris, Semitendinosus and forequarter muscles (Infraspinatus andSupraspinatus) was affected least by the seasonal differences in the plane of nutrition and activitylevels of the blesbok at the study area. However, season had a larger impact on the chemicalcomposition of the Semimembranosus muscle.Season did not have a significant impact on the fatty acid profile of blesbok muscles, butthe difference in the fatty acid profiles between male and female muscles was significant. APrincipal Component Analysis (PCA) bi-plot indicated that female blesbok muscles wereassociated with a higher saturated fatty acid (SFA) and mono-unsaturated fatty acid (MUFA)content. Male blesbok muscles had higher (p<0.01) proportions of total polyunsaturated fatty acids(PUFA) (40.15 ± 5.39) and polyunsaturated to saturated fatty acid ratios (P:S) (0.85 ± 0.18), incomparison to female muscles (27.18 ± 8.04 and 0.54 ± 0.20, respectively). Differences in theanatomical locations of the selected blesbok muscles furthermore influenced the fatty acid profiles.The less active Longissimus dorsi muscle had higher (p<0.05) total PUFA (38.34 ± 8.62), totalomega-6 (ω6) PUFA (34.46 ± 7.83), total ω3 PUFA (3.44 ± 0.84) and P:S (0.85 ± 0.24) contents, incomparison to the Infraspinatus muscle (28.96 ± 8.65, 26.23 ± 7.86, 2.31 ± 0.70 and 0.56 ± 0.19,respectively) and Supraspinatus muscle (28.85 ± 9.23, 26.05 ± 8.24, 2.28 ± 0.76 and 0.55 ± 0.21,respectively). The hindquarter muscles (Biceps femoris, Semimembranosus and Semitendinosus)had intermediate fatty acid content.Season had an impact on the calcium and zinc contents of blesbok muscles. The calciumcontent was higher (p<0.05) in the muscles of the animals harvested in spring (6.92 ± 1.94)compared to winter (5.61 ± 1.79). The zinc content was higher (p<0.05) in the muscles of maleblesbok harvested in winter (4.04 ± 1.70) compared to spring (3.41 ± 1.67). The mineralcomposition was furthermore significantly different between the selected blesbok muscles. TheBiceps femoris muscle had the highest (p<0.05) potassium (183.25 ± 12.79), phosphorus (180.21± 10.36) and magnesium (32.18 ± 1.72) content, while the sodium and calcium content was highest in the forequarter muscles. The Longissimus dorsi muscle had the highest (p<0.05) iron(3.67 ± 0.51), but significantly lower zinc content (1.63 ± 0.28), in comparison to the forequartermuscles.The pH value ≈24 h post mortem was higher (p<0.05) in the Longissimus dorsi muscle ofthe animals harvested in spring (5.60) compared to winter (5.54). The CIE a* (14.63 ± 0.86) andchroma (17.09 ± 0.63) values were higher (p<0.05) for winter than for male blesbok meat in spring(13.62 ± 1.08 and 16.10 ± 1.03, respectively). The latter values were also higher (p<0.05) for malecompared to female (13.49 ± 0.88 and 16.22 ± 0.98) blesbok meat, at the end of the matingseason (winter). The forequarter muscles had higher chroma values in comparison with thehindquarter muscles, which had higher (p<0.01) hue-angle values. Season had no influence(p<0.05) on the drip loss percentages and tenderness of blesbok muscles. The drip losspercentages were lowest (p<0.05) in the Biceps femoris and Semimembranosus muscles. TheInfraspinatus and Supraspinatus muscles had the lowest (p<0.01) Warner Bratzler shear forcevalues (20.89 ± 3.23 and 24.90 ± 5.35 N, respectively).Seasonal differences in the chemical composition of blesbok muscles were statisticallysignificant. However, these differences were numerically small and it is therefore debatablewhether they are of any biological relevance relating to human nutrition. The differences in thefatty acid profile and mineral composition as well as the physical meat quality attributes of blesbokmuscles were more attributed to differences in the anatomical locations of the selected muscles, asopposed to the impact of season or gender.

[发布机构] Stellenbosch University