Sarcoplasmatic and myofibrillar protein changes caused by acute heat stress in broiler chicken

Scientia Agricola

Carolina De Castro Santos²  Eduardo Francisquine Delgado¹  José Fernando Machado Menten¹  Aparecida Carla De Moura Pedreira¹  Carmen Josefina Contreras Castillo¹  Gérson Barreto Mourão¹  Camila Brossi¹  Iran José Oliveira Da Silva¹ 

[1] ,USP ESALQ

关键词: broiler;    heat stress;    lightness;    fragmentation index;    shear force;    frangos de corte;    estresse térmico;    luminosidade;    índice de fragmentação;    força de cisalhamento;   

DOI  :  10.1590/S0103-90162008000500002

来源: SciELO

【 摘 要 】

Acute heat stress (AHS) modifies the structure of myofibrils affecting functional properties of meat, mainly the water holding capacity. This experiment aimed to identify changes in proteolysis and migration between the myofibrillar and sarcoplasmatic fractions due to pre-slaughter AHS. Myofibrillar fragmentation index (MFI), SDS-PAGE, western blot of vinculin (WB) and shear force (SF) were determined. Six hundred broilers (Gallus gallus) were slaughtered in three different days (ST). In each ST, groups of ten animals were placed in transport crates and submitted to AHS (35ºC, 75 - 85% RH) for 2 hours. Simultaneously, the non-stressed broilers (NS) were kept in thermoneutral environment (22ºC, 83 ± 6.6% RH) within the crates in the same density. After slaughter, the breast muscles were kept refrigerated until the withdrawal of all samples (0, 1, 2, 6 and 24 hours after slaughter). Sampling within AHS and NS birds was collected according to lightness value (normal L* < 49, and high > 51), except for determination of MFI and SF. The lightness was used later to perform SDS-PAGE and WB analyses. MFI kinetics showed that the fragmentation rate was superior in animals NS, indicating that AHS can harm proteolysis and rate of myofibrillar fragmentation. However, the extent of fragmentation did not change, as well as SF values. SDS-PAGE for Troponin fragments indicated a differentiated pattern between AHS and NS. The WB did not show alterations in vinculin fragmentation. Modifications in sarcoplasmatic fraction are observed in meat with high L*values, independent of environmental condition.

【 授权许可】

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