Effect of different short-term high ambient temperature on chicken meat quality and ultra–structure

Abstract

Objective This study investigated the effect of different acute heat stress (HS) levels on chicken meat quality and ultra-structure. Methods Chickens were randomly divided into 7 groups to receive different HS treatments: i) 36°C for 1 h, ii) 36°C for 2 h, iii) 38°C for 1 h, iv) 38°C for 2 h, v) 40°C for 1 h, vi) 40°C for 2 h, and vii) un-stressed control group (25°C). Blood cortisol level, breasts initial temperature, color, pH, water holding capacity (WHC), protein solubility and ultra-structure were analyzed. Results HS temperatures had significant effects on breast meat temperature, lightness ( L *), redness ( a *), cooking loss and protein solubility (p<0.05). The HS at 36°C increased L * 24 h value (p<0.01) and increased the cooking loss (p<0.05), but decreased a * 24 h value (p<0.05). However, as the temperature increased to 38°C and 40°C, all the values of L * 24 h , cooking loss and protein denaturation level decreased, and the differences disappeared compared to control group (p> 0.05). Only the ultimate pH 24 h at 40°C decreased compared to the control group (p<0.01). The pH in 36°C group declined greater than other heat-stressed group in the first hour postmortem , which contributed breast muscle protein degeneration combining with high body temperature, and these variations reflected on poor meat quality parameters. The muscle fiber integrity level in group 40°C was much better than those in 36°C with the denatured position mainly focused on the interval of muscle fibers which probably contributes WHC and light reflection. Conclusion HS at higher temperature (above 38°C) before slaughter did not always lead to more pale and lower WHC breast meat. Breast meat quality parameters had a regression trend as HS temperature raised from 36°C. The interval of muscle fibers at 24 h postmortem and greater pH decline rate with high body temperature in early postmortem period could be a reasonable explanation for the variation of meat quality parameters.

The Increase of Short-term Heat Exposure Temperature at Extreme Range Decreased Phosphofructokinase-1 Activity and AMPK Phosphorylation in Postmortem Chicken Breast Muscle

“…However, no difference was observed in pH among different temperature treatments at 4 and 24 h postmortem. A similar pH decline and ultimate pH values after SHE have been reported in previous studies as well [29][30][31]. This indicated that the increase of SHE temperature from 36 °C to 40 °C caused a slower pH decline at early postmortem.…”

“…In support, previous research indicated that two-hour heat exposure under 40 °C could increase the expression of Hsp70 in chicken breast muscle to more than three times [52], which suggests that SHE of 40 °C might have increased the cellular defensive mechanism in chicken breast meat. Moreover, the chicken PM muscle after antemortem SHE of 40 °C exposure had better meat quality, less mitochondrial damage, greater protein solubility, and higher muscle ber integrity as compared to SHE of 36 °C [30]. Some studies have indicated that Hsp70 can directly interact with PFK1 in chicken PM muscle during the early postmortem period [49] and have a negative correlation with p-AMPK-α[Thr172] [13].…”

“…Our recent study also indicated that poultry meat quality was affected by short-term heat exposure (SHE) of 36 °C, but exposure to temperatures above 38 °C did not always lead to more pale and lower WHC breast meat [30]. Moreover, the breast meat quality defects were reduced as heat exposure temperatures raised from 36 °C to 40 °C [30]. One possible explanation for this variation in meat quality with different exposure temperatures could be the change in of muscle metabolism postmortem [30].…”

“…Moreover, the breast meat quality defects were reduced as heat exposure temperatures raised from 36 °C to 40 °C [30]. One possible explanation for this variation in meat quality with different exposure temperatures could be the change in of muscle metabolism postmortem [30]. However, the biochemical basis of this variation is not clearly understood.…”

Influence of Long-Distance Transportation Under Various Crating Densities on Broiler Meat Quality During Hot and Humid Weather

“…Moreover, no effect ( p >0.05) of different transportation distances, crating density, and their interactions on 24 h PM meat redness, yellowness, and hue were observed. Zhang et al (2019) also reported an increase in lightness (L*) and decrease in a* and b* of the broiler breasts reared in summer compared to those reared in winter. Bianchi et al .…”