Dynamics of broilers thighs chemical composition and energy content, under the influence of different technological temperatures during slaughter

Abstract

Are the variations of temperature applied on certain key points quite significant in affecting the ultimate compositional and nutritional features of the chicken broiler meat? This was the question leading the research to further investigate three groups of carcasses (one control - CG, and two treatments - T1 and T2) in relation with the single experimental factor – temperature - variations on certain technological flow moments in the slaughterhouse: scalding station (CG:51-53⁰C,T1:53- 54⁰C,T2:55-56⁰C); chilling process (CG:1-4⁰C, T1:2-3⁰C; T2:1-2⁰C); sorting- packaging moment (CG<2⁰C; T1:8-10⁰C; T2:6-8⁰C); storage before delivery (CG:0-2⁰C; T1 and T2:0-1⁰C). The biological material comprised 150 ROSS-308 carcasses (50 per group), stored by refrigeration 1 day in slaughterhouse before shipping. Meat pieces weighing 50-100 grams, without skin, were cut around femoral bone from the thighs musculature of each carcass, in order to form homogenous samples per group; they were submitted to analytical laboratory assessment to quantify the main nutritional compounds (water, dry matter, crude ash, total lipids and protein content, nitrogen free extract) as well as gross energy value, using conventional A.O.A.C.-I.S.O. methods in 15 replications per compound. Thus, total dry matter varied between 28.34 g/100 g in CG and 28.81 g/100 g in T2 (P<0.05), while crude ash was found at 1.00g/100 g in CG, at 0.93g/100 g in T1, at 0.95 g/100 g in T2 (P<0.01 for T1, T2 vs. CG). Total lipids content was the most variable feature of thigh meat, thus in CG reached 8.00 g/100g, while in T1 was 3.25% higher (8.26 g/100 g, P<0.001 vs. CG) and in T2 was 4.88% higher (8.39 g/100 g, P<0.001 vs. CG and P<0.05 vs. T1). Total nitrogen matter slightly decreased from 18.78 g/100 g in CG till 18.59 g in T2, but the differences were not big enough to generate reaching of 95% significance threshold. The gross energy content was influenced by experimentally induced variable temperature, via lipids and nitrogen free extract differences and was calculated at 154.04 kcal/100 g meat in CG, at 156.71 kcal/100 g meat in T1 and at 157.93 kcal/100 g sample in T2, that resulted in highly significant differences between control and experimental treatments samples.