Title: Impact of broiler processing scalding and chilling profiles on carcass and breast meat yield
Authors: Buhr RJ, Walker JM, Bourassa DV, Brooke CA, Brian KH, Zhuang H
Journal: Poultry Sci
Accepted date: 2014 Feb 8
Interpretive summary: The impact of scalding and chilling procedures was evaluated on carcass and breast meat yield in broilers Breast skin was collected before scalding, after scalding, and after defeathering for skin proximate analysis. Each batch of carcasses was subjected to either hard (60.0C for 1.5 min) or soft (52.8C for 3 min) immersion scalding. Following defeathering and evisceration; 8 carcasses/batch were air chilled (0.5C, 120 min, 86% RH) and 8 carcasses/batch were immersion chilled in water and ice (0.5C, 40 min). Carcasses were reweighed individually following evisceration and chilling. Breast meat (combined left and right fillets and tenders) was removed from the carcass and weighed within 4 h post-mortem. Post-feed withdrawal mean live weight resulted in only a 26 g difference in overall mean weight between the scalding treatment groups (2,610 g for soft-scald and 2,636 g for hard-scald). Post-scald defeathered-eviscerated carcass weight was 1% higher for soft-scalded carcasses (73.6%) than for hard-scalded carcasses (72.6%). During air chilling all carcasses lost weight resulting in post-chill carcass yield of 73.0% for soft-scalded and 71.3% for hard-scalded carcasses, a difference of 1.7%. During water chilling all carcasses gained weight resulting in post-chill carcass yield of 78.2% for soft-scalded and 76.1% for hard-scalded carcasses, a difference of 2.1%. Breast meat yield was greater by 0.7% for soft-scalded carcasses (17.6% for air-chilled and 17.9% for water-chilled) than for hard-scalded carcasses (16.8% for air-chilled and 17.3% for water-chilled). Neither air nor water chilling treatments significantly influenced breast meat yield. Proximate analysis revealed that the skin from hard-scalded and defeathered carcasses lost 3.9% moisture and 1.7% protein compared to skin from soft-scalded and defeathered carcasses that lost 0.8% moisture and 1.2% protein. Skin percentage lipid increased for both hard-scalded and defeathered carcasses by 3.2% compared to an increase of 1.9% for soft-scalded and defeathered carcasses. Although the sample size is small (n=9), there is no indication from proximate analysis that skin associated lipid was liquefied and lost during scalding or after defeathering. Therefore, the lower eviscerated carcass yield for hard-scalded carcasses is likely due to removal of the cuticle layer from the skin surface of the carcass during defeathering and not due to lipid liquefaction and loss during scalding.
Publication date: 2014 Jun