Abstract:

This study aimed at investigating the effects of chilling temperature, length of chilling time and length of standing time at the segmentation workshop on water-holding capacity of chicken and investigating the effects of chilling temperature, length of chilling time and sodium hypochlorite amount on total number of bacteria and coliform bacteria on the surface of chicken carcasses by a 3-facor, 4-level orthogonal array design. The results indicated that the water-holding capacity of chicken was enhanced by controlling chilling temperature, length of chilling time and length of standing time at the segmentation workshop and the production of blood ice was reduced. An obvious reduction in total number of bacteria and coliform bacteria could be achieved by controlling chilling temperature, length of chilling time and sodium hypochlorite amount. The effects of chilling conditions on water-holding capacity and water-losing rate decreased in the following order: chilling temperature ＞ length of chilling time ＞length of standing time at the segmentation workshop. The optimum chilling conditions for retaining water-holding capacity of chicken were chilling at (15, 8 ℃) for 35 min and subsequent standing for 30 min at the segmentation workshop, while chilling at (10, 4 ℃) for 30 min and subsequent standing for 40 min at the segmentation workshop were able to minimize water-losing rate. The effects of chilling conditions on the production of blood ice decreased in the order of chilling temperature＞length of standing time at the segmentation workshop＞length of chilling time. The optimal chilling conditions for reducing the production of blood ice were chilling at (10, 4 ℃) for 30 min and subsequent standing for 25 min at the segmentation workshop. Chilling temperature, length of chilling time and sodium hypochlorite amount exhibited different effects on total number of bacteria and coliform bacteria on the surface of chicken carcasses in the decreasing order: chilling temperature ＞sodium hypochlorite amount ＞length of chilling time. Chilling at (10, 4 ℃) for 30 min and sodium hypochlorite treatment at 80 mg/kg presented the best effect for reducing total bacteria and preventing coliform bacteria.

Key words: primary chilling, chicken, water-holding capacity, total bacteria, coliform bacteria