The Improvement And Effect Of Immersion Chilling And Bacteria Reduction On Chicken Quality

According to the quality control concept of HACCP,GMP and SSOP,we know the pre-cooling and bacteria reduction is one of the critical control points in the process of chicken slaughtering.Now immersion chilling technology is widespread used in the Chinese chicken slaughtering industry.This process is closely related to the water-holding capacity(WHC),color,and microbial control of chicken.The control of meat's WHC,color and microorganism are not so good after immersion chilling process.This phenomenon may be a direct cause of decline in product quality and bring huge economic losses to enterprises.Improving the process of immersion chilling and the chicken quality have become an urgent and difficult problem to be solved for so many food science and technology workers.In this paper,we mainly study the technology of immersion chilling and bacteria reduction in the process of chicken slaughtering.Firstly,we investigated the actual production situation of the workshop in march,April and May.Secondly,the experiment is designed to obtain the optimal level combination by measuring the drip loss according to the result of first stage.Finally,we adopted the method of contrast test,which chose peracetic acid,lactic acid,glacial acetic acid,sodium hypochlorite and water as control.Analysis the effect of different disinfectant on chicken quality.The aim is to break through the trade barriers of the European Union and Arabia,and to provide the theoretical basis and technical support for the Chinese export enterprises.The results showed that:(1)According to the survey of pre-cooling pool's temperature in three months,we found the chicken center temperature and pre-cooling pool's temperature has been significantly related.So,the control of pre-cooling pool's temperature is the key to control the center temperature of the chicken carcass.The chicken center temperature and pre-cooling pool's temperature is not stable;The control of total number of colonies is not good in March,but it decrease in April and May.Sodium hypochlorite has influence on chicken color.The disinfectant before spray will increase the chicken's a* value significantly.The disinfectant after pre-cooling will increase the chicken's b* value significantly;After regular pre-cooling,the meat's drip loss of two stages is 3.24%,which is the lowest.But the chicken center temperature is the highest,which is 11.46?.The chicken center temperature of three stages is the lowest,but the meat's drip loss is 4.04%,which is the highest.(2)Based on the investigation of the factory,the experiment design was carried out on the basis of the two factors,which were the water cooling mode and the chicken center temperature after pre-cooling,this study measured the pre-cooling time,drip loss and color,the result showed that the A3B1(three stages,4?)group's cooling time is 87 min,the b*value is 12.41 which is the minimum and it's drip loss is 3.67%.So,A3B1(three stages,4?)is the best group.(3)On the basis of the optimal level combination of the pre-cooling process,we studied the effect of bacteria reduction on chicken carcasses by using lactic acid,acetic acid,peracetic acid,sodium hypochlorite and water control as disinfectant.The results showed that there is no significant difference in p H value and color between 0.015% peracetic acid group,1% glacial acetic acid group and water control group after ensuing the decontaminating effect.0.025% sodium hypochlorite will significantly increased the p H value of chicken breast.Therefore,we can choose peracetic acid or glacial acetic acid to replace sodium hypochlorite which is commonly used in chicken slaughtering industry.