The Study On The Water-holding Capacity Of Chilled Pork

The paper is consisted of two chapters. Chapterl :The study on the correlations among pH, temperature and different terms of water-holding capacity of longgissum dor si post-mortem; Chapter 2: Influence of pre-slaughter handling and breeds on water-holding capacity of chilled pork.Chapterl: the object of this study was to investigate the correlation among pH45, pH24,145 and different terms water-holding capacity(drip loss, purge loss, centrifugation loss, cooking loss) of longgissum dor si from chilled pork. Fifty crossed (Huaibei x Landracex Yorkshire) pigs were used in the study. The pH45, T45 were correlated with drip loss (p<0.05 ) and the model to predict drip loss by pH45 and T45 was built(p<0.05). The pH24 was correlated with cooking loss (p<0.05 ) and the model to predict cooking loss by pH45 and T45 was built(p<0.05).Drip was highly correlated with purge loss(p<0.0001). The greatest amount of drip is generally lost during the first 24 to 48 h during storage. Cooking loss is correlated with all the other terms of water-holding capacity (p<0.05) . Chapter 2:This chapter includes four parts.Part I :The influence of different methods of moving pig from the lairage pen to stunning pen on water-holding capacity of chilled pork was determined. Sixty crossed (Landrace x Yorkshire x Duroc) pigs were divided to two equal group. One group were moved using electric goad and the other one were whipped to force them move to stunning pen. The the pH and temperature at 45min post-mortem were determined in longgissum dorsi (LD) and at 24 hours post-mortem the pH24, drip loss and centrifugation loss were determined. The pH45 in the group of whipped and moving with electric goad were 6.46 and 6.28 seperately and the former was higher (p<0.01) . The ,T45 in the group of whipped and moving with electric goad were was 37.5 C 38.4C and the former was lower (p<0.01). The drip loss in the group of whipped and moving with electric goad were 1.7283% and 2.3284% seperately and the former was lower (p<0.01) . No significant differences of pH24 and centrifugation loss were found between the two groups. The study showed that rejecting the method of using electric goad to move the animals can decrease the drip loss of chilled pork.Part II : This study investigated the effect on water-holding capacity of systematic showering during the Ihour lairage time pre-slaugher. Forty crossed (Henanbai x Landrace x Yorkshire) pigs were divided equally into two group. One group were showered systematically for 2 min followed by 10 min break during 1 hour of lairage. The other group had the same lairage time without showering. The pH and temperature at 45min post-mortem were determined in longgissum dorsi(LD) and at 24 hours post-mortem the pH24, drip loss and centrifugation loss were determined. The T45 in the group of showering and non-showering were 38.3 C and 38.3 C seperately and the former was lower (p<0.01) . The drip loss in the group of showering and non-showering 1.7283% and 2.3284% seperately and the former was lower (p<0.06). The centrifugation loss in the group of in the group of showering and non-showering were 22.2952 and 25.7971 seperately the former was lower (p<0.01) . No significant difference of pH45 and pH24 were found between the two groups. The study showed that systematic showering during the 1hour lairage time pre-slaugher can efficiently improve the water-holding capacity of chilled pork. PartIII: The effect of different lairage time (0h,1h, 2h) on water-holding capacity of crossed (Henanbai x Landrace x Yorkshire) pigs was investigated. Sixty pigs were equally divided into three groups, the three group were held in lairage for 0h,1h and 3h separately. The pH and temperature at 45min post-mortem were determined in longgissum dorsi(LD) and at 24 hours post-mortem the pH24, drip loss and centrifugation loss were determined. The pH45 in the group of 3h was higher than in the group of 1h (p<0.05) .No significant difference of pH45 was found between the group of 0h and 1h and the group of 1h and 3h.but pH45 show...