Standardization Of Measurement On Eating Quality Of Chilled Pork

Eating quality is the most important determinant of the commodity value of pork, but we do not have a standardized measurement on this yet. The aim of this study was to investigate the effects of different condition, pretreatment and measurement on the results of pork color, Warner-Braztler shear force and water-holding capacity and discuss the correlation among color, PH24and water-holding capacity. Furthermore, the goal of this study was to provid a theoretical basis to formulate standardized measurement on eating quality of chilled pork. The experiment is divided into three parts:Part1:Standardization of measurement on chilled pork color evaluated by colorimeter. The influence of instrumental calibration, light intensity (60lux,600lux), background (white, red, brown), meat thickness (1-3cm), blooming time (0-60min) and temperature (0-25℃) on pork colour data was investigated. The porcine longissmus doris after24h cooling was selected and each processing was set with9replications. Results indicated that CV of color data was less after calibration. Light intensity did not affect the results when colorimeter closely buckled to the sample surface. Background and meat thickness had significant effects on a*value (P<0.05), darker background and thinner thickness could result in decrease of a*value. Blooming time and temperature had significant effects on both a*value and b*value (P<0.05), longer time and higher temperature could result in increased of a*and b*value. In conclusion, the condition of pork color measured by colorimeter should be: sample thickness of2cm, blooming30min at0-4℃on red plastic board, colorimeter closely buckled to the sample surface after calibration.Part2:Standardization of measurement on chilled pork Warner-Braztler shear force. Weight loss through cooking and Warner-Braztler shear force of pork loins were measured after they were subjected to different heating temperature (65-80℃), cooking temperature (70-80℃), holding time (0-20min) and chilling temperature (0-25℃), the influence of different equipments (tenderometer, texture analyzer) on pork Warner-Braztler shear force data was also investigated. The porcine longissmus doris after24h cooling was selected and each processing was set with9replications. Results indicated that higher heating and cooking temperature and longer holding time could result in increase of weight loss through cooking and Warner-Braztler shear force (WBSF, using WBSF in the later part of manuscript) of pork loins, CV of WBSF was the least when pork loins were obtained and sheared at0-4℃. Therefore, different pretreatment had significant effects on pork WBSF (P<0.05). Texture analyzer and tenderometer did not have significant effects on the results of pork WBSF (P>0.05). In general, the pre-conditions of pork WBSF should be: cooking temperature of70-75℃, heating temperature of70℃, no holding, refrigerating cooked meat overnight at0-4℃, measured with both tenderometer and texture analyzer.Part3:Standardization of measurement on chilled pork water-holding capacity and the correlation with color, PH24. The study investigated the effects of different sample sizes (1*3*5,2*3*3,3*3*3,2*3*5,3*3*5cm) and different telpher time (24-96h) on drip loss, analyzed the effects of different pressure strength (30-40kg) and time (3-7min) on press loss, researched the correlation among color, pH24and water-holding capacity. The porcine longissmus doris after24h cooling was selected and each processing was set with10replications. Results indicated that the larger sample size and shorter telpher time could be associated with decreased of drip loss, unified the size of2*3*5cm and time of24h. Press loss turned to get increase with the stronger pressure strength and longer pressure time, unified the strength of35kg and time of5min. There was significantly negative correlation between pH24*and L*value (P<0.05), PH24was negativly correlated with centrifugation loss and cooking loss (P<0.05) and positively correlated with napole yield (P<0.05). L*value was significantly correlated with different terms of water-holding capacity (except press loss)(P<0.05), it was the best water-holding capacity indicator parameter. There was significant correlation between different terms of water-holding capacity except press loss (P<0.05).