The Irradiation Sterilization Effects Of Animal Food And Application Of ATP Detecting In Irradiated Meat

As a newly emerging food preservation technique,irradiation can kill pathogenic micro-organisms and saprogenicity bacteria in food,which puts this method into wide application prospects,but currently the overall research of micro-organisms in irradiated food is scarce,and the detection of bacterial content of irradiation food before and after sterilization mainly relies on the traditional method which is quite timeconsuming,so the overall research of micro-organisms and modern microbiological testing of irradiation food requires fast,efficient and convenient method urgently.As a new micro-organisms detection technique,ATP bioluminescence rapid method has been widely used in all aspects of food testing.In this research,radiation effects of animal-derived microorganisms and the application and influencing factors of irradiation meat products with ATP bioluminescence rapid technology were studied simultaneously.The results were as follows:1.We studied the sterilization effect by gamma irradiation of Listeria monocytogenes in cooled pork,Campylobacter jejuni in cooled chicken and Vibrio parahaemolyticus in Short necked clam,and on the total numbers of colony and E.coli in the three samples, and determined D₁₀ values and the irradiation dose to control microorganisms in cooled pork,chicken and short necked clam.The results showed negative correlation linear between the radiation dose and the number of micro-organisms.The D₁₀ values of the total numbers of colony,E.coli 10003,Listeria monocytogenes were 1.478kGy,0.370kGy, 0.523kGy,and D values were 4.71kGy,2.289kGy,2.889kGy in cooled pork respectively.The D₁₀ values of the total numbers of colony,E.coli 10003,Campylobacter jejuni33560 and CY04 were 1.434kGy,0.408kGy,0.175kGy,0.2kGy,and D values were 4.806kGy,2.649kGy,1.117kGy,0.181kGy in cooled chicken respectively.The D₁₀ values of the total numbers of colony,E.coli 10003,Vibrio parahaemolyticus 27969 were 0.751kGy,0.56kGy,0.199kGy,and D values were 4.212kGy,3.44kGy,1.279kGy in the short necked clam respectively.The storage time of three samples were more than 28 days by irradiation at 5kGy under the temperature of 0～4℃,which corresponds to hygiene standards.2.We tested the sensory quality characteristics of irradiated cooled pork,chicken,and short necked clam,and on the correlation between sensory evaluation and instrumental measurement showed that after 28 days storage in 0～4℃,the detection of sensory quality of cooled pork,chicken and short necked clam that were irradiated with the dose of 5kGy were better than the non-irradiated samples,but the color of irradiated ones were reder,a little irradiation flavor which disappeared gradually during storage,which were still in the evaluation of the acceptable range.In addition,it showed good dependability between sensory evaluation and instrumental measurement.The hardness,elastic,adhesive and chewing sexual,e value and F value of instrumental measurement showed positive correlation with a number of target sensory testing.So it was feasible to replace the traditional methods of sensory evaluation with instrumental measurement.3.We analysed the relationship between the ATP concentration and ATP standard luminous intensity and on the relationship between the radiation dose and ATP standard luminous intensity.The results showed positive correlated between ATP concentration and the ATP standard luminous intensity,the correlation of coefficient is 0.9998;the results also showed negatively correlated between radiation dose and the ATP luminescence intensity,the correlation of coefficient is 0.997.4.We applied ATP detecting to irradiated meat.The results showed that the trend of ATP luminescence intensity is nverse "S" in irradiated cooled pork,chicken,pure culture of E.coli,the luminous intensity of ATP achieved the maximum when the sample was dealed with 6kGy,and achieved the minimum value when the sample was dealed with 4,8kGy.By studying the relationship between ATP luminous intensity and irradiation dose of samples sterile water,autoclave ones,E.coli and so on,we found that the correlation between E.coli concentration and ATP luminous intensity was significant positive,the correlation of coefficient is 0.94,so we can make conclusion that the reason why the peak and nadir of meat ATP bioluminescence intensity came when the samples was dealed with 4,6,8kGy was because that the bacteria were interference during irradiation process.