The Influence Of Irradiation Dose And Packing Materials On The Quality Of Pot Chicken’ During Storage

This experiment used pot chicken as the samples, which packed by PA/PE and PET/A1/PE material; these samples were irradiated by 0,4kGy,5kGy,6kGy and 7kGy (actual absorbed dose was 0,4kGy,6kGy,7kGy,8.4kGy). Studied the sensory quality, microbiological, physical and chemical index and the change of flavor substance during storage, according to the change of the corresponding index to select the suitable sterilization dose and packing and get the shelf life. The main contents and conclusions about the study as follows:1 Irradiation doses and packing materials had significant effect on the sterilization effect ofpot chicken. The total numbers of colonies of PA/PE material samples irradiated by 4kGy and 5kGy dose were beyond the standard on the zero day; and irradiated by 6kGy and 7kGy dose were beyond the standard on the 15th day. The samples irradiated by 4kGy dose which packed by PET/A1/PE material were up to 9.1×105 cfu/g on the 30th day, but the total numbers of colonies of 5kGy,6kGy and7kGy were still<100cfu/g in 60d. The storage experiment of 37℃ after 10 days that all plastic packaging samples were up to 106 cfu/g.The coli group of no sterilized samples>1100MPN/100g, seriously exceed the national standard (≤30MPN/100g), all the samples of coli group after irradiation during storage were less than 30 MPN/100g. And haven not checked out pathogenic bacteria.According to the sterilization effect can be obtained by pot chicken was suitable for the 5kGy dose and PET/A1/PE material.2 The sensory quality changes significantly. Different groups of sensory score was declined with the extension of storage time. Heat treatment of the samples due to high temperature and high pressure, made the meat loose, contented dissolved in liquid, lost elasticity and chewiness, was badly damaged the sensory quality and lost the characteristics of traditional pot chicken products. During the period of 60d except 5kGy, 6kGy and 7kGy PET/Al/PE material sanples smell was normal, other irradiation groups appeared different levels of corruption. These samples containing liquid, so different groups of meat would gone soft with the extension of storage time, and even some meat dissolution, The colour was dim and the taste of meat had weakened. Therefore, it can use the 5kGy dose and PET/A1/PE material.3 Irradiation effect on physical and chemical indicators of samples along with the change of dose and packing materials.Studied from pH, TBA, TVB-N, shear force, protein, etc. Results show that with the extension of storage time, different groups of the pH were declined, but the changes were different, the pH value of PA/PE material drop was greater than the same irradiation dose of PET/Al/PE material. The shear force declined sharply during storage. Irradiation accelerated fat oxidation; the TBA value of the same irradiation dose and storage period of PET/Al/PE material less than PA/PE material, showed that the fat oxidation degree was relatively small. Different treatment groups in normal temperature storage period of TVB-N values with the extension of storage time were on the rise. Muscle plasma protein and myofibril protein most bands remained stable in the process of storage and no significant change.4 Irradiation influence the flavor of the sample. Electronic tongue and GC-MS method was used to compare the flavor change of the samples. Electronic tongue and principal component analysis (PCA) was used to analyze the sample taste, irradiation samples had significantly difference with the no sterilized samples.5kGy,6kGy and 7kGy irradiation samples were similar in flavor. With 6kGy irradiation samples for example, found that the sample of flavor in storage period has been changed.Using GC-MS method for determining the volatile components of the sample,41 compounds were detected, including 27 kinds of hydrocarbons,5 kinds of aldehydese and aromatic compounds,3 kinds of alcohols,1 kind of ketone. Different groups all had linalool, terpineol, sabenene, myrcene, pinene, arborvitae, thujone, caryophyllene, because in the process of making pot chicken joined the green chili oil.Taking an example of 6kGy, found that the relative content of all kinds of compounds during the storage had a little change.