Salmonel1a enteritidis在鹹蛋與皮蛋加工及儲存期間之存活   全文下載

Survival of Salmonella enteritidis During the Processing and Storage of Processed Duck Egg

本研究使用二株Salmonella enteritidis，S. enteritidis CCRC 10744購自菌種保存及研究中心（CCRC），另一株S. enteritidis strain SEP係從食品中毒患者人體檢體中分離。新鮮鴨蛋以50~100 CFU ／ egg yolk之菌量接種，分別進行鹹蛋及皮蛋之加工及儲存試驗。鹹蛋蛋黃之NaCl含量由0.56%增加至0.98%，菌數之變化二菌株均很相似，在加工第二天菌數已增加至107~108 CFU ／ g，至加工完菌數仍維持在107 CFU ／ g，隨後經2個月之室溫（25~30°C）儲存，每月取5枚予以檢驗，多數蛋中仍可檢出二菌株。至於皮蛋加工，則顯示隨時間之進行，皮蛋蛋黃之pH值由6.5逐漸增高至10.3，菌數之變化與鹹蛋相似，二菌株之變化趨勢亦相似，惟最終因蛋黃pH值偏鹼而使菌數減少量較多，加工完之菌數約106 CFU ／ g。將含菌皮蛋與鹹蛋以相同方式儲存，一個月後二菌株之菌數皆降至約105 CFU ／ g，儲存至後期，接種S. enteritidis CCRC 10744組，於儲存2及3個月，分別於5個蛋中各檢出2及1個蛋黃殘存有菌株，接種SEP組則於5個蛋中皆仍能檢出菌株。 Salmonella enteritidis CCRC 10744 from the Culture Collection and Research Center (CCRC) and S. enteritidis strain SEP from a patient specimen, were used for the survival test in the salted duck egg and the thousand-year egg during processing and storage. After inoculation of S. enteritidis at levels of 50-100 CFU / egg yolk, the NaCl content of the egg yolk increased from 0.56% to 0.98% during processing of the salted egg. Similar growth curves were obtained for S. enteritidis CCRC 10744 and strain SEP. The viable cells increased to 107-108 CFU / g in the first 2 days and maintained 107 CFU / g by the end of the process. After processing, the salted eggs with S. enteritidis were stored at 25 ~ 30°C. Five eggs were examined every month, and both strains were found in most of the eggs even after 2 months storage. Similar procedure was followed for the thousand-year egg. During processing period, the pH value of the yolk increased from 6.5 to 10.3. The changes of viable cell count in the thousand-year eggs were similar as those in the salted egg. However, due to the final alkaline pH of the egg yolk, the viable counts in the thousand- year egg decreased to about 106 CFU / g by the end of the process. After processing, the thousand- year eggs were also stored at 25 ~ 30°C. The viable cells of both strains decreased to roughly 105 CFU / g in the first month of storage. After 2 and 3 months' storage, S. enteritidis CCRC 10744 could still be found in 2 and 1 egg yolks of the 5 sampled eggs respectively, while strain SEP could be detected in all 5 eggs even after 2 or 3 months' storage."

Salmonella enteritidis CCRC 10744 from the Culture Collection and Research Center (CCRC) and S. enteritidis strain SEP from a patient specimen, were used for the survival test in the salted duck egg and the thousand-year egg during processing and storage. After inoculation of S. enteritidis at levels of 50-100 CFU / egg yolk, the NaCl content of the egg yolk increased from 0.56% to 0.98% during processing of the salted egg. Similar growth curves were obtained for S. enteritidis CCRC 10744 and strain SEP. The viable cells increased to 107-108 CFU / g in the first 2 days and maintained 107 CFU / g by the end of the process. After processing, the salted eggs with S. enteritidis were stored at 25 ~ 30°C. Five eggs were examined every month, and both strains were found in most of the eggs even after 2 months storage. Similar procedure was followed for the thousand-year egg. During processing period, the pH value of the yolk increased from 6.5 to 10.3. The changes of viable cell count in the thousand-year eggs were similar as those in the salted egg. However, due to the final alkaline pH of the egg yolk, the viable counts in the thousand- year egg decreased to about 106 CFU / g by the end of the process. After processing, the thousand- year eggs were also stored at 25 ~ 30°C. The viable cells of both strains decreased to roughly 105 CFU / g in the first month of storage. After 2 and 3 months' storage, S. enteritidis CCRC 10744 could still be found in 2 and 1 egg yolks of the 5 sampled eggs respectively, while strain SEP could be detected in all 5 eggs even after 2 or 3 months' storage.