Suwannarach Nakarin, Kaewyana Chariya, Yodmeeklin Arpaporn, Kumla Jaturong, Matsui Kenji, Lumyong Saisamorn
Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand; Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
Int J Food Microbiol. 2017 Mar 6;244:52-61. doi: 10.1016/j.ijfoodmicro.2016.12.021. Epub 2016 Dec 28.
The presence of microorganisms on the eggshell surface is a factor of consideration in determining egg quality. These microorganisms can contribute to egg spoilage and can infect the egg. In this study, 18 morphotypes of microorganisms were isolated from eggshells. Morphological, biochemical, physiological and molecular analyses were used to identify these morphotypes into 7 species; Bacillus drentensis, Staphylococcus arlettae, Stap. cohnii, Stap. kloosii, Stap. saprophyticus, Stap. sciuri and Stap. xylosus. The potential of Muscodor cinnamomi to reduce the presence of microorganisms on eggshells by biological fumigation was investigated. The result showed that 16 strains of the tested microorganisms were inactivated after the exposure of the fungal volatile organic compounds. The most abundant compound was 2-methylpropanoic acid, followed by 3-methylbutan-1-ol. Our results indicated that a 24-h period of fumigation of 100g rye grain culture of M. cinnamomi was the minimum dose that could significantly reduce the number of microorganisms on the eggshell surface. Fumigated eggs from both box and cabinet fumigation trials showed significantly lower microbial numbers on the eggshell than non-fumigated eggs during the storage period of 14days. It was found that the values of the yolk index, albumen index and the Haugh unit of the eggs decreased during this storage time. However, those values of the fumigated eggs from both fumigation trials were found to be significantly higher than the non-fumigated eggs after the 24-h fumigation period and following storage for 5, 7 and 14days. However, the values of the albumen index were not found to have significantly increased over 5days of the box trial. This study is the first to report on mycofumigation activity for the purposes of reducing the presence of microorganisms on the surface of eggshells.
蛋壳表面存在微生物是决定鸡蛋品质时需要考虑的一个因素。这些微生物会导致鸡蛋变质并可能感染鸡蛋。在本研究中，从蛋壳中分离出了18种微生物形态型。通过形态学、生化、生理和分子分析，将这些形态型鉴定为7个物种；德伦特芽孢杆菌、阿氏葡萄球菌、科氏葡萄球菌、克氏葡萄球菌、腐生葡萄球菌、松鼠葡萄球菌和木糖葡萄球菌。研究了肉桂麝香对通过生物熏蒸减少蛋壳上微生物存在的潜力。结果表明，在暴露于真菌挥发性有机化合物后，16株受试微生物被灭活。含量最丰富的化合物是2-甲基丙酸，其次是3-甲基丁醇。我们的结果表明，对100克肉桂麝香黑麦谷物培养物进行24小时熏蒸是能够显著减少蛋壳表面微生物数量的最小剂量。在14天的储存期内，来自箱式和柜式熏蒸试验的熏蒸鸡蛋蛋壳上的微生物数量明显低于未熏蒸鸡蛋。发现在这段储存时间内，鸡蛋的蛋黄指数、蛋白指数和哈夫单位值下降。然而，在24小时熏蒸期以及储存5天、7天和14天后，发现来自两个熏蒸试验的熏蒸鸡蛋的这些值明显高于未熏蒸鸡蛋。然而，在箱式试验的5天内，未发现蛋白指数值有显著增加。本研究首次报道了用于减少蛋壳表面微生物存在的真菌熏蒸活性。
