Yuan Jing, Wang Luxin
Food Microbiology and Safety Laboratory, Department of Animal Sciences, Auburn University , Auburn, Alabama.
Foodborne Pathog Dis. 2018 Sep;15(9):560-567. doi: 10.1089/fpd.2018.2446. Epub 2018 Jun 19.
Kiwifruit (Actinidia deliciosa) is a high-acidity fruit, with two varieties available on the market. One is the green-fleshed, fuzzy, sweet but tangy-tasting kiwifruit, and the other is the yellow-fleshed variety called "golden" kiwifruit. While the whole kiwifruit is sold at room temperature at grocery stores, sliced kiwifruit is usually sold as a part of fruit salad in the refrigerated section. The survival of a five-strain Escherichia coli O157:H7 cocktail, a five-strain Salmonella cocktail, and a five-strain Listeria monocytogenes cocktail was evaluated on whole and sliced green and golden kiwifruit. Two inoculation levels were tested (∼7 and ∼4 Log colony-forming unit (CFU)/kiwi). A significantly higher amount of wet inoculum was attached to the green kiwifruit than to the golden kiwifruit (p < 0.05). The scanning electron microscope examination showed that pathogens can attach on both the surface and the hair structure of green kiwi skin. At room temperature, all three pathogens survived for 30 days on whole kiwifruit. Although the pH of sliced kiwifruit was low (∼3.5), all three pathogens survived on sliced kiwifruit for 7 days when stored at 4°C. These results highlight the importance of preventing contamination of fresh fruit during the preharvest and processing stages.
猕猴桃（中华猕猴桃）是一种高酸度水果，市场上有两个品种。一种是绿肉、带毛、味道香甜但有酸味的猕猴桃，另一种是被称为“黄金”猕猴桃的黄肉品种。虽然整个猕猴桃在杂货店室温下销售，但切片猕猴桃通常作为水果沙拉的一部分在冷藏区出售。对五株大肠杆菌O157:H7混合菌、五株沙门氏菌混合菌和五株单核细胞增生李斯特菌混合菌在完整和切片的绿肉及黄金猕猴桃上的存活情况进行了评估。测试了两种接种水平（约7和约4个对数菌落形成单位（CFU）/猕猴桃）。附着在绿肉猕猴桃上的湿接种物量明显高于黄金猕猴桃（p < 0.05）。扫描电子显微镜检查表明，病原体可附着在绿肉猕猴桃果实的表面和毛状结构上。在室温下，所有三种病原体在完整的猕猴桃上存活30天。虽然切片猕猴桃的pH值较低（约3.5），但在4°C储存时，所有三种病原体在切片猕猴桃上存活7天。这些结果突出了在收获前和加工阶段防止新鲜水果污染的重要性。
