著者
民谷 万里子 左官 愛野 西島 基弘 タミヤ マリコ サカン アヤ ニシジマ モトヒロ Mariko Tamiya Aya Sakan Motohiro Nishijima
雑誌
実践女子大学生活科学部紀要
巻号頁・発行日
vol.46, pp.15-21, 2009-03-01

Recently rice balls with various stuffing are seen sold in many places like convenience stores and delicatessen. We surveyed bacterial contamination in them mainly mixed with marine food. Research was made on bacterial action after purchase to expiry date, and also on how they react to an added Escherichia coli, in particular when the preserving condition is worse. The level of general bacteria, coliforms and Staphylococcus aureus in rice balls are kept at 10^5CFU/g, but some expired rice balls indicate over 10^7CFU/g. Also, some rice balls showed increased bacteria over 10^7CFU/g, when E.coli is added and it is left at room temperature. Therefore, rice ball products need to be eaten soon after purchase and there is need to be cautious about the temperature of its preservation.