Lathrop Amanda A, Taylor Tiffany, Schnepf James
Food Science and Nutrition Department, California Polytechnic State University, San Luis Obispo, California 93407, USA.
J Food Prot. 2014 Apr;77(4):635-9. doi: 10.4315/0362-028X.JFP-13-408.
Peanuts and peanut-based products have been the source of recent Salmonella outbreaks worldwide. Because peanut butter is commonly used as an ingredient in baked goods, such as cookies, the potential risk of Salmonella remaining in these products after baking needs to be assessed. This research examines the potential hazard of Salmonella in peanut butter cookies when it is introduced via the peanut-derived ingredient. The survival of Salmonella during the baking of peanut butter cookies was determined. Commercial, creamy-style peanut butter was artificially inoculated with a five-strain Salmonella cocktail at a target concentration of 10(8) CFU/g. The inoculated peanut butter was then used to prepare peanut butter cookie dough following a standard recipe. Cookies were baked at 350 °F (177 °C) and were sampled after 10, 11, 12, 13, 14, and 15 min. Temperature profiles of the oven and cookies were monitored during baking. The water activity and pH of the inoculated and uninoculated peanut butter, raw dough, and baked cookies were measured. Immediately after baking, cookies were cooled, and the survival of Salmonella was determined by direct plating or enrichment. After baking cookies for 10 min, the minimum reduction of Salmonella observed was 4.8 log. In cookies baked for 13 and 14 min, Salmonella was only detectable by enrichment reflecting a Salmonella reduction in the range of 5.2 to 6.2 log. Cookies baked for 15 min had no detectable Salmonella. Results of this study showed that proper baking will reduce Salmonella in peanut butter cookies by 5 log or more.
花生及花生制品是近期全球沙门氏菌爆发的源头。由于花生酱常用作烘焙食品（如曲奇）的原料，因此需要评估烘焙后这些产品中残留沙门氏菌的潜在风险。本研究考察了通过花生衍生成分引入沙门氏菌时，其在花生酱曲奇中的潜在危害。测定了沙门氏菌在花生酱曲奇烘焙过程中的存活情况。将市售的奶油状花生酱用含五种菌株的沙门氏菌混合菌液人工接种，目标浓度为10⁸CFU/g。然后按照标准配方，用接种后的花生酱制备花生酱曲奇面团。曲奇在350°F（177°C）下烘焙，并在10、11、12、13、14和15分钟后取样。烘焙过程中监测烤箱和曲奇的温度曲线。测定接种和未接种的花生酱、生面团及烘焙曲奇的水分活度和pH值。烘焙后立即冷却曲奇，通过直接平板计数或富集培养法测定沙门氏菌的存活情况。烘焙曲奇10分钟后，观察到沙门氏菌的最小减少量为4.8个对数级。在烘焙13和14分钟的曲奇中，沙门氏菌仅通过富集培养才可检测到，这表明沙门氏菌减少了5.2至6.2个对数级。烘焙15分钟的曲奇中未检测到沙门氏菌。本研究结果表明，适当烘焙可使花生酱曲奇中的沙门氏菌减少5个对数级或更多。
