Center for Food Safety and Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797, USA.
J Food Prot. 2011 Sep;74(9):1441-50. doi: 10.4315/0362-028X.JFP-11-080.
Studies were done to determine the effectiveness of hot air drying, dry roasting, and oil roasting in killing Salmonella on pecan nutmeats. Pecan halves and pieces were inoculated by immersion in a five-serotype suspension of Salmonella or by surface application of powdered chalk containing the pathogen. Hot air treatment of low-moisture (2.8 to 4.1%) and high-moisture (10.5 to 11.2%) immersion-inoculated nutmeats (initial population, 6.18 to 7.16 log CFU/g) at 120°C for 20 min reduced the number of Salmonella by 1.18 to 1.26 and 1.89 to 2.04 log CFU/g, respectively. However, regardless of the moisture content, hot air treatment of pecan halves containing 0.77 log CFU/g at 120°C for 20 min failed to eliminate Salmonella. Reductions were >7 log CFU/g when dry pieces were dry roasted at 160°C for 15 min. Treatment of halves at 140°C for 20 min, 150°C for 15 min, or 170°C for 10 min reduced Salmonella by 5 log CFU/g. The pathogen was slightly more heat resistant in immersion-inoculated nutmeats than on surface-inoculated nutmeats. Exposure of immersion-inoculated pieces to peanut oil at 127°C for 1.5 min or 132°C for 1.0 min reduced the number of Salmonella by 5 log CFU/g. Treatment of halves at 138°C for 2.0 min reduced Salmonella by 5 log CFU/g; treatment at 132°C for 2.5 to 4.0 min did not always achieve this reduction. Hot air treatment cannot be relied upon to reduce Salmonella by 5 log CFU/g of raw pecan nutmeats without changing sensory qualities. Treatment temperatures and times typically used to oil roast nutmeats appear to be sufficient to reduce Salmonella by 5 log CFU/g.
研究旨在确定热空气干燥、干烤和油烤在杀灭山核桃坚果中的沙门氏菌的效果。将山核桃半壳和碎片通过浸泡在五种沙门氏菌悬浮液中或通过表面应用含有病原体的粉状粉笔来接种。在 120°C 下对低水分（2.8 至 4.1%）和高水分（10.5 至 11.2%）浸泡接种的坚果（初始菌数为 6.18 至 7.16 log CFU/g）进行 20 分钟的热空气处理，可使沙门氏菌数量分别减少 1.18 至 1.26 和 1.89 至 2.04 log CFU/g。然而，无论水分含量如何，在 120°C 下对含有 0.77 log CFU/g 沙门氏菌的山核桃半壳进行 20 分钟的热空气处理都无法消除沙门氏菌。当干块在 160°C 下干烤 15 分钟时，减少量>7 log CFU/g。将半壳在 140°C 下处理 20 分钟、150°C 下处理 15 分钟或 170°C 下处理 10 分钟可使沙门氏菌减少 5 log CFU/g。病原体在浸泡接种的坚果中的耐热性略高于表面接种的坚果。将浸泡接种的碎片暴露于 127°C 的花生油中 1.5 分钟或 132°C 的花生油中 1.0 分钟，可使沙门氏菌数量减少 5 log CFU/g。将半壳在 138°C 下处理 2.0 分钟可使沙门氏菌减少 5 log CFU/g；在 132°C 下处理 2.5 至 4.0 分钟并不总能达到这种减少量。未经感官品质改变，热空气处理无法使生山核桃坚果中的沙门氏菌减少 5 log CFU/g。通常用于油烤坚果的处理温度和时间似乎足以使沙门氏菌减少 5 log CFU/g。
