Tolen Tamra N, Ruengvisesh Songsirin, Taylor Thomas M
Department of Animal Science, Texas A & M University, College Station, TX 77843-2471, USA.
Department of Nutrition and Food Science, Texas A & M University, College Station, TX 77843-2253, USA.
Foods. 2017 Aug 16;6(8):69. doi: 10.3390/foods6080069.
Beef safety may be compromised by O157 and non-O157 Shiga toxin-producing (STEC) contamination. The capacity of surfactant micelles loaded with the plant-derived antimicrobial eugenol to reduce STEC on beef trimmings that were later ground and refrigerated for five days at 5 ± 1 °C was tested to determine their utility for beef safety protection. STEC-inoculated trimmings were treated with free eugenol, micelle-encapsulated eugenol, 2% lactic acid (55 °C), sterile distilled water (25 °C), or left untreated (control). Following treatment, trimmings were coarse-ground and stored aerobically at 5 ± 1 °C. Ground beef was then sampled for STEC immediately post-grinding, and again at three and five days of storage. STEC minimum inhibitory concentrations (MICs) in liquid medium for free eugenol and 1% sodium dodecyl sulfate (SDS)-loaded micelles were 0.5% and 0.125%, respectively. STEC numbers on beef trimmings treated by sterile water (6.5 log CFU/g), free eugenol (6.5 log CFU/g), micelle-loaded eugenol (6.4 log CFU/g), and lactic acid (6.4 log CFU/g) did not differ compared to untreated controls (6.6 log CFU/g) ( = 0.982). Conversely, STEC were significantly reduced by refrigerated storage (0.2 and 0.3 log CFU/g at three and five days of storage, respectively) ( = 0.014). Antimicrobial treatments did not significantly decontaminate ground beef, indicating their low utility for beef safety protection.
牛肉安全可能会因O157和非O157产志贺毒素大肠杆菌（STEC）污染而受到影响。测试了负载植物源抗菌剂丁香酚的表面活性剂胶束对牛肉碎末上STEC的减少能力，这些牛肉碎末随后被研磨并在5±1°C下冷藏5天，以确定它们对牛肉安全保护的效用。用游离丁香酚, 胶束包裹的丁香酚, 2%乳酸（55°C）, 无菌蒸馏水（25°C）处理接种了STEC的碎末，或不进行处理（对照）。处理后，将碎末粗磨并在5±1°C下需氧储存。然后在研磨后立即对绞碎牛肉进行STEC采样，并在储存三天和五天时再次采样。游离丁香酚和负载1%十二烷基硫酸钠（SDS）的胶束在液体培养基中的STEC最低抑菌浓度（MIC）分别为0.5%和0.125%。用无菌水（6.5 log CFU/g）、游离丁香酚（6.5 log CFU/g）、负载丁香酚的胶束（6.4 log CFU/g）和乳酸（6.4 log CFU/g）处理的牛肉碎末上的STEC数量与未处理的对照（6.6 log CFU/g）相比没有差异（P = 0.982）。相反，冷藏储存可显著减少STEC数量（储存三天和五天时分别减少0.2和0.3 log CFU/g）（P = 0.014）。抗菌处理并未显著净化绞碎牛肉，表明它们对牛肉安全保护的效用较低。
