PDF(Pubmed)
Abstract：
Contamination with Salmonella spp. and Listeria monocytogenes is concerning across low-moisture food (LMF)-processing environments due to the pronounced survival of these organisms under dry conditions. This study treated desiccated bacteria with acetic acid delivered by oil with and without water-in-oil (W/O) emulsion. The influences of cellular desiccation, emulsion water concentration, water activity (aw), and treatment temperature were investigated. Acetic acid dissolved in oil (i.e., acidified oil) showed low levels of antimicrobial efficacy. After treatment with acidified oil (200 mM acetic acid at 22°C for 30 min), Salmonella enterica serovar Enteritidis phage type 30 cells desiccated to 75% equilibrium relative humidity (ERH) and 33% ERH were reduced by 0.69 and 0.05 log CFU/coupon, respectively. The dispersion of a low level of water (≥0.3%, vol/vol) within the acidified oil with the surfactant (i.e., acidified W/O emulsion) significantly enhanced the antimicrobial efficacy. After treatment with the acidified W/O emulsion (200 mM acetic acid at 22°C for 20 min), desiccated Salmonella (4-strain cocktail) and L. monocytogenes (3-strain cocktail) cells were reduced by >6.52 log most probable number (MPN)/coupon, regardless of the desiccation levels. Increased efficacy was observed with temperature elevation. Reduced efficacy was observed when glycerol was added to the aqueous phase of the emulsion to decrease the solution aw, indicating that the enhanced efficacy of the acidified W/O emulsion was associated with differential osmotic pressure. The antimicrobial mechanism may be due to the membrane disruption induced by acetic acid, in combination with the hypoosmotic stress provided by W/O emulsion, creating cellular lysis, as illustrated by electron micrographs. IMPORTANCE Aqueous-based cleaning and sanitation are undesirable in processing facilities that manufacture low-moisture foods such as peanut butter and chocolate. Alcohol-based sanitization is advantageous because it leaves no residue on the contact surface but requires the processing facility to close temporarily due to flammability. At >6.52 log kill of desiccated Salmonella and Listeria monocytogenes cells, the developed oil-based formulation has the potential to be an effective dry sanitation method.
摘要：
沙门氏菌污染。由于这些生物在干燥条件下的显着存活，因此在低水分食品（LMF）加工环境中，单核细胞增生李斯特菌备受关注。这项研究用有或没有油包水（W/O）乳液的油传递的乙酸处理了干燥的细菌。细胞干燥的影响，乳化水浓度,水活度(AW)，和处理温度进行了研究。溶解在油中的乙酸(即，酸化油)显示出低水平的抗微生物功效。用酸化油（200mM乙酸在22°C下30分钟）处理后，干燥至75％平衡相对湿度（ERH）和33％ERH的30型肠炎沙门氏菌噬菌体减少了0.69和0.05logCFU/couple，分别。低水平水的分散(≥0.3%，vol/vol)在酸化油中含有表面活性剂(即，酸化的W/O乳液）显着增强了抗菌功效。用酸化的W/O乳液处理后（200mM乙酸在22°C持续20分钟），干燥的沙门氏菌（4株鸡尾酒）和单核细胞增生李斯特菌（3株鸡尾酒）细胞减少>6.52log最可能数（MPN）/优惠券，无论干燥水平。随着温度升高，观察到功效增加。当将甘油添加到乳液的水相以降低溶液aw时，观察到功效降低。表明酸化的W/O乳剂的功效增强与渗透压差有关。抗菌机制可能是由于乙酸诱导的膜破坏，结合W/O乳剂提供的低渗胁迫，产生细胞裂解，如电子显微照片所示。重要性水基清洁和卫生在生产低水分食品如花生酱和巧克力的加工设施中是不可取的。基于醇的消毒是有利的,因为其在接触表面上不留下残余物,但由于可燃性而需要处理设施暂时关闭。在>6.52对数杀死干燥的沙门氏菌和单核细胞增生李斯特菌细胞时，开发的油基配方有可能成为一种有效的干燥卫生方法。
