Impacts of Clarification Techniques on Sample Constituents and Pathogen Retention
Impacts of Clarification Techniques on Sample Constituents and Pathogen Retention
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DOI：
10.3390/foods8120636
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发表时间：
2019-12-01
期刊：
影响因子：
5.2
通讯作者：
Capobianco, Joseph A.
中科院分区：
文献类型：
--
作者：
Armstrong, Cheryl M.;Gehring, Andrew G.;Capobianco, Joseph A.
食品中微生物含量的测定不仅对安全消费，而且对食品质量、价值和产量都很重要。目前有多种分子技术可用于鉴定和定量样品中的微生物含量;然而，当调查对象是复杂的成分混合物（如食物）时，它们的成功往往取决于适当的样品制备。由于样品制备的重要性，本研究采用了系统的方法来比较四种不同的分离技术（玻璃棉，50 μ m聚丙烯过滤器，石墨毡，和连续流离心（CFC））对样品制备的影响。为了定义与使用这些分离方法相关的物理效应，进行了多因素分析，其中对四种不同的食品基质（包括瘦碎牛肉、碎猪肉、碎火鸡肉和菠菜）进行了处理前和处理后的粒度和组成分析。保留三个重要的食源性细菌病原体（大肠杆菌O 157：H7，沙门氏菌，李斯特菌）也进行了检查，以评估上述方法的可行性，利用在食源性病原体检测的背景下。来自多因素分析的数据不仅描绘了粒度范围，而且还定义了独特的组成特征并量化了细菌截留。三种过滤膜允许细菌以最小的损失通过，而CFC浓缩接种的细菌。此外，与菠菜相比，肉类样品中观察到的CFC沉积和食物基质浓度要高得多。然而，在氟氯化碳之前用玻璃棉过滤有助于澄清肉类样品，这导致氟氯化碳容器中的固体量大大降低，并增加了细菌的回收。总的来说，通过为样品制备技术的演绎选择奠定框架，研究结果可以应用于一系列应用，其中科学地指导与下游检测方法相关的标准与最有利的样品制备技术配对，用于复杂基质，如食品。
Determination of the microbial content in foods is important, not only for safe consumption, but also for food quality, value, and yield. A variety of molecular techniques are currently available for both identification and quantification of microbial content within samples; however, their success is often contingent upon proper sample preparation when the subject of investigation is a complex mixture of components such as foods. Because of the importance of sample preparation, the present study employs a systematic approach to compare the effects of four different separation techniques (glass wool, 50 mu m polypropylene filters, graphite felt, and continuous flow centrifugation (CFC)) on sample preparation. To define the physical effects associated with the use of these separation methods, a multifactorial analysis was performed where particle size and composition, both pre- and post-processing, were analyzed for four different food matrices including lean ground beef, ground pork, ground turkey and spinach. Retention of three important foodborne bacterial pathogens (Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes) was also examined to evaluate the feasibility of the aforementioned methods to be utilized within the context of foodborne pathogen detection. Data from the multifactorial analysis not only delineated the particle size ranges but also defined the unique compositional profiles and quantified the bacterial retention. The three filtration membranes allowed for the passage of bacteria with minimal loss while CFC concentrated the inoculated bacteria. In addition, the deposition and therefore concentration of food matrix observed with CFC was considerably higher for meat samples relative to spinach. However, filtration with glass wool prior to CFC helped clarify meat samples, which led to considerably lower amounts of solids in the CFC vessel post processing and an increase in the recovery of the bacteria. Overall, by laying a framework for the deductive selection of sample preparation techniques, the results of the study can be applied to a range of applications where it would be beneficial to scientifically guide the pairing of the criteria associated with a downstream detection method with the most advantageous sample preparation techniques for complex matrices such as foods.