Development and evaluation of a new device to effectively detach micro-organisms from food samples

Abstract

Aims: To develop a new instrument of great versatility for recovering micro‐organisms from all types of food samples and to compare the effects with existing sample preparation methods. Methods and Results: To detach micro‐organisms from large‐size unbroken food samples such as apples, carrots, potatoes and tomatoes without preprocessing, the Spindle apparatus was newly developed. The Spindle was used to effectively detach micro‐organisms from large‐size samples. In a comparative study involving 51 food samples, treatment with the Spindle and Stomacher showed that recovery of total aerobic micro‐organisms (naturally occurring mesophilic microflora) and foodborne pathogens (from samples inoculated with Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes) for both methods was highly correlated (R2 = 0·98). Furthermore, diluents treated by the Spindle contained much less food debris than those treated by stomaching. Conclusions: These results indicate that Spindle is a novel, effective alternative method for detaching micro‐organisms from food samples including four kinds of large‐size samples without the need for preprocessing. Significance and Impact of Study: The Spindle might be used to widely detaching micro‐organisms from all types of food samples for microbiological assay.

Evaluation of micro-organism-detaching efficacy from meat samples by spindle or stomacher treatment and quality analysis of suspensions

“…The Spindle has nearly the same ability as a stomacher for detaching like numbers of bacteria from general food samples (Kim et al . ) and previously we demonstrated a high correlation of micro‐organism‐detaching capacity from various fresh vegetables between a stomacher and a 4‐section Spindle apparatus composed of four sample containers allowing simultaneous treatment of four samples (Kim et al . ).…”

“…Efficacy of the Spindle as an alternative to stomaching of fresh produce was validated by previous studies (Kim et al . , ). Therefore, we evaluated its detachment capacity for meat samples and especially focused on the real applicability of Spindle‐treated microbial solution in the present investigation.…”

“…The Spindle produced a much clearer diluent than stomacher treatment of vegetable samples (Kim et al . , ). We proved that meat samples showed the same tendency as vegetables through the turbidity measurement test, validating the status of Spindle over stomacher treatment, but meat homogenates following stomacher treatment were far more turbid than those of vegetables, because proteinaceous meat tissues are more prone to disintegration.…”

“…The Spindle can also treat large samples (>200 g) at once without prepreparation or any cutting process (Kim et al . ), which allows for treating whole fruits and large cuts of meat easily. The Spindle has nearly the same ability as a stomacher for detaching like numbers of bacteria from general food samples (Kim et al .…”

“…In order to compensate for these limitations, our laboratory developed a new 'Spindle' apparatus which effectively detaches bacteria on surfaces of food by rotation and vibration, resulting in a treated diluent that is much clearer and can easily be used in further assays. The Spindle can also treat large samples (>200 g) at once without prepreparation or any cutting process (Kim et al 2012), which allows for treating whole fruits and large cuts of meat easily. The Spindle has nearly the same ability as a stomacher for detaching like numbers of bacteria from general food samples (Kim et al 2012) and previously we demonstrated a high correlation of micro-organismdetaching capacity from various fresh vegetables between a stomacher and a 4-section Spindle apparatus composed of four sample containers allowing simultaneous treatment of four samples (Kim et al 2015).…”