Quantity-based microbiological sampling plans and quality after inspection

•The effect of increasing the analytical unit amount on the performance of microbiological sampling plans is discussed.•Quality of batches cleared after inspection is assessed and shown to be appropriate for consumers.•Both concentration-based and regular variables plans are considered.•Design of sampling plans for a desired limiting quality level is provided.

Sampling inspection plans are principally used to determine whether a batch of food is contaminated or not. In this theoretical research, we study the effect of increasing the analytical unit amount on the performance of microbiological sampling plans, and on the resulting quality after inspection. We discuss several scenarios of homogeneous and inhomogeneous contamination for assessing the consumer's risk. Several statistical approaches to describe the effect of an increase in analytical amount are studied. We provided a procedure for designing of the sampling plan for a given consumer's risk and according to different dispersion parameters and contamination levels.