Generalized variable quick-switch sampling as a novel method for improving sampling efficiency of food products

Abstract

The variable acceptance sampling plan (VASP) is commonly applied in the food industry to qualify and validate food product safety and quality. Variable quick-switch sampling systems (VQSSs) consisting of a pair of VASPs are highly efficient schemes. Nevertheless, the existing VQSSs only switch the decision rule by adjusting either the required sample size or acceptance criterion. In this paper, we introduce a microbial safety index and propose a novel variable sampling system, called the generalized VQSS (GVQSS), based on this index to improve the sampling efficiency of the VQSSs for food product safety and quality validation. The proposed GVQSS adjusts the sample size and acceptance criterion simultaneously to provide a modified dynamic decision rule for lot disposition for food safety according to the sample information of the previous lot, safeguarding the requirements of the producer and consumer. Moreover, an interactive web application for calculating the optimal system design online is created to increase the practicality of the proposed GVQSS. Comparing the performance of the proposed GVQSS with the existing VQSSs, the GVQSS has superior cost-efficiency and discriminatory power. The proposed GVQSS can improve cost-efficiency significantly, which is more attractive regarding high testing costs and laboratory workloads in microbiological testing. Finally, two cases on microbial safety validation for cheese and ice cream are illustrated using the proposed GVQSS to demonstrate its applicability. ● A GVQSS is proposed based on the microbial safety index. ● The GVQSS can adjust the sample size and acceptance criterion simultaneously. ● The GVQSS outperforms the existing VQSSs in terms of cost-efficiency. ● Compared to VSSP, the GVQSS reduces the sample size by 52%–75%. ● A web app for the online calculation of the optimal system design is created.