Catfish Special Edition: Microbial Quality of Catfish Nuggets

Kathleen T Rajkowski

doi:10.4172/2157-7110.s11-007

Abstract

Catfish nuggets the pieces of muscle tissue are produced by trimming filets during processing and cannot be sold as whole catfish fillets. There is little information regarding the microbial quality of raw nuggets. Catfish nuggets, purchased either fresh or frozen from local retailers in the northeast United States (NJ, NY, PA, and DE), were tested for aerobic plate count (APC) at 22 and 37°C, Enterobacteriaceae, and Escherichia coli/coliform using Petrifilms™. The BAX® polymerase chain reaction system was used to determine the presence of Salmonella, Staphylococcus aureus, Listeria spp., and O157:H7. The overall average for APC at 22 and 37°C was 6.0 and 5.4 log10 CFU/g, respectively, which is within the finfish standard recommended by the International Commission on Microbiological Specifications for Food (ICMSF). No E. coli or E. coli O157:H7 was detected. Of the 150 nuggets tested, three were positive for Salmonella spp. and two were positive for enterotoxin negative S. aureus. Listeria spp. was detected, which is consistent with the findings of previous reports. The results obtained in this study were consistent with those obtained in other studies which assessed the microbial quality of finfish products.

Highlights

IntroductionThe reported aerobic bacteria counts of finfish fillet products varies, depending if the product was purchased fresh or frozen at local retail establishment, or ordered from the Internet [6,7,8,9]
The colonies on the psychrotrophic plate counts (PPC) and aerobic plate count (APC) films were counted by hand or counted using the 3M electronic reader
The plate counts, determined after incubation at 22°C and at 37°C were compared and statistical analysis showed that the psychrotrophic counts were significantly higher (p

Summary

Introduction

The reported aerobic bacteria counts of finfish fillet products varies, depending if the product was purchased fresh or frozen at local retail establishment, or ordered from the Internet [6,7,8,9]. Pao et al [9] obtained a variety of raw aquacultured fish fillets (catfish, salmon, tilapia and trout) via the Internet and at local markets and reported a mean aerobic count of 5.7 log CFU/g and a psychrotrophic count of 6.3 log CFU/g. Listeria spp. was isolated from fish fillets, including catfish, purchased from local retail markets and via the Internet [9] and from raw fish at a sushi bar [7]. J Food Process Technol S11: 007. doi:10.4172/2157-7110.S11-007

Materials and Methods

Background analysis

Results and Discussion

Conclusion