EFFECT OF FILMS OF DIFFERENT OXYGEN TRANSMISSION RATE ON TOXIN PRODUCTION BY CLOSTRIDIUM BOTULINUM TYPE E IN VACUUM PACKAGED COLD AND HOT SMOKED TROUT FILLETS

Abstract

Studies were done to determine the effect of film oxygen transmission rate (OTR) on the time to toxicity in vacuum packaged cold and hot smoked rainbow trout fillets challenged with C. botulinum type E (102 spores/g) and stored at refrigerated conditions (4C), and under mild (8C) and moderate (12C) temperature abuse conditions. While no samples were toxic at 4C, toxin was detected within 28 days at 8C for cold smoked trout fillets vacuum packaged in films with high OTR. Toxin was also detected for most vacuum packaged hot smoked trout fillets within 14–28 days at 8C, with the exception of trout fillets packaged in films with an OTR > 10,000 cc/m2/day. In most cases at 8C, spoilage, based on odor/color scores, preceded or occurred simultaneously with toxigenesis. At 12C all cold and hot smoked trout were toxic after 14–21 days and samples packaged in films with an OTR <5000 cc/m2/day became toxic before, or at the same time as, samples became spoiled. This study has shown that vacuum packaging of trout fillets in low gas barrier films, ranging in OTR from approximately 3,000 to approximately 10,000 cc/m2/day at 24C and 0% relative humidity (RH), did not prevent the growth and toxin production by C. botulinum in vacuum packaged cold and hot smoked trout fillets at 12C. Additional barriers, other than the OTR of the packaging film, need to be considered to ensure the safety of vacuum packaged trout fillets, particularly at mild to moderate temperature abuse storage conditions.

Extensive growth and growth boundary model for non-proteolytic Clostridium botulinum – Evaluation and validation with MAP and smoked foods

“…The model was successfully validated for seafood and poultry irrespectively of packaging in air, vacuum or MAP (Table 2, Table 4). This is important, as non-proteolytic C. botulinum although anaerobic can grow and form toxin in food stored aerobically (Dufresne et al, 2000;Huss et al, 1980;Kautter, 1964;Thatcher et al, 1962). Furthermore, oxygen in MAP can be depleted by spoilage bacteria, which will make the environment favorable for the growth of C. botulinum (FDA, 2020).…”

Preservation of Fish by Curing

“…One of the potential hazards in smoked fish, particularly in cold-smoked products, is contamination by Clostridium botulinum which produces toxic compounds. Appropriate combinations of NaCl and low temperature are sufficient to guarantee that growth of this organism is eliminated during the shelf life of the product under vacuum packaging (Huss, 1980;Dufresne et al, 2000). No toxic compounds were detected in cold-smoked trout stored for 4 weeks at 4 • C or 8 • C at a salt concentration of 1.7% (w/w) (Dufresne et al, 2000).…”

“…Appropriate combinations of NaCl and low temperature are sufficient to guarantee that growth of this organism is eliminated during the shelf life of the product under vacuum packaging (Huss, 1980;Dufresne et al, 2000). No toxic compounds were detected in cold-smoked trout stored for 4 weeks at 4 • C or 8 • C at a salt concentration of 1.7% (w/w) (Dufresne et al, 2000). Also, no toxin was detected by Cann and Taylor (1979) at 2.5-3.5% NaCl (w/w) in hot-smoked trout stored at 10 • C. In addition, vacuum packaging is one of the effective methods for inhibition of Clostridium botulinum growth.…”

Comparison of New Dynamic Accumulation Method for Measuring Oxygen Transmission Rate of Packaging against the Steady‐State Method Described by ASTM D3985

“…This method has been used by several researchers, including George et al ., Laohakunjit and Noomhorm and Raj et al ., but is experimentally difficult and not considered as accurate as other methods. One of the most popular methods for measuring OTR is ASTM D3985, which is used by many researchers, including Brennan et al ., Dufrense et al ., Kim et al . and Mexis et al .…”

“…This method has been used by several researchers, including George et al, 2 Laohakunjit and Noomhorm 3 and Raj et al, 4 but is experimentally difficult and not considered as accurate as other methods. One of the most popular methods for measuring OTR is ASTM D3985, 5 which is used by many researchers, including Brennan et al, 6 Dufrense et al, 7 Kim et al 8 and Mexis et al 9 ASTM D3985 is considered to be a steady-state, isostatic method using a coulometric sensor. Commercially available instruments have been developed around ASTM D3985 and are available from several vendors, including Illinois Instruments (Johnsburg, IL, USA) and Mocon, Inc. (Minneapolis, MN, USA).…”