5.1.1. Non-traditional foods and non-traditional processes
Today, consumers demand foods that are minimally processed, as "natural" as possible, and yet are convenient to use. Complicating these factors is a consumer preference toward cured and smoked foods that are processed with lower salt, lower nitrate and higher moisture levels. These parameters have a tremendous impact on the safety of a given cured/smoked food or process. Preferences for low fat and low sugar have less impact on the safety, but these factors can change the traditional curing and smoking process. It will be difficult to completely eliminate the use of nitrite, as there is no known substitute for it as a curing agent for meat. Nonetheless, the demand for fewer chemicals added to foods has put pressure on the industry and the scientific community to seek new alternatives.
In-home vacuum packaging machines have become popular in recent years. It is important to realize that in-home vacuum packaging is not a substitution for cooking or any form of food preservation, e.g., refrigeration, freezing, or curing (Andress 2001). In-home vacuum packaging can reduce the quality deterioration of foods catalyzed by oxygen, such as rancidity. Many food spoilage and food poisoning organisms require oxygen for growth and would also be inhibited by this process. However, the most deadly food poisoning organism, Clostridium botulinum requires a low oxygen atmosphere and therefore, vacuum packaging favors its growth (Andress 2001). In cured meats, careful attention must be paid to proper use of nitrates/nitrites that inhibit Clostridium botulinum prior to use of in-home vacuum packagers. To further reduce the risk of botulism after vacuum packaging, properly refrigerate the cured/smoked meats. Under normal processing, freezing of salt-cured meats is not recommended, due to oxidative rancidity that affects the quality and flavor of the product.
5.2.2. Clostridium perfringens
Spores of some strains of Clostridium perfringens are so heat resistant that they survive boiling for four or more hours. Furthermore, cooking drives off oxygen, kills competitive organisms, and heat-shocks the spores, all of which promote germination to vegetative or growing cells. Once the spores have germinated, a warm, moist, protein-rich environment with little or no oxygen is necessary for growth. If such conditions exist (i.e., incorrectly holding meats at warm room temperature for smoking), sufficient numbers of vegetative cells may be produced to cause illness upon ingestion of the contaminated meat product.
5.2.3. Listeria monocytogenes
L. monocytogenes has been found in fermented raw-meat sausages, raw and cooked poultry, raw meats (all types), and raw and smoked fish. Its ability to grow at temperatures as low as 3°C, permits multiplication in refrigerated foods. The organism grows in the pH range of 5.0 to 9.5 and is resistant to freezing. It is salt tolerant and relatively resistant to drying, but easily destroyed by heat. (It grows between 34 - 113°F).
For more information, please refer to the following resources:
1.Potential Hazards in Cold Smoked Fish: Listeria monocytogenes (US FDA 2001c).
5.4.4. Fish
Listeria monocytogenes has been found in commercial samples of cold smoked fish leading to product recalls in New York (Cold smoked sea bass FDA Recall No.F-313-1) and Seattle, WA (Cold smoked salmon FDA Recall #F-265-1). These recalls demonstrate that even with HACCP and careful plant sanitation, commercial processors have contamination incidences in their cold smoked fish processes. In New York, fish sausage was recalled because laboratory analysis found pH (acidity), salt and water activity levels in the product were such that they could potentially permit Clostridium botulinum to develop and produce the toxin (NY State Agriculture Commissioner 2000).
For more information, please refer to the following resources:
1.Uneviscerated Fish Products that are Salt cured, Dried, or Smoked (US FDA 2000).
2.International Outbreak of Type E Botulism Associated With Ungutted, Salted Whitefish (CDC 1987).
3.Vibrio parahaemolyticus Infections Associated with Eating Raw Oysters -- Pacific Northwest, 1997 (C.D.C. 1997c).
4.Vibrio vulnificans (US FDA CFSAN 1998).
5.Processing Parameters Needed to Control Pathogens in Cold Smoked Fish (US FDA 2001c).
5.5.3. Greening of Cured/Smoked Meats (Members have seen this on bacon)
Lactobacillus viridescens, or similar bacteria that produce hydrogen peroxide may cause greening in meats. The H2O2 reacts with myoglobin to produce a green sheen pigment. The meat, while less appealing, is not dangerous to consume.
