An Evaluation of the On-Site Preservation of Traditional Foodstuff at Tl’azt’en and Lheidli Tenneh Nations

For many generations, First Nations across Canada have been smoking, drying and salting their traditional foods as a method for food preservation. Members of the Tl’azt’en and Lheidli Tenneh Nations were concerned about the by-products that could be generated by using these preservation techniques and were interested in finding out if they can be improved upon.

In this study, samples of raw and preserved food were collected including raw, dried, smoked, half-smoked and/or salted salmon as well as raw, dried, smoked, and salted moose meat. The samples of preserved fish and game along with the control samples of raw fish and game were analysed for polycyclic aromatic hydrocarbons (PAHs) and heavy metals. Food chemistry parameters were also analysed to measure salt, fat and nitrite content, fatty acid composition, and lipid oxidation,

The results indicated that benzo[a]pyrene and other well-recognized PAHs were detectable and quantifiable in smoked fish and moose, but not in fresh samples. Total PAH content increased significantly in salmon samples according to the degree of smoking. Half-smoked salmon that was subsequently canned or frozen contained up to 5 times less total PAHs than fully smoked salmon. In addition, smoked samples had a much higher salt content compared to fresh samples. The study investigators cautioned that the dry salt used in preserving smoked fish can cause risks to human health such as high blood pressure. They suggested reducing the amount of salt used at the curing step. Heavy metal levels were low in both moose and salmon. The study investigators concluded that smoked foods prepared by Tl’azt’en and Lheidli T’enneh Nations could represent a potential health hazard from the standpoint of exposure to relatively high levels of PAHs and high salt content. Additional studies evaluating traditional preservation methods were encouraged to explore how reductions in smoking time might lower PAH levels in smoke processed foods. More work is also needed to assess the potential antimicrobial benefits of smoke processing that could lead to improved food safety and food quality.