4) (40pts) Sous Vide Cooking -- Cooking the Perfect Albacore Tuna Background Sous Vide is the latest trend in cooking fish, meat, poultry, eggs, etc. using an immersion heater/circulator to maintain

a constant temperature hot water bath with the food typically in a "sealable plastic bag". I want to use this method to cook a perfect albacore filet. Note: Not required to solve problem but if you want perspective there is a link to Sous Vide Cooking in the CANVAS Lecture Notes Module. Question Statement #1 Cooking Method: The albacore filet is vacuum packed in a 2mm thick HDPE plastic bag and submerged by hanging in the center of the temperature-controlled, well-stirred water bath at 90°C. How long will it take for the center temperature of the albacore to reach 60°C wrapped in a 2mm HDPE bag? #2 Cooking Method: The sustainable, eco-friendly method to cook sous vide is to use a reusable silicone bag. The only problem with the silicone bag is that they are thicker than the typical plastic film, so cooking times may have to be adjusted. How long will it take for the center temperature of the albacore to reach 60°C wrapped in a 10mm silicone bag. GIVEN Information - Albacore Steak dimensions: L=12", W=3", thickness = 1.5" - HDPE film thickness (t) = 2mm - Silicone film thickness (t) = 10mm - Initial albacore temperature (To) = 5°C (out of fridge) - Convective heat transfer coefficient (h) = 95 W/m²-K. Physical Properties of Materials NOTE: As a first approximation, the material properties of the composite structure (plastic + fish) should be taken as a thickness weighted average value for the physical properties. Example: k (composite) = k₁*(t₁/total) +k2* (tz/total), where total=t₁ + 1₂ (where t = thickness of each material) Albacore properties: Thermal conductivity (k)= 0.47 W/m-K; thermal diffusivity (a) = 1.53 x 107 m²/sec HDPE: thermal conductivity (k)= 0.5 W/m-K; thermal diffusivity (a)=2.77 x 107 m²/sec Silicone: thermal conductivity (k)= 0.2 W/m-K; thermal diffusivity (a) = 1.55 x 107 m²/sec