Preheat oven to 475 F. Set a wire rack inside a rimmed baking sheet and spray the rack with cooking spray; set aside.
In a 12 inch skillet, combine the breadcrumbs and canola oil. Cook over medium-high heat, stirring constantly, until golden brown. Transfer the breadcrumbs to a wide, shallow dish and set aside to cool.
In a second shallow dish, combine flour, garlic powder, and cayenne pepper.
In a third shallow dish, whisk together egg whites, water, Dijon mustard and thyme until the egg whites are broken up and the mixture is foamy.
Season the chicken with salt and pepper. Dredge each piece of chicken in the flour mixture, shaking to remove excess, then dip in the egg whites coating both sides completely. Finally, place in the toasted breadcrumbs, turning to coat both sides. Transfer to the wire rack and repeat with all chicken tenderloins.
Spray the chicken lightly with cooking spray then bake for 10-12 minutes, or until a meat thermometer reads 165°.