Breads containing 30% and muffins containing 50% flaxseed were rated better than their counterparts regarding overall acceptability scores.
That is a surprisingly high level. It's worth noting that 30% is the highest level tested in bread, so the highest level tested was the best. Given that they tested muffins up to 66%, it seems plausible that the 50% found optimal in muffins may also be optimal in bread.
1/4 cup (60 mL) ground flax3/4 cup (175 mL) warm water1/2 tsp (2 mL) salt2 tsp (10 mL) canola or flax oil1 3/4 cups (425 mL) all-purpose flour (approx)
I calculate that that's a flax content of about 18 baker's percentage.
Especially at 250°C, lignans were degraded rapidly in sesame seeds and rye but not in flax seeds.
Cool. That's about 480 Fahrenheit, which is over a hundred degrees more than I roast my flax (350F). However, they only roasted for three and a half minutes (from full text), compared to the 10 minutes that I use. Nevertheless, heat sensitive degradation tends to be logarithmic, so I'd likely still be fine if I cooked it for an hour (at least for lignans. The omega-3 would probably oxidize, though)