Tapioca Starch (Best Option)
1:1 (1 tablespoon tapioca starch per 1 tablespoon arrowroot powder)Tapioca starch is chemically similar to arrowroot powder, both being starches derived from tubers. It provides excellent thickening properties and moisture retention, which helps keep banana bread moist and tender without adding off-flavors.
When substituting, use the same amount as arrowroot powder. Tapioca starch gelatinizes at a similar temperature, so it integrates well into the batter without requiring recipe adjustments. Avoid overmixing to prevent gumminess.
The final banana bread will have a texture and moisture level nearly identical to that made with arrowroot powder, preserving the desired soft crumb and subtle chew.