ABSTRACT
Pup-loaf bread was made with 10, 30, and 50% substitution of flour with wheat starch phosphate, a cross-linked resistant starch (XL-RS4), while maintaining flour protein level at 11.0% (14% mb) by adding vital wheat gluten. Bread with 30% replacement of flour with laboratory-prepared XL-RS4 gave a specific volume of 5.9 cm3/g compared with 6.3 g/cm3 for negative control bread (no added wheat starch), and its crumb was 53% more firm than the control bread after 1 day at 25°C, but 13% more firm after 7 days. Total dietary fiber (TDF) in one-day-old bread made with commercial XL-RS4 at 30% flour substitution increased 3–4% (db) in the control to 19.2% (db) in the test bread, while the sum of slowly digestible starch (SDS) plus resistant starch (RS), determined by a modified Englyst method, increased from 24.3 to 41.8% (db). The reference amount (50 g, as-is) of that test bread would provide 5.5 g of dietary fiber with 10% fewer calories than control bread. Sugar-snap cookies were made at 30 and 50% flour replacement with laboratory-prepared XL-RS4, potato starch, high-amylose (70%) corn starch, and commercial heat-moisture-treated high-amylose (70%) corn starch. The shape of cookies was affected by the added starches except for XL-RS4. The reference amount (30 g, as-is) of cookies made with commercial XL-RS4 at 30% flour replacement contained 4.3 g (db) TDF and 3.4 g (db) RS, whereas the negative control contained 0.4 g TDF and 0.6 g RS. The retention of TDF in the baked foods containing added XL-RS4 was calculated to be >80% for bread and 100% for cookies, while the retention of RS was 35–54% for bread and 106–113% for cookies.
