Waste wheat-rye bread (after shelf-life, returns from shops)
was obtained from local bakery. Whole loafs were manually cut
into dices of ca. 2–4 cm size. Obtained dices were dried in a forced
air oven at 40 °C for 12 h and ground in a knife mill (Rotary Mill,
Brabender, Germany) with 1.5 mm internal mesh sieve. Raw mate-
rial was stored in an air tight jar at room temperature until used.
Starch content in waste bread was determined using Evers polari-
metric method [25] and it ranged 689.13 ± 4.52 g kgÀ1 of raw
material dry matter. The amount of total sugars (as glucose) was
measured using the DNS method [26] after mild acid hydrolysis
(70 °C, 10 min) with 80 g LÀ1 HCl solution (1:7.5 m/v raw material
to HCl solution ratio) and it ranged 866.87 ± 2.85 g kgÀ1 of raw
material dry matter. Raw material moisture content was measured
using WPS 50P weighing dryer (Radwag, Poland) and it ranged
41.43 ± 1.38 g kgÀ1.