Premium
Effect of toasting time on the browning of sliced bread
Author(s) -
RamírezJiménez Antonio,
GarcíaVillanova Belén,
GuerraHernández Eduardo
Publication year - 2001
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.840
Subject(s) - browning , chemistry , maillard reaction , absorbance , food science , lysine , linear relationship , oxygen radical absorbance capacity , hydroxymethylfurfural , 5 hydroxymethylfurfural , chromatography , biochemistry , amino acid , antioxidant capacity , mathematics , furfural , fructose , catalysis , statistics , oxidative stress
Slices of wheat bread were toasted for different times until a distinct intensity of brown colour was reached. Two assays were carried out: prolonged toasting times (5–60 min) and reduced toasting times (0.5–5 min). The browning indicators (furosine, available lysine, hydroxymethylfurfural (HMF), colour and absorbance at 284 and 420 nm) were determined. The precision of all indicators used was high (CV < 4%). No furosine or HMF was detected in the dough before baking. The furosine content increased until 7 min (299 mg per 100 g protein) and then decreased to 2.9 mg per 100 g protein at 60 minutes. For the first toasting times (0.5, 1 and 2 min) the furosine content decreased slightly. Available lysine reached losses of 50% after 25 min of heating. The toasting of bread increased HMF values from 12 to 2025 mg kg −1 for the assay at prolonged times of heating and from 1.3 to 4.2 mg kg −1 at reduced times (0.5–5 min). The HMF content decreased (1000 mg kg −1 ) when the sliced bread was toasted until it burnt. Colour (Δ E , 100 − L *) and absorbance at 284 and 420 nm always increased. High linear correlations ( r 2 > 0.860) were obtained between browning indicators and time ( A 284 /time, A 420 /time, 100 − L */time and HMF/time). © 2001 Society of Chemical Industry