Impact of melon seed oil cake with different particle sizes on bread quality

Abstract

Melon seed oil cake (MSOC), as the secondary by-product from melon seed oil pressing process, has high potential nutritional value. The aim of this study was to assess the effect of incorporating MSOC as wheat flour substitute and its particle size on bread quality; three particle size fractions of MSOC (coarse, medium, and fine) and two substitution levels (3 and 6%, w/w) were employed. Functional properties and colour of different particle sizes of MSOC were assessed, and the physical properties of bread made with MSOC were explored and compared to control bread (100% wheat flour). Results showed that bread made with 3% MSOC had relatively satisfactory quality in terms of specific volume (2.64–2.86 mL/g), hardness (14.31–15.04 N) compared to the control bread (specific volume 2.79 mL/g and hardness 13.87 N). Bread made with fine particle size of MSOC (2.64 mL/g and 15.04 N at 3% substitution level; 2.44 mL/g and 16.03 N at 6% substitution level) had lower specific volume and higher hardness values than the bread made with medium (2.80 mL/g and 14.31 N at 3% substitution level; 2.50 mL/g and 15.50 N at 6% substitution level) and coarse (2.86 mL/g and 14.72 N at 3% substitution level; 2.52 mL/g and 15.12 N at 6% substitution level) particle sizes of MSOC. These results indicate that using 3% MSOC with larger particle size could be more suitable for making bread with relatively satisfactory quality. Overall, MSOC could be re-introduced into food chain as ingredient for bread production, which offers possibilities to develop novel sustainable foods. Future work will be conducted on sensory quality and consumer acceptance to provide a desirable quality of bread. Graphical Abstract