The food industry by-products in bread making: single and combined effect of carob pod flour, sugar beet fibers and molasses on dough rheology, quality and food safety

Obtaining high-quality value-added bread with extended shelf-life by utilizing food industry by-products that would have minimal negative effect on gluten structure while avoiding the usage of synthetic preservatives, was the challenge of this study. For this purpose the influence of the combination of carob pod flour (C, 0-15%), sugar beet fibers (F, 0-10%) and sugar beet molasses (M, 0-6%) on dough rheology and bread quality was investigated. Selected materials were of good microbiological quality, while carob flour and sugar beet fibers were rich in dietary fibers (43.6% and 67.0%, respectively). The presence of high share of dietary fibers (combination of C and F) increased dough resistance to extension up to 2.5 times, while dough extensibility was reduced by 50%. The addition of molasses had less pronounced single effect on dough properties however its impact in combination with fiber-rich materials outweighed the individual effect (an increase of dough resistance at about 55%). Molasses alone and in combination with other ingredients had positive effect on bread quality. Sample M6F5 attained crumb quality score (6.0 of maximum 7.0) higher than in control sample (5.6). High share of C and F reduced loaf volume and crumb quality of bread up to 56% and 50%, respectively and increased hardness 7.5 times. However, carob flour (7.5%) increased polyphenols content and antioxidant capacity 3 and 4 times, respectively. Moreover, carob flour and molasses and their combination showed inhibitory effect on mold mycelia growth and spores formation. Regarding all of the above, C7.5M3F5 was chosen as optimal sample.

Automated summary

This study explored the utilization of food industry by-products to produce high-quality value-added bread with extended shelf-life, while avoiding synthetic preservatives. The combination of carob pod flour, sugar beet fibers, and sugar beet molasses had a significant impact on dough rheology and bread quality. The optimal sample chosen was C7.5M3F5 after considering various factors such as dough resistance, extensibility, crumb quality, and mold inhibition.