Natural Bio-Sourced Additives for Bread Technology Improvement and Highly Nutritive Products

Hydrolyzed collagen (HC) and konjac glucomannan (KGM) were used as additives in non-frozen and frozen doughs (NFDs and FDs). Both additives were characterized using specific techniques, i.e., SEM-EDX, MALDI-TOF MS, TGA, and DSC analyses. Rheological analysis of NFD samples was performed using a Chopin Mixolab Profiler. According to a central composite design (CCD), two sets of twelve experiments were conducted to evaluate the influence of percentages of HC and KGM in the mixture of flour and both additives (c_HC = 0.79-2.21% and c_KGM = 0.79-2.21%) on the porosity (PO = 58.96-78.76%), humidity (HU = 42.51-45.60%), electrical conductivity (EC = 2.06-2.29 μS/cm), and pH (pH = 5.5-5.9) of bread samples prepared from NFD and FD. The freezing led to a significant decrease in PO and pH, as well as a significant increase in HU, whereas its effect on EC was not statistically significant. The highest values of response variables that were significantly affected by the process factors, i.e., PO_FD = 70.8%, pH_FD = 5.6, and pH_NFD = 5.9, were obtained in the center point runs (c_HC = c_KGM = 1.50%). For bread samples prepared from FD, the mold development process began approximately four days later than for those prepared from NFD. Bread samples produced from FD and NFD samples in the center point runs showed a low rate of mold formation.