No abstract

This study aimed at investigating the effect of enzymatic bioprocessing and the addition of green coffee infusion on the nutritional, technological, and sensory characteristics of whole-wheat bread as well as of information on sensory profile. The proposed strategies increased minerals and soluble fibre content. Green coffee addition increased phenolics content up to 58% and incorporated caffeine to its composition. Bioprocessing increased bread volume up to 18%. Both strategies modified breads' colour perception. In the blind CATA test, breads were grouped according to the employment of enzymatic bioprocessing, but not to the addition of green coffee infusion. Non-bioprocessed samples were characterised with more favourable terms. The acceptance of bioprocessed breads was improved once information regarding the presence of healthy substances were given. Therefore, the use of both strategies was successful to improve technological and nutritional benefits when information was given to consumers, yielding a bread with promising market potential.

Research background. This study aimed to monitor the growth of the methylotrophic bacteria Methylobacterium organophilum in a culture medium with methanol as a carbon source and to verify the production of unicellular proteins and other biomolecules, such as carotenoids, exopolysaccharides and polyhydroxyalkanoates, making a compound more attractive as food intended for animal feed. Experimental approach. Microbial growth was studied in shaken flasks to evaluate bacterial growth with different carbon: nitrogen ratios (C: N) and determine the best results in terms of cell volumetric productivity and substrate consumption rate. This condition was to be further applied in an in a fed-batch operating bioreactor system, which depicted the kinetic profile of cell growth, which concentrations were determined by dry cell weight, methanol consumption, measured by HPLC analysis, accumulation of carotenoids, which was analyzed by mass spectrometry, and the production of exopolysaccharide, which was characterized in terms of its chemical composition and submitted to chemical rheological analysis. Results and conclusions. The best experimental condition was verified using an initial methanol concentration of 7 g/L in the culture medium. This same initial substrate concentration was used in the bioreactor in the fed-batch operation, and the biomass concentration was 5 g/L, after 60 hours of cultivation. The accumulation of carotenoids associated with cell growth was monitored, reaching a concentration of 1.6 mg/L at the end of the process. These pigments were then analyzed and characterized as a set of xanthophylls (oxidized carotenoids). In addition, two other products were identified during the fed-batch operation: an exopolysaccharide (EPS), which reached a concentration of 8.9 g/L at the end of the culture, and an intracellular granular structure which was detected by transmission electron microscopy (TEM), suggesting the accumulation of polyhydroxyalkanoate (PHA), most likely polyhydroxybutyrate. Novelty and scientific contribution. M. organophilum demonstrated a unique ability to produce compounds of commercial interest, leading to a genuine understanding that this species has a metabolism distint. The use of Methylobacterium organophilum makes room for platform integration in the context of biorefineries as a result of its distinct metabolic diversity.