RESUMO
Biocomposites create attractive alternatives to match packing needs with available agricultural residues. Growing native fungal strains developed a mycelium biocomposite over a mixture of Peach Palm Fruit Peel Flour and Sugar Cane Bagasse Wet Dust. A methodology was proposed to analyze their main characteristics: 1) morphological, 2) chemical, and 3) biodegradability. 1) SEM analysis evidenced the structural change of the dried vs pressed material and mycelium morphology for both species. 2) The ratio lignin:carbohydrate showed that P. ostreatus degrades the cellulose-hemicellulose fraction of the substrate at a higher rate than T. elegans, and 3) the curve BMP indicated that these materials are readily biodegradable with a maximum yield of 362,50 mL biogas/g VS. An innovative tangible valorization strategy based on mass balances is also presented: from just 50 kg of peel flour, up to 1840 units can be manufactured, which could pave the way for a more sustainable future.
RESUMO
This study investigated softwood hemicelluloses degradation pathways during alkaline hydrogen peroxide (AHP) pretreatment of Douglas fir. It was found that glucomannan is much more susceptible to alkaline pretreatment than xylan. Organic acids, including lactic, succinic, glycolic and formic acid are the predominant products from glucomannan degradation. At low treatment temperature (90°C), a small amount of formic acid is produced from glucomannan, whereas glucomannan degradation to lactic acid and succinic acid becomes the main reactions at 140°C and 180°C. The addition of H2O2 during alkaline pretreatment of D. fir led to a significant removal of lignin, which subsequently facilitated glucomannan solubilization. However, H2O2 has little direct effect on the glucomannan degradation reaction. The main degradation pathways involved in glucomannan conversion to organics acids are elucidated. The results from this study demonstrate the potential to optimize pretreatment conditions to maximize the value of biomass hemicellulose.
