Obtention and Characterization of Microcrystalline Cellulose from Industrial Melon Residues Following a Biorefinery Approach

• Published in: Molecules (Basel, Switzerland) Vol. 29; no. 14; p. 3285
• Main Authors: Gómez-García, Ricardo, Sousa, Sérgio C, Ramos, Óscar L, Campos, Débora A, Aguilar, Cristóbal N, Madureira, Ana R, Pintado, Manuela
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 11-07-2024
• Subjects: Biomass; biopolymer; Cellulose; Cellulose - chemistry; circular bioeconomy; Circular economy; crystalline cellulose; Cucurbitaceae - chemistry; Energy consumption; Food; food-waste biorefinery; Hydrogen bonds; Landfill; Lignin; Lignocellulose; melon residues; Polymers; Raw materials; Seeds; Spectroscopy, Fourier Transform Infrared; Waste management; X-Ray Diffraction; X-ray diffraction; biopolymer; melon residues; circular bioeconomy; crystalline cellulose; food-waste biorefinery
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules29143285

Residual melon by-products were explored for the first time as a bioresource of microcrystalline cellulose (MCC) obtention. Two alkaline extraction methods were employed, the traditional (4.5% NaOH, 2 h, 80 °C) and a thermo-alkaline in the autoclave (2% NaOH, 1 h, 100 °C), obtaining a yield of MCC ranging from 4.76 to 9.15% and 2.32 to 3.29%, respectively. The final MCCs were characterized for their chemical groups by Fourier-transform infrared spectroscopy (FTIR), crystallinity with X-ray diffraction, and morphology analyzed by scanning electron microscope (SEM). FTIR spectra showed that the traditional protocol allows for a more effective hemicellulose and lignin removal from the melon residues than the thermo-alkaline process. The degree of crystallinity of MCC ranged from 51.51 to 61.94% and 54.80 to 55.07% for the thermo-alkaline and traditional processes, respectively. The peaks detected in X-ray diffraction patterns indicated the presence of Type I cellulose. SEM analysis revealed microcrystals with rough surfaces and great porosity, which could remark their high-water absorption capacity and drug-carrier capacities. Thus, these findings could respond to the need to valorize industrial melon by-products as raw materials for MCC obtention with potential applications as biodegradable materials.