Inthalaeng Natthamon, Dugmore Tom I J, Matharu Avtar S
Green Chemistry Centre of Excellence, Department of Chemistry, University of York, York YO10 5DD, UK.
Gels. 2023 Aug 22;9(9):674. doi: 10.3390/gels9090674.
The exploitation of unavoidable food supply chain wastes resulting from primary and secondary processing for chemicals, materials, and bioenergy is an important concept in the drive towards circular-based, resource-efficient biorefineries rather than petroleum refineries. The potential production of hydrogels (materials) from unavoidable food supply chain wastes, which are naturally rich in biopolymers such as cellulose, hemicellulose, pectin, and lignin, represents an interesting opportunity. However, these intertwined and interconnected biopolymers require separation and deconstruction prior to any useful application. Thus, this study aims to explore the formation of hydrogels from defibrillated celluloses (MW-DFCs) produced via acid-free stepwise microwave hydrothermal processing of blackcurrant pomace residues. Initially, pectin was removed from blackcurrant pomace residues (MW, 100-160 °C), and the resultant depectinated residues were reprocessed at 160 °C. The pectin yield increased from 2.36 wt.% (MW, 100 °C) to 3.07 wt.% (MW, 140 °C) and then decreased to 2.05 wt.% (MW, 160 °C). The isolated pectins were characterized by attenuated total reflectance infrared spectroscopy (ATR-IR), thermogravimetric analysis (TGA), and C NMR (DO). The cellulosic-rich residues were reprocessed (MW, 160 °C) and further characterized by ATR-IR, TGA, and Klason lignin analysis. All the MW-DFCs contained significant lignin content, which prevented hydrogel formation. However, subsequent bleaching (HO/OH) afforded off-white samples with improved gelling ability at the concentration of 5% /. Confocal laser microscopy (CLSM) revealed the removal of lignin and a more pronounced cellulosic-rich material. In conclusion, the microwave-assisted defibrillation of blackcurrant pomace, an exploitable unavoidable food supply chain waste, affords cellulosic-rich materials with the propensity to form hydrogels which may serve useful applications when put back into food products, pharmaceuticals, cosmetics, and home and personal care products.
将初级和二级加工过程中不可避免产生的食品供应链废弃物用于生产化学品、材料和生物能源，这一做法在推动建立基于循环利用、资源高效的生物精炼厂而非石油精炼厂的进程中是一个重要理念。利用天然富含纤维素、半纤维素、果胶和木质素等生物聚合物的不可避免的食品供应链废弃物来生产水凝胶（材料），是一个有趣的机会。然而，这些相互交织和连接的生物聚合物在进行任何有用的应用之前都需要进行分离和解构。因此，本研究旨在探索通过对黑加仑果渣残余物进行无酸分步微波水热处理所制备的去纤纤维素（MW-DFCs）来形成水凝胶。首先，从黑加仑果渣残余物中去除果胶（微波，100-160℃），然后将所得的脱果胶残余物在160℃下再处理。果胶产率从2.36 wt.%（微波，100℃）增加到3.07 wt.%（微波，140℃），然后降至2.05 wt.%（微波，160℃）。通过衰减全反射红外光谱（ATR-IR）、热重分析（TGA）和碳核磁共振（C NMR）对分离出的果胶进行了表征。对富含纤维素的残余物进行再处理（微波，160℃），并通过ATR-IR、TGA和克拉森木质素分析进一步表征。所有的MW-DFCs都含有大量的木质素，这阻碍了水凝胶的形成。然而，随后的漂白（HO/OH）得到了灰白色样品，在5%的浓度下具有改善的胶凝能力。共聚焦激光显微镜（CLSM）显示木质素被去除，且富含纤维素的物质更加明显。总之，对黑加仑果渣进行微波辅助去纤处理，这是一种可利用的不可避免的食品供应链废弃物，可得到具有形成水凝胶倾向的富含纤维素的材料，当将其重新应用于食品、药品、化妆品以及家居和个人护理产品时可能会有有用的应用。
