Application of the Products from the Maillard Reaction of Polyglutamic Acid and Glucose to Prepare Colored and Bioactive Silk

Abstract

Abstract:In this work, the Maillard reaction of polyglutamic acid (PGA) and glucose (Glc) was studied, and its functional, polymeric, and colored products were used to dye silk fiber with the aim of imparting bioactivities to silk. The UV-Vis spectroscopic analysis, which was employed to monitor the reaction, revealed the rapid formation of yellowish-brown products at pH 12 and 90 • C, and the great impact of glucose content on the quantity of the products. The FT-IR analysis validated the formation of melanoidin colorants. The silk fiber dyed with the PGA/Glc reaction products at pH 3 displayed a yellowish-brown color, and had very good wash and rub fastness, but poor light fastness. The incorporation of the UV-absorbing moiety into the PGA/Glc reaction products enhanced their light stability. The SEM analysis revealed that the dyed silk fiber was covered by polymeric substances. The dyed silk exhibited durable antibacterial activity against Staphylococcus aureus and Escherichia coli, and good antioxidant activity. This research expands the application field of the Maillard reaction and provides a novel and eco-friendly approach to prepare the colored and bioactive silk materials.

Physicochemical Characterization of Chitosan/Poly-γ-Glutamic Acid Glass-like Materials

“…Regarding R1 and R2, the characteristic peaks observed at 3400, 1727, 1645, 1557, and 1410 cm −1 correspond to N-H bonds, C=O stretching vibration of the carboxylic acid, C=O of amide I, C-N stretching modes vibration, and CH2 bending deformations, respectively. Notably, the prominent peaks at 1129 cm −1 could be related to the melanoidin C-O bending bands [25]. The In light of these findings, our materials can be described as thermoplastic and saloplastic, signifying vast applications in the field of PECs, including the creation of 3D forms, PEC micro-chambers (opening up new possibilities for innovative uses), and further explorations in the realm of polyelectrolyte complexes [22,23].…”

“…Regarding R1 and R2, the characteristic peaks observed at 3400, 1727, 1645, 1557, and 1410 cm −1 correspond to N-H bonds, C=O stretching vibration of the carboxylic acid, C=O of amide I, C-N stretching modes vibration, and CH 2 bending deformations, respectively. Notably, the prominent peaks at 1129 cm −1 could be related to the melanoidin C-O bending bands [25]. The complexation between the two biopolymers was investigated by comparing the infrared spectra of CHR1 and CHR2 with the neat biopolymers (CH, R1, and R2).…”