Obtaining bioactive nanofibers from fish gelatin via the Maillard reaction

Nanotechnology enables advances in various fields through the manipulation of matter at the nanoscale. Although electrospun nanofibers show great application potential, they typically exhibit low antioxidant activity. To overcome this limitation, the Maillard reaction, a non-enzymatic reaction between proteins and reducing sugars emerges as a promising strategy to generate desired bioactive antioxidant compounds prior to electrospinning, thereby adding functional value to the material. Given this context, the objective of this study is to develop fish gelatin nanofibers modified via the Maillard reaction prior to electrospinning, aiming to enhance their antioxidant potential. The Maillard reaction was conducted using solutions of fish gelatin (40% w/v) and fructose (10% w/v), adjusted to pH 8 and incubated in an oven (Nova, NI 1514-DCR) at 90 °C for 36 hours, with evaluations performed at 12-hour intervals to monitor the formation of melanoidins and compounds with bioactive potential. As a control, a solution containing only fish gelatin, without added fructose, was subjected to the same reaction conditions for comparison. Following the reaction period, the solutions were characterized via spectroscopy (Kasuaki, UV–VIS IL–593) to assess the formation of Maillard reaction intermediates (304 nm) and melanoidins (420 nm). These same solutions were then electrospun into nanofibers, and the resulting materials were evaluated for antioxidant activity using the ABTS method. Spectrophotometric analysis confirmed the high extent of the reaction, evidenced by the accumulation of products throughout the reaction period. The absorbance corresponding to intermediate products increased from 0.534 ± 0.02 at 0 h to 41.33 ± 0.40 at 36 h, while the absorbance associated with melanoidins rose from 0.667 ± 0.01 to 26.32 ± 0.12 over the same interval. Therefore, the electrospinning yielded nanofibers effectively incorporating these newly formed biocompounds; notably, the high concentration of these melanoidins and intermediate products imparted excellent activity to the material, increasing from 37.72% at the initial time point to 56.77% by the end of the reaction period, demonstrating maximum efficiency in ABTS radical scavenging. Structural modification via advanced Maillard products prior to electrospinning proved an efficient strategy to enhance the bioactivity of the materials. This innovative approach expands the application of fish gelatin nanofibers in the biomedical, food, and environmental sectors, particularly in controlled-release systems capable of carrying various bioactives without compromising the material's structural or functional integrity.