Mucilage and hydrocolloids are hydrophilic biopolymers with high molecular weight and due to their functional properties are used as stabilizer, emulsifier or in film formatting agent in food industries. Recently biodegradable and biocompatible polymers are used in nanofiber formation. Cress seed mucilage (CSM) is a new source of hydrocolloid and because of its inherited biodegradability and biocompatibility can be used in this field. In this study CSM was used to fabricate nanofiber. To obtain CSM, the mucilage was extracted from cress seeds at pH=10, water/seeds ratio= 30:1 for 15 minutes and then freeze dried. The viscosity and electrical conductivity of electrospun solutions were measured. With increasing CSM in the solutions, the viscosity and electrical conductivity were increased. CSM (3%)/PVA (10%) at different ratios (80:20, 40:60, 60:40 and 20:80) with voltage/distances ratio of 18/17 and 23/17 kV/CM were produced. SEM analysis showed the effect of voltage and CSM/PVA ratio on nanofiber diameters. With increasing CSM ratio the diameters of nanofibers reduced whereas by increasing voltage, nanofiber diameters increased. CSM/PVA nanofibers in the ratio of 60:40 and the mean diameter of 172.2±43.5 were recognized as the best sample and were used for further analysis. FTIR analysis showed no interaction between CSM and PVA. Amorphous structure of nanofibers verified by XRD analysis. TGA analysis showed three thermal degradation steps for nanofibers and it was indicated that the thermal stability of CSM nanofiber was higher than CSM. Vitamin A was encapsulated in CSM/PVA (60:40). Encapsulation efficiency decreased from 99% to 97% and encapsulaiton load increased from 9.9% to 29.5% by increasing of vitamin A ratio. Based on SEM results, with encapsulation of vitamin A, the nanofiber diameters increased from 172/2± 43/50 to276/36 ±99/33. FTIR analysis verified the presence of main peaks of vitamin A without any reaction with CSM and PVA in nanofibers. Crystalline structure of nanofiber encapsulated with vitamin A with the crystallinity of 55% was observed by XRD analysis. TGA analysis showed that thermal resistance of encapsulated vitamin A was higher than non-encapsulated vitamin A. The release of vitamin A was analyzed in gastrointestinal media and showed higher release rate in intestine in comparison to gastric media. Release modeling of vitamin A also performed and Hixson-Crowell, Kopcha and Ritger-Peppas, showed the best fitness with experimental data by having the highest amount of R 2 /MSE, i gastric, intestine and whole time of the release, respectively. Keywords: Electrospinning, Cress Seed Mucilage، nanofibers, Encapsulation, Vitamin A
