Formation of polymeric micro/nano particles and fibers including bitter melon (Momordica charantia L.) extract by electrospinning method

In this study we tried to produce polymeric micro/nano particles and fibers by electrospinning method using natural polymers such as maltodextrin, gelatin and zein for to be used in food formulations and bitter melon extract was used to provide functional features to the structures. In the first part of the study we obtained the structures from neat feed solutions that prepared with water for maltodextrin, 20% diluted acetic acid for gelatin and 70% ethanol for zein. We determined appropriate electrospinning parameters (flow rate, voltage and distance) parameters for each polymer. We examined the effect of different polymer concentration on diameters that formed after electrospinning. In the second part of the study bitter melon was extracted with water and 70% ethanol and used as a solvent instead of neat water and alcohol for preparing feed solutions. While water extract was used for maltodextrin and gelatin, alcohol extract was used for zein polymer. The total phenolic contents of water and alcohol extracts were found as 196.95 and 287.50 mg GAE/l extract, respectively. When we compared the total andioxidant activities; alcohol extracts showed higher antioxidant activity (32%) than water extracts (27%). We compared infeed solutions prepared with/without bitter melon extract and structures obtained from them after electrospinning process. We want to know how to change electrospun samples with adding extract. To determine the characterization of the feed solutions; pH, electrical conductivity, surface tension and rheology analyzes were performed. SEM images, surface zeta potential values, DSC thermogram, FTIR spectrum, total phenol and antioxidant content were obtained for characterization of electrosprayed particles and electrospun fibers. According the results it was observed that electrospun samples obtained from infeed solutions prepared with bitter melon extracts had better surface morphology and smaller diameter. And among polymers, zein nanofibers including bitter melon extract showed the best properties. Zeta potential, total phenolic content and total antioxidant capacity (DPPH) analyses results of zein fibers were 21.77 mV, 2.6 mg GAE/100 g fiber and 32.90%, respectively. The results indicated that bitter melon extracts could be used to obtained structures in better properties via electrospinning process. These particles and fibers may be used to enhance functional properties by adding as an ingredient in food formulations.