Evaluation of the quality properties of grape pomace and flaxseed oil microcapsules stabilized with different ratios of maltodextrin and gum tragacanth

Encapsulation is a process to protect bioactive compounds against unfavorable environmental conditions in order to increase their stability and bioavailability. Regarding the existence of bioactive compounds in grape pomace and flaxseed oil, the aim of this research was to encapsulation of grape pomace (Vitis viniferae cv. Rash (and flaxseed oil with different ratios of maltodextrin and gum tragacanth (1:1, 1:2, 2:1) using a spray drier and evaluation of the quality properties of obtained microcapsules. The produced microcapsules were analyzed in terms of microcapsulation yield, solubility and humidity contents, total phenolic contents, antioxidant activity, the interaction between wall and core materials and microstructure. According to the results, there were no significant differences between the microcapsules in terms of humidity and solubility contents (P<0.05). The highest microencapsulation yield, total phenolic contents and antioxidant activity were observed in the microcapsules produced with equal ratios (1:1) of maltodextrin and gum tragacanth. While the spherical shape was observed by scanning electron microscope for all of microcapsule samples, the microcapsules produced with equal ratios (1:1) of maltodextrin and gum tragacanth had a more compact and homogeneous structure. FT-IR analysis also confirmed the creation of new interactions between the wall and core materials of the obtained microcapsules. The results of the present research showed that using maltodextrin and gum tragacanth as wall material in an equal ratio (1:1) had a proper performance in order to microencapsulation of grape pomace and flaxseed oil.