The Effect of Free and Encapsulated forms of Quercus persica Extract on the Quality of Minced Kilka (Clupeonella cultriventris caspia)

Quercus persica has a natural antimicrobial and antioxidant properties that are effective on pathogens and retard lipid oxidation. The aim of this study is using two concentrations of free and encapsulated forms (with two covers: maltodextrin + carrageenan and gelatin + carrageenan) of Q. persica extract (0.5% and 1%) in order to improve the shelf life of minced kilka at the refrigeration temperature. Chemical tests (Peroxide value, total volatile nitrogen, thiobarbituric acid, and free fatty acid) and microbial parameters (total viable count and psychrotrophic count) were carried out. Minced Kilka samples treated with encapsulated form of extract at the concentration of 1% showed significantly lower chemical changes as compared to other treatments during the storage period. The results of microbial examination indicated at different period (0, 4, 8, 12 and 16 days) that the treatments containing encapsulated form of extract showed improvements, however of the twelve days all parameters were outside of the standard range (7 log CFU/g). The results of this study indicated that the encapsulation of 1% showed better results as compared to other concentration employed and improved the shelf life of kilka.