عنوان مقاله [English]
In this study the effect of preliminary ascorbic acid soaking treatments with two concentration 100 and 300 mg on the microbial growth and rancidity development in common carp fillet during refrigerated storage (4±1ºC) up to 21 days was investigated. Microbial analysis including total viable counts and psychrophilic bacteria counts as well as the peroxide, total volatile basic-nitrogen, free fatty acids, thiobarbituric acid and pH were periodically measured every 7 days during storage period. According to the results, the treated sample with 300 mg ascorbic acid significantly reduced the total viable counts as well as psychrotrophic bacteria counts in comparison to other groups (p<0.05). The maximum and minimum amounts of peroxide value was calculated in the control (6.113±0.471 meq/kg) and 300 mg of ascorbic acid (3.933±0.045 meq/kg), respectively (p<0.05). The amount of total volatile base nitrogen was controlled just in 300 mg of ascorbic acid treatment than other treatments at the end of storage day (p<0.05). Increasing trend of thiobarbituric acid was significantly inhibited in 300 mg ascorbic acid treatment compared to control group during storage (p<0.05). The maximum value of free fatty acids (FFA) was obtained in the control (18.378±0.966%) (p<0.05), while the amount of FFA in 100 and 300 mg of ascorbic acid treatments were reached 9.967±0.911% and 7.017±0.267%, respectively. Results of bacterial and chemical analyses showed that bacterial growth and formation of primary and secondary lipid oxidation compounds were controlled by increasing ascorbic acid concentration which was corroborated by a longer shelf-life time.