The antioxidant effects of green macroalgae Ulva intestinalis hydroalcoholic extract on farm-raised Beluga minced meat during refrigerated storage

The present study was carried out to investigate the physicochemical changes of farm-raised Beluga minced meat during the storage period in the refrigerator under the influence of hydroalcoholic extract of Ulva intestinalis macroalgae as a natural preservative. The minced fish was prepared with concentrations of 0 (control), 12.5, 25 and 37.5 mg/kg of the macroalgae extract. A sample with synthetic antioxidant (BHT) was included. Physicochemical properties (peroxide, volatile nitrogen, free fatty acids, thiobarbituric acid and color) of the samples were measured on 0, 4, 8 and 12 days. On the fourth day of the storage, the lowest values of peroxide index (5.1 meq/kg oil), thiobarbituric acid (0.23 mg malondialdehyd/ kg of meat), volatile nitrogen (25.55 mg N/100 g) and free fatty acids (0.47% oleic acid) was measured in treated samples with 36.5 mg of macroalgae extract compared to control and BHT treatments (P<0.05). The results of color indicated that the red and yellow indexes were increased during the storage period, while the highest amount of them were observed in treated samples with the macroalgae extract compared to control and BHT samples. Therefore, this algal extract might be considered a natural preservative and the best antioxidant effects was obtained in 37.5 mg of the extract per kilogram of the minced meat, which can be prolonged Beluga minced meat up to 12 days.