Determination of antioxidant and antimicrobial effects of pomegranate peel extract in trout burgers stored at cold temperatures (4±1°C)

Recently, it has become a common practice to utilize food processing waste as natural additives in food products by evaluating their antioxidant and antimicrobial activities. Pomegranate peel is also an important by-product involved in the pomegranate processing industry and has strong antioxidant and antimicrobial properties. Therefore, the aim of this study is to examine the quality changes of trout burgers prepared with pomegranate peel extract during the refrigerated (4±1°C) storage. For this purpose, peroxide value, thiobarturic acid (TBARs), total aerobic mesophilic bacteria (TAMB) count, total psyschophilis bacteria (TPB) count, total coliform bacteria, total yeast-mold, total lactic acid bacteria (LAB) count and sensory quality parameters were evaluated in trout burgers. Peoxide value was found to be 2.75 meq O2/kg at the beginning with increasing in all groups and were observed significantly lower in the groups prepared with pomegranate peel extract than the control group (24.85 meq O2/kg). TBARs value of trout fillet was 0.07 mg MDA/kg and increased in all groups until the end of storage. The lowest values compared to the control group were found in the group prepared with 1% pomegranate peel extract. At the end of storage, TBARs values of the control, groups enriched with 0.5% and 1% pomegranate peel extract reached 2.78, 2.32 and 2.25 mg MDA/kg, respectively. It has been determined that pomegranate peel extract has a suppressive effect on TAMB, TPB, total coliform, total yeast-mold and LAB growth in trout burgers. As a result of sensory evaluations, pomegranate peel extract has been observed to extend the shelf life of trout burgers by 6 days compared to the control group. All these data revealed that pomegranate peel extract can be used as an alternative natural additive in trout burgers.