The effects of ascorbic acid and packaging methods on quality and shelf life of uncoated burger made from Silver carp (Hypophthalmichthies molitrix) stored at -18°C

Uncoated fish burgers were produced in order to expand the variety of products from Silver carp, Hypophthalmichthies molitrix ,and increase the consumption of this fish species. On the other hand in order to compare the effect of ascorbic acid and vacuum packaging on rancidity inhibition and microbial quality, 3 different treatments of fish burger were produced: 1. Burger with common packaging (Control group), 2. Burger with vacuum packaging 3. Burger with 500 ppm ascorbic acid in common packaging. All the treatments were stored in -18 ºC for 6 months after freezing by a spiral freezer in -35 ºC. Chemical, microbiological and sensory evaluations were determined from time 0 and after that monthly until the 6th month. The TVB-N value increased during the storage period but it never passed out of the standard range. The TBA value increased in all treatments but in ascorbic acid treatment it was significantly lower than the other two groups. The pH amounts during storage period decreased in all treatments homogeneously. Microbial counts in all treatments and especially in vacuum packed burgers decreased during the storage period. Organoleptic test demonstrated the preference of burgers treated by ascorbic acid. The shelf life of control group and burgers with vacuum packaging was determined 3 months at least. The shelf life of treated burgers with ascorbic acid was determined about 6 months specially based on the TBA index and sensory evaluation. Vacuum packaging was more effective to protect burgers of chemical and microbial changes compared to common packaging.