Effects of Modified Atmosphere Packaging and Green Tea Extract on the Shelf-life of Silver Carp (Hypophthalmichthys molitrix) Minced at Refrigerated Storage

Silver carp (Hypophthalmichthys molitrix) minced (SCM), as ready-to-cook and high nutritious product, can successfully introduce to consumers and significantly dissolves current problems of limited demand for whole/fresh market. Short shelf-life is one of the most important barriers to developing industrial production of minced fish. Application of Hurdle technology with minimally processing to improve storage life of fresh seafood has become increasingly popular. The main objective of this study was to compare the effects of lowring temperature (3-5 oC), Modified Atmosphere Packaging (MAP) (condition 50:5:45 for N2:O2:CO2) and Green Tea Extract (GTE) (1000 ppm) with normal or Aerobic packaging (AP), on the chemical and sensory characteristics of SCM within refrigerated storage. Total polyphenolic compounds measured in GTE was 14.33±0.88 μg/ml. Results of Peroxide Value showed that all treatments can effectively protect SCM against oil oxidation, compared with AP, after 4 days. Using MAP and/or GTE treatments reduced the Free Fatty Acids (FFAs) formation ratio, because, in contrast with AP treatment, FFAs increased significantely (P<0.05), only after 16 days storage. Thiobarbitoric Acid Reactive Substances (TBARS) of AP samples in 16th days was 2.51±0.21 mg that was upper than accepted limits. Effects of GTE treatment on TBARS increasing was not significantly different compared with AP. pH trends were ascending and GTE and MAP treatments had no significant effects on pH increasing. According to sensory evaluation, MAP had higher total quality score compared with GTE treatment and showed no significant difference with MAP+TE during storage, suggested that MAP more effectively retards and/or inhibits microbial growth in refrigerated SCM.Combined treatment (MAP+GTE) was selected as an effective method that can extend the shelf-life of SCM up to 4 days at refrigerated storage.