The effect of frozen storage on chemical and sensory quality of horse mackerel (Trachurus trachurus) coated whey protein isolate enriched with thyme essential oil


Tokur B., AKSUN E. T.

SU URUNLERI DERGISI, cilt.35, ss.295-304, 2018 (ESCI İndekslerine Giren Dergi) identifier

  • Cilt numarası: 35 Konu: 3
  • Basım Tarihi: 2018
  • Doi Numarası: 10.12714/egejfas.2018.35.3.09
  • Dergi Adı: SU URUNLERI DERGISI
  • Sayfa Sayıları: ss.295-304

Özet

In this study, the effectiveness of whey protein isolate (WPI) and WPI enriched thyme essential oil coating to improve the quality of horse mackerel during frozen storage at -18 degrees C +/- 2 were evaluated for nine month. Whey protein isolate without thyme essential oil (WPIO) and three different proportion thyme essential oil (3, 5 and 7 %, v/v) in whey protein isolate (WPI3, WPI5 and WPI7) coating solutions were applied to horse mackerel. As a control, non-coated and distillated water coating (DW) horse mackerel were used. The results showed that the lowest peroxide value (PV) (meq of peroxide oxygen kg-1) and thiobarbutiric acid value (TBA) (mg malonaldehyde/kg muscle) were determined in WPI coatings enriched with 3% thyme essential oil treated group (p<0.05) while the highest PV and TBA values were determined in WPI coatings enriched with 5% and 7% thyme essential oil treated groups (p<0.05). Among the treatment, DW and the WPI coatings enriched with 7% thyme oil gave significantly higher protein solubility than other treatments during frozen storage (p<0.05). Electrophoretic studies in the presence and absence of beta-mercaptoethanol showed that high molecular weight polymers via non-disulfide and disulfide cross-linking occurred in the horse mackerel proteins extracted in 5% NaCI in all groups during frozen storage. Sensory assessment showed that the horse mackerel coated WPI enriched with 5 and 7% thyme essential oil could not be stored for more than 9 months.