RESEARCH ARTICLE The impact of gravading process on the quality of carp fillets (Cyprinus carpio): sensory, microbiological, protein profiles and textural changes MustafaDurmus¸ 1 • Krzysztof Suro ´wka 2 • Fatih Ozogul 1 • Ireneusz Maciejaszek 2 • Iwona Tesarowicz 2 • Yesim Ozogul 1 • Ali Rıza Kosker 1 • Yılmaz Ucar 1 Received: 2 February 2017 / Accepted: 5 April 2017 Ó Bundesamt fu ¨r Verbraucherschutz und Lebensmittelsicherheit (BVL) 2017 Abstract The chemical, sensory, microbiological, protein profile and textural changes of vacuum- packaged ‘gravad’ carp fillets (Cyprinus carpio) were investigated during storage at 3 °C. Sensory analyses showed that vacuum-packed gravad was still acceptable at the end of 8 weeks of storage. Due to gravading, the total viable count did not exceed the acceptable limit of 10 6 –10 7 cfu g -1 . Our SDS-PAGE analysis revealed that gravading caused a slight decrease in the relative intensity of myosin heavy chain (MHC), while the level of actin remained unchanged. Due to gravading, we found an increase in the values for cohesiveness and chewiness. The values for hardness and chewiness decreased which was accompanied by a slight reduction in springiness and cohesiveness. Texture profile analysis revealed that the a-value was higher in raw carp (RC) than in gravad carp before (GB) and after storage (GA); whereas the b-value was lower in RC than in GB and GA. Keywords Gravad Á Carp Á Texture Á Protein profile Á Storage stability 1 Introduction Seafood and freshwater products have a high nutri- tional value and are steadily favoured by consumers in the world. These products play an important role in human nutrition, disease prevention and health promotion (Khoddami et al. 2009). Hence, seafood consumption is continually increasing from year to year due to high value properties. Fish and fish products are valuable products, demanded on inter- national and domestic markets. However, these products can easily be deteriorated owing to their susceptible structure. Hence, due to quick deteriora- tion, fresh fish must either be quickly consumed or technologically processed. Consumers generally pre- fer fresh products, eaten raw, minimally processed, traditionally processed (salted, smoked, cured, mari- nated) and ready-to-eat (RTE). Minimally-processed products play a fundamental role in fish-derived food. Thus, gravads, traditional Scandinavian prod- ucts belonging to this group, are basically obtained from salmon, trout, and Greenland halibut though sometimes also from mackerel and herring (Michal- czyk and Suro ´wka 2007). Gravads can be consumed without heating or cooking since they are RTE products (Lyhs et al. 2001). Thus, gravading is an important preservative pro- cessing technology because of the reduction of water activity and the inhibition of many spoilage microorganisms. The formation of more membra- nous surface also prevents further growth of microorganisms. The process involves filleting and constantly sprinkling the fillets with a mixture of salt and sugar, pepper and dill, followed by 1–4 days of cold storage. The final product can either be eaten & MustafaDurmus¸ mdurmus@cu.edu.tr 1 Department of Seafood Processing Technology, Faculty of Fisheries, Çukurova University, Balcalı, 01330 Adana, Turkey 2 Department of Refrigeration and Food Concentrates, Agricultural University of Cracow, ul. Balicka 122, 30-149 Krako ´w, Poland J Consum Prot Food Saf DOI 10.1007/s00003-017-1106-0 Journal of Consumer Protection and Food Safety Journal fu ¨ r Verbraucherschutz und Lebensmittelsicherheit 123