Determination of the shelf life, flesh yield and chemical composition of shrimps (Penaeus sp.) caught in the gulf of Antalya

ABSTRACT DETERMINATION OF THE SHELF LIFE, FLESH YIELD AND CHEMICAL COMPOSITION OF SHRIMPS (Penaeus sp.) CAUGHT IN THE GULF OF ANTALYA Ruhan ILHAN M. Sc. In Fisheries Engineering, Adviser: Prof. Dr. Ramazan İKİZ May 2005, 85 Pages In this study, Penaeus shrimps (Penaeus kerathurus, Penaeus japonicus and Penaeus semisulcatus) which caught in the Gulf of Antalya and has the high economic value were used as materials. The flesh yields and chemical compositions of these shrimps were researched depending on the sex and seasons. Furthermore, a part of shrimps were packed by the stretch film and aliminium foil and stored at the room temperature. The other part was placed in to the water with ice and stored at 4°C. The shelf lives of shrimps stored in these conditions were determined. The flesh yields of P. kerathurus and P. japonicus were mean 52%, flesh yield of P. semisulcatus was 57%. According to the results of this study, flesh yield of P. semisulcatus was higher than the others (p<0.01). It was found that percentages of mean moisture, lipid, protein and ash in P. kerathurus were 76.27%, 1.63%, 16.52%, 1.98%, respectively. Although the chemical composition of P. kerathurus changed depending on the season (p<0.01), didn't change mwith the sex. The percentages of mean moisture, lipid, protein and ash in P. japonicus were found to be 75.85%, 1.88%, 17.31%, 2.01%, respectively. The chemical composition of P. japonicus (except moisture) changed depending on the seasons (p<0.01) and didn't change depending on the sex. The percentages of mean moisture, lipid, protein and ash in P. semisulcatus were 76.47%, 3.97%, 16.59%, 1.85%, respectively. The chemical composition of P. semisulcatus (except for the percentage of mean protein) changed depending on the seasons (p<0.01) and the percentages of mean lipid and ash in them changed depending on the sex (p<0.05). It was found that moisture contents in these shrimps were ranged between 75.85-76.47%. Lipid content of P. semisulcatus was higher than the others (p<0.01). Protein contents of these species were ranged between 16.52-17.31%. Ash contents of these species ranged between 1.85- 2.01%. According to sensory, chemical and microbiological analyses, it was found that the shrimps wrapped by aliminium foil and stretch film and stored at room temperature had a shelf life of 1 day for P. kerathurus, P. japonicus and 2 days for P. semisulcatus. The shelf lives of the shrimps stored in the water with ice at 4°C were found 10 days and 12 days for P. kerathurus, P. japonicus and P. semisulcatus, respectively. KEY WORDS: Penaeus kerathurus, Penaeus japonicus, Penaeus semisulcatus, flesh yield, chemical composition, shelf life. COMMITTEE: Prof. Dr. Ramazan İKİZ Prof. Dr. Nalan GÖKO?LU Asst. Prof. Dr. Mehmet ÖZBAŞ iv