Tolga Dincer

Effects of Gutting and Ungutting on Microbiological, Chemical, and Sensory Properties of Aquacultured Sea Bream (Sparus aurata) and Sea Bass (Dicentrarchus labrax) Stored in Ice

The effect of gutting and ungutting on microbiological, chemical, and sensory properties of aqua-cultured sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) stored in ice were studied. The total viable mesophilic and psychrophilic bacterial counts increased throughout the storage period of gutted and ungutted sea bream and sea bass. The mesophilic counts reached 8.19 log cfu/g for ungutted sea bream and 7.93 log cfu/g for ungutted sea bass after 14 days of storage. The mesophilic counts reached 8.89 log cfu/g for gutted sea bream and 8.16 log cfu/g for gutted sea bass after 14 days of storage. On day 14 of storage the psychrophilic counts of ungutted sea bream and sea bass were 8.24 log cfu/g and 8.03 log cfu/g, respectively, and for gutted sea bream and sea bass were 8.93 and 8.22, respectively. At the end of the storage period of 14 days, TVB-N, TBA, and TMA-N values of ungutted sea bass were determined as 50.13 ± 0.25 mg/100 g, 2.66 ± 0.06 mg malonaldehit/kg, 9.86 ± 0.01 mg/100 g respectively. TVB-N, TBA, and TMA-N values of ungutted sea bream reached 55.90 ± 0.36 mg/100g, 2.51 ± 0.21 mg malonaldehit/kg, 9.79 ± 0.01 mg/100 g on day 14 respectively. And also at the end of the storage period of 14 days, TVB-N, TBA, and TMA-N values of gutted sea bass were determined as 48.00 ± 0.26 mg/100 g, 2.48 ± 0.03 mg malonaldehit/kg, 8.71 ± 0.06 mg/100 g respectively. TVB-N, TBA, and TMA-N values of gutted sea bream reached 49.66 ± 0.77 mg/100g, 2.64 ± 0.07 mg malonaldehit/kg, 8.97 ± 0.01 mg/100 g on day 14 respectively. The result of this study indicates that the shelf-life of whole ungutted sea bass and sea bream stored in ice as determined by the overal acceptibility sensory scores, chemical quality, and microbiological results show us that the fish were spoilt on day 14. Each chemical, sensory, and microbiological result for sea bream showed us that there was a correlation and similarity and on day 14 it was spoilt.

Chemical composition and biometrical measurements of the Turkish sea urchin (Paracentrotus Lividus, Lamarck, 1816).

We determined the monthly percentage values of biochemical components in paracentrotus lividus, for a 6-month period, and evaluated the findings in relation to seasonal fluctuations in water temperature and weather. Our study is the first to present a long-term biochemical profile of p. lividus in Turkey. They contained an average varied between 78.36 and 80.93 7% for moisture, 1.5 and 1.7% for ash, 2.37 and 4.27% for lipid, 9.26 and 11.75% for protein, and 1.95 and 2.53% for carbohydrate. Significant seasonal differences in sea urchin weight were noted between the winter and the summer months. Biometrical height measurements were done according to four criteria: total height, main height, diameter, and width. Weight measurements were done according to two criteria: living weight and weight of the roe. Also chemical composition analyses have been done in the parallel time periods of measurements. As a result of this study it has been determined that the spawning period of the sea urchin Paracentrotus lividus is in the time period between February and July. Amino acid contents of the Paracentrotus lividus were also determined.

Microbiological, chemical, sensory, color, and textural changes of rainbow trout fillets treated with sodium acetate, sodium lactate, sodium citrate, and stored at 4°C.

The influence of dipping rainbow trout fillets for 10 min in 2.5% solutions containing sodium acetate (NaA), sodium lactate (NaL), and sodium citrate (NaC) on microbiological, chemical, color, textural, and sensory analyses of fish fillets were assessed. According to the results of microbiological analyses, total mesophilic counts for rainbow trout fillets exceeded 7 log cfu/g, which is considered the maximum level of acceptability for freshwater and marine fish after 6 days for the control, and 9 days for NaA, NaL, and NaC treatment. The shelf life of the treated trout fillets was extended by 3 days. NaA, NaL, and NaC were efficient in preventing the proliferation of total mesophilic bacteria (TMC), psychrotrophic (PC), and coliform bacteria (CB) counts. The general order of antibacterial activity of different organic salts used was: NaA > NaL > NaC. Organic salts treatment did not affect lipid oxidation and textural qualities. NaA, NaL, and NaC treatment can be an alternative way to improve the shelf life of fish and fish products.

Determination of Quality Characteristics of Holothuria tubulosa, (Gmelin, 1788) in Turkish Sea (Aegean Region) Depending on Sun Drying Process Step Used in Turkey

ABSTRACT There are around 500 species of sea cucumber but few (around 10-17) are valuable commercially. In Turkey, an Aegean region species, Holothuria tubulosa, is collected by divers and kept alive until processed. Generally, Chinese methods and processing techniques of sea cucumbers are applied in Turkey. Processing steps in Turkey consist of cleaning, gutting, boiling, cooling, sun drying, packaging and storage. In this study, quality characteristics of Holothuria tubulosa were determined depending on a sun drying process step used in Turkey: water activity (aw) and microbial quality of the sea cucumber were determined during sun drying period at different air conditions (temperature, wind velocity, humidity). Proximate analysis (crude protein, crude fat, moisture, carbohydrate) and chemical quality control analyses (total volatile base-nitrogen, trimetylamine-nitrogen, and thiobarbituric acid reactive substances) were also determined before and after sun drying of Holothuria tubulosa. According to the results of analysis, no quality criteria reached the maximum acceptability limit for the product.

Textural and Sensory Properties of Fish Sausage from Rainbow Trout

The aim of this study was to determine the textural and sensory properties of fish sausage which were prepared from refrigerated and frozen rainbow trout (Onchorynchus mykiss) and stored for 14 days at 0−4 °C. These two groups of sausages were compared for texture, physical, and sensory properties by carrying out texture profile analysis (TPA), shear test, water holding capacity (WHC), cook loss, color, and sensory analyses. According to TPA and shear test, sausages prepared from frozen fillets exhibited a texture significantly (p < 0.05) weaker than those prepared from refrigerated fillets, but no difference in overall liking was observed.

Effects of Using Slurry Ice During Transportation on the Microbiological, Chemical, and Sensory Assessments of Aquacultured Sea Bass (Dicentrarchus Labrax) Stored at 4°C

Slurry ice, a biphasic system consisting of small spherical ice crystals surrounded by seawater at subzero temperature, was evaluated as a new chilled storage method for whole sea bass (Dicentrarchus labrax) a sparidae fish species of remarkable commercial interests. In this study two different group of chilling methods were used during transportation; in slurry ice packaged (Group A), and flake ice packaged (Group B). The effect of this advanced system during transportation on quality losses and the shelf life of aquacultured sea bass was evaluated. Mesophilic counts for sea bass exceeded 7 log cfu/g, which is considered the maximum level for acceptability for freshwater and marine fish after 13 days for groups A and B. On day 13 TVB-N values of groups A and B, reached the legal limits (35 mg/100 g set for TVB-N) for consumption. According to the results of sensory analyses, up to day 9 all the groups were determined as “acceptable” but on day 13 the groups A and B were no longer acceptable. The main negative aspect related to quality loss in slurry ice group corresponded to the appearance of eyes and gills. Using slurry ice during transportation did not extend the shelf life of sea bass stored at 4°C.

DIFFERENCES OF TURKISH CLAM (RUDITAPES DECUSSATES) AND MANILA CLAM (RUDITAPES PHILIPPINARUM) ACCORDING TO THEIR PROXIMATE COMPOSITION AND HEAVY METAL CONTENTS

Abstract The aim of this study is to determine the proximate composition, biometrical measurements and heavy metal content differences of marine bivalve Ruditapes philippinarum (Venice, Italy) and Ruditapes philippinarum (Izmir, Turkey. No statistical (P < 0.05) difference was observed in the values of crude lipid, moisture, ash and carbohydrate but statistical differences occurred in their crude protein values. They were 0.98 ± 0.169%; 83.98 ± 0.16%; 3.3 ± 0.424%; 1.14 ± 0.02%; 9.56 ± 0.06% for Ruditapes decussatus, respectively. They were 0.78 ± 0.16%; 85.91 ± 1.22%; 3.1 ± 0.232%; 1.10 ± 0.02%; 8.71 ± 0.18%, for Ruditapes phillippinarum, respectively. Each of the clam was determined as fresh and in perfect quality according to their TVB-N values but in the comparison of color values statistical difference was observed(P > 0.05).Trace metal levels were below the legal limits set by national standards of Turkish governments.

Quality and Shelf-Life Assessment of Pasteurized Trout Soup During Refrigerated Storage

The aim of this study was to investigate the quality changes of pasteurized soup prepared from smoked trout trimmings during 8 months of refrigerated storage at 3°C. Thiobarbituric acid (TBA, mg malonaldehyde/kg), total volatile content (TVB-N, mg N/100 g), total aerobic mesophilic plate count, pH value, color measurement, and sensory evaluation were used to determine quality changes. After 8 months of storage, TBA values reached 0.83 ± 0.09 mg malonaldehyde/kg. Despite a marked increase in the TBA value at Month 8, the soup was still of acceptable quality. The TVB-N value was close to the European Commission limit on fresh fish at Month 4, and further increase was not significant (p > 0.05). Total aerobic mesophilic count reached a maximum value of 4.15 ± 0.23 log cfu/g at Month 2 with 3.20 ± 0.02 log cfu/g at Month 8. The soup had an overall acceptability score of 7.16 ± 0.68 (“like moderately” on a 1- to 9-point hedonic scale). Results suggest that smoked trout trimmings can be used to maximize the value of co-products by producing a ready-to-eat soup.

Determination of the Tissue Distribution of PPO on Caramote Prawn (Melicertus kerathurus, Forskal, 1755) and Jinga Shrimp (Metapenaeus affinis, H. Milne Edwards, 1837) Caught from Izmir

Tissue distribution of polyphenol oxidase (PPO) was studied in caramote prawn (Melicertus kerathurus) and jinga shrimp (Metapenaeus affinis) postmortem. Activity was analyzed in different tissues: the head (cephalothorax + carapace), carapace, exoskeleton of the abdomen, pereopods, and maxillipeds, individually. Based on the results, PPO activity of jinga shrimp was determined to be higher than caramote prawn during the research period. Partial tissue distribution showed that the highest activity was determined in carapace by using 70% ammonium sulfate fractions. Partial tissue distribution was also used to determine the spread of black spots. In addition, comparison between the PPO levels of caramote prawn and jinga shrimp was performed. The importance of these species is their economic value. However, there is no available data in the literature about caramote prawn and jinga shrimp. The determined data showed us that using antioxidant chemicals would be suitable for jinga shrimp.