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The aim of this study is to investigate the effects of organic acid treatments on tenderizing of squid muscle. Squid samples removed head, skin, viscera, and tentacles and cut into square pieces of 4 x4 cm were soaked into the citric and lactic acid solvents (1 and 2%) and kept in a refrigerator (4°C) for 24 h. It was found that organic acid treatments affected the physicochemical properties of squid. While acid application decreased pH values and water holding capacity, its increased cooking loss and free amino acid content. Texture profile parameters and sensory texture scores did not change significantly after acid treatments. The type and concentration of acids were not effective for all parameters except cooking loss.Keywords: Physicochemical; Organic acids; Squid; Texture

The aim of this study was to investigate the effects of different freezing and thawing methods on physical, chemical, and sensory characteristics of red shrimp (Aristaeomorpha foliacea). Shell-on and shell-off shrimps were subjected to three different freezing (blast freezing, still freezing and cryogenic freezing) and thawing (on air, in refrigerator and in microwave oven) methods and stored for 30 days at -18ºC. Quality control analyses were carried out in samples after thawing. The lowest total volatile nitrogen and trimethylamine contents, pH values and cooking losses were found in cryogenically frozen shrimp, compared with other freezing methods. However, cryogenic freezing caused colour fading and softening in texture. It was determined that microwave thawing conditions used in this study are not suitable for thawing of frozen shrimp as it negatively affects texture and colour and increases cooking loss. It was found that blast freezing, and thawing methods preserved the physical, chemical and sensory properties of shrimp better than other methods.Keywords: Aristaeomorpha foliacea; Freezing; Red shrimp; Shrimp quality

The use of protein restructuring enzyme transglutaminase (TGase) for extending the shelf-life of rainbow trout mince was determined during refrigerated storage. TGase added into the fish mince in the proportions of 0.0%, 0.2%, 0.5% and 1.0% and the quality alterations were evaluated in terms of chemical, microbiological and sensory parameters. The scores of TVB-N and TIVIA-N, fish spoilage indicators, of the fish mince treated with TGase had lower levels than control samples. It was recorded that the progress in total free amino acids was suppressed with the addition of TGase. The increase in enzyme concentration met successful results in hindering the growth of total psychrophilic bacteria and coliform bacteria. The best results were obtained with the addition of TGase in the concentration of 1.0%. Overall, utilization of TGase can be a useful tool for seafood processing technology to achieve products with extended shelf life. (C) 2017 Elsevier Ltd. All rights reserved.

The aim of this study was to investigate the effects of tumbling on the physicochemical and textural characteristics of squid (Loligo vulgaris), octopus (Octopus vulgaris) and cuttlefish (Sepia officinalis) muscles. Before tumbling the cephalopod samples were placed in plastic bags and 0.5 M NaCl was added. Tumbling process was performed continuously in three different tumbling times (2, 4, and 6 h). The results of the analyses showed that tumbling affected the physicochemical properties of cephalopod muscles. The increase in the time of tumbling resulted in the tenderness of the cephalopod muscles. The total soluble protein, the total free amino acid, and pH values increased with the increase of the tumbling time. The water holding capacity decreased and the cooking loss increased. The squid and octopus hardness and shear force values decreased after tumbling, according to instrumental and sensorial texture measurements. As a result, tumbling was found to be an effective method for tenderizing of squid and octopus muscle, but not for cuttlefish.

The aim of this study was to investigate the effects of bromelain and papain enzymes for tenderizing of squid (Loligo vulgaris) muscle. Squid samples were immersed into the enzyme solutions and then they were kept in a water bath at 60 degrees C for 20 min to activate enzymes. After enzyme treatment, pH values, hardness and shear force values of squid muscle decreased. Total protein, free amino acid contents and sensory scores increased. Use of bromelain and papain enzymes was found as effective method to tenderize of squid muscle. Better results were obtained with papain compared to bromelain.

With this study, ascorbic acid and erythorbic acid were used for the first time to prevent melanosis in shrimp. Three shrimp species (Aristaeomorpha foliacea, Plesionika edwardsi and Melicertus hathor) were used. It was determined that melanosis scores were higher in the control groups. Combination of ascorbic acid and erythorbic acid with metabisulphite was found to be more effective in inhibiting of melanosis than the application alone. No significant differences were found between the groups in terms of TVB-N values. The TMA-N value of the control group was significantly higher than those of application groups. Ascorbic acid, Erythorbic acid and their combinations with sodium metabisulphite were found effective on inhibition of melanosis and quality changes in three shrimp species.Keywords: reducing agents; ascorbic acid; erythorbic acid; melanosis; quality; shrimp

The aim of this study was to investigate the effects of raw material freshness on the quality of marinated fish. The raw material anchovy (Engraulis encrasicolus) was divided into two batches. One batch (A) was kept at ambient temperature (20°C) for 6 h and the other one was kept at 0°C for 72 h. Then, they were marinated by soaking into marination solution containing 3% acetic acid and 8% NaCl. Total volatile basic nitrogen (TVB-N), trimethylamine (TMA), thiobarbituric acid (TBA), para-anisidine (p-Av) values in both marinated samples increased significantly during storage at 4°C. Increases in quality parameters were higher in samples produced with raw anchovy kept at 20°C compared to samples kept at 0°C. Although the sensory scores of both samples decreased during storage, higher scores were obtained for samples kept at 0°C compared to samples kept at ambient temperature. According to the results of the study, it has been determined that the quality of the raw material significantly (p

Inhibitory effects of high pressure processing (HPP) on the biogenic amine formation (histamine, tyramine, putrescine and cadaverine) in marinated herring fillets (2% acetic acid+8% NaCl; or 4% acetic acid+8% NaCl solutions) were investigated. Marinated fillets were inoculated with M. psychrotolerans followed by vacuum-packaging and HPP treatment at 100, 300 and 500 MPa for 5 and 10 min. One batch was left untreated for each marination group and the batches were stored at 4 °C for 3 months. HPP in combination with 4% acetic acid had a strong inhibitory effect on the growth of M. psychrotolerans, since there was no growth in samples treated with 300 MPa for 10 min and 500 MPa for 5, 10 min. Psychrophilic bacteria growth was not detected in samples marinated with 4% acetic acid and treated with 500 MPa H2S-producing bacteria were not observed in marinated herring during the storage period. Histamine and cadaverine formation were not observed in the samples marinated with 4% acetic acid along the storage. Taken together, the findings of this research might be helpful to enhance the safety of consumption of marinated herring. © 2018 Elsevier Ltd, Deutscher Akademischer Austauschdienst Firat University Scientific Research Projects Management Unit, This research was supported by the Scientific and Technological Research Council of Turkey (TUBITAK), Deutscher Akademischer Austauschdienst (DAAD) and The Scientific Research Projects Administration Unit of Akdeniz University under project no. FDK-2015-273 . The authors thank to management and staff of Deutsches Institut für Lebensmitteltechnik (German Institute of Food Technologies) for providing opportunity to work and infrastructure.

In this study, shrimp (Aristeus antennatus) immediately after trawling was treated with plant extracts (rosemary and green tea), sodium metabisulphite solution, and their combinations. After dipping into the solutions, melanosis and selected quality changes of shrimp were investigated during the storage at 4°C. Plant extracts were found effective in delaying melanosis in shrimp. Combinations of sodium metabisulphite and plant extracts were found more effective than those groups separately treated with plant extracts. Plant extracts, sodium metabisulphite, and combinations showed lower trimethylamine and total volatile nitrogen values as compared to the control group. It is concluded that use of plant extracts decreased the need for sodium metabisulphite.

The aim of this study was to investigate the effects of freezing and frozen storage on protein functionality and texture of squid (Loligo vulgaris), octopus (Octopus vulgaris), and cuttlefish (Sepia officinalis) muscles. Squid, octopus, and cuttlefish samples were cut into pieces of 4x4cm. These pieces were packed in polyethylene bags. The bags were frozen in a blast freezer at -45 degrees C until the thermal center reached -18 degrees C. Frozen samples were stored in a deep freezer at -18 degrees C for 30days. After freezing and during frozen storage, total soluble protein and water holding capacity decreased and total free amino acid and cooking loss increased in all cephalopod muscles. According to instrumental texture analysis results, freezing and frozen storage affected textural characteristics of squid and cuttlefish but not of octopus. Sensory hardness and chewiness values of all cephalopods increased after freezing, but elasticity values did not change. There were no significant differences between storage days in hardness values of squid and octopus. However, significant differences in hardness values of cuttlefish were observed between the 1st day of storage and the last day.

The Study describes the potential use of pomegranate peel extract as antioxidant in fish oil. The effects of pomegranate (Punica granatum) peel extract (PPE) of three different concentrations (100, 500 and 1.000 ppm) and synthetic antioxidant butylated hydroxytoluene (BHT), on the lipid oxidation of fish oil were compared. Formation of primary and secondary oxidation products in anchovy (Engraulis encrasicholus) oil in an elevated temperature (60 °C) storage trial was examined by conducting peroxide value, UV spectrum, thiobarbituric acid and para-anisidine analyses. The results showed that the two (500 and 1.000 ppm) concentrations of PPE were more effective in retarding of lipid oxidation in fish oil, in which a dose–response relationship was observed. The antioxidant capacity of 500 ppm of PPE was with that of 100 ppm of BHT, but still weaker than that of 1.000 ppm of PPE. Anchovy oil pomegranate peel extract, byproduct of pomegranate juice fabric, exhibited favorable antioxidant effects and is preferable for effectively avoiding lipid oxidation in fish oil.

Summary The aim of this study was to produce a functional emulsion product enriched with anchovy (Engraulis encrasicholus) oil. Tomato and garlic extracts were added to perform oxidative stability. Tomato and garlic extracts were added to avoid oxidative degradation in such a product. The plant extracts delayed the formation of primary and secondary oxidation products. The value of conjugated diens (3.07 ± 0.15) was markedly low in the emulsions containing garlic extract at the end of the storage period. The p–Av values of the emulsions treated with the extracts were significantly (P

The effects of modified atmosphere packaging on the quality and shelf life of frankfurter-type sausages, prepared exclusively from beef meat, were investigated. Sausages were packed under varying modified atmosphere conditions (30% CO2/70% N2; 70% CO2/30% N2; 100% CO2; 80% CO2/20% O2) and vacuum, and stored at 4C for 28 days. Lower pH values were observed in the samples packed under modified atmospheres compared to vacuum. Inhibition effect of carbon dioxide concentration on the oxidation was seen. Carbon dioxide caused microbial inhibition. The lowest total viable count was found in the samples packed under 100% CO2. It was concluded that modified atmosphere packaging had significant effect on the quality and shelf life of frankfurter-type sausages compared to vacuum packaging. The most suitable atmosphere among the tested atmospheres was that with 70% CO2, 30% N2 atmosphere. The shelf life of sausages under this atmosphere was 28 days. PRACTICAL APPLICATIONS Meat and meat products are susceptible to spoilage. Several preservation techniques are used to extend their shelf life. Packaging of fresh meat is a common application to protect its quality. Modified atmosphere packaging (MAP) means to replace the air in a package of food with some different mixture of gases. The success in MAP is to choose the suitable gas combination, packaging system, package application and the package material. Proper gas combination to keep meat quality should be provided. Several studies have been performed to extent shelf life of pork sausages and local-type sausages using modified atmosphere packaging technique. However there is no data on beef sausages. The results of this research will form the basis for further studies and also will be beneficial for industry.

Summary The aim of this study was to investigate inhibition effects of green tea and grape seed extracts on lipid oxidation in bonito (Sarda sarda) fillets during frozen storage. Dried and powdered green tea and grape seed were extracted using ethanol. Extract solutions of 1 g 100 g−1 were prepared using concentrated extracts and distilled water. Bonito fillets were divided into two groups. The first group was dipped into extract solutions and then frozen. The second group of fillets was glazed by extract solutions. Oxidation increased progressively through the storage period. 2-Thiobarbituric acid and para-anisidine values of samples treated with green tea and grape seed extracts remained at low levels. Both plant extracts displayed successful effects in delaying lipid oxidation compared to the control groups. The best results were obtained by extract treatment of fillets before freezing.

Effects of pomegranate sauce on the quality of marinated anchovy during storage at 4 °C were investigated. Anchovy were marinated with 30 g/L acetic acid and 150 g/L salt, put into glass jars, filled with either sunflower oil or pomegranate sauce and stored at 4 °C. Total volatile basic nitrogen (TVB-N) and trimethylamine (TMA-N) values increased during the storage. Higher values for free fatty acid (FFA), conjugated diens (k-dien) and para-anisidine (p-Av) were found in samples with sunflower oil than those with pomegranate sauce. Samples in pomegranate sauce showed better oxidative stability. Higher taste and flavour and lower appearance scores were found for samples in pomegranate sauce than those samples in sunflower oil. It was found that pomegranate sauce was as least effective as the traditional sunflower oil to keep quality. Pomegranate sauce also produced desirable taste and flavour but the coloration should be studied in further studies.

Summary The aim of this study was to investigate the effects of grape seed extracts on inhibition of melanosis in shrimp. Defatted grape seed powder was extracted using ethanol. Dipping solutions in five different concentrations (0, 2.5, 5.0, 10 and 15 g L−1) were prepared using grape seed extract and distilled water. The shrimps were dipped into the solutions and stored at 4 °C. Melanosis was investigated by sensory analysis and lightness, redness and yellowness values were measured by chromometer during the storage for 3 days. According to the results, grape seed extracts showed inhibition effect on the formation of melanosis. The best results were obtained with the solution of 15 g L−1.

Summary Some quality characteristics of frankfurters manufactured in three different fat levels (20%, 10% and 5%) and added citrus fibre (CF) and soy protein concentrate (SPC) were investigated. While moisture content of frankfurters increased with decreasing fat levels, protein contents increased. Lower fat levels resulted in lower water-holding capacity (WHC), cooking losses and penetrometer values. Lower L* values and higher a* values were obtained in low fat frankfurters. SPC significantly increased the cooking losses in the sausages with 5% and 20% fat, but decreased in the sausages with 10% fat. The lower cooking loss values were obtained in sausages added CF for all fat levels. Addition of fat replacers decreased the L values but did not affect the a and b values. Addition of fat replacers increased hardness in case of low fat levels. The softer product was obtained with high-fat formulation than low-fat formulation. Lower taste scores were observed with addition of fat replacers.

The objective of this study was to investigate the effects of ice with albedo and flavedo fragments of Citrus (Grapefruit (Citrus paradisi) and Bitter orange (Citrus aurantium L.)) extracts on the quality of common pandora (Pagellus erythrinus). Concentrated citrus extracts were diluted with distilled water (1/100 w/v) before making of ice. The ice cubes were spread on each layer of fishes and stored at 0 °C for 15 days. The pH value showed a regular increase in all samples. TVB-N levels of bitter orange treatment groups were recorded lower than the other groups reaching to 25.11 ± 0.02 mg/100 g at the end of the storage. The TMA-N values of bitter orange treatment groups were lower than that of control and grapefruit treatment groups. In terms of TBARS value, alteration was observed in the control samples and this value significantly (p

Quality changes of anchovy patties at the storage temperature of 4 degrees C were investigated. After patties had been prepared using minced anchovy meat they were stored in a refrigerator. Quality control analyses were conducted for every day of storage. Total volatile basic nitrogen and thiobarbutiric acid values increased, and acidity and sensory scores decreased during the storage. The peroxide value significantly increased until the fifth day of storage then decreased on days 5 and 6 of storage. Anchovy patties were consumable up to 6 days.

A sensory analysis panel was trained to evaluate the sensory properties of mussels using descriptive analysis method. For this purpose, freshly harvested mussels were evaluated by experienced panellists. Odour, colour, texture and appearance were assessed. Expressions of the panellists were used to generate sensory terms. Terminology characterising sensory attributes were developed from the panellists' opinions. A final list of attributes with definitions was chosen by consensus of the panellists and a verbal scale was created. A numerical scale was pointed out on the verbal scale.

The aim of this study was to determine the nutritional and quality characteristics of anchovy after cooking. The fish were cooked by different methods (frying, baking and grilling) at two different temperatures (160 °C, 180 °C). Crude ash, crude protein and crude fat contents of cooked fish increased due to rise in dry matter contents. While cooking methods affected mineral content of anchovy, cooking temperature did not affect. The highest values of monounsaturated fatty acids were found in baked samples. Polyunsaturated fatty acids in baked samples were also high and similar in fried samples. Fried samples, which were the most preferred, lost its nutritional characteristics more than baked and grilled samples. Grilled and baked fish samples can be recommended for healthy consumption. However, grilled fish samples had hard texture due to more moisture loss than other methods. Therefore, it is concluded that baking is the best cooking method for anchovy.

In this study the usage of eye fluid refractive index as a freshness indicator for sardine (Sardina pilchardus) was investigated. Eye fluid refractive index measurements and quality control analyses of sardine during storage at 0°C and +4°C were performed at 24h intervals. According to the sensory analysis results, the sardines stored at 0°C and +4°C had a shelf life of 6 and 4days, respectively. The changes in eye fluid refractive index values during storage at 0°C were not significant while the changes at +4°C were significant (p

Green tea (Camelia sinensis), grape seed (Vitis vinifera) and pomegranate peel (Punica granatum) extracts were used to keep quality characteristics of bonito (Sarda sarda) fillets during frozen storage. Fillets were dipped into plant extract solutions before freezing, then glazed and stored at -18°C for 5 months. Preference of panellists was focused on green tea applied fillets, means of odour and texture at the end of the storage period. Also, brightness values were found to be high. Redness and yellowness of the fillets were affected from natural colour of grape seed and pomegranate peel extracts, respectively. More stiff and less adhesive product was obtained with control groups, followed by green tea extract applied fillets. Deformation of muscle structure was considerably decreased by dipping fillets into plant extracts before glazing.

Sensory properties (colour, general appearance and taste) were investigated in rainbow trout, Oncorhynchus mykiss, fed standard diets supplemented with either 60 mg/kg astaxanthin, shrimp waste meal or red pepper meal. The fish were divided into three experimental groups (fed diets supplemented with pigments) and one control group, and fed experimental and control diets for 100 days. After the feeding period, the fish were evaluated for sensory properties. Colour was evaluated using a colour card for salmonids. General appearance and taste were evaluated using hedonic scaling. Significant differences between the fish fed diets with and without pigment supplementation were found. Feeding of rainbow trout with diets supplemented with pigments affected their sensory properties.