Osman Kadir Topuz

Effects of olive oil and olive oil-pomegranate juice sauces on chemical, oxidative and sensorial quality of marinated anchovy.

This study describes the potential use of olive oil and olive oil-pomegranate juice sauces as antioxidant, preservative and flavoring agent in fish marinades. The olive oil and sauces, produced from emulsifying of olive oil and pomegranate juice with gums, were blended with marinated anchovy (Engraulis encrasicholus) fillets. The aim of the present study was to produce a new polyphenol-rich marinade sauces by emulsifying pomegranate juice with olive oil in different proportions (25%, 35% and 50%v:v). In order to evaluate the effects of olive oil and olive oil-pomegranate juice sauces on quality of anchovy marinades, the chemical (TVB-N and TMA), oxidative (peroxides value, K230, thiobarbituric acid and K270) and sensory analyses were carried out during storage at 4°C. The present study showed that saucing of anchovy marinades with olive oil-pomegranate sauce can retard the undesirable quality changes, prolong the lipid oxidation and improve the sensory properties.

Physical and antimicrobial properties of anise oil loaded nanoemulsions on the survival of foodborne pathogens.

The purpose of this research was to investigate antimicrobial effects of nano emulsions of anise oil (AO) on the survival of common food borne pathogens, Listeria monocytogenes and Escherichia coli O157:H7. Series of emulsions containing different level of anise oil as potential antimicrobial delivery systems were prepared. Antimicrobial activities of bulk anise oil and its emulsions (coarse and nano) was tested by the minimum inhibitory concentration and time kill assay. Our results showed that bulk anise oil reduced the population of E. coli O157:H7 and L. monocytogenes by 1.48 and 0.47 log cfu/ml respectively after 6 h of contact time. However, under the same condition anise oil nanoemulsion (AO75) reduced E. coli O157:H7 and L. monocytogenes count by 2.51 and 1.64 log cfu/ml, respectively. Physicochemical and microbial analyses indicated that both nano and coarse emulsions of anise oil showed better and long-term physicochemical stability and antimicrobial activity compared to bulk anise oil.

Effects of plant extracts on lipid oxidation in fish croquette during frozen storage

The aim of this study was to investigate the effects of tomato and garlic extracts on lipid oxidation in fish croquette during frozen storage. The fish for croquette was purchased from the main fish market in Antalya, Turkey. Commercial tomato and garlic extracts were added into the croquette formulation. Lipid quality of frozen croquettes was analyzed at monthly intervals. There was no difference in free fatty acids and UV absorbance values of treatment groups. Treatment of tomato and garlic extracts kept oxidation at low levels. The results for thiobarbutiric acid, para-anisidine, and conjugated-diene values showed that tomato extract was the most effective in delaying lipid oxidation than garlic extract.

Fatty Acid Profiles of Different Shrimp Species: Effects of Depth of Catching

The aim of this study was to investigate fatty acid profiles of different shrimp species caught from deep water and shallow water. The shrimp species investigated in the study were Aristeus antennatus, Aristeomorpha foliacea, Plesionica martia, Parapenaeus longirostris, and Plesionica edwardsi from deep water; and Metapenaeus monoceros, Penaeus semisulcatus, Penaeus kerathurus, and Penaeus japonicus from shallow water. Fatty acid composition of shrimps varied. The main fatty acids were C18:1n9, C16:0, C25:6n3, C22:5n3, and C18:0. Saturated, monounsaturated, and polyunsaturated fatty acid (PUFA) contents of P. longirostris, P. edwardsi, and M. monoceros were markedly different, respectively. The ratio of n6/n3 of the edible tissue of M. monoceros was found to be 0.795, whereas this value was 0.152 in A. foliacea. Among the species studied, the highest docosahexaenoic acid + eicosapentaenoic acid value was found for P. kerathurus. The levels of PUFAs of shallow water shrimps (ranging from 33.44 to 42.77%) were found to be higher than those of deep water shrimps (ranging from 29.68 to 33.95%). Marine animals in the upper water layers gain nutrition through phytoplankton which provides n-3 PUFA depending on solar energy. Shallow water shrimp species provide a satisfying amount of PUFA.

Optimization of Antioxidant Activity and Phenolic Compound Extraction Conditions from Red Seaweed (Laurencia obtuse)

ABSTRACT Response surface methodology was used to investigate the effect of ultrasound-assisted extraction conditions including solvent:seaweed ratio (10:1–30:1), extraction temperature (30–50°C), and extraction time (30–60 min) on the total phenolic compounds and antioxidant activity of red seaweed (Laurencia obtuse) extracts. The optimum extraction parameters for maximum phenolic content were as follows: solvent:seaweed ratio, 30:1; extraction temperature, 50°C; and extraction time, 42.8 min. The experiment results showed that the solvent:seaweed ratio was the most significant parameter for the extraction. The optimum extraction conditions for maximum antioxidant activity were as follows: solvent:seaweed ratio, 24.3:1; extraction temperature, 45.3°C; and extraction time, 58 min. Under the above-mentioned conditions, the experimental total phenolic content and antioxidant activity value were 26.23 ± 0.75 mg GAE/g seaweed and 120.89 ± 0.81 TEAC, respectively, of seaweed tested, which are well compatible with the predicted contents.

Quality Changes in Marinated Anchovy (Engraulis encrasicolus) Sauced with Olive Oil-Lemon Juice Emulsions

ABSTRACT This study describes the potential use of olive oil-lemon juice emulsions containing different levels of lemon juice (0, 25, 35, and 50% v/v) as a flavoring, preservative, and antioxidant agent in marinated anchovy. The phenolic content and antioxidant activity of lemon juice, olive oil, and olive oil-lemon juice sauces as well as chemical, oxidative, and sensorial changes of marinade samples were analyzed. Increasing the level of lemon juice in sauces retarded the chemical and oxidative changes of marinated anchovy. However, increasing the level of lemon juice more than 35% in sauces led to a decrease in sensorial acceptability. Chemical and oxidative qualities of all the sauced samples were in the limit of deterioration during 100 days of storage. Although marinated anchovy samples treated with sauce containing 50% lemon juice had a significant inhibitor effect on chemical and oxidative deterioration, samples treated with sauce containing 35% lemon juice received the highest overall acceptability score.

Effects of Freezing and Frozen Storage on Protein Functionality and Texture of Some Cephalopod Muscles

ABSTRACT 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 4 × 4 cm. These pieces were packed in polyethylene bags. The bags were frozen in a blast freezer at −45°C until the thermal center reached −18°C. Frozen samples were stored in a deep freezer at −18°C for 30 days. 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.

Antioxidant Activities of Citrus Albedo and Flavedo Fragments Against Fish Lipid Oxidation

ABSTRACT This research aimed to inhibit the oxidation of fish lipid by adding the ethanol extracts of albedo and flavedo fragments of grapefruit, sour orange, and bergamot. The samples were stored at 25°C, and analyses were performed on weekly intervals. The albedo fragments of sour orange extract had the highest antioxidant activity (0.342 ± 0.002 µM Trolox) and total phenolic content (5.29 ± 0.00 g GAE/100 g dry matter). Lipid oxidation increased rapidly in control samples compared to the extract treatments. The lowest scores for thiobarbituric acid reactive substances (TBARS), para-anisidine value, peroxide value, and UV absorbance values were determined in sour orange albedo extracts as 5.21 mg MDA/kg, 17.81 and 4.78 meq O2/kg, 2.24, and 0.403, respectively, at the end of the storage. More successful results were obtained with the peels of grapefruit and bergamot in supressing the lipid oxidation. Bergamot extract was the most preferred citrus in terms of sensory analyses.

ANISAKIASIS: PARASITIC HAZARD IN RAW OR UNCOOKED SEAFOOD PRODUCTS AND PREVENTION WAYS

Parasitic infections related to the consumption of raw or uncooked seafood products have always been a concern for the consumers and for seafood economy. Anisakiasis is a serious zoonotic disease related with a wide range of syndromes in humans caused by member of Anisakidae. In last decade, an increasing number of anisakiasis disease have been reported, and this has been connected to the increase of globalized eating habits, ready to eat practices, the trend to avoid excessive cooked foods for nutrient preservation, consumption of fresh seafood for health reasons. Raw or slightly cooked ready-to-eat seafood products such as marinated, salted and cold smoked fish products, sushi and sashimi are the tool for transmission of Anisakis spp. larvae to human gastrointestinal system. As well as the factors that have yielded to an increase of the Anisakiasis cases, public health issues, anisakiasis symptoms, and methods to kill the Anisakis spp. larvae such as freezing, cooking, salting, marinating, irradiation, high hydrostatic pressure and chemicals have been reviewed in this study.