Piotr Kulawik

Significance of antioxidants for seafood safety and human health.

The demand for high-quality seafood products is constantly growing worldwide. Nevertheless, seafood is susceptible to rapid rancidity mainly due to lipid oxidation and microbiological spoilage. Thus, treatment with antioxidants offers a preservation technique that can prolong the shelf life of seafood. However, because of food safety and health concerns about the use of synthetic antioxidants, there is growing interest in the application of natural antioxidants, mainly plant extracts and compounds, as an alternate means of confronting the problem of lipid oxidation. In this review, up-to-date information and recent discoveries about different naturally occurring antioxidants on the oxidation progress, synthetic antioxidants and their health concerns, health benefits of antioxidants, antioxidants used for seafood, and food safety concerns are addressed. The antibacterial effects of natural antioxidants are also reviewed. Finally, the most effective methods for analyzing a wide range of antioxidants in plants are described.

Microbiological and chemical safety concerns regarding frozen fillets obtained from Pangasius sutchi and Nile tilapia exported to European countries

BACKGROUND Microbiological and chemical safety concerns regarding frozen fillets from pangasius catfish (Pangasius hypophthalmus) exported to Poland, Germany and Ukraine and Nile tilapia (Oreochromis niloticus) exported to Poland and Germany were investigated by analyzing heavy metal residues, microbiological hazards, biogenic amines, and thiobarbituric acid (TBA) and total volatile basic nitrogen (TVB-N) content. RESULTS The heavy metal residues from all studied samples were far lower than the limits established by authorities. The most abundant biogenic amine found was histamine, with a maximum content of 9.6 mg 100 g(-1) , found in pangasius exported to Poland. The total viable counts were from 2.8 log cfu g(-1) in pangasius exported to Ukraine to 4.3 log cfu g(-1) in pangasius exported to Germany. Vibrio spp. were present in 70-80% of all studied pangasius groups, whereas there no Vibrio spp. were found in the studied tilapia samples. 30% of Pangasius fillets exported to Poland were contaminated with coagulase-positive staphylococci. No E. coli was found in any of the studied samples. Although the results of TBA analysis differed significantly between studied groups, the malonic aldehyde content in all studied groups was still very low. The TVB-N content in frozen fillets from pangasius was significantly lower than in frozen tilapia fillets. CONCLUSIONS We reported that pangasius catfish frozen fillets were widely contaminated with Vibrio spp., which could prove hazardous for the final consumer if the fish is eaten raw or undercooked. The rest of the analysis showed no other reason for concern associated with Nile tilapia and Pangasius catfish frozen fillet consumption.

Quality Properties, Fatty Acids, and Biogenic Amines Profile of Fresh Tilapia Stored in Ice

This work determines quality properties and fatty acids content of Nile tilapia (Oreochromis niloticus) stored in ice for 21 d. The quality properties consist of thiobarbituic acid (TBA), total volatile basic nitrogen (TVB-N), trimethylamine (TMA), and microbiological analysis (total viable count (TVC), total coliform, Salmonella and Staphylococcus aureus) and determination of biogenic amines content (histamine, cadaverine, putrescine, spermine, spermidine, 2-phenylethylamine, agmatine, tyramine, and ammonia). Moreover, the fat, moisture, and ash composition as well as fatty acids profile have also been analyzed. The TBA, TVB-N, and biogenic amines analysis showed rather low levels of spoilage even after 21 d of storage. The microbiological analysis, however, showed that tilapia was unsuitable for consumption after just 10 d. The fat, ash, moisture, and fatty acids profile analysis showed that tilapia is not a good source of n-3 fatty acids. The research indicated that the microbiological analysis was the best method to establish spoilage of tilapia stored in ice, of all analytical methods performed in this study.

Assessment of Color and Sensory Evaluation of Frozen Fillets from Pangasius Catfish and Nile Tilapia Imported to European Countries

The current study was designed to assess the color and sensory evaluation of frozen fillets of Pangasius catfish and Nile tilapia imported to Poland, Germany, and Ukraine in order to evaluate the possible impact of negative media image of these fish fillets on the sensory expectations of the consumers. The study used two trials of sensory evaluation: Blind and informed, on a group of untrained respondents and additional color analysis using the Commission Internationale de l’Éclairage (CIE) L*a*b* scale. The lowest grades during sensory evaluation in all measured parameters were given to Pangasius imported to Ukraine and Poland. The grades of Pangasius and tilapia imported to Germany were similar and significantly higher than of other Pangasius groups. Generally tilapia fillets were marked as better than Pangasius fillets. Moreover the present study found that there was considerable percentage of customers which are susceptible to various commercial frauds since they marked Pangasius higher when they thought they are consuming turbot. This study also showed that the negative image of Pangasius presented through various mass-media might have a negative impact on consumer’s perspective of Pangasius consumption.

The quality of carp (Cyprinus carpio L.) cultured in various Polish regions

BACKGROUND Although environmental factors greatly affect the quality of carp meat, no regulations impose labelling the place of cultivation of freshwater fish. That is why the purpose of this study was to determine the quality of carp meat cultivated in several regions of Poland as well as to assess the necessity of implementing such regulations. RESULTS The influence of the cultivation region on colour, nutrition value, health safety and sensory quality of carp meat was assessed. The analysis included colour measurement, determination of fatty acid profile and sensory evaluation of carp muscle. Moreover, microbiological analysis of the fish surface was performed. The results show that the place of cultivation does not influence the lightness (L*) of fillet, but has an impact on other colour parameters (a*, b*). The microbiological quality of fish from all studied farms was satisfactory, since no pathogenic microorganisms were observed on the fish surface. The fatty acid profile was fairly varied (P < 0.01), depending on the place of cultivation. CONCLUSION Since final results seem ambiguous, further analyses of quality features of carp from various regions and cultures should be performed, before any recommendation for the necessity of labelling the place and method of cultivation should be suggested.

The effect of hyaluronic acid addition on the properties of smoked homogenized sausages

BACKGROUND This research studied the possibility of using hyaluronic acid (HA) as a food additive for meat emulsions to create a novel functional food with improved rheological and water binding properties. Sausages with 200 and 500 g kg-1 water addition were supplemented with 0, 0.01, 0.05 and 0.1 g kg-1 of HA and stored for 14 days in vacuum. Rheology, texture, weight losses, proximate composition and microbiological analyses were performed together with the sensory evaluation of produced sausages. RESULTS Surprisingly, the results show that the addition of 0.05 and 0.1 g kg-1 HA reduced yield and the stability of meat emulsion by causing water outflow from the product and decreased the sensory scores of the produced sausages. The sausage with 500 g kg-1 water and 0.01 g kg-1 HA addition was the only economically viable option for introducing the product on the market. CONCLUSION HA has a potential of being a perfect functional food additive for meat industry, although further research regarding processing conditions should be performed.

Biogenic Amine Formation and Microbiological Quality of Anchovy (Engraulis encrasicolus) Treated with Lavender and Lemon Balm Ethanol Extracts

Biogenic amine formation and bacterial growth of vacuum-packed European anchovy treated with 1% lemon balm (LB) or lavender (LD) ethanol extracts was investigated. The treated samples were stored at 2 ± 1 °C for 11 d and analyzed for biogenic amines, total viable count, fecal coliform count, and lactic acid bacterial count. The analyses were done on 0, 4, 7, 9, and 11 d of storage. Both LB and LD extracts proved effective in reducing most biogenic amines, with histamine reduced by 3-fold compared to control. The calculated biogenic amine index showed that LB extract was the most effective in inhibiting the biogenic amine formation. The reduction in total viable count was low and the bacterial contamination reached more than 7 log cfu/g at the end of the storage period for all the samples. Moreover, the reduction in fecal coliform and lactic acid bacterial count by LB and LD extracts was below 1 log cfu/g. Treatment of European anchovy with LB and LD extracts proved to be a very effective preservation technique to reduce the biogenic amine formation and lower the risk of histamine fish poisoning but is not effective in reduction of bacterial load. Consequently, LB and LD extracts could be used to reduce the biogenic amine formation which provides additional safety prior to spoilage for histamine sensitive fish species.

Nutritional Composition of Frozen Fillets from Pangasius Catfish (Pangasius hypophthalmus) and Nile Tilapia (Oreochromis nilotcus) Imported to European Countries

Abstract The proximate composition, fatty acids and amino acids profile as well as mineral composition of frozen fillets from Pangasius catfish (Pangasius hypophthalmus) imported to Poland (PP), Germany (PG) and Ukraine (PU) and fillets from Nile tilapia (Oreochromis nilotcus) imported to Poland (TP) and Germany (TG) were investigated. PU contained ten times more fat than PG and PP. Tilapia fillets contained higher levels of n-3 fatty acids and showed more preferable n-6/n-3 ratio than pangasius fillets. The fillets of PG contained higher levels of protein and essential amino acids than PU and PP, however the amino acids composition of pangasius and tilapia fillets was similar for all specimens. The fillets of PP and PU contained significantly higher amounts of sodium than other studied groups, which suggests that they were subjected to additional treatment to increase their water holding capacity. The results show significant differences in the nutritional composition of pangasius depending on their place of import, thus it was recommended that more information regarding the nutritional composition of the frozen fillets sold through self-service freezers should be provided for the final consumer.

The Quality of Rainbow Trout (Oncorhynchus Mykiss) Cultured in Various Polish Regions

Abstract There is a lack of regulations regarding labeling of the place of cultivation of freshwater fish, even though some research indicates that environmental factors can influence the quality of rainbow trout meat. The purpose of this study was to assess the necessity of such regulations and to determine the meat quality of rainbow trout cultivated in different regions of Poland. The analysis of color measurement, fatty acid profile, sensory evaluation and microbiological analysis of trout muscle were performed to assess the influence of cultivation region on the quality of trout meat. The place of cultivation did not influence the redness (a*) and yellowness (b*) of fillet, but had impact on lightness (L*). The microbiological analysis showed no pathogenic microorganisms on the fish surface. The fatty acids composition differed highly significantly (P<0.01) depending on the place of cultivation. Since there are significant differences in quality and nutritional value between studied samples, the necessity of labeling the place of cultivation of rainbow trout for the final consumer should be implemented.

Heavy metal contamination, microbiological spoilage and biogenic amines content in sushi available on the Polish market

BACKGROUND The present study determined the heavy metal contamination (mercury, cadmium, lead, arsenic and nickel) of nori, restaurant-served sushi and ready-to-eat sushi meals available via retail chains. Moreover, both microbiological load and biogenic amine content in ready-to-eat sushi meals were analysed. RESULTS All of the nori samples contained high levels of Cd (2.122 mg kg-1 ), Ni (0.715 mg kg-1 ), As (34.56 mg kg-1 ) and Pb (0.659 mg kg-1 ). The studied sushi samples contained high levels of Ni and Pb, reaching 0.194 and 0.142 mg kg-1 wet weight, respectively, being potentially hazardous to women during pregnancy and lactation and small children. None of the studied samples contained high levels of Hg. Overall, 37% of ready-to-eat sushi meals exceeded a microbiological load of 106  cfu g-1 . However, biogenic amine content in all of the samples was low, with a highest histamine content of 2.05 mg kg-1 . CONCLUSION Sushi is not the source of high levels of biogenic amines even with high microbiological loads. Nevertheless, the high microbiological loads at the end of the shelf-life indicate that some processors might have problems with the distribution chain or implement a poor hygienic regime. Moreover as a result of possible risk associated with heavy metal contamination, the present study highlights the need to establish new regulations regarding the contamination of nori and sushi.