Hot Smoking Research Articles

Influence of Smoking on Indicatory Congeners Residues Levels in Fish Slices

The aim of this study was do determine changes in concentrations of indicatory PCB congeners (IUPAC numbers: 28, 52, 101, 118, 153, 138, 180) during industrial hot smoking of mackerel (Scomber scombrus L.) and herring (Clupea harengus L.) slices and cold smoking of mackerel slices. PCB content in raw mackerel slices averaged from 1.32±0.29 ng/g wet w. for PCB 52 to 4.66±0.72 ng/g wet w. for PCB 153. In herring slices, PCB content ranged from 1.36±0.25 ng/g wet w. for PCB 28 to 16.50±1.94 ng/g wet w. for PCB 153. During hot smoking, losses of the examined compounds were observed - in herring slices by 15% (PCB 153) to 32% (PCB 52), while in mackerel slices by 3.7% (PCB 80) to 38% (PCB 28). Simultaneously, a slight increase in the content of PCB 180, PCB 118, PCB 153, PCB 138 and PCB 101 occurred during the proper smoking, between 1.5ᵗʰ and 2.5ᵗʰ hour of the smoking process. During cold smoking (26°C, 8 h), PCB concentrations increased significantly (p<0.05) by 26% (PCB 28, PCB 138) to 43% (PCB 180). In the final stage of smoking, PCB content in the alder sawdust and in the smoke had a significant effect on the levels of the analysed PCB congeners in the smoked slices. The main parameter determining the change of these compounds contents was their decrease in co-distillation with steam. In the final phase of the hot smoking a little increase of PCB compounds contents was a consequence of their penetration with smoke to the fish meat tissue.

Effect of Hot Smoking Process Parameters on Microbiological and Shelf Stability of Nile Tilapia (Oreochromis niloticus) Fillets

The study was aimed to investigate the effect of hot smoking process parameters on the physico-chemical, microbiological and shelf stability of Nile tilapia fillets. Smoking loss mean value was ranged from 57.87-63.44%. After six weeks storage of smoked fillet at 4°C the log10 microbial counts were 8.78 for aerobic plate count, 7.36 for yeast and mould. The mean log10 microbial counts at room temperature after 20th day’s storage were 7.05 for aerobic plate count, 8.39 for yeast and mould. The entrobacteriaceae counts for both storage temperatures were not detected. Mean TVB-N of smoked fillets has also increased through storage time from 10.25 to 18.06 mg N/100 g at 4°C storage and increment was obseved from 10.25 to 23.69 mg N/100 g at room temprature storage. This research has revealed that hot smoking process diminishs the microbial load and elongate the shelf stability of Tilapia fillets.

Determination of the fundamental nutritional components in fresh and hot smoked spiny eel (Mastacembelus mastacembelus, Bank and Solander, 1794)

In this study the nutritional components of spiny eel obtained from Ataturk Dam Lake within the borders of Turkey by using fishing nets was investigated when it was fresh and after smoking process. While the quantity of the raw protein, raw fat, raw ash and carbohydrates in fresh spiny eel were determined as 19.88 ± 0.18%, 2.10 ± 0.62, 1.38 ± 0.24%, 0.07 ± 0.01%, respectively, it was ascertained that accounts were 36.69 ± 1.15%, 4.8 ± 0.28%, 13.76 ± 1.86%, 0.1 ± 0.01%,respectively after the hot smoking process and the changes were observed to be important (p<0.05). In the study, it was concluded that spiny eel was a crucial species meeting individual needs in terms of mineral substances such as Zn and Cu, beside being a good source of Fe. It was determined that it was poor in vitamin A, while it was rich in vitamin E as well. Besides, in the study, it was seen that thermal process applied during cooking and smoking had an effect of decreasing the quantity of essential fatty acids particularly such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Along with this, considering that the fat content of materials, which would be used in smoking process and which was the main criteria for smoking technology, it was concluded that hot smoking process was not a suitable method for spiny eel that contains low fat and that it could be utilized by using alternative process methods. Key words: Mastacembelus mastacembelus, spiny eel, hot smoking, nutritional components.

Smoking Impact on the Microbial Load of &lt;i&gt;Clarias gariepinus&lt;/i&gt;

Effects of different smoking methods on microbial load on freshly collected freshwater mud fish, Clarias gariepinus samples from Oyo State Fisheries Department, Ibadan in South-Western Nigeria was carried out. Seventy-two C. gariepinus (505 &plusmn; 0.45g and 25.5 &plusmn; 1.30cm) were collected and sorted into 4 groups. 10 fish samples from groups 1, 2 and 3 were subjected to cold smoking, hot smoking and oven drying methods respectively using group 4 as standard. Samples were tested for microbial loads in triplicate at the end of 24, 48 and 72 hrs. Some of the microbes identified were; Streptococcus faecium, Proteus vulgaricus, Pseudomonas aureginiosa, Bacillus cereus; Micrococcus acidiophilus, Aerobacter aerogenes, E. Coli, Streptococcus pyrogenes, Streptococcus lactis, Bacillus subtilis, Pedio cerevisiae, Sacchomyces Sp, Fusarium oxysporum, F. compacticum, Penicillium oxalicum, P. chrysogenum, Aspergillus tamari, A. niger, Cladosporum sphacrosporum, Aspergillus terreus and Rhizopus nigericans. Others are Pseadomonas, Alteromonas, Moraxella, Acinetobacter, Flavobacterium, Cytophaga, Vibrio, Aeromonoas, Staphylococcus aureus, Samonella faecuim, P. fragii. Microbial load for cold smoked products were 72%, 66% and 38%; hot smoked products had 61%, 32% and 08%; while oven-dried had 12%, 0% and 0% at 24, 48 and 12 hrs respectively. Positive correlation r = 0.94, 0.92 and 0.51 were observed between the microbial load processing methods &ndash; oven dried, hot-smoked and cold-smoked respectively. Cold smoked had 41.63% C.P and oven-dried had 25.73% C.P. Consumers had highest preference (40%) for hot smoked, 35% for oven dried and 25% for cold smoked products.Key Words: Processing, storage, smoking, bacteria, Clarias gariepinus.

Effect of Various Processing Methods on Quality of Mackerel (Scomber scombrus)

The effects of combinations of processes (hot smoking, marinating, vacuum packing and seasoning with dill (Anethum graveolens) on the quality parameters of mackerel (Scomber scombrus) stored at 4 °C were investigated in terms of sensory, chemical (total volatile basic nitrogen [TVB-N], thiobarbituric acid [TBA], peroxide value [PV], free fatty acids [FFA]) and microbiological parameters (total viable count [TVC], coliform, Escherichia coli, Staphylococcus aureus) during 9 months of storage. Sensory quality of smoked mackerel marinates with or without dill leaves (Group A, Group B, respectively) decreased throughout storage period. However, at the end of storage period, both the products were still acceptable by the panellist. At the beginning of storage, the initial TVB-N values were 24.14 mg/100 g and showed fluctuations during storage period. TBA values significantly increased (p < 0.05) for both products during storage period. PV showed fluctuations. FFA increased gradually from 2.46 to 7.33 (expressed as % of oleic acid) for Group A and from 2.57 to 6.90 for Group B at the end of storage period. Coliform, E. coli and S. aureus were not detected during storage period. TVC remained lower than the acceptability limit of 106 log CFU/g at the end of storage period. The results of this study suggest that shelf life of both products was 9 months and also the combination of hot smoking, marinating, vacuum packing and seasoning led to high-quality food item and was found to be effective in controlling the growth of bacteria and biochemical indices.

Contents of polycyclic aromatic hydrocarbons (PAH) and phenolic substances in Frankfurter-type sausages depending on smoking conditions using glow smoke

The contents of polycyclic aromatic hydrocarbons (PAH) and phenolic substances in Frankfurter-type sausages were investigated depending on hot smoking conditions (glow smoke). For the 24 smoking experiments (performed in duplicates) three different smoke densities and ventilator velocities as well as wood chips with five different moisture contents were tested. During the smoking process, concentrations of O2, CO2 and CO, humidity and temperature in the smoking chamber as well as smoke generation temperature were determined. The chemical analysis included the contents of the 15+1 EU priority PAH and the phenolic substances guaiacol, 4-methylguaiacol, syringol, eugenol and trans-isoeugenol. The smoking conditions had a significant influence on smoke generation temperature, organoleptic properties and the formation of PAH and phenolic substances. The PAH contents increased with smoke density and ventilator velocity. No correlation between the contents of PAH and phenols was observed.

Presence of Listeria spp. in fish samples, fish products and sea products

Listeria monocytogenes is a bacterium that is pathogenic for man and for most animal species. Listeriosis is a generalized infection that starts after ingestion of the causative agent L. monocytogenes (Finlay, 2001). Food that is not properly thermically processed, long storage of such food, food that is produced in inadequate hygienic food plants, as well as cooked-cooled ready to eat food (RTE) is the ideal medium for listeria multiplication. High risk food originated from fish, fish products and sea products comprised of: molluscs (fresh of frozen shellfish, crustaceans shelled or not), fresh fish (ready to eat without cooking), fish products packed with brine (NaCl<6%), (salted, marinated, fermented, cold smoked and fish in brine), thermically treated fish and crustacean products (pasteurization, cooking, hot smoking, including pre-cooking and panning). In this research, fish samples, fish products and sea products from Serbian markets were examinated such as: fresh fish (cooled), frozen food (fish and sea products - cuttlefish, squid, octopus, shellfish, crustaceans and shrimps), panned products; smoked fish, salted fish, thermally treated fish and fish products, semi-canned fish and canned fish. Microbiological testing has been performed according to internationally prescribed standards ISO 11290-1 (1996) "Microbiology of food and animal feed stuffs - Horizontal method for the detection and enumeration of Listeria monocytogenes". There were 470 samples from fish products and sea products. Presence of Listeria spp was registered in 58 samples (12.34%). Listeria monocytogenes was found in 1.92% samples (9 isolates), which makes 15.52% of the total Listeria that were isolated from the tested food. Other isolated Listeria belong to the following species: L. innocua (8.51%), L.welshimeri (1.28%), L.welshimeri/innocua (0.21%), L. grayi (0.21%) and L. seeligeri (0.21%). Exceptional viability of Listeria monocytogenes in the food tested was documented, also (freezing temperature - 18oC, five months).

The Chemical and Sensory Quality of Smoked Sturgeon (Huso huso): A Case Study

In this study, the tail flesh of sturgeon acquired from the fish market in Beşiktaş-Istanbul, Turkey was put through hot smoking. The chemical composition of raw and smoked sturgeon was determined. The protein, lipid, ash, and moisture of the muscle tissue in raw and smoked sturgeon were found to be 17.63 to 17.49, 6.07 to 9.59, 0.79 to 2.71, and 75.42 to 68.40%, respectively. Both the raw fish and the smoked fish meat were categorized to possess high quality characteristics with pH, total volatile base nitrogen (TVB-N), and trimethylamine nitrogen (TMA-N) values. After smoking, the skin color lightness (L*) of raw fish was determined to decrease, while the flesh color lightness of raw fish was determined to increase. The redness (a*) and the yellowness (b*) of both the skin and the flesh were determined to increase. Sensory parameters of color, smoke aroma, flavor, texture, chewiness, and overall acceptance for smoked sturgeon was described as excellent and its flesh tasty.

Rendimento, umidade, aceitabilidade e preferência da tilápia submetida à defumação

On account of being considered a species of great importance for the global aquaculture the Oreochromis niloticus (Nile tilapia) was selected to execute this experiment. The aim was to evaluate yield, humidity, acceptance and preference for individuals of this species submitted to the hot and liquid smoking processes. The flattened fish yields were 38.46 and 54.44% for the hot and liquid smoking processes, respectively. The humidity verified during the treatment was 81.01% for individuals submitted to the liquid treatment and 69.30% for the hot-smoked ones. The sensorial analysis reveals that both treatments exhibited good acceptance, however the hot-smoked ones were preferred. Thus, the smoking process, whatever the form, traditional or liquid, is an alternative to aggregate value to the fish.

Effects of hot and cold smoking processes on organoleptic properties, yield and composition of matrinxa fillet

The effects of hot (45-90ºC/5 hours) and cold (27-45ºC/10 hours) smoking processes on the organoleptic properties, yield and composition of matrinxa (Brycon cephalus) fillets are evaluated. No significant differences were observed for fillet yield in both non-smoked and smoked fillets. Smoking process losses were significantly higher for hot smoked (19.37%) when compared to cold smoked (17.08%). Smoking process reduced moisture (in natura = 72.91%, for hot = 58.51% and cold = 59.68%) and increased crude protein, lipid and ash contents. However, there was a significant difference only for protein level between hot smoked (28.07%) and cold smoked (27.14%). Cold smoked process resulted in better fillet appearance and color, while hot smoked presented superior flavor, salt content and general acceptance. Aroma and texture did not differ significantly among processes. Therefore, hot smoking process shows the best results for organoleptic properties and protein levels.

Characterization of particulate matter concentrations during controlled indoor activities

Indoor sources have been identified as a major contributor to the increase of particle concentration in indoor environments. The work presented here is a study of the characteristics of particulate matter number size distribution and mass concentration under controlled indoor activities in a laboratory room. The objective is to characterize particulate matter concentrations indoors resulted under the influence of specific sources. Measurements were performed in an empty laboratory (period September–October 2006) using a GRIMM SMPS+C system (particle size range between 11.1 and 1083.3 nm), a DustTrak Aerosol Monitor (TSI) and a P-Trak Ultrafine Particle Counter (TSI). The studied indoor activities included candle burning, hot plate heating, water boiling, onion frying, vacuuming, hair drying, hair spraying, smoking and burning of incense stick. The AMANpsd computer algorithm was used to evaluate the modal structure of measured particle number size distribution data. Furthermore, the change of the particle number size distribution shape under the influence of different emission sources was studied versus time. Finally the particle emission rates were computed. High particle number concentrations were observed during smoking, onion frying, candle burning and incense stick burning. The highest particle mass concentrations were measured during smoking and hair spraying. The shift of the particle size distribution to larger diameters suggests the presence of strong coagulation effect during candle burning, incense stick burning, smoking and onion frying. The size distribution was mainly bimodal during onion frying and candle burning, whereas the size distribution remained unimodal during incense stick burning and smoking experiments.

THE EFFECTS OF HOT SMOKING ON THE CHEMICAL COMPOSITION AND SHELF LIFE OF MEDITERRANEAN MUSSEL (MYTILUS GALLOPROVINCIALISL. 1819) UNDER CHILLED STORAGE

ABSTRACT In this study, effects of boiling and hot smoking on proximate composition and shelf life of mussels stored at 4 ± 1C were investigated. Dry matter, crude protein, crude fat and crude ash levels were determined as 13.94, 10.30, 1.14 and 0.95% in fresh mussels 20.75, 13.83, 2.11, 0.77% after boiling and 39.57, 22.22, 10.04%, 6.02% after hot smoking, respectively. Trimethylamine nitrogen values in fresh, boiled and hot smoked mussels were determined as 1.13, 1.01 and 1.07 mg/100 g, respectively, and increased to 24.35 mg/100 g at 18th day of the storage period. pH value in hot smoked mussels ranged between 4.85 and 4.51 during the chilled storage. According to the results, mussels smoked by hot smoking and stored at refrigerator temperature (4 ± 1C) for 12 days can be consumed. PRACTICAL APPLICATIONS In many countries, smoking is used to obtain products that are popular for their texture and flavor. Mussels, scallops and oysters are some of the important mollusk species that are smoked and eaten in different parts of the world. In this research, the effects of hot smoking process (for 30 min at 82C) on proximate composition and shelf life of Mediterranean mussel stored at 4C was investigated.

Effect of Hot Smoking on the Content of Selected Polychlorinated Biphenyl Congeners in Herring (Clupea harengus) Slices

Herring ( Clupea harengus) (as well as sprat and mackerel) is a fish species intensively harvested by the Polish fishing fleet. Its relatively low price and the habits of Polish consumers contribute to its high economic importance in Poland. Among 125.6 thousand tons of marine fish harvested in 2006, herring constituted 22.2 thousand tons (including 7.6 thousand tons harvested from the North Sea). Fish are usually subjected to various culinary treatments, which can influence the concentrations of contaminants in final products. Therefore, the present study aimed at determining the effect of three non- ortho-polychlorinated biphenyl (PCB) congeners (PCB 77, PCB 126, and PCB 169) and three mono- ortho-PCB congeners (PCB 114, PCB 156, and PCB 157) in the tissues of herring slices. Concentrations of dry matter and lipids in the final product were increased by 15.9 and 20.5%, respectively. Brining, which preceded the process of smoking, did not significantly influence concentrations of PCB congeners in herring slices. However, smoking resulted in significant ( p < 0.05) changes in concentrations of three non- -ortho PCBs. The biggest dynamics of losses in relation to smoking duration was observed for PCB 77 (30.2%). For PCB 126, the biggest losses occurred after 1 h of drying, followed by slight changes after 1.5 and 2 h of proper smoking and another increase of losses in the final product after 2.5 h. The duration of smoking did not significantly influence PCB concentrations in wet weigh, as their losses in lipids were much bigger. The observation is derived from strong negative correlations between concentrations of the congeners in lipids and lipid concentrations in herring slices during hot smoking ( r ranging from -0.824 to -0.950). Although the lipid concentration in the smoked fish increased, the PCB content diminished. It shows that during drying of the fish slices, PCBs codistilled with water vapor, settling on the walls of the smoking chamber and smoking trolleys. During the proper smoking, the compounds released with the smoke back to the smoking chamber and settled on the surface of smoked fish together with the disperse phase of the smoke (aerosol). Hot smoking contributed to a reduction of toxic equivalents (TEQs) by 22.7% (converted into lipids 41.9%), and in the final product, it amounted to 0.0188 +/- 0.0023 ng TEQ/kg of wet weight (0.0977 +/- 0.0064 ng TEQ/kg of lipids). The reduction was significantly higher than resulting from hot smoking of mackerel slices, when TEQs were reduced by 17.9% wet weight (converted into lipids 31.7%).

COMPARATIVE STUDY OF THE DSC PATTERN, COLOR, TEXTURE AND WATER-BINDING CAPACITY OF RAINBOW TROUT MUSCLE DURING HEATING

ABSTRACT The effect of heating the muscle of rainbow trout at different temperatures ranging from 30 to 70C on thermal stability, texture, water-holding ability and color was investigated with regard to the possibility of discriminating between thermally treated and untreated fish muscle. Including the skin of fish it was possible to differentiate heat-treated fish in 5C steps in the range of 35–65C by means of their differential scanning calorimetry (DSC) patterns. Heating the fish muscle resulted in a marked increase in lightness with rising temperature as well as significant changes in hardness (increase) and water-holding capacity (decrease). Heating effects were compared with those of pressure treatments at 100 and 200 MPa for 20 min. The DSC patterns of both trout muscle and skin were comparable for samples that were pressure treated at 200 MPa or heated at 40C. PRACTICAL APPLICATIONS Differential scanning calorimetric (DSC) patterns of both muscle proteins and skin proteins of rainbow trout preheated at temperatures ranging from 30 to 70C show a gradual denaturation of protein fractions, with myosin being the most susceptible and almost completely denatured in samples preheated at 50C. In samples preheated at 70C, the actin peak also disappeared and proteins available in muscle and skin were fully denatured. This offers the possibility of checking whether heat treatment has been performed (e.g., in the case of illegal tariff savings) or whether minimum cooking temperatures have been met (e.g., in the case of hot smoking).

Changes in physicochemical and sensory characteristics of smoke-dried fish species stored at ambient temperature

This study assessed the comparative changes in the physical and chemical components of five different species of smoked freshwater fish: Bony tongue, Heterotis niloticus, African carp, Labeo coubie, Snake fish, Parachanna obscura, Nile Tilapia, Oreochromis niloticus and African mud catfish, Clarias gariepinus during storage. The fish were smoke-dried to average moisture content of 10.41 ± 0.02% and stored. Fish were packaged in black polythene bags and kept in perforated plastic containers. The fish were left in the plastic baskets for 56 days at ambient temperature (25-32oC). Samples of fish were assessed weekly for physical attributes such as colour, fragmentation, odour, taste and texture. Proximate composition was assessed using changes in moisture content, crude protein, lipid and ash content. Biochemical indexes carried out were: Total Volatile Nitrogen (TVN), pH, Peroxide Value (PV) and Free Fatty Acid (FFA) levels. There was a general decline in physical attributes i.e. colour, fragments or cracks, odour, taste and texture of fish during storage. Fluffy woolly mat of moulds were noticed on the Clarias gariepinus from the 5th week of storage. There was a significant (P <0.05) colour change in most species as from the 6th week. During this study, the moisture content increased weekly in the five smoked fish species from the initial average of 10.41±0.02%. This could be attributed to the difference in the moisture of the smoked fish relative to the surroundings. Oreochromis niloticus and Heterotis niloticus had the best taste value. Apart from Parachanna obscura , the other fatty species, C. gariepinus and L. coubie became less firm as the weeks progressed. There were significant changes (P <0.05) in most of the physical and chemical characteristics except odour from the 6th week (42 days) of storage. There were also significant differences (P <0.05) between the initial and final values of the proximate and chemical constituents of the different species of fish. The study showed that keeping quality of smoked fish under ambient conditions decreases with increase in length of storage. Keywords : Freshwater fish, hot smoking, storage

DEFUMAÇÃO DE OSTRAS Crassostrea gigas: A QUENTE E COM FUMAÇA LÍQUIDA

The present study had as objective evaluates two techniques of traditional smoking the hot and with use of the liquid smoke, tends as control the Pacific oysters Crassostrea gigas cooked. They were appraised the sensorial characteristics and revenue of the processing. The animals were distributed in three treatments and the experimental design was completely randomized, with nine repetitions. For the sensorial analysis 30 fitting room were used, where each one was considered a block. There was not significant difference among the independent of the applied technique smoky oysters (T1 = 8.42% and T2 = 7.61%), but they differed of the control (T3 = 16.25%).In agreement with the applied methodology and with the results obtained in the sensorial analysis, the smoke oysters (independent of the applied technique) are products with great acceptability and increased your sensorial characteristics. KEY-WORDS: Crassostrea gigas, oysters, hot smoking, liquid smoke.

Investigations of dry matter and fat content in carp species smoked by hot and cold methods

In recent years the freshwater fish market has required more processed goods, as young consumers purchase ready-to-cook food products. In Middle European aquaculture systems carp are the main species. The appearance of new species (African catfish, trout, salmon), as well as the improved import possibilities of value-added fish products have introduced new challenges for fish farmers. In order to maintain the share of carps in fish sales, it is indispensable to develop up-to-date products that meet the needs of present generations. It is necessary to find processing methods that remove the fish bone and the off flavours occurring in Cyprinids. Smoking of carp has a strong tradition in the region, thus there are advantages to the development of smoked carp products, mainly in the form of boned fillets. The present study investigates two smoking methods aimed at ensuring basic information for product innovation. Analyses of the variation of weight, dry matter and lipid content during hot and cold smoking are presented for the case of three species: the common, silver, and grass carp. To determine the most acceptable products, the paper details the results of organoleptic tests, in which five characteristics (appearance, consistence, flavour, smell, and succulence) were investigated. Evaluation results indicate that the hot-smoked carp products are more acceptable, therefore it is hoped that these products, packed in a modified atmosphere, will achieve a strong market share in the near future.

The differences in whole body chemical composition of the rainbow trout (Oncorhyncus mykiss), black sea pilchard (Engraulis encrasicolus) and sardine (Sardina pilchardus) following hot smoking.

The differences in whole body chemical composition of the rainbow trout (Oncorhyncus mykiss), black sea pilchard (Engraulis encrasicolus) and sardine (Sardina pilchardus) following hot smoking.

Effect of Smoking Process on Changes in the Content of Selected Non-ortho- and Mono-ortho-PCB Congeners in Mackerel Slices

The study involved determination of changes in the content of toxic dioxin-like coplanar non-ortho (PCB 77, PCB 126, PCB 169) and mono-ortho (PCB 156, PCB 157, PCB 114) congeners in mackerel slices during cold and hot smoking. In addition, the risk of toxicological exposure of the consumers of examined smoking products was assessed by calculating toxic equivalency (TEQs) in relation to 2,3,7,8-TCDD dioxin. In the final stages of hot smoking a small increase was observed in the content of analyzed compounds due to the presence of PCBs in the smoke. The main factor determining the changes in the content of these compounds in fish slices may have been their loss with the lipid leakage and in codistillation with water vapor. The hot smoking of mackerel slices contributed to a decrease in the content of examined non-ortho- and mono-ortho-PCB congeners in final products and in consequence to a drop of TEQs by 14.2%. On the other hand, cold smoking led to a rise in the content of analyzed PCB congeners in the final product, which significantly affected the increase of TEQs level by 31.7% in relation to initial raw material.

Changes in total PCB content in selected fish products during hot- and cold smoking

Background. Stability and high bioaccumulation coefficients of polychlorinated biphenyls (PCB) in aqueous organisms may constitute a health hazard for their consumers (it is really the potential toxicity of PCBs that determine their hazard&mdash;not stability). As the fish are mostly eaten in the form of processed products, the influence of technological processes and different methods of cooking on changes in the levels of toxic compounds in final products is of great importance and may be helpful for appropriate processing. Since smoked fish products are in great demand in Poland, the goal of this study was to determine changes in total PCB content in herring fillets during hot smoking and in hot and cold smoked mackerel fillets. Materials and methods. Herring fillets were hot smoked under industrial conditions, whereas mackerel fillets were cold- and hot smoked. Analyses were carried out using a capillary gas chromatograph coupled with a mass spectrometer GC-MS (HP 6890/5973) with a HP-5 column. Results. The hot smoking process affected the loss of total PCB content in mackerel and herring fillets, with its highest value in the first hour of partial drying. The main factor determining the changes in the content of these compounds in wet matter and lipids was their escape in co-distillation with water vapour. The increase of their content, in the final stage of hot smoking and during the whole cold smoking process, was caused by contamination of fish fillets with polychlorinated biphenyls present in the curing smoke. Conclusion. From the toxicological point of view the process of hot smoking, is much healthier for people because it causes the reduction of total PCB content in final smoked products. Cold smoked mackerel is much more popular on the Polish market for its stronger taste and aromatic smell. However, lengthy exposure to smoke in low temperature increased the total PCB content in cold smoked fish. The consumption of these products should be limited based on these results.