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Fillets were soaked in water, 8% sucrose/sorbitol (S/S) or 1% sodium lactate (SL) with or without 0.5% phosphate and 0.05% MgC12. After treatment, fillets were frozen stored at -20°C for 90 days. Smoked fillets and gels were subsequently prepared from those frozen fillets. L* and a* values of fillets following treatments with cryoprotectants and freezing, were lower than water-soaked fillets. Cryoprotectants (S/S and SL) significantly improved hardness and cohesiveness of gels prepared from frozen fillets, but did not affect the fillet shear force, and they increased smoke-oven yield of fillets compared to untreated and water controls. [ABSTRACT FROM AUTHOR]

Tetrahydro-β-carboline alkaloids are biologically active compounds that occur in foodstuffs. 1,2,3,4-Tetrahydro-β-carboline-3-carboxylic acid, a tetrahydro-β-carboline derived from a Pictet–Spengler condensation reaction among l-tryptophan and formaldehyde, was identified by GC–MS as its N-methoxycarbonyl methyl ester derivative in smoked fish, sausage and cheese. The occurrence of this β-carboline was determined by RP-HPLC-fluorescence in numerous commercially available samples of these products and the concentrations ranges were 0.03–12.2 μg/g, 0.07–6.06 μg/g and 0.01–14.8 μg/g in smoked fish, smoked cheeses and smoked sausages and meats, respectively. These results showed that 1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid is the main β-carboline in such products. Smoked foods contained a higher relative amount (2–7 fold) of this compound in their exterior part exposed to the smoke than in their interior counterpart suggesting a reaction involving formaldehyde from smoke and tryptophan. Smoked products appear to be one of the food stuffs with the highest amount of this particular tetrahydro-β-carboline. [Copyright &y& Elsevier]

Longissimus dorsi muscles from beef carcasses were dry-salted at doses of 0, 25, 50, 75 and 100 g salt/kg meat. Salted samples were kept in a cooler at 2°C for 5 days after which time one treatment group of the cured meat was pre-dried at 35°C for 2 h, smoked at 88°C for 6 h and then dried at 95°C to a constant weight for about 52 h. Proximate analysis showed that the moisture and protein contents of the samples decreased with increased salt content of the meat, while the ash content increased. The pH of the fresh meat increased with increasing salt. In general, the addition of salt significantly (P<0.05) increased the degree of oxidation, while smoking produced antioxidant activity. Iron and phosphorus decreased with increasing salt content. With salting, smoking and drying of the meat the microbial loads generally decreased but the halophilic microorganisms increased. [ABSTRACT FROM AUTHOR]

Presents a study which examined the effects of application of natural wood smoke on the ripening of Cheddar cheese. Materials and methods used; Composition of cheese; Detection of lactobacilli growth in cheese; Levels of water-soluble nitrogen; Results of sensory analysis of the cheese.

BSTRACT: Sensory-evaluated hardness of smoked Atlantic salmon ( Salmo salar L.) was correlated with various response variables from instrumental texture analysis of raw or smoked cutlets (25 mm thick) using 4 different probes: 12.5- and 23- mm-dia cylinders, a Warner-Bratzler blade, and a 25.4-mm-dia sphere. Sensory hardness correlated significantly with analyses using all mechanical methods, but it was most accurately predicted by the 12.5-mm-dia cylinder in raw salmon (force and area at 90% compression; r = 0.70, P < 0.0001), and by the 23-mm-dia cylinder in smoked salmon (force at 90% compression and the area from origo to the 1st significant break; r = 0.63 to 0.64, P < 0.0001). [ABSTRACT FROM AUTHOR]

The effects of fog sanitization with peroxyacetic acid (hydrogen peroxide, peracetic acid, and acetic acid in combination) on general hygiene (aerobic plate count) and on Listeria monocytogenes were assessed in a slicing area at a salmon smokehouse and compared with the effects of foam sanitization with sodium hypochlorite (routinely performed at the smokehouse). Two hundred twenty-three environmental samples were collected with sponges and swabs after each of the sanitization procedures, and 68 samples were collected during production. The total culturable aerobic plate count was determined for each sample, and a total of 288 bacterial strains were randomly isolated and tentatively identified to genus level by physiological and biochemical tests. The microflora was dominated by Neisseriaceae, Enterobacteriaceae, and lactic acid bacteria during production. Foam sanitization caused a change in the composition of the flora, with Pseudomonas spp. and Alcaligenes spp. being the dominant gram-negative bacteria and Kurthia spp. and Bacillus spp. being the surviving gram-positive bacteria. Bacteria were very sensitive to fog sanitization, and yeasts accounted for almost half of the surviving flora. By a selective isolation method, strains of L. monocytogenes were isolated and subsequently characterized by random amplified polymorphic DNA (RAPD) typing. Following foam sanitization, 14 to 42% of the samples contained <10 CFU per site, whereas 29 to 78% of the samples collected after fog sanitization contained this level of bacteria. The prevalence of L. monocytogenes was unchanged, but L. monocytogenes was found only in poorly cleaned areas such as drains. The RAPD types for all positive samples were identical to the type that had persisted in the smokehouse since 1995, indicating the importance of drains as a niche. [ABSTRACT FROM AUTHOR]

Research on the comparison of textural properties of lowfat, fullfat and smoked cheeses is yet to be reported. The objective of this study was to find textural differences in these cheeses by sensory and instrumental methods and to try to correlate the sensory and the instrumental data. Nine commercial cheeses were evaluated for aroma, flavor, and texture by descriptive analysis and were also subjected to instrumental texture profile analysis. The sensory evaluation by a panel of nine judges separated the cheeses into ‘smoked’ and ‘non-smoked’ based on aroma and flavor. On the basis of texture the judges categorized the cheeses into either ‘dry and crumbly’ or ‘sticky and creamy’. The texture profile analysis segregated the cheeses into ‘smoked’ and ‘non-smoked’. ‘Hardness’ (instrumental) was positively correlated to sensory texture attributes such as ‘dry’, ‘hardness’ and ‘crumbly’, which might indicate hardness of cheeses during mastication. The judges that participated in the panel were found to be very consistent as a group in their evaluation. [Copyright &y& Elsevier]

The antimicrobial effect of four smoke wood condensates against the psychrotrophic pathogensListeria monocytogenes and Aeromonas hydrophila was tested in vacuum-packed cold-smoked rainbow trout (Oncorhynchus mykiss) stored at refrigeration temperature. Salted trout samples were surface inoculated with L. monocytogenes or A. hydrophila, cold smoked, vacuum packaged and stored at 4 °C for 21 days. At different times of storage, samples were taken and analysed for L. monocytogenes and A. hydrophila by quantitative and qualitative procedures. All smoke extracts showed activity against A. hydrophila. However, only smoke extracts L1 and L2 were effective against L. monocytogenes. Although these extracts caused a reduction in viable cell counts of L. monocytogenes below the detectable level by surface plating procedure, this organism was detected by qualitative analysis in most of the samples. Finally, extracts L1 and L2 also reduced total viable cell counts to undetectable levels. [Copyright &y& Elsevier]

Hot smoked fish should fulfill the requirements set up for ready-to-eat foods. The total bacterial count on the raw material is 10(3) to 10(5) CFU per cm2 of skin and 10(2) to 10(9) CFU per gram of intestines. Contamination with pathogenic bacteria is very low, mainly with Clostridium botulinum, Listeria monocytogenes, Staphylococcus aureus, and Vibrio parahaemolyticus. In the premises of low hygiene, the contamination may increase due to unsanitary procedures, rotation of assigned duties of workers, and airborne microorganisms during packing of the product. Hot smoking in mild conditions at temperature in the fish not exceeding 65 degrees C and low concentration of salt does not inactivate all pathogens or inhibit bacteria during storage. Thus the required safety can be obtained only by using very fresh fish handled in hygienic conditions, controlling the processing and the plant hygiene in critical control points, and chilling of the product to about 2 degrees C. Most critical are the hygienic conditions in handling of the product after smoking. The use of preservatives for extending the shelf life of smoked fish is being investigated. High-quality shelf life of mild hot smoked mackerel at about 2 degrees C is at least 3 weeks. [ABSTRACT FROM AUTHOR]

The sensory, instrumental, and chemical profile of a smoked tuna product comparable and competitive to smoked turkey and pork was studied, based on four experimental factors. Despite their different brining times, all brined, sliced portions of tuna were assessed by panelists as quite acceptable products in terms of firmness, juiciness, color, and saltiness. Protein denaturation seemed to be affected by the brining time. Lipid oxidation seemed quite extensive; the ratio of C22:6n-3/C16:0 was decreased at 15% and 20%. Histamine content was between 3.7 mg/100 g and 7.5 mg/100 g. After 3 mo in refrigeration, the aerobic bacteria was 19.105 to 250.106 in contrast to the unprocessed samples at 28.105. [ABSTRACT FROM AUTHOR]

This appendix provides a brief summary of the cold-smoking process as a complement to Chapter VI, Control of Food Safety Hazards During Cold-Smoked Processing, which includes a more detailed description of the process and identifies potential hazards, control points, and processing parameters. Both Chapter VI and this summary address some recommendations by the Association of Food and Drug Officials (AFDO 1991). It bears repeating that although developed by experts and widely used, these recommendations have not necessarily been scientifically evaluated. The recommendations from the Fish & Fishery Products Hazards & Controls Guide (FDA 1998) are indicated for reference. [ABSTRACT FROM AUTHOR]

This chapter of the report presents research data on the production of biogenic amines by fish species that are likely to be cold-smoked. Factors that affect the production of biogenic amines, particularly histamine, are discussed. The effect of the cold-smoking process on biogenic amine production or growth of biogenic amine-producing microorganisms is also assessed. Finally, areas requiring research to adequately determine the hazard of biogenic production in cold-smoked fish and fishery products are listed. [ABSTRACT FROM AUTHOR]

Aims: The aim of the study was to assess the relationships between the remaining shelf-life (RSL) of cold-smoked salmon and various microbiological and physico-chemical parameters, using a multivariate data analysis in the form of stepwise forward multiple regression. Methods and Results: Thirteen batches of French cold-smoked salmon were analysed weekly during vacuum-packed storage at 5°C for their lipid, water, salt, phenol, pH, total volatile basic nitrogen (TVBN) and trimethylamine contents, total psychrotrophic count, lactic acid bacteria, lactobacilli, B. thermosphacta, Enterobacteriaceae and yeast counts. At the sensory rejection time, the flora was dominated by lactobacilli, lactobacilli/Enterobacteriaceae or Carnobacteria/B. thermosphacta. Shelf-life was very variable (1->6 weeks) and was related to the initial Enterobacteriaceae load (P < 0·05), depending on hygienic conditions in the smokehouse. High correlations existed between the RSL and lactobacilli count (P < 0·01), yeast count (P < 0·05) and TVBN concentration (P < 0·01). A polynomial fitting the RSL as a function of those three factors was proposed (R² = 0·80). Assuming that lactobacilli count could not exceed 109 cfu g-1, a minimum of 36 mg-N 100 g-1 was necessary for a product to be rejected, with a yeast count of 104 cfu g-1. Conclusions: Estimation of cold-smoked salmon quality is possible by measuring three parameters: lactobacilli and yeast counts and TVBN concentration. Significance and Impact of the Study: The technical content is important for the smoked salmon industry and for development of quality standards for cold-smoked salmon. [ABSTRACT FROM AUTHOR]

The effectiveness of the steps of a general method, which includes alkaline treatment of the samples, extraction, clean-up and analysis, for the determination of polycyclic aromatic hydrocarbons in liquid smoke flavourings and smoked foods have been studied, by using mixtures of pure polycyclic aromatic hydrocarbons and of smoke flavouring compounds. All these products were applied to samples of liquid smoke flavourings in order to test the effectiveness of each step of the method, as well as to investigate its effect on real samples, and thus obtain a suitable procedure for the study of polycyclic aromatic hydrocarbons in liquid smoke flavourings. The alkaline treatment has been proved to be necessary because of its capability for removing some smoke components. Both cyclohexane and dichloromethane are able to extract polycyclic aromatic hydrocarbons with high recovery percentages; however, cyclohexane is more adequate due to its lower ability to extract other smoke flavourings components. It is important to note that the elution sequence of polycyclic aromatic hydrocarbons during the clean-up step is quite different depending on the solvent used to dissolve the extract, which determines the ability of this process to isolate polycyclic aromatic hydrocarbons for their accurate identification and quantification by gas chromatography-mass spectrometry in selected ion monitoring mode. Finally, the PAHs present in a liquid smoke flavouring and their concentrations were determined; it was observed that, despite the different extraction solvents and clean-up procedures used, the results were very similar. [ABSTRACT FROM AUTHOR]

• β-Carboline alkaloids (βCs) are a class of pharmacologically active compounds. • Foodstuffs are rich in βCs, especially norharman, harman and tetrahydro-β-carbolines (THβCs). • The highest levels of norharman and harman are found in coffee. • Smoked foods seem to contain the highest concentrations of THβCs. • Long-term consumption of foodstuffs rich in βCs may be beneficial or noxious to human. Pharmacologically active β-carboline alkaloids (βCs) such as harman, norharman and some others are naturally present in plants and occur in many foodstuffs. They have a lot of pharmacological properties, including antitumor, antioxidant, anti-inflammatory and antimicrobial effects, and possess the potential for treating Alzheimer's disease, Parkinson's disease, depression and other central nervous system diseases. Dietary intake is proven to be an important source of βCs. Therefore, it is important to know the amounts of βCs that can be gotten from daily diets. This review summarizes the pharmacological activities, toxicology and formation of βCs, and gives collective information on contents of βCs in different foodstuffs. [ABSTRACT FROM AUTHOR]

Smoking is mainly used to impart desirable flavour, colour and texture to the products. Various food smoking methods can be divided into traditional and industrial methods. The influences of three different smoking methods, including traditional smouldering smoke (TSS), industrial smouldering smoke (ISS) and industrial liquid smoke (ILS), on quality characteristics, sensory attributes and flavour profiles of Harbin red sausages were studied. The smoking methods had significant effects on the moisture content (55.74–61.72 g/100 g), L*-value (53.85–57.61), a*-value (11.97–13.15), b*-value (12.19–12.92), hardness (24.25–29.17 N) and chewiness (13.42–17.32). A total of 86 volatile compounds were identified by headspace solid phase microextraction combined with comprehensive two-dimensional gas chromatography mass spectrometry (GC × GC-qMS). Among them, phenolic compounds were the most abundant compounds in the all sausages. Compared with sausages smoked with smouldering smoke, the ILS sausages showed the highest content of volatile compounds, especially phenols, alcohols, aldehydes and ketones. Principal component analysis showed that the sausages smoked with different methods had a good separation based on the quality characteristics and GC × GC-qMS data. These results will facilitate optimising the smoking methods in the industrial production of smoked meat products. [ABSTRACT FROM AUTHOR]

In order to investigate the levels of the potently carcinogenic benzo[a]pyrene (BP), 31 samples of smoke foods were analysed. The samples tested included five samples of meat products, three samples of cheese and 22 samples of fish. A liquid chromatographic method was developed using a fluorescence detector. BP was found in 74% of the samples analysed. The levels varied from not detected to 2.46 mug/kg. Only one sample showed a BP level above 1 mug/kg, the maximum level that the EU intends to set for smoked foods. [ABSTRACT FROM AUTHOR]

Liquid smoke as an all-natural food indigent is traditionally produced by smouldering. This process has a low efficiency and causes air pollution. Biomass pyrolysis is an advanced thermochemical process, which can replace smouldering and hence, transition the production towards a circular process. Liquid smoke has a mature and steadily growing market, which provides an opportunity to commercialise biomass pyrolysis. This study addresses opportunities to produce liquid smoke by pyrolysis technologies. Recently developed technologies are reviewed including biomass pretreatment, fast pyrolysis, microwave pyrolysis and fractional condensation. They are considered as promising approaches for liquid smoke production. The advantage of liquid smoke production by fast pyrolysis is the higher gross profit over biofuel oil production. Challenges also exist in this transformation because of more requirements for food products manufacture such as food safety standards and sensory quality specifications. • Liquid smoke food flavouring is a high value product from woody biomass. • Liquid smoke and biofuel production via pyrolysis share a similar technology base. • Opportunities of pyrolysis technologies to improve the production are reviewed. • Fast pyrolysis has technical and economic benefits for liquid smoke production. • Challenges remain with respect to food safety standards and the flavour profile. [ABSTRACT FROM AUTHOR]