Peer reviewed: genetic engineering: the frontier of bioremediation

New molecular tools and an improved understanding of biodegradative processes are slowly increasing prospects for successful technology deployment.     

Use of carbon dioxide enriched atmospheres in the refrigerated storage (2 °C) of salmon (Salmo salar ) steaks

 Selected microbial counts (total viable microbiota, Brochothrix thermosphacta, lactic acid bacteria and Enterobacteriaceae), biochemical parameters [pH, total volatile nitrogen, nucleotide breakdown products, non-volatile amines, d(–) and l(+)-lactic acids and short-chain fatty acids] and sensory attributes (colour and odour) of refrigerated (2  °C) salmon (Salmo salar) steaks stored under CO₂-enriched [CO₂/air (20/80, v/v), CO₂/air (40/60, v/v)] and air atmospheres were determined. When compared with air, sensory results showed shelf-life extension of 6 days and 15 days for 20% and 40% CO₂-enriched atmospheres, respectively. Microbial and biochemical results also revealed that the 40% CO₂-enriched atmosphere was the most effective packaging type for refrigerated salmon. Received: 22 April 1999     

Volatile compound generation in dry fermented sausages by the surface inoculation of selected mould species

The effect of the inoculation of dry fermented sausage surface with an atoxigenic, proteolytic and lipolytic strain of Mucor racemosus, Penicillium aurantiogriseum and Penicillium camemberti on the volatile composition was studied. The analysis of the headspace volatile compounds using gas chromatography/mass spectrometry enabled the identification of 55 volatiles. The study showed that every mould species produced a different volatile profile which was also different from that of the control sausages. Compounds derived from amino acid catabolism, i.e. branched aldehydes and the corresponding alcohols, were produced in higher amounts in sausages inoculated with Penicillium spp. On the other hand, volatiles coming from the microbial esterification were related to sausages inoculated with M. racemosus. The development of the fungal mycelia on the sausage surface protected lipids from oxidation, thus giving rise to fewer lipid oxidation products in the inoculated sausages.     

Rocket salad (Diplotaxis and Eruca spp.) sensory analysis and relation with glucosinolate and phenolic content

BACKGROUND: Salad crops of the Brassicaceae family, such as Diplotaxis tenuifolia and Eruca vesicaria, commonly referred to as ‘rocket salads’, have attracted considerable interest as culinary vegetables because of their strong flavour and their content of putative health‐promoting compounds. Among such compounds, glucosinolates and phenolics are well‐known phytochemicals with an important role also in determining the characteristic flavour of these species. In this study, to identify potentially high‐value rocket salads, 37 cultivated types were examined for sensory characters and their relations with glucosinolate and phenolic contents, which ranged from 0.76 to 3.03 g kg^?1 dry weight (DW) and from 4.68 to 31.39 g kg^?1 DW, respectively. RESULTS: The perception of bitter taste was significantly affected by specific glucosinolates, namely progoitrin/epiprogoitrin and dimeric glucosativin. Aroma intensity was negatively related to glucoalyssin content, whereas pungency was significantly related to total glucosinolate content. Kaempferol‐3‐(2‐sinapoyl‐glucoside)‐4′‐glucoside was positively and significantly related to all flavour trait perceptions. Aroma intensity, pungency, crunchiness and juiciness were positively related to typical rocket salad flavour perception through a prominent direct effect. CONCLUSION: Aroma intensity, pungency, crunchiness and juiciness were strong determinants of overall rocket salad flavour perception. Visual traits also characterised sensory components. Bitterness, usually considered a negative flavour trait, was moderately perceived in the examined material, without negatively affecting typical flavour perception. In the range of the examined material, glucosinolate content did not contrast with typical flavour, demonstrating that good taste and putative health‐promoting properties may coexist. Copyright © 2011 Society of Chemical Industry     

Polycyclic aromatic hydrocarbons (PAHs) in two Spanish traditional smoked sausage varieties: "Chorizo gallego" and "Chorizo de cebolla"

The polycyclic aromatic hydrocarbon (PAH) content in two traditional smoked sausages from Spain was determined. Results showed, that total average levels of PAHs found were higher in "Chorizo de cebolla" (101.81 vs. 98.48 μgkg(-1)). Most contents of PAHs found in both sausages were phenanthrene, naphthalene and anthracene. The maximum level for benzo[a]pyrene (BaP) of 5 μgkg(-1) in smoked meat products was not exceeded in any samples. BaP represented a 0.73% and 1.15% with respect to the total sum of the 15 PAHs that were investigated in this study for "Chorizo gallego" and "Chorizo de cebolla", respectively. Correlation statistic analysis (P < 0.01) of the contents from samples analysed, showed that BaP was a good marker for Σ15 PAHs in "Chorizo gallego" samples (R(BaP/Σ15PAHs) = 0.77; P < 0.01) and it was a good marker for 7 U.S. EPA probably carcinogenic PAHs in "Chorizo de cebolla" samples (R(BaP/7EPA) = 0.95) and in "Chorizo gallego" samples (R(BaP/7EPA) = 0.81).     

Intramuscular fatty acid composition of “Galician Mountain” foals breed: Effect of sex,slaughtered age and livestock production system

The effects of sex, slaughtered age (9 vs. 12 months) and livestock production system (freedom extensive system vs. semi extensive system) of “Galician Mountain” foals breed on the fatty acid composition were studied. The sex and slaughtered age of the animals had no statistical significance in the intramuscular fatty acids. Furthermore, the livestock production system showed differences in the fatty acid profiles from the Longissimus dorsi. The feeding system showed significant differences in PUFA content (P < 0.001) higher in freedom extensive production system that semi extensive system, whereas MUFA content was significantly (P < 0.001) higher in semi extensive system. This major PUFA content in freedom extensive production showed a significant (r = 0.70, P < 0.01) correlation with C18:3n− 3 content and can be attributed to their eaten only pasture until slaughtered. The higher MUFA contents (P < 0.001) observed for semi extensive production system foals were very significant (r = 0.98, p < 0.01) correlated with C18:1cis−9 content and less significant (r = 0.81, P < 0.01) correlated with C16:1cis−9 content. In addition, the data reinforced the evidence that foals from extensive production system on wood pasture have a higher nutritional quality (mainly due to the higher levels of n−3 PUFA) when compared to concentrate-fed foals, as a result of the beneficial effects of grass on meat fatty acid profiles.     

Changes in selected biochemical and sensory parameters as affected by the superficial inoculation of Penicillium camemberti on dry fermented sausages

An atoxigenic strain of Penicillium camemberti was superficially inoculated on fermented sausages in an attempt to improve their sensory properties. The growth of this mould on the surface of the sausages resulted in an intense proteolysis and lipolysis, which caused an increase in the concentration of free amino acids, free fatty acids (FFA) and volatile compounds. Many of these were derived from amino acid catabolism and were responsible for the "ripened flavour", i.e. branched aldehydes and the corresponding alcohols, acids and esters. The development of the fungal mycelia on the surface of the sausages also protected lipids from oxidation, resulting in both lower 2-thiobarbituric acid (TBARS) values and lipid oxidation-derived compounds, such as aliphatic aldehydes and alcohols. The sensory analysis of superficially inoculated sausages showed clear improvements in odour and flavour and, as a consequence, in the overall quality of the sausages. Therefore, this strain is proposed as a potential starter culture for dry fermented sausage production.     

Characterisation of Bobal and Crujidera grape cultivars,in comparison with Tempranillo and Cabernet Sauvignon: Evolution of leaf macronutrients and berry composition during grape ripening

We present characterisation data for two Spanish autochthonous grapevines, Bobal and Crujidera, in comparison with the well-known cultivars Tempranillo and Cabernet Sauvignon. Microsatellite markers were used for the molecular characterisation of Crujidera grapevines. Leaf macronutrient contents of the four cultivars were evaluated, as well as their changes at different vine developmental stages, and veraison was seen as the most suitable time to evaluate the nutritional status. Quantitative changes in some physiological parameters and the phenolic composition of the four grape varieties were measured during the last month of ripening. Polyphenols, tannins and anthocyanins increased with grape maturation, although the accumulation of these phenolic compounds and their patterns of evolution varied considerably with the cultivar. The biosynthetic potential of these grapes to produce resveratrol largely depended on the grape variety, with a remarkably high content found in Bobal berry skins.     

Differentiation of co-winemaking wines by their aroma composition

Co-winemaked Monastrell wines with Cabernet Sauvignon or Merlot, at different proportions have been studied for first time in terms of its odor activity value (OAV) in young wines, aging wines (after 9 months in French oak barrels) and bottled aging wines (aging wines after 6 months in the bottle). The co-winemaking wines showed a different aromatic complexity as they were fruitier and sweeter than the monovarietal ones, enhancing their aroma characteristics, being more evident at 60:40 proportion in case of Merlot for young and aging wines and Cabernet Sauvignon for bottled ones. In terms of extractable oak compounds, Monastrell–Merlot wines showed the highest values suggesting that they may need a shorter period within the barrel than Monastrell–Cabernet Sauvignon ones.     

Curcumin and the cellular stress response in free radical-related diseases

Free radicals play a main pathogenic role in several human diseases such as neurodegenerative disorders, diabetes, and cancer. Although there has been progress in treatment of these diseases, the development of important side effects may complicate the therapeutic course. Curcumin, a well known spice commonly used in India to make foods colored and flavored, is also used in traditional medicine to treat mild or moderate human diseases. In the recent years, a growing body of literature has unraveled the antioxidant, anticarcinogenic, and antinfectious activity of curcumin based on the ability of this compound to regulate a number of cellular signal transduction pathways. These promising data obtained in vitro are now being translated to the clinic and more than ten clinical trials are currently ongoing worldwide. This review outlines the biological activities of curcumin and discusses its potential use in the prevention and treatment of human diseases.