Risk assessment of the lead intake by consumption of red deer and wild boar meat in Southern Spain

The presence of heavy metals in big game meat may pose a risk to human health. The main objective of this paper is to carry out a risk assessment study (using a probabilistic and point-estimate approach) of lead intake by consumption of red deer and wild boar meat in Southern Spain based on Spanish data collected in the period 2003-2006. In general, the concentration levels found for wild boar meat (mean?=?1291?μg?kg(-1)) were much higher than those observed in red deer meat (mean?=?326?μg?kg(-1)). The results from a point-estimate risk assessment showed that the estimated average intake of lead among different exposure scenarios varied from 0.1 to 6.5 and from 0.3 to 38?μg?kg(-1)?week(-1) for red deer and wild boar meat, respectively; and from 0.3 to 35?μg?kg(-1)?week(-1) for individuals consuming both red deer and wild boar meat, and that the estimated intake of lead by consumption of big game meat differed significantly between hunters and non-hunters, it being higher for hunters. Besides this, results from the probabilistic risk assessment study corroborated the fact that risk is greater in hunter populations, reaching a maximum in individuals consuming only wild boar and both types of meat, with 0.4% and 0.2% of the population above the provisional tolerable weekly intake (PTWI), respectively. Likewise, the hunter populations consuming wild boar and both types of big game meat (red deer and wild boar meat) were exposed to the maximum lead level (56?μg?kg(-1)?week(-1)), which corresponded approximately to 224% of the PTWI. Further data and studies will be needed to give a complete risk estimation in which it will be crucial to consider the contribution to the lead intake level of other foods in the diet of both population groups.     

Effect of housing system, slaughter weight and slaughter strategy on carcass and meat quality, sex organ development and androstenone and skatole levels in Duroc finished entire male pigs

This study aimed at evaluating the effect of housing system (HS), slaughter weight (SW) and strategy (SS) on carcass a nd meat quality, sexual organ development and boar taint in entire males. Twelve pens of 10 pigs were used (two trials). Half of male pens were allowed visual contact with females (MF) and half with males (MM). Half MM or MF were slaughtered at 105 or 130 kg in trial 1, or penwise or by split marketing in trial 2 at 120 kg. Housing system showed no significant effect on carcass or meat quality. MF presented significantly longer testicles and heavier bulbourethral glands compared to MM. The distribution of androstenone and skatole levels was affected by SW but not by HS or SS, samples with androstenone >1 μg/g of the different groups falling within the range of 16 to 22%. All correlations between androstenone and sex organs were significant. Housing system and slaughter strategy did not reduce the risk of boar tainted carcasses.     

Antioxidant activity and free radical-scavenging capacity of a selection of wild-growing Colombian plants

BACKGROUND: The replacement of some synthetic food antioxidants by safe natural antioxidants has fostered research on the screening of raw materials to find new vegetable sources of antioxidants. In this study the antioxidant activity of eight wild‐growing Colombian plants was assessed by four complementary assays. RESULTS: An evaluation of the antioxidant activity of ten ethanolic extracts from Baccharis chilco, Cinnamomum triplinerve, Ilex laurina, Lachemilla orbiculata, Lepechinia conferta, Quercus humboldtii, Rubus urticifolius and Tephrosia cinerea was carried out. Furthermore, the total phenolic content was determined by the Folin–Ciocalteu method, and the relationship between phenolic content and activity was also statistically investigated. Cinnamomum triplinerve, L. conferta and I. laurina were found to have the highest phenolic contents. Baccharis chilco, C. triplinerve, I. laurina, L. conferta, Q. humboldtii and R. urticifolius showed higher radical‐scavenging activity (DPPH and superoxide assays) than commercial rosemary oleoresin (reference). Lachemilla orbiculata and R. urticifolius showed higher antioxidant activity (β‐carotene‐bleaching test) than the reference. The protection factor of all studied plant extracts was below that of the reference according to the Rancimat test. CONCLUSION: On the basis of the results obtained, C. triplinerve, Q. humboldtii and R. urticifolius seem to be the most promising species for further investigation in order to identify the compounds responsible for their activity. Copyright © 2011 Society of Chemical Industry     

Carbon and sulfur cycling by microbial communities in a gypsum-treated oil sands tailings pond

Oil sands tailings ponds receive and store the solid and liquid waste from bitumen extraction and are managed to promote solids densification and water recycling. The ponds are highly stratified due to increasing solids content as a function of depth but can be impacted by tailings addition and removal and by convection due to microbial gas production. We characterized the microbial communities in relation to microbial activities as a function of depth in an active tailings pond routinely treated with gypsum (CaSO(4)·2H(2)O) to accelerate densification. Pyrosequencing of 16S rDNA gene sequences indicated that the aerobic surface layer, where the highest level of sulfate (6 mM) but no sulfide was detected, had a very different community profile than the rest of the pond. Deeper anaerobic layers were dominated by syntrophs (Pelotomaculum, Syntrophus, and Smithella spp.), sulfate- and sulfur-reducing bacteria (SRB, Desulfocapsa and Desulfurivibrio spp.), acetate- and H(2)-using methanogens, and a variety of other anaerobes that have been implicated in hydrocarbon utilization or iron and sulfur cycling. The SRB were most abundant from 10 to 14 mbs, bracketing the zone where the sulfate reduction rate was highest. Similarly, the most abundant methanogens and syntrophs identified as a function of depth closely mirrored the fluctuating methanogenesis rates. Methanogenesis was inhibited in laboratory incubations by nearly 50% when sulfate was supplied at pond-level concentrations suggesting that in situ sulfate reduction can substantially minimize methane emissions. Based on our data, we hypothesize that the emission of sulfide due to SRB activity in the gypsum treated pond is also limited due to its high solubility and oxidation in surface waters.     

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).     

Spermatogenic and sperm quality differences in an experimental model of metabolic syndrome and hypogonadal hypogonadism

The synergistic effect of the co-morbidities that comprise metabolic syndrome (MetS) is increasingly being recognised as an important contributor in the pathology of a broad spectrum of seemingly disparate conditions. However, in terms of male reproductive function, beyond erectile dysfunction, little is known about the influence of this cohort (collectively or separately) on spermatogenesis and sperm quality. The aims of this study were to assess the reproductive tract of a MetS animal model for detrimental changes, to determine whether a group of compounds (advanced glycation end products and their receptor) known to cause cell dysfunction and DNA damage was present and assess whether hypogonadotropic hypogonadism was the main contributing factor for the changes seen. Animals fed a high-fat diet were found to have significantly increased cholesterol, triglycerides, blood glucose, mean arterial pressure and visceral fat levels. Although serum testosterone was decreased, no changes were seen in either testicular or epididymal histology. Immunolocalisation of N(ε)-carboxymethyl-lysine and the receptor for advanced glycation end products was found in the testes, epididymides and sperm of the two treated groups of animals; however, ELISA did not show any difference in protein levels. Similarly, assessment of sperm nuclear DNA (nDNA) fragmentation by acridine orange test did not find significant differences in nDNA integrity. We conclude that the minimal effect on spermatogenesis and sperm quality seen in our model is probably due to the moderate increase of blood glucose rather than the hypogonadism.     

Enzymatic production of human milk fat substitutes containing palmitic and docosahexaenoic acids at sn-2 position and oleic acid at sn-1,3 positions

This paper studies the synthesis of structured triacylglycerols (STAGs) rich in palmitic and docosahexaenoic acids (PA and DHA) at sn-2 position and oleic acid (OA) at sn-1,3 positions by a four step process. First, triacylglycerols (TAGs) were obtained with 63–66 mol PA/100 mol total fatty acids and 10 mol DHA/100 mol by acidolysis of tuna oil and commercial PA, catalyzed by the non-positionally specific lipase Novozym 435. Then these TAGs were purified neutralizing the free fatty acids (FFAs) by KOH hydroethanolic solutions and extracting TAGs with hexane; these TAGs were completely recovered as pure TAGs (without FFAs). The third step involved the displacement of fatty acids located at sn-1,3 positions by acidolysis of PA and DHA enriched TAGs with OA rich FFAs, catalyzed by the sn-1,3 specific lipase DF from Rhizopus oryzae, immobilized on Accurel MP-1000; TAGs with 67 mol OA/100 mol at sn-1,3 positions and 52.1 and 15.4 mol PA and DHA, respectively, per 100 mol at sn-2 position were obtained. Both acidolysis reactions were carried out in stirred tank reactors (STRs) with lipase both dispersed in the reaction medium and contained in a cartridge filter attached to the stirrer rod. Finally STAGs were purified and obtained with yields of over 80 mol STAGs/100 mol STAGs in the reaction product (no FFAs were detected).     

Influence of water activity and temperature on growth and mycotoxin production by Alternaria alternata on irradiated soya beans

The aim of this study was to determine the effects of water activity (a_w) (0.99-0.90), temperature (15, 25 and 30 °C) and their interactions on growth and alternariol (AOH) and alternariol monomethyl ether (AME) production by Alternaria alternata on irradiated soya beans. Maximum growth rates were obtained at 0.980 a_w and 25 °C. Minimum a_w level for growth was dependent on temperature. Both strains were able to grow at the lowest a_w assayed (0.90). Maximum amount of AOH was produced at 0.98 a_w but at different temperatures, 15 and 25 °C, for the strains RC 21 and RC 39 respectively. Maximum AME production was obtained at 0.98 a_w and 30 °C for both strains. The concentration range of both toxins varied considerably depending on a_w and temperature interactions. The two metabolites were produced over the temperature range 15 to 30 °C and a_w range 0.99 to 0.96. The limiting a_w for detectable mycotoxin production is slightly greater than that for growth. Two-dimensional profiles of a_w × temperature were developed from these data to identify areas where conditions indicate a significant risk from AOH and AME accumulation on soya bean. Knowledge of AOH and AME production under marginal or sub-optimal temperature and a_w conditions for growth can be important since improper storage conditions accompanied by elevated temperature and moisture content in the grain can favour further mycotoxin production and lead to reduction in grain quality. This could present a hazard if the grain is used for human consumption or animal feedstuff.     

Lipase-catalyzed process in an anhydrous medium with enzyme reutilization to produce biodiesel with low acid value

One major problem in the lipase-catalyzed production of biodiesel or fatty acid methyl esters (FAME) is the high acidity of the product, mainly caused by water presence, which produces parallel hydrolysis and esterification reactions instead of transesterification to FAME. Therefore, the use of reaction medium in absence of water (anhydrous medium) was investigated in a lipase-catalyzed process to improve FAME yield and final product quality. FAME production catalyzed by Novozym 435 was carried out using waste frying oil (WFO) as raw material, methanol as acyl acceptor, and 3 Å molecular sieves to extract the water. The anhydrous conditions allowed the esterification of free fatty acids (FFA) from feedstock at the initial reaction time. However, after the initial esterification process, water absence avoided the consecutives reactions of hydrolysis and esterification, producing FAME mainly by transesterification. Using this anhydrous medium, a decreasing in both the acid value and the diglycerides content in the product were observed, simultaneously improving FAME yield. Enzyme reuse in the anhydrous medium was also studied. The use of the moderate polar solvent tert-butanol as a co-solvent led to a stable catalysis using Novozym 435 even after 17 successive cycles of FAME production under anhydrous conditions. These results indicate that a lipase-catalyzed process in an anhydrous medium coupled with enzyme reuse would be suitable for biodiesel production, promoting the use of oils of different origin as raw materials.