Influence of crossbreed on the degradation of myofibrillar proteins and on the cathepsin B+L activity in dry cured hams

Enzymatic activity and proteolysis undergone by the proteins extracted from the Semimembranosus and Biceps femoris muscles using high ionic strength buffer were studied in raw hams and hams dry-cured for 11 months. The hams were taken from three different crosses of three breeding enterprises: cross A (75% Duroc-25% Landrace); cross B (50% Duroc-25% Landrace-25% Large White); and cross C (75% Duroc-25% Landrace). Higher cathepsin B+L activity levels were recorded in the Semimembranosus muscle than in the Biceps femoris muscle both in the raw hams and in the cured hams, residual enzymatic activity in the hams being 1% of the initial levels; significant differences were not found for the three crosses. The proteolysis index was higher for the Biceps femoris muscle, similar values being observed for all three crosses. The raw hams from cross A exhibited the highest relative density values for low molecular mass peptides and the lowest relative density values for high molecular mass peptides. After 11 months of curing, proteolysis levels were highest in the hams from cross B, which had the highest levels of 8, 9 and 22 kDa fragments (in the Semimembranosus muscle) and 25 and 9 kDa fragments (in the Biceps femoris muscle). This finding confirms that genetic factors have an influence on proteolysis.     

Ergovaline occurrence in grasses infected by fungal endophytes of semi‐arid pastures in Spain

Ergovaline is a mycotoxin produced by fungal endophytes belonging to Neotyphodium and Epichloë spp in several host grass species. Owing to the production of this alkaloid, the ingestion of endophyte‐infected grasses causes toxicosis in grazing animals. The aim of this work was to determine if ergovaline is produced in several grasses (Agrostis castellana Boiss and Reuter, Brachypodium phoenicoides (L) Roemer and Schultes, Dactylis glomerata L, Festuca arundinacea Schreb, Festuca arundinacea Schreb subsp fenas (Lag) Arcangeli, Festuca ovina L, Festuca rubra L, Holcus lanatus L and Lolium perenne L) infected by fungal endophytes in ‘dehesa’ pastures in Spain. Forage and seed samples of several ecotypes of these grass species were analysed for their ergovaline content by HPLC with fluorescence detection. The ergovaline content ranged between 0.03 and 0.85 µg g^?1 in forage and 0.28 and 3.17 µg g^?1 in seed samples of F arundinacea, between 0.00 and 0.08 µg g^?1 in forage and 0.02 and 0.19 µg g^?1 in seed samples of F rubra, between 0.00 and 0.02 µg g^?1 in forage samples of H lanatus, and was 0.11 µg g^?1 in one ecotype of F ovina. All nine ecotypes of F rubra had ergovaline in seed samples, but in three ecotypes the alkaloid was not detected in forage samples. No ergovaline was detected in the other four endophyte‐infected grasses analysed. The ergovaline content should be considered as an anti‐quality parameter to be measured when the nutritional quality of these pastures is evaluated. © 2003 Society of Chemical Industry     

Trends in exposure to polyfluoroalkyl chemicals in the U.S. Population: 1999-2008

Since 2002, practices in manufacturing polyfluoroalkyl chemicals (PFCs) in the United States have changed. Previous results from the National Health and Nutrition Examination Survey (NHANES) documented a significant decrease in serum concentrations of some PFCs during 1999-2004. To further assess concentration trends of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorohexane sulfonate (PFHxS), and perfluorononanoate (PFNA), we analyzed 7876 serum samples collected from a representative sample of the general U.S. population ≥12 years of age during NHANES 1999-2008. We detected PFOS, PFOA, PFNA, and PFHxS in more than 95% of participants. Concentrations differed by sex regardless of age and we observed some differences by race/ethnicity. Since 1999-2000, PFOS concentrations showed a significant downward trend, because of discontinuing industrial production of PFOS, but PFNA concentrations showed a significant upward trend. PFOA concentrations during 1999-2000 were significantly higher than during any other time period examined, but PFOA concentrations have remained essentially unchanged during 2003-2008. PFHxS concentrations showed a downward trend from 1999 to 2006, but concentrations increased during 2007-2008. Additional research is needed to identify the environmental sources contributing to human exposure to PFCs. Nonetheless, these NHANES data suggest that sociodemographic factors may influence exposure and also provide unique information on temporal trends of exposure.     

Microbiological,chemical, textural and sensory characteristics of Hispánico cheese manufactured using frozen ovine milk curds scalded at different temperatures

Hispánico cheese is a semi-hard variety, manufactured in Spain from a mixture of pasteurized bovine and ovine milk. To study one strategy for overcoming a seasonal shortage of ovine milk in summer and autumn, curds made from ovine milk, scalded at 32, 35 or 38 °C, were pressed for 30 min and frozen at ?24 °C for 4 months. After thawing, they were added to fresh bovine milk curd for the manufacture of experimental Hispánico cheeses. Control cheese was made from a mixture of pasteurized bovine and ovine milk in the same (80:20) proportion. No significant effect of the addition of frozen ovine milk curd or scalding temperature was found for lactic acid bacteria counts, dry matter content, hydrophilic and hydrophobic peptides, 45 out of 65 volatile compounds, texture, and sensory characteristics throughout a 60-day ripening period. Differences between cheeses, of low magnitude and little practical significance, were found for pH value, aminopeptidase activity, proteolysis, free amino acids, free fatty acids, and the remaining 20 volatile compounds. Thus, the addition of frozen ovine milk curd to fresh bovine milk curd does not alter the main physicochemical and sensory characteristics of Hispánico cheese.     

State of art of nanotechnology applications in the meat chain: A qualitative synthesis

Background: Nanotechnology is a promising area in industry with a broad range of applications including in the agri-food sector. Several studies have investigated the potential benefits deriving from use of nanomaterials in the context of the whole food chain drawing scenarios of benefits but also potential for concerns. Among the agri-food sector, animal production has potential for nanomaterial application but also for safety concerns due to the possibility of nanomaterial accumulation along the farm-to-fork path.

Scope and Approach: The aim of this work was to define the state of the art of nanomaterial applications in the animal production sector by assessing data belonging to recently publishes studies. To do this, a qualitative synthesis approach was applied to build a fit-for-purpose framework and to summarise relevant themes in the context of effectiveness, feasibility and health concerns.

Key findings and conclusions: Nanomaterials have potential for use in a wide range of applications from feed production and farming to food packaging, including several detection tools designed for the benefit of consumer protection. The current high degree of variability in nanomaterials tested and in study designs impairs external validation of research results. Further research is required to clearly define which safe nanomaterial applications have the potential to reach the market.     

Proximate composition and vitamin E levels in egg yolk: losses by cooking in a microwave oven

The proximate composition, fatty acid and tocopherol levels of egg yolk were determined in raw eggs and after different cooking processes: boiling for 3 and 10 min, heating in a microwave oven, and frying. Of the protein, lipid, ash and moisture contents, only the last decreased with microwave cooking. The predominant fatty acid was oleic (18:1) (36.10–42.6%), followed in decreasing amounts by palmitic (16:0), linoleic (18:2), linolenic (18:3) = arachidonic(20:4) = docosanoic (22:0), docosahexanoic (22:6) and myristic acid (14:0). Of the polyunsaturated fatty acids, 18:2, 18:3, 20:4 and 22:6 decreased in the samples subjected to microwaves. α-Tocopherol (6.1–2.9 mg per 100g) was the predominant isomer in all the samples followed by (β + γ)-tocopherol and δ-tocopherol, while α-tocotrienol was detected in trace amounts. All these tocopherols were reduced during cooking by up to 50% in omelettes and microwave treatments. © 1999 Society of Chemical Industry     

French Fries oleuropein content during the successive deep frying in oils enriched with an olive leaf extract

Olive oil, sunflower oil and soybean oil were enriched with an olive (Olea Europaea) leaf extract rich in oleuropein at a supplementation level of 100 mg total phenolics per kg oil. Supplemented oils were used for deep frying of potatoes for eight successive frying sessions without replenishment under domestic frying conditions. Supplemented oils contained oleuropein while deep frying resulted in a gradual decrease in oils oleuropein content. After the eighth successive frying, oleuropein was still detected in oils, its retention being 3.2–12.4%. Deep frying of potatoes in supplemented oils succeeded in preparing French fries containing oleuropein even after eight successive fryings. Contrary to the oil type, the number of frying sessions affected potatoes oleuropein content. Oleuropein intake by consuming French fries deep‐fried in enriched oils was approximately ten times higher in potatoes prepared in the first frying session as compared to the respective intake after the eighth frying.     

Simultaneous and Fast Determination of Malachite Green, Leucomalachite Green, Crystal Violet, and Brilliant Green in Seafood by Ultrahigh Performance Liquid Chromatography–Tandem Mass Spectrometry

A new procedure has been developed for the simultaneous analysis of malachite green (MG), leucomalachite green (LMG), crystal violet (CV), and brilliant green (BG) in seafood using a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure and subsequent determination by ultrahigh performance liquid chromatography coupled to tandem mass spectrometry in <5.5 min. The developed method was validated at 2, 10, 25, and 100 μg kg^?1, obtaining recoveries in the range of 48–112 %, with repeatability and interday precision values (expressed as relative standard deviation) ≤17 and ≤24 %, respectively. Matrix effect was evaluated for different types of seafood (shrimp, salmon, and trout), indicating that shrimp can be chosen as representative matrix for the determination of the selected dyes, except for LMG. Limits of quantification (LOQs) were <0.5 μg kg^?1, which were always below the minimum required performance limits established by the European Union. The decision limit (CC_α) and detection capability (CC_β) values were also estimated in the three matrices evaluated, and CC_β ranged from 0.46 to 1.22 μg kg^?1. Finally, several types of seafood were analyzed, and some dye residues (MG, CV and BG) were detected in a salmon sample.     

Determinants of fetal exposure to polyfluoroalkyl compounds in Baltimore, Maryland

Polyfluoroalkyl compounds (PFCs), such as perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), are ubiquitous, man-made chemicals. Human data suggest that in utero exposures to these chemicals occur and some evidence of developmental toxicity in animals exists. To assess the distribution and determinants of fetal exposure to PFCs, we analyzed cord serum samples from 299 singleton newborns delivered between 2004 and 2005 in Baltimore, MD for 10 PFCs by employing on-line solid-phase extraction coupled with reversed-phase high-performance liquid chromatography-tandem mass spectrometry. PFOS and PFOA were detected in 99 and 100% of umbilical cord sera, with geometric mean concentrations of 4.9 and 1.6 ng/mL, respectively. PFOS and PFOA concentrations were highly correlated (Pearson's r = 0.64 after natural log transformation, p < 0.01). Eight other PFCs were detected less frequently and at lower concentrations than PFOS and PFOA. Geometric mean concentrations of PFOS for Asians (6.0 ng/mL) and Blacks (5.1 ng/mL) were higher than those for Whites (4.2 ng/mL), while PFOA levels were more evenly distributed by race. Other maternal demographic and socioeconomic characteristics, including age, education, marital status, and living in the city limits were not significantly associated with cord concentrations. Our findings suggest that in utero exposure to PFOS and PFOA is ubiquitous in a population of babies born in Baltimore, MD.     

Control of food spoiling bacteria in cooked meat products with nisin,lacticin 3147, and a lacticin 3147-producing starter culture

Nisin, in the form of the commercial product Nisaplin, and lacticin 3147 in whey powdered form were added to minced pork-meat in amounts of 0.15% (w/w) and 1.5% (w/w), respectively. The meat was cooked and inoculated with a Staphylococcus aureus strain of meat origin and a Listeria innocua strain at a level of 10⁷ or 10⁵ CFU g^–1. The batches were stored vacuum-packaged for 21 days at 8 °C. Nisin and lacticin 3147 immediately reduced the L. innocua population at the time of inoculation. Nisin showed higher inhibitory activity than lacticin 3147. During the storage period, a slight L. innocua growth was observed in the batches inoculated with the larger inoculum, and a bacteriostatic effect was observed against Listeria in the batches inoculated with 10⁵ CFU g^–1. Nisin maintained a constant S. aureus population in the cooked batch inoculated with 10⁷ CFU g^–1, although the bacteriocin was capable of reducing the amount of S. aureus by 90% in the batch inoculated with 10⁵ CFU g^–1. On the other hand, lacticin 3147 did not show an inhibitory effect against S. aureus in the cooked meat. The starter culture Lactococcus lactis DPC 303-T4 (containing the conjugative plasmid encoding production of lacticin 3147) was inoculated in a portion of a Longissimus dorsi pork muscle with brine. L. lactis DPC 303-T4 performed a good fermentation, but lacticin 3147 production was not found after 7 days at 12 °C of storage.