Combined effect of salt addition and high-pressure processing on formation of free radicals in chicken thigh and breast muscle

The effect of working pressure, processing time, and salt addition on formation of free radicals in chicken breast and thigh muscle was investigated by electron spin resonance (ESR) spectroscopy using α-(pyridyl-1-oxide)-N-tert-butylnitrone (POBN) as spin trap in order to detect early events in lipid oxidation following high-pressure meat processing. Chicken breast and thigh with and without 3.0% salt added were subjected to high hydrostatic pressure at 200, 400, 600, 800, and 1000 MPa for 5, 15 (only breast), and 30 min. Radical formation increased with increasing pressure and processing time and reached a maximum value in chicken breast for 15 min of processing at 1000 MPa and in chicken thigh for 5 min of processing at 600 MPa. Radical formation was found to be more significant in thigh meat compared to breast meat and salt addition further promoted radical formation in chicken breast and especially in chicken thigh.     

Photooxidation of nitrosylmyoglobin at low oxygen pressure. Quantum yields and reaction stoechiometries

Photooxidation of the nitrite-cured meat pigment, nitrosylmyoglobin, in aqueous solution saturated with a 20% CO₂/80% N₂ gas mixture with varying oxygen contents (0.1, 0.5 or 1.0%) was found to depend linearly on the oxygen content for both visible (436 nm) and UV-light (366 nm). Quantum yields were similar for the two wavelengths of excitation in agreement with previous findings at higher oxygen pressures. The reaction stoechiometry for photooxidation was different from that of thermal oxidation (investigated at the same oxygen pressures) with a unity MbFe(II)NO/O₂ ratio in the thermal reaction and a ratio larger than one for the photooxidation. For cured meat products packed in modified atmospheres light exposure may be even more harmful for the oxidative stability than expected from the concentration of residual oxygen.     

Next-Generation Sequencing as a Tool for Detailed Molecular Characterisation of Genomic Insertions and Flanking Regions in Genetically Modified Plants: a Pilot Study Using a Rice Event Unauthorised in the EU

Precise molecular characterisation of genetic modifications integrated into the genomes of genetically modified organisms (GMOs) and of their flanking genomic regions forms a key component for the development of event-specific detection methods. In the EU, this information is of particular importance for risk management in cases where genetic modifications of unauthorised GM food, feed or seeds are detected. PCR-based chromosome walking approaches are commonly used for DNA sequence determination of the genetic modifications and of the flanking genomic regions in yet undescribed GM plants. If the plant contains complex and re-arranged modifications, sequencing and molecular characterisation are often difficult and laborious. Next-generation sequencing (NGS) of DNA is a powerful alternative tool to rapidly generate primary sequence data on the genome of so far uncharacterised sample material if pure GMO material is available. Recently, robust NGS platforms and affordable sequencing services are accessible for food and feed control laboratories. We here present a NGS-based study for whole-genome sequencing of the GM rice event LLRice62 as a proof-of-principle experiment to develop bioinformatics easy-to-use data analysis tools for rapid molecular characterisation. A total of 171,657,155 read mate pairs of approximately 75 bp each were obtained. Sequence reads belonging to the genetic modifications and their flanking genomic regions in LLRice62 were identified by bioinformatic comparison to the corresponding Oryza sativa ssp. japonica reference genome sequence using the Illumina InDel caller software and subsequent iterative mapping of retrieved NGS reads. An entire genetic modification of 1,493 bp in the genome of the LLRice62 sample material was determined and correctly mapped on chromosome 6. The determined nucleotide sequence coincides to the genetic modification described by the developer of this rice event. This study demonstrates for the first time the applicability of NGS for molecular characterisation of uncharacterised GMOs.     

Mineral nutrient interaction: Improving bioavailability of calcium and iron

Insufficient uptake of essential metals leads to serious malnutrition, which is a worldwide problem. Low bioavailability of iron and calcium may lead to anemia and osteoporosis, respectively, even in individuals with a high dietary intake. For iron, fractionation of meat proteins was studied in order to increase iron bioavailability from other meal components, and uptake of iron was found to increase with minimal risk of increasing oxidative damage. Calcium binding to peptides was found to prevent formation of insoluble calcium salts otherwise hampering absorption particularly in combination with calcium hydroxycarboxylates, entailing spontaneous supersaturation. Based on a review of results from different strategies available for increasing bioavailability, safe iron fortification is suggested to be supported by calcium, with modulation of iron as a prooxidant.     

Factors influencing energy efficiency investments in existing Swedish residential buildings

We used the data from a survey conducted in 2008 of 3,000 owners of detached houses to analyse the factors that influence the adoption of investment measures to improve the energy efficiency of their buildings. For the majority of Swedish homeowners, it was important to reduce their household energy use, and most of them undertook no-cost measures as compared to investment measures. Personal attributes such as income, education, age and contextual factors, including age of the house, thermal discomfort, past investment, and perceived energy cost, influence homeowners’ preference for a particular type of energy efficiency measure. The implications for promoting the implementation of energy efficiency investment measures are discussed.     

Subfractionation and characterization of native and incubation enlarged human plasma high density lipoprotein particles by high performance gel filtration

Incubation of human plasma in vitro at 37 C results in an increase of the mean particle size of the high density lipoproteins (HDL) accompanied by an almost complete disappearance of the original particles present prior to incubation. A rapid high performance gel filtration technique has been developed in order to study the chemical composition of subfractions of native and incubation enlarged HDL particles as a function of particle size. Subfractionation of HDL isolated by preparative ultracentrifugation from 3 normal human plasmas incubaed in vitro at 0 and 37 C for 24 hr have been performed using a 150 cm long TSK-G 3000 SW column. The separation time was less than 65 min. The curves obtained at high performance gel filtration of HDL, by monitoring the effluents from the column at 280 nm, agreed well both in positions of peak maxima and relative peak intensities with the particle distribution patterns observed at polyacrylamide gradient gel electrophoresis of the corresponding HDL preparations run in parallel. The different HDL particle subfractions of the effluents from the gel filtration column have been characterized by quantification of free and esterified cholesterol, total phospholipids and apolipoprotein A-I and A-II. The incubation enlarged HDL particles, subfractionated by the high performance gel filtration technique, were found to have a composition which differed from that of native HDL particles of corresponding size. Incubation enlarged HDL had a generally higher and almost constant relative cholesteryl ester content over the whole particle range compared to native HDL in which a continuous increase in relative cholesteryl ester content could be observed when going from large to small particles. The molar ratio of phospholipids to free cholesterol was higher in small native HDL particles than in the corresponding large ones. The relation between apolipoprotein A-I and A-II remained nearly constant between small and large HDL particles in each subfractionation experiment. The results demonstrate that the high performance gel filtration technique is a rapid and reproducible means for studying the composition of subfractions of HDL particle populations.     

Mate (<Emphasis Type=Italic>Ilex paraguariensis</Emphasis>) as dietary additive for broilers: performance and oxidative stability of meat

Aqueous extract of mate (dried leaves of Ilex paraguariensis) added to drinking water for broilers for the last 14 days prior to slaughter did not affect performance at 25 days of age, but improved oxidative stability of the chicken meat. Oxidative stability of precooked breast meat made from control meat (CON) and from meat of broilers raised on water with mate added was investigated during chill storage for up to 7 days. The use of mate showed no influence on the content of lipids in chicken breast meat; however, lipid oxidation measured as thiobarbituric acid–reactive substances (TBARS) was significantly lower for meat from broilers raised on water with mate extracts in different concentrations (MA0.1, MA0.5, and MA1.0 corresponding to 0.1, 0.5, and 1.0% of mate dried leaves). The relative effect was largest at 1 day of storage with more than 50% reduction on TBARS; the result was still significant after 3 days, but almost vanished after 7 days, when oxidative rancidity was very high in all samples. In meat from broilers raised on water with mate extract, vitamin E was protected during cooking, although in the very rancid meat balls at 7 days of storage, the protection almost disappeared. Nevertheless, mate can be an interesting natural alternative to be used in chicken diets to improve lipid stability of the meat.     

Energy efficiency measures and conversion of fossil fuel boiler systems in a detached house

There is a large potential to reduce primary energy use and CO₂ emissions from the Swedish building stock. Here detached houses heated by oil, natural gas or electric boilers were assessed. CO₂ emissions, primary energy use and heating costs were evaluated before and after implementing house envelope measures, conversions to more efficient heating systems and changes to biomass fuel use. The study included full energy chains, from natural resources to usable heat in the houses. The aim was to evaluate the societal economic cost effectiveness of reducing CO₂ emission and primary energy use by different combinations of changes. The results demonstrated that for a house using an electric boiler, a conversion to a heat pump combined with house envelope measures could be cost efficient from a societal economic perspective. If the electricity was based on biomass, the primary energy use was at the same time reduced by 70% and the CO₂ emission by 97%. Large emission reductions were also seen for conversions from oil and gas boilers to a biomass-based system. However, for these conversions the heating cost increased, leading to a mitigation cost of around €50/tonne C avoided. The price of oil and natural gas greatly influenced the competitiveness of the alternatives. House envelope measures were more cost-effective for houses with electric boilers as the cost of energy for this system is high. The results are specific to a Swedish context, but also give an indication of the potential in other regions, such as northern European and large parts of North America, which have both a cold climate and a widespread use of domestic boilers.     

Effects of dietary soybean oil on lipid and protein oxidation in pork patties during chill storage

The effect of dietary soybean oil on lipid and protein oxidation in low and high fat pork patties made from quadriceps femoris during chill storage in a high oxygen atmosphere packaging (80% O(2)/20% CO(2)) in the dark for 7 days was investigated. Pigs were fed either a standard diet or a diet added 2% soybean oil. After slaughter high fat pork patties were prepared for both feeding regimes by addition of back fat from pigs fed the same diet whereas low fat pork patties were prepared without addition of back fat. The 2% soybean diet increased the amount of unsaturated fat in the pork. Secondary lipid oxidation products determined as thiobarbituric acid reactive substances (TBARS) were found to increase in the pork patties with increased unsaturated fat. Increased unsaturated fat in the pork patties had no effect on protein oxidation determined as free protein thiol content and protein carbonyl content. A small, but significant increase in protein oxidation was found in the high fat pork patties independent on dietary fat. In conclusion, protein oxidation is unaffected by dietary fat in pork patties during chill storage for periods normally used in retail trade, and lipid and protein oxidation are not coupled under these conditions.