Sodium reduction in foods: Challenges and strategies for technical solutions

In many parts of the world, sodium consumption is higher than recommended levels, representing one of the most important food-related health challenges and leading to considerable economical costs for society. Therefore, there is a need to find technical solutions for sodium reduction that can be implemented by food producers and within food services. The aims of this review are to discuss the barriers related to sodium reduction and to highlight a variety of technical solutions. The barriers relate to consumer perception, microbiology, processing, and physicochemistry. Existing technical solutions include inhomogeneous salt distribution, coated salt particles, changing particle sizes and forms, surface coating, multisensory combinations, sodium replacements, double emulsions, adapted serum release by microstructure design, and adapted brittleness by microstructure design. These solutions, their implementation and the associated challenges, and applicable product categories are described. Some of these solutions are ready for use or are in their early development stages. Many solutions are promising, but in most cases, some form of adaptation or optimization is needed before application in specific products, and care must always be taken to ensure food safety. For instance, further research and innovation are required in the dynamic evolution of saltiness perception, consumer acceptance, the binding and migration of sodium, juiciness, microbiological safety, and the timing of salt addition during processing. Once implemented, these solutions will undoubtedly support food producers and food services in reducing sodium content and extend the application of the solutions to different foods.     

Empowering Smallholder Farmers in Markets: strengthening the advocacy capacities of national farmer organisations through collaborative research

The Empowering Smallholder Farmers in Markets programme (ESFIM) supported the advocacy capacities of national farmer organisations (NFOs) for improving smallholder market access. The programme gave NFOs in 11 countries the opportunity to contract local experts to strengthen the evidence-base of their advocacy proposals. By means of a participative process, each NFO analysed the key advocacy issues for which research support was most needed. This resulted in a diversity of themes and advocacy processes. These ranged from research and advocacy on the role of cooperatives in Uruguayan innovation policies to a simulation game on market dynamics in a commodity exchange in the Philippines, and from the review of various seed multiplication programmes in Malawi to the legal and administrative hurdles preventing smallholders from selling to government procurement programmes in Peru and Bolivia. We describe the dynamics surrounding research partnerships in each of the 11 countries and reflect on results of this research-for-advocacy. We also assess the impact of the ESFIM programme on the advocacy capacity of the NFOs. We used a self-evaluation technique, in which board members considered a list of statements covering five capacities that are deemed necessary for effective advocacy. We compared their scores with the observations of external stakeholders who were active in the agricultural sector and knowledgeable about the NFOs’ activities. We conclude that ESFIM has helped to increase coherence in advocacy priorities and has influenced decision making on key policy issues, with encouraging results. In most organisations, ESFIM contributed to the advocacy process, together with many other actors and factors defining advocacy. Based on these experiences, we suggest earmarking funds for NFO-led research support, in order to facilitate the participation of smallholders in the design and monitoring of development policies.     

Purification and characterisation of a panel of peanut allergens suitable for use in allergy diagnosis

Peanut is a major cause of type 1 hypersensitive reactions including anaphylaxis. This results from the presence of a number of protein allergens, six of which are being studied as part of the EU FP6 EuroPrevall programme. These are Ara h 1 (7S globulin), Ara h 2, Ara h 6 (2S albumins), Ara h 3/4 (11S globulins) and Ara h 8 (Bet v 1 homologue). Methods for the purification of Ara h 1, Ara h 3/4, Ara h 2 and Ara h 6 from peanut seeds and for the production of recombinant Ara h 8 in Escherichia coli are described with spectroscopic analyses being used to confirm that they are authentically folded. N-terminal sequencing of the proteins purified from peanut seeds also revealed details of the differences between isoforms and their generation by proteolytic processing within the seed. Preliminary IgE binding studies of the purified allergens confirmed that they retained their immunological properties indicating their suitability for use in allergy diagnosis.     

Comparison of natural and recombinant forms of the major fish allergen parvalbumin from cod and carp

Allergic reaction following fish consumption can trigger life-threatening reactions in predisposed individuals. Parvalbumins from different species have been identified as the major fish allergens. There are two distinct phylogenetic lineages of parvalbumins, alpha and beta. Most allergic reactions are caused by beta-parvalbumins. We cloned and expressed cDNAs encoding cod (Gadus morhua) and carp (Cyprinus carpio) beta-parvalbumins and purified natural cod beta-parvalbumin. CD spectra of the purified proteins showed that their overall secondary structure contents were very similar. No differences in thermal stability were monitored in the calcium-bound or calcium-depleted form of natural cod parvalbumin. IgE reactivity was assessed using 26 sera of fish allergic patients from Spain, The Netherlands, and Greece in immunoblot and ELISA experiments. Twenty-five of the 26 patients with IgE reactivity to native and recombinant cod parvalbumin also reacted to the recombinant carp parvalbumin. IgE inhibition assays were performed using cod and carp extracts and purified recombinant parvalbumin of cod and carp. High crossreactivity among cod and carp parvalbumins was observed in immunoblots as well as in fluid phase assays. Natural and recombinant parvalbumins gave comparable results when performing various in vitro diagnostic assays.     

Co-firing—A strategy for bioenergy in Poland?

Biomass provides the largest reduction of carbon dioxide (CO₂) emission when it replaces coal, which is the dominating fuel in heat and electricity production in Poland. One means of replacing coal with biomass is to co-fire biofuels in an existing coal-fired boiler. This paper presents an analysis of the strengths and weaknesses of co-firing biofuels in Poland with respect to technical, environmental, economical and strategic considerations. This analysis shows that co-firing is technically and economically the most realistic option for using biofuels in the large pulverized fuel (PF) boilers in Poland. However, from an environmental perspective, co-firing of biofuels in large combined heat and power (CHP) plants and power plants provides only a small reduction in sulphur dioxide (SO₂) emission per unit biofuel, since these plants usually apply some form of desulphurization technology. In order to maximize the SO₂ emission reduction, biofuels should be used in district heating plants. However, co-fired combustion plants can handle disruptions in biofuel supply and are insensitive to moderate changes in fuel prices, which makes them suitable utilizers of biofuels from perennial energy crops. Co-firing could therefore play an important role in stimulating perennial crop production.     

High-resolution models of motion of macromolecules in cell membranes

The path of a macromolecule on a cell membrane is modeled by a sum of independent identically distributed random variables. Random variables with simple discrete distribution functions capture some important aspects of the jump or hop diffusion reported from single particle tracking experiments that measure the motion of single molecules on a cell membrane. The detail provided by the distribution function for the random variables is critical for accurate simulations of the motion and interactions of macromolecules on the cell membrane. Additionally, the probability distribution for the random variables is easily estimated from single-particle tracking data. The diffusion constant is given by the second moment of the probability distribution, which agrees with the diffusion constant estimated from the mean-square displacement, and thus represents far less information than the distribution function.     

Solid contact potentiometric sensors for trace level measurements

A simple procedure for the development of a range of polymeric ion-selective electrodes (ISEs) with low detection limits is presented. The electrodes were prepared by using a plasticizer-free methyl methacrylate-decyl methacrylate copolymer as membrane matrix and poly(3-octylthiophene) as intermediate layer deposited by solvent casting on gold sputtered copper electrodes as a solid inner contact. Five different electrodes were developed for Ag+, Pb2+, Ca2+, K+, and I-, with detection limits mostly in the nanomolar range. In this work, the lowest detection limits reported thus far with solid contact ISEs for the detection of silver (2.0 x 10(-9) M), potassium (10(-7) M), and iodide (10(-8) M) are presented. The developed electrodes exhibited a good response time and excellent reproducibility.     

Replication of continuous-profiled micro-optical elements for silicon integration

A novel scheme for the integration of diffractive optical elements onto silicon is presented. The processing is made in reverse order, meaning that the process of structuring the optical elements on the wafer precedes the silicon microstructuring. The first processing step on the wafer is the hot embossing of the optical microstructures into an amorphous fluorocarbon polymer spin coated on the wafer. The cured polymer forms a highly stable material with excellent optical properties. The remaining silicon processing is thus performed with the diffractive optical elements already in place. Two different diffractive structures were used in the development of the method-a (Fresnel) lens with a rather low f-number and a diffractive element producing a fan-out of a large number of paraxial beams.     

Monitoring of the Synthesis of Hyperbranched Poly(urea‐urethane)s by Real‐Time Attenuated Total Reflection (ATR)‐FT‐IR Spectroscopy

Summary: The reaction of 2,4‐TDI and DEA, as an A₂ + B^*B₂ polymerization system towards hyperbranched HPUs was followed using in situ ATR‐FT‐IR spectroscopy. The decrease in intensity of the NCO absorption band of the reactive isocyanate group of 2,4‐TDI along with the formation and growth of the new characteristic bands of urethane and urea groups were detected. The reactivity difference of both NH and OH groups towards the NCO group at low temperatures was proven. The rate of the reaction was found to be affected by changing the temperature, the rate of addition of the B^*B₂ monomer and the type of solvent. Moreover, the increase of the carbonyl vibration and the amide II bands of urea was very obvious during the addition of the stopper DEA. Thus, it was possible to verify the individual reaction steps of this complex polyreaction and to correlate these with the structural development of the resulting macromolecules.

Characteristic vibration bands of urethane and urea groups in the IR spectra (1 780–1 480 cm^?1) during the polymerization reaction.