Quantitative Textual Analysis as a means to explore corporate interests in food safety.

The growing body of scholarship on the commercial determinants of health has, so far, mostly employed qualitative methods but this is now being complemented by a small, yet growing, corpus of quantitative studies. We illustrate the use of one such method, quantitative text analysis (QTA), in a case study of submissions to a public consultation on a draft scientific opinion by the European Food Safety Authority on the chemical acrylamide, demonstrating how this method can be used and insights that might be drawn from it. We use Wordscores as one example of QTA to illuminate the diverse positions taken by actors submitting comments and then assess whether the final policy documents moved towards or away from the positions taken by different stakeholders. We find a broadly uniform position among the public health community, opposed to acrylamide, contrasting with industry positions that were not monolithic. Some firms recommended major amendments to the guidance, largely reflecting the impact on their practices, while policy innovators seeking ways to reduce acrylamide in foods aligned with the public health community. We also find no clear movement in the policy guidance, likely because most submissions supported the draft document. Many governments are required to conduct public consultations, some attracting enormous numbers of responses, with little guidance on how best to synthesise the responses so the default position is often a count of those for and against. We argue that QTA, primarily a research tool, might usefully be applied in analysing public consultation responses to understand better the positions taken by different actors.

Enhancement of the Catalytic Performance and Operational Stability of Sol-Gel-Entrapped Cellulase by Tailoring the Matrix Structure and Properties.

Commercial cellulase Cellic CTec2 was immobilized by the entrapment technique in sol-gel matrices, and sol-gel entrapment with deposition onto magnetic nanoparticles, using binary or ternary systems of silane precursors with alkyl- or aryl-trimethoxysilanes, at different molar ratios. Appropriate tailoring of the sol-gel matrix allowed for the enhancement of the catalytic efficiency of the cellulase biocatalyst, which was then evaluated in the hydrolysis reaction of Avicel microcrystalline cellulose. A correlation between the catalytic activity with the properties of the sol-gel matrix of the nanobiocatalysts was observed using several characterization methods: scanning electron microscopy (SEM), fluorescence microscopy (FM), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA/DTA). The homogeneous distribution of the enzymes in the sol-gel matrix and the mass loss profile as a function of temperature were highlighted. The influence of temperature and pH of the reaction medium on the catalytic performance of the nanobiocatalysts as well as the operational stability under optimized reaction conditions were also investigated; the immobilized biocatalysts proved their superiority in comparison to the native cellulase. The magnetic cellulase biocatalyst with the highest efficiency was reused in seven successive batch hydrolysis cycles of microcrystalline cellulose with remanent activity values that were over 40%, thus we obtained promising results for scaling-up the process.

Development of a Tailored Sol-Gel Immobilized Biocatalyst for Sustainable Synthesis of the Food Aroma Ester n-Amyl Caproate in Continuous Solventless System.

This study reports the synthesis of a hybrid sol-gel material, based on organically modified silanes (ORMOSILs) with epoxy functional groups, and its application in the stabilization of lipase type B from Candida antarctica (CalB) through sol-gel entrapment. The key immobilization parameters in the sol-gel entrapment of lipase using epoxysilanes were optimized by the design of numerous experiments, demonstrating that glycidoxypropyl-trimethoxysilane can allow the formation of a matrix with excellent properties in view of the biocatalytic esterifications catalyzed by this lipase, at an enzyme loading of 25 g/mol of silane. The characterization of the immobilized biocatalyst and the correlation of its catalytic efficiency with the morphological and physicochemical properties of the sol-gel matrix was accomplished through scanning electron microscopy (SEM), fluorescence microscopy (FM), as well as thermogravimetric and differential thermal analysis (TGA/DTA). The operational and thermal stability of lipase were increased as a result of immobilization, with the entrapped lipase retaining 99% activity after 10 successive reaction cycles in the batch solventless synthesis of n-amyl caproate. A possible correlation of optimal productivity and yield was attempted for this immobilized lipase via the continuous flow synthesis of n-amyl caproate in a solventless system. The robustness and excellent biocatalytic efficiency of the optimized biocatalyst provide a promising solution for the synthesis of food-grade flavor esters, even at larger scales.

Enzymatic synthesis of short-chain flavor esters from natural sources using tailored magnetic biocatalysts.

Immobilized lipases are excellent biocatalysts for the enzymatic synthesis of short- and medium-chain fatty esters used as food flavor compounds. Herein a new approach for a magnetic core-shell biocatalyst by immobilization of Candida antarctica B lipase is reported, coating single-core magnetic nanoparticles with an organic shell, preferably poly(benzofurane-co-arylacetic acid), followed by the covalent attachment of the enzyme and embedment of the primary biocatalyst in a silica layer. Although covalent and sol-gel immobilization were efficient on their own, their combination can ensure additional operational stability through multi-point linkages. Moreover, silanes holding glycidoxy groups, which can also form covalent linkages, have been successfully used as precursors for the silica coating layer. The structural, magnetic and morphological characteristics were assessed by TEM, SEM-EDX, X-ray photoelectron spectroscopy and vibrating sample magnetometry. The new biocatalysts demonstrated high catalytic efficiency in the solventless synthesis of isoamyl esters of natural carboxylic acids, also in multiple reaction cycles.

High concentration aqueous magnetic fluids: structure, colloidal stability, magnetic and flow properties.

This paper is an in-depth analysis devoted to two basic types of water based magnetic fluids (MFs), containing magnetite nanoparticles with electrostatic and with electro-steric stabilization, both obtained by chemical coprecipitation synthesis under atmospheric conditions. The two sets of magnetic fluid samples, one with citric acid (MF/CA) and the other with oleic acid (MF/OA) coated magnetic nanoparticles, respectively, achieved saturation magnetization values of 78.20 kA m-1 for the electrostatically and 48.73 kA m-1 for the electro-sterically stabilized aqueous ferrofluids which are among the highest reported to date. A comprehensive comparative analysis combining electron microscopy, X-ray photoelectron spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy, vibrating sample magnetometry, small-angle X-ray and neutron scattering, dynamic light scattering and magneto-rheometry revealed similarities and essential differences on the microscopic and macroscopic level between the two kinds of water-based ferrofluids. While the saturation magnetization values are quite different, the hydrodynamic volume fractions of the highest concentration MF/CA and MF/OA samples are practically the same, due to the significantly different thicknesses of the particles' coating layers. The results of volume fraction dependent structure analyses over a large concentration range by small-angle X-ray and neutron scattering, correlated with magneto-rheological investigations for the electrostatically stabilized MFs, demonstrate formation of short chains of magnetic nanoparticles which are relatively stable against coagulation with increasing concentration, while for MFs with electro-steric stabilization, magnetic field and shear rate dependent loosely bound structures are observed. These particle structures in MF/OA samples manifest themselves already at low volume fraction values, which can be attributed mainly to magnetic interactions of larger size particles, besides non-magnetic interactions mediated by excess surfactant.