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Abstract: Sucrose solutions, with concentrations near or superior to saturation, present high potentialities for the candy and pastry industries. The development of colour in a neutral and highly concentrated sucrose solution (16.32%(w/w) water content) subjected to isothermal heat treatment (in the 100–160°C range) was investigated. Under such conditions, sucrose degrades through caramelisation and 5-hydroxymethylfurfural (HMF) is formed. Colour development was monitored through lightness/darkening (L/L 0) and total colour difference (TCDH) changes during reaction course. Kinetic behaviour was mathematically described using modified Gompertz equations. The effect of temperature on the reaction was described by an Arrhenius type dependency. Colour development and sucrose degradation kinetic parameters were compared and similar lag phases were found. However, the same was not observed for reactions rate, indicating that not only sucrose degradation contributes to colour development. To investigate the colour development/HMF content relationship, a fractional conversion and a power law models where successfully proposed to express, respectively, L/L 0 and TCDH dependence on HMF content. [Copyright &y& Elsevier]

Abstract: Multilayer nanocoatings composed of κ-carrageenan, a sulphated anionic polysaccharide, and chitosan, a cationic polysaccharide, were produced by layer-by-layer deposition. The model cationic compound Methylene Blue (MB) was incorporated in different positions of the nanolayered coating and its loading and release behavior was evaluated. UV–VIS spectroscopy and quartz crystal microbalance analysis showed that the amount of MB loaded increased with the distance from the first layer, suggesting that the MB was able to diffuse into the κ-carrageenan/chitosan nanolayered coating and not only adhered to the surface of the layer immediately below it. For most of the tested conditions, the MB release from the κ-carrageenan/chitosan nanolayered coatings was successfully described by the linear superimposition model, which allowed concluding that MB transport is due to both concentration gradient and the polymer relaxation of the nanolayers. However, depending on temperature and pH of the medium and on the position of MB incorporated on the nanolayered coatings, different mechanisms prevail. Industrial relevance: The development of novel edible coatings with improved functionality and performance for e.g. fresh and minimally processed fruits is one of the challenges of the post-harvest industry. This work contributes to the understanding of the loading and release phenomena involved in structures at the nano-scale, which is useful for the development of bioactive compounds release systems for application in food industry. Moreover, the κ-carrageenan/chitosan nanolayered coatings represent a promising platform from which the controlled release of different bioactive compounds may be explored. [Copyright &y& Elsevier]

Molecular mobility is a fundamental parameter which reflects the dynamic properties of food components and contributes to food degradation reactions comprehension. Fresh-cut fruits have become an important food market segment. However, processing of fruits promotes faster its physiological deterioration, biochemical changes and microbial degradation. The purpose of this work was to use NMR methodology as a tool to evaluate fresh-cut fruit quality, during storage at refrigerated conditions. The fresh-cut melon transverse relaxation time ( T 2 ) was measured for a period of 7 days of storage at 5 °C. The relationship between the obtained values, microstructure and quality parameters was investigated. In general, results show the existence of one class of water fluidity in the system, the one present in cells after processing. T 2 , a measure of this fluidity, is affected by the processing and storage time. Also, it is possible to find a close relationships between T 2 and quality parameters of total colour difference (TCD), firmness and a w . As T 2 increases TCD also increases, while firmness and a w decrease. These results highlight the usefulness of NMR methodology application in food science. [ABSTRACT FROM AUTHOR]

Foods are partially crystalline partially amorphous systems. Edible films are considered good models for food systems due to their interesting physical properties, quite straightforward matrices, and easy reproduction. Chitosan is a semicrystalline biopolymer, biocompatible, biodegradable, with antimicrobial activity and filmogenic properties, thoroughly used in edible films' studies. This work aims to investigate the relationship between chitosan films' molecular relaxation time, their microstructure (crystallinity) and functional properties. Analyses were carried out using data on chitosan/glycerol films prepared with different polymer/plasticisant concentrations. Results demonstrate that there is a relationship between macroscopic properties and water and glycerol relaxation times. Moreover, results show that while water is free in the matrix, glycerol is linked to the chitosan polymeric chains, decreasing intermolecular attractions and increasing free volume, thus facilitating molecular migration. Also the data analysis reveals the usefulness of NMR and molecular mobility studies in the matrix for characterisation and development of polymeric structures. Industrial relevance NMR spectroscopy is currently one of the key methods for food characterisation. Foodstuff is a complex matrix including many different compounds with different chemical structures, concentrations, solubility, properties and nutritional values. From a fundamental perspective, foods are mainly edible and digestible biopolymers that are partially crystalline/partially amorphous and thus edible films, specifically chitosan/glycerol films can be very interesting food model systems for mobility and microstructure studies. Studies on water and solids' mobility and thermo-mechanical properties in food systems (real or model systems) are fundamental to fully attain food physical properties and stability. These studies may be extremely useful for food product and process design, safety and sensorial attributes and also for better understanding and predicting, for example, food storage stability conditions. [ABSTRACT FROM AUTHOR]

Highlights: [•] Total plasticisant in FFS is responsible for film structure development. [•] Molecular mobility contributes to understanding films molecular rearrangement. [•] Not only water content (/activity) affects water mobility but, also structural differences. [ABSTRACT FROM AUTHOR]

Abstract: The transport mechanism of protein-based bioactive compounds (a peptide fraction from whey protein concentrate, glycomacropeptide and lactoferrin), from chitosan films to liquid medium, was studied. Mathematical models were used to discuss the transport mechanism. Data from release experiments was successfully described by a model which accounts for both Fick and Case II transport – the linear superimposition model. Results show that the mechanism of transport and the effect of temperature and peptide type could be related with physical properties of chitosan films where the tested bioactive compounds were incorporated. The approach presented here allows interpretation of the phenomena involved in mass transport in the systems studied and, once extended to other systems, may contribute to an understanding of transport in hydrophilic bio-polymeric matrices. [Copyright &y& Elsevier]

Abstract: Training food scientists and technologists (FSTs) to have appropriate skills begins with identification of those skills most desired by employers. Between March 2010 and August 2011, 16 workshops in 16 countries had 315 local FST employers contribute ideas of skills desired in their FSTs. Attendees provided as many skills as possible and these descriptive data were quantifed and then analysed with multiple contingency tables and chi squared testing. Of the 3348 skill ideas provided, the most desired skill overall was Communicating, which was identified 13% of the time. Separate analysis of the 792 food sector skills indicated Product Development, at 28%, as the most desired. Geographical region, employment area and FST level of responsibility all significantly influenced the top 3 choices of overall skills and of food sector skills, indicating that most desired skills in the food industry are not uniform. These results should contribute to the improvement of FST training and thus benefit the European food industry. Industrial relevance: The data presented here suggest that improvements in FST training, particularly the acquisition of ‘soft skills’, will improve Europe's food workforce as these are the skills employers most desire. These data further suggest that geographical region significantly influences those skills most desired by industrial employers. Differences in desired skills at different levels of FST responsibility further suggest that continual FST training i.e., continual professional development, will contribute to improved FST performance. Overall, this study presents data which can improve FST performance and thus contribute to increased innovation and competitiveness of the food and drink industry. [Copyright &y& Elsevier]

Abstract: Chitosan packaging films containing different bioactive compounds (a peptide fraction from whey protein concentrate (WPC) hydrolysate, glycomacropeptide (GMP) and lactoferrin) were produced and their mechanical and barrier properties were evaluated. The molecular weight of protein-based compounds was determined using SDS–PAGE. The addition of GMP and lactoferrin to chitosan film caused a significant reduction of tensile strength and the elongation-at-break significantly increased with the incorporation of lactoferrin. The addition of protein-based compounds also affected gas permeability: a significant decrease in water vapor permeability was observed with the incorporation of lactoferrin; oxygen permeability significantly decreased with the addition of GMP and lactoferrin and carbon dioxide permeability significantly decreased with the incorporation of all of the protein-based compounds. Such results were related with film’s hydrophilicity and crystallinity. This manuscript contributes to the establishment of an approach to optimize edible films performance based on physico-chemical properties, aiming at a higher benefit for the consumer. [Copyright &y& Elsevier]

Abstract: Nanoemulsions of β-carotene were prepared using a high-energy emulsification–evaporation technique based on a 23 level factorial design. Results show that it is possible to obtain dispersions at a nanoscale range. Process parameters such as time and shear rate of homogenization affected significantly particle size distribution in terms of volume-weighted mean diameter and surface-weighted mean diameter. The obtained nanoemulsions presented a volume-surface diameter ranging from 9 to 280nm immediately after the production of particles, displaying in all cases a monomodal size distribution. Those nanoemulsions showed a good physical stability during 21days storage. The stability was evaluated by the maintenance of size distribution. However, β-carotene retention inside the micelles and color were affected by storage. Processing conditions also influenced storage stability. [ABSTRACT FROM AUTHOR]

Abstract: Nanolaminates have been reported to have applications in different areas, such as the preparation of multilayer films, coating biomedical appliances or multilayer edible coatings with enhanced properties for applications in the food industry. This work aims at characterizing the surface properties, water vapor permeability, and thermal and mechanical properties of a nanolayered film. The film was produced using two polysaccharides with opposite charges, chitosan and sodium alginate deposited on to aminolyzed/charged PET. Contact angle measurements showed differences in the films with a successively higher number of layers. SEM images allowed the measurement of the thickness of the layers. The nanolayered film had a water vapor permeability of (0.85±0.04)×10−11 gm−1 s−1 Pa−1 and a hardness increase of 0.245±0.06GPa. DSC and TG analyses of the nanolayered film showed increases of 39.2% in the melting energy when compared with the PET film used as support, and a decrease in the decomposition temperature from 386 to 331°C. [Copyright &y& Elsevier]