Development of Photonic Multi-Sensing Systems Based on Molecular Gates Biorecognition and Plasmonic Sensors: The PHOTONGATE Project.

This paper presents the concept of a novel adaptable sensing solution currently being developed under the EU Commission-founded PHOTONGATE project. This concept will allow for the quantification of multiple analytes of the same or different nature (chemicals, metals, bacteria, etc.) in a single test with levels of sensitivity and selectivity at/or over those offered by current solutions. PHOTONGATE relies on two core technologies: a biochemical technology (molecular gates), which will confer the specificity and, therefore, the capability to be adaptable to the analyte of interest, and which, combined with porous substrates, will increase the sensitivity, and a photonic technology based on localized surface plasmonic resonance (LSPR) structures that serve as transducers for light interaction. Both technologies are in the micron range, facilitating the integration of multiple sensors within a small area (mm2). The concept will be developed for its application in health diagnosis and food safety sectors. It is thought of as an easy-to-use modular concept, which will consist of the sensing module, mainly of a microfluidics cartridge that will house the photonic sensor, and a platform for fluidic handling, optical interrogation, and signal processing. The platform will include a new optical concept, which is fully European Union Made, avoiding optical fibers and expensive optical components.

Development of a novel smoke-flavoured salmon product by sodium replacement using water vapour permeable bags.

BACKGROUND: Food manufacturers need to reduce sodium content to meet consumer and public health demands. In the present study, the use of sodium-free (SF) salt and KCl to develop a novel smoke-flavoured salmon product with reduced sodium content was evaluated. Fifty percent of NaCl was replaced with 50% of SF salt or 50% KCl in the salmon smoke-flavouring process, which was carried out using water vapour permeable bags. RESULTS: Triangle tests showed that samples with either SF salt or KCl were statistically similar to the control samples (100% NaCl). Because no sensorial advantage in using SF salt was found compared to KCl and given the lower price of KCl, the KCl-NaCl samples were selected for the next phase. The changes of physicochemical and microbial parameters in smoke-flavoured salmon during 42 days showed that partial replacement of NaCl with KCl did not significantly affect the quality and shelf-life of smoke-flavoured salmon, which was over 42 days. CONCLUSION: Smoke-flavoured salmon with 37% sodium reduction was developed without affecting the sensory features and shelf-life. This is an interesting option for reducing the sodium content in such products to help meet the needs set by both health authorities and consumers. © 2017 Society of Chemical Industry.

Do Consumers Value Agri-Food Industries' Environmental Commitment? The Case of the Table Olive Industry.

An increasing number of food companies are voluntarily adopting environmental policies and sustainability initiatives to tackle climate change. The aims of this study were to analyse the presence of environmental labels on table olive products, to explore consumer perceptions of these companies' environmental commitment and initiatives, and to evaluate the influence of these messages on purchasing decisions. For this purpose, a market study was conducted in different hypermarkets and supermarkets in Spain, and an online survey was submitted to consumers (n = 227). The results show that environmental claims and/or certifications related to sustainability do not appear on table olive products, despite most of the companies that produce and/or market table olives having adopted environmental and sustainability policies and commitments (34.3% have their environmental policy published on their website). More than 85% of consumers positively value these companies' sustainability commitments and consider environmental initiatives to be very important. As a sector of consumers pays close attention to environmental commitments, it would be interesting for table olive companies to identify their sustainability policies on their products' labelling to, thus, facilitate pro-environmental consumer purchase choices. These results could help the food industry develop the best strategies to publicise their social and environmental policies and commitments.

Importance of the origin, organic production and other extrinsic parameters in fruit and vegetable choices.

The aims of the present work were to evaluate consumers' perceptions and purchasing habits in relation to fruit and vegetables and to determine the importance of the production type, price and geographical origin of such products for consumers' purchasing decisions. For this purpose, an online consumer survey was conducted to determine Spanish people's opinions and consumption habits in relation to fruit and vegetables, especially those from organic farming. The survey also included a part to assess the importance that consumers attach to different extrinsic attributes in oranges and avocado pears (with a conjoint analysis), and a section to determine the participants' ethnocentrism. Consumers agree that organic food respects the environment more, contains fewer 'chemicals' and is more natural. Price is the first reason why many people do not buy organic food, followed by them thinking that they do not offer any added value and they are difficult to find. For the Spanish population, country of origin, local production, seasonality and price are much more important attributes for purchasing fruit and vegetables than them being organic. This study reflects a relatively high ethnocentrism level of the surveyed population, especially in older individuals. Given consumer preference for km 0/local and seasonal products, and the importance of these parameters for the environment, promoting the market of such products would help to achieve some Sustainable Development Goals. This study offers a vision of the trends of Spanish consumers in relation to fruit and vegetable preferences, which can help producers and distributors to design new strategies that focus on meeting consumer demands.

Assessment of the attributes that most affect the choice of minced meat and hamburgers.

The objectives of this work were to identify the parameters that most influence Spanish consumers' choice of minced meat and hamburgers, and to determine the importance of different extrinsic attributes in meat products. A consumer survey was conducted by combining three methodologies: free listing task, rating the importance of different extrinsic attributes and a conjoint analysis. The free listing task showed that, of all the factors considered when selecting minced meat or hamburgers, price, expiration date, colour and appearance stood out. In the rating test, expiration date obtained the highest average score, followed by price and country of origin. The conjoint analysis showed consumers clearly preferred origin Spain, along with low price and the animal welfare label, which presented higher utility value than the sustainable packaging label. No presented label negatively impacted product choice. The information provided can be very useful for developing and marketing meat products that seek to meet today's consumer demands.

Immobilization of Natural Antimicrobial Compounds on Food-Grade Supports as a New Strategy to Preserve Fruit-Derived Foods.

The use of natural antimicrobials in the food industry is being proposed as an eco-friendly postharvest technology to preserve fruit-derived foods. In this context, this systematic review aims to describe and discuss the application of naturally occurring antimicrobial compounds in the processing of fruit-derived foods by the PRISMA methodology. In a first step, the use of free natural antimicrobials was investigated as an approach to identify the main families of bioactive compounds employed as food preservatives and the current limitations of this dosage form. Then, the use of immobilized antimicrobials, in an innovative dosage form, was studied by distinguishing two main applications: addition to the food matrix as preservatives or use during processing as technological aids. Having identified the different examples of the immobilization of natural antimicrobial compounds on food-grade supports, the mechanisms of immobilization were studied in detail to provide synthesis and characterization guidelines for future developments. Finally, the contribution of this new technology to decarbonization and energy efficiency of the fruit-derived processing sector and circular economy is discussed in this review.

Nanotechnology in the agri-food sector: Consumer perceptions.

The purpose of this work was to evaluate Spanish consumers' opinions on using nanotechnology in food processing and packaging. For this purpose, a literature review was carried out in the main research database to determine the most widespread uses of nanotechnology in the food industry and the most promising developments. Of all the nanotechnology uses in food, five areas of application were identified: developing new ingredients or additives, formulating new antimicrobial systems, and designing new processing methods, sensors and packaging with nanostructured materials. Subsequently, a consumers' opinion study was carried out by means of a survey, in which the opinions and purchase intention of a representative product of all five categories were evaluated, as well as the neophobia level to new food technologies. All the products obtained positive evaluations, and the applications in which nanotechnology did not form part of food were generally better valued than those in which it did form part. The respondents had a medium neophobia level, with an average score of 4.59 (out of 7 points), being consumers with more knowledge about new technologies the least neophobic and those who gave products higher scores. This study provides relevant information for using nanotechnology in the food processing and packaging sector.

Perception of fat and other quality parameters in minced and burger meat from Spanish consumer studies.

This study examined Spanish consumer knowledge and perceptions of fat content in minced meat products, as well as the most relevant aspects considered to accept or reject these products. The majority of respondents overestimated the fat content of different minced meat types. Most consumers would not detect fat variations between ±2 g fat/100 g. The word association task evidenced different perceptions of minced meat according to both meat types (beef-pork or chicken-turkey) and packaging (on trays, bulk). The colour and appearance of the products were very important for consumers, who did not attach much importance to the presence of additives. Unpackaged beef-pork meat was perceived as more natural, but fattier and less healthy. Chicken-turkey meat was associated with health and low-fat, but also with dislike. This study provides relevant information to develop or reformulate new meat products.

Characterization of Spanish powdered seaweeds: Composition, antioxidant capacity and technological properties.

This work aimed to characterise four seaweed species: nori (Phorphyra), kombu (Laminaria), wakame (Undaria) and sea spaghetti (Himanthalia elongata). Their nutritional composition, total phenolic compounds (TPC), antioxidant capacity, oil and water holding capacity (OHC and WHC), and swelling capacity (SC) were determined. Wakame and nori exhibited the highest proteins contents, rich in essential amino acids and in those related to umami flavour. All the samples had a low lipid content and high ash content values. High fibre levels were observed, especially in kombu. The TPC content and antioxidant capacity of sea spaghetti was significantly higher than in the other samples. The OHC, WHC and SC of the seaweeds demonstrated their potential influence on texture of food products. The incorporation of these seaweeds into different foodstuffs could entail an improvement of the nutritional quality and texture properties, and could also reduce the use of Na and synthetic additives.

Development of a colorimetric sensor array for squid spoilage assessment.

The aim of this work was to develop and evaluate a rapid, easy-to-use optoelectronic system for the shelf-life assessment of squid in cold storage. For this purpose, an optoelectronic nose was designed, which consisted of an array containing six sensing materials prepared by combining different dyes and two inorganic supports (aluminium oxide and silica gel). Samples were packaged with the colorimetric array and kept in cold storage for 12 days. Squid spoilage was monitored simultaneously by the colorimetric array and by the physico-chemical and microbial analyses during storage. Samples exceeded the acceptability limits for microbial counts on the third day. PCA analysis carried out with CIELab showed that the colorimetric array was able to discriminate between fresh squid fit for consumption and spoiled squid. The statistical models obtained by PLS, with the optoelectronic nose, successfully predicted CO2 and O2 content in the headspace as well as microbial growth.

Antimicrobial activity of essential oil components against Escherichia coli depends on the food components present in a food matrix.

Despite numerous studies evaluating the antimicrobial activity of essential oil components (EOCs) against different microorganisms, the effect of the composition of the matrix in which they are applied remains unexplored. Hence, the effect of different food components (i.e., proteins, lipids, carbohydrates, acids, ethanol) on vanillin antimicrobial activity was carried out by assessing the growth of E. coli at different incubation times (0, 1, 4, 8 and 24 h). Based on these outcomes, the food components that most adversely affected vanillin antimicrobial activity were subsequently tested with four other EOCs (i.e., carvacrol, eugenol, geraniol, thymol). The effective concentration of antimicrobials after coming into contact with food components was quantified. The results indicated that bovine serum albumin (BSA), sunflower oil and carbohydrates partially or completely inhibited the antimicrobial efficacy of the tested EOCs, and the inhibition rate depended on the specific EOC-food component combination. Geraniol was notably the most efficient with BSA present. Eugenol performed best with sunflower oil. Carvacrol, eugenol, geraniol and thymol were more effective than vanillin with D-lactose present. This study confirmed that loss of EOCs' effective concentration due to an interaction with food constituents is a significant cause of antimicrobial activity inhibition. These findings underscore the importance of considering matrix composition when selecting antimicrobials to combat a particular strain in real food applications.

Evaluation of sea bream (Sparus aurata) shelf life using an optoelectronic nose.

A new optoelectronic nose for the shelf-life assessment of fresh sea bream in cold storage has been developed. The chromogenic array used eight sensing materials (based on aluminium oxide and silica gel) containing pH indicators, Lewis acids and an oxidation-reduction indicator. The colour changes of the sensor array were characteristic of sea bream spoilage. Colour modulations were measured on day 0 and for the samples held in cold storage for 2, 4, 7, 9 and 11 days. Determination of moisture content, pH, total volatile basic nitrogen (TVB-N), drip loss, ATP-related compounds and K(1)-value and microbial (mesophilic bacteria and Enterobacteriaceae) analyses were carried out on the same days. The changes in the chromogenic arrays data were processed by statistical analysis (PCA). Moreover, PLS statistical studies allowed the creation of models to correlate the chromogenic data with concentrations of mesophilic and Enterobacteriaceae. The results suggest the feasibility of this system to help develop optoelectronic noses for fish freshness monitoring.

Physico-chemical and microbiological changes in commercial tilapia (Oreochromis niloticus) during cold storage / Cambios fisico-químicos y microbiológicos en tilapia comercial (Oreochromis niloticus) durante almacenamiento refrigerado

Background: The microbiological and chemical processes are the main responsible for deterioration of fresh fish. Therefore, it is essential to avoid these processes by applying good manufacturing practices during fish handling, distribution and storage. Objective: The aim of this paper was to evaluate the physico-chemical and microbial changes in commercial tilapia (Oreochromis niloticus) during cold storage in order to establish the shelf life since its arrival at the supermarket. Methods: 27 aquacultured tilapia specimens were analyzed at 0, 2, 4, and 7 days of storage at 4ºC. Measurements of texture, color, water holding capacity, total volatile basic nitrogen (TVB-N), thiobarbituric acid index, ATP-related compounds, as well as microbial analyses were carried out. Results: The TVB-N content was high at the beginning of the study, remaining stable during the storage. Lipid oxidation of samples was minimum, so this process did not contribute to the fish spoilage. It was observed the breakdown of inosine-5'- monophosphate (IMP) into Ino (inosine), and Ino into Hx (hypoxantine). The texture parameters and colour underwent changes as a consequence of the fish spoilage. Low microbial counts were observed at day 0, but Enterobacteriaceae and mesophilic counts gradually increased throughout storage. Conclusions: The K1 -value showed the progressive spoilage of the fish during the cold storage. The decrease of hardness and firmness confirmed the loss of quality throughout the time of study. The low microbial counts at the beginning of the study demonstrated the good quality of the tilapia; however, the increase of the mesophilic counts at the end of the studied period showed that tilapia was not fit for human consumption at day 7.

Antecedentes: Los procesos microbiológicos y químicos son los principales responsables del deterioro del pescado fresco. Por tanto, es esencial evitar estos procesos aplicando buenas prácticas de fabricación durante la manipulación, distribución y almacenamiento del pescado. Objetivo: El objetivo de este trabajo fue evaluar los cambios físico-químicos y microbiológicos en tilapia comercial (Oreochromis niloticus) durante el almacenamiento refrigerado con el fin de establecer la vida útil desde su llegada al supermercado. Métodos: 27 especímenes de tilapia fueron analizados a día 0, 2, 4 y 7 de almacenamiento a 4 ºC. Se llevaron a cabo medidas de textura, color, capacidad de retención de agua, nitrógeno básico volátil total (N-BVT), índice del ácido tiobarbitúrico, compuestos relacionados con el ATP, así como análisis microbianos. Resultados: El contenido en N-BVT fue alto al principio del estudio, siendo estable durante el almacenamiento. La oxidación lipídica de las muestras fue mínima, por lo que este proceso no contribuyó al deterioro del pescado. Se observó la degradación de inosina-5'- monofosfato (IMP) a Ino (inosina), y de Ino a Hx (hipoxantina). Los parámetros de textura y color sufrieron cambios como consecuencia del deterioro del pescado. Se observaron bajos recuentos microbianos a día 0, pero los recuentos de Enterobacteriaceae y de mesófilos aumentaron gradualmente durante el almacenamiento. Conclusiones: El valor K1 mostró el deterioro progresivo del pescado durante el almacenamiento en refrigeración. La disminución de dureza y firmeza confirmó la pérdida de calidad a lo largo del tiempo de estudio. Los bajos recuentos microbianos al principio del estudio demostraron la buena calidad de la tilapia; sin embargo, el aumento de los recuentos de mesófilos al final del periodo estudiado mostraron que la tilapia no era adecuada para el consumo humado a día 7.