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.

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.

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.

Impact of food preservatives based on immobilized phenolic compounds on an in vitro model of human gut microbiota.

To address concerns about the biocompatibility of novel phenolic immobilization-based food preservatives, their impact on the composition and metabonomic profile of a defined community of human gut microbiota was evaluated. Three phenolics (eugenol, vanillin and ferulic acid) presented in two forms (free or immobilized on different supports) were tested at two concentration levels (0.5 and 2 mg/mL). Free eugenol was the phenolic with the greatest impact on gut microbiota, with a remarkable increase in the abundance of Lachnospiraceae and Akkermansiaceae families. In contrast, immobilized phenolics produced an increase in the abundance of Bacteroides with a reduction in the ratio of Firmicutes to Bacteroidetes. The metabonomic profile was also affected by free and immobilized phenolics differently in terms of fermentation by-products and phenolic biotransformation metabolites. Thus the results suggest the importance of evaluating the impact of new compounds or materials added to food on human gut microbiota and their potential use to modulate microbiota composition.

Influence of free and immobilized chitosan on a defined human gut microbial ecosystem.

In this work, the influence of different forms of presentation of chitosan in the human gut microbiota with a defined bacterial community was evaluated. First, the susceptibility of individual gut bacterial isolates against chitosan was studied within a concentration range between 0.125 and 1 mg/mL. Then, the impact of chitosan (0.25 and 1 mg/mL) on a defined human gut microbial ecosystem was studied by metagenomic and metabonomic analyses. The results showed that chitosan in its free form had a high impact on individual isolates with a minimum inhibitory concentration below 1 mg/mL for most of the strains studied. In comparison, chitosan immobilized in the different carriers displayed a diverse effect on gut microbiota. The most susceptible strains were Agathobacter rectalis strain 16-6-I 1 FAA, Clostridium spiroforme strain 16-6-I 21 FAA and Mediterraneibacter faecis strain 16-6-I 30 FAA. The impact of the different modes of presentation of chitosan was strain-specific and species-specific when compared to results obtained from analysis of other strains within the genera Agathobacter, Clostridium and Mediterraneibacter, and therefore a study using a defined ecosystem was needed to extrapolate the results. Significant decreases in defined community richness and diversity and changes in metabolic profile were observed after exposure to free chitosan. Free chitosan produced significant reductions in the abundance of the genera Lachnoclostridium, Anaerotignum, Blautia, Enterococcus, Eubacterium and Ruthenibacterium together with a slight decrease of the production of SCFAs, among other fermentation by-products. The immobilized chitosan significantly alleviated the impact caused by the antimicrobial polymer and significantly increased the relative abundance of the Bacteroidetes phylum compared to free chitosan. These results suggest the significance of assessing the impact of new ingredients and materials included in food on the human gut microbiota with models that simulate the gastrointestinal environment, such as in vitro bioreactor systems.

Studying process variables to obtain undisturbed shaped soft meat for people with poor oral health.

This study evaluated injection (I) and vacuum impregnation (VI) as the best methods to apply papain, and other important processing conditions (batch, aging and cooking conditions), to obtain soft meat (suitable for people with poor oral health) without disturbing its original shape. Two aging times were evaluated and four cooking conditions by immersion in soup. Meat samples were injected or vacuum-impregned (0.85 kPa) with a papain solution (5% w/v). After cooking, they were analyzed by the compression test, and by image and sensory analyses. The results indicated that by using both methods to apply the enzyme, the obtained meat was suitable for people with poor oral health, even if VI was the better method because it minimized the factors batch, aging and cooking condition. Therefore, the best meat processing method to obtain panelists' highest softness values and the best appreciation was employing aged meat pretreated by VI and cooked at 65 °C for 10 min.

Gated Organonanoclays for Large Biomolecules: Controlled Release Triggered by Surfactant Stimulus.

The low toxicity and high adsorption capacities of clay minerals make them attractive for controlled delivery applications. However, the number of controlled-release studies in the literature using clay minerals is still scarce. In this work, three different clays from the smectite group (Kunipia F, montmorillonite; Sumecton SA, saponite; and Sumecton SWN, hectorite) were successfully loaded with rhodamine B dye and functionalized with oleic acid as a gatekeeper to produce organonanoclays for active and controlled payload-release. Moreover, hematin and cyanocobalamin have also been encapsulated in hectorite gated clay. These organonanoclays were able to confine the entrapped cargos in an aqueous environment, and effectively release them in the presence of surfactants (as bile salts). A controlled delivery of 49 ± 6 µg hematin/mg solid and 32.7 ± 1.5 µg cyanocobalamin/mg solid was reached. The cargo release profiles of all of the organonanoclays were adjusted to three different release-kinetic models, demonstrating the Korsmeyer-Peppas model with release dependence on (i) the organic-inorganic hybrid system, and (ii) the nature of loaded molecules and their interaction with the support. Furthermore, in vitro cell viability assays were carried out with Caco-2 cells, demonstrating that the organonanoclays are well tolerated by cells at particle concentrations of ca. 50 µg/mL.

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.

Characterisation of chemical damage on tissue structures by multispectral imaging and machine learning procedures: Alkaline hypochlorite effect in C. elegans.

Multispectral imaging represents a powerful technique to maximise data collection and analysis for biological materials. It improves the exploitation and understanding of in vivo/vitro experiments. This work focused on testing the capability of multispectral imaging to characterise the tissue damage produced by alkaline hypochlorite on the body and eggs of the biological model C. elegans. To that end, three synchronisation processes with different final bleach and sodium hydroxide concentrations were performed. The impact of treatments was characterised by measuring egg viability and morphology, besides capturing multispectral images of both nematode bodies and eggs. Multispectral images consisted of seven slices captured from different wavelengths within the visible/infrared spectrum by different light-pass filters. The results showed dependence between increased alkaline hypochlorite concentration and loss of egg viability/morphology. This relation was also observed for the imaging data, which showed alterations to tissue transmittance for all the tested wavelengths for both bodies and eggs. Localised alterations related to alkaline hypochlorite diffusion through anatomical nematode orifices were recognised. Applying multivariate methods to imaging data successfully characterised tissue alterations, from which treatment type was predicted for both nematodes and eggs. Moreover, the alterations recorded by imaging data were also used to predict egg viability regardless of treatment type (0.94). The high correlation between the imaging data from nematodes and eggs with egg viability evidenced multispectral imaging's ability to characterise tissue damage and its possible practical application to study alterations to the tissues of this biological model.

In vitro susceptibility of human gut microbes to potential food preservatives based on immobilized phenolic compounds.

The development of novel food preservatives based on natural antimicrobials such as phenolic compounds is increasing, but their safety should be established before use, including evaluating their impact on the gut microbiota. This work explored the influence of antimicrobial phenolics presented in different forms on selected human gut microbiota members through in vitro susceptibility tests. The bacteria tested exhibited a wide range of susceptibilities to phenolics depending on the molecule structure and mode of administration. Agathobacter rectalis and Clostridium spiroforme, members of the phylum Firmicutes, were the most sensitive strains. Susceptibility was strain- and species-specific, suggesting that it may not be possible to easily extrapolate results across the human microbiome in general. Species of other phyla including Bacteroidetes, Actinobacteria, Proteobacteria and Verrucomicrobia were more resistant than Firmicutes, with growth of some strains even enhanced. Our results provide insights into the biocompatibility of free and immobilized phenolics as potential food additives.

Efficient reduction in vegetative cells and spores of Bacillus subtilis by essential oil components-coated silica filtering materials.

Inactivation of bacterial spores is a key objective for developing novel food preservation technologies. In this work, the removal properties of filtering materials based on silica microparticles functionalized with essential oil components (EOCs) (carvacrol, eugenol, thymol, and vanillin) against Bacillus subtilis, a spore-forming bacterium, in two liquid matrices were investigated. The viability of vegetative cells and spores after treatment was also evaluated. The results exhibited marked removal effectiveness against B. subtilis vegetative cells and spores after filtration with the different silica supports coated with EOCs in either sterile water or nutrient broth, with reductions of 3.2 to 4.9 log units and 3.7 to 5.0 log units for vegetative cells and spores, respectively. The fluorescent viability images revealed the poor viability of the treated B. subtilis vegetative cells and spores due to damage to the cell envelope when coming into contact with the immobilized antimicrobials. The culture counts results revealed the great inhibitory capacity of the EOC-functionalized silica microparticles against B. subtilis vegetative cells and spores after a single filtration. Hence, the present work suggests the feasibility of using EOC-functionalized supports as filtering aids to enhance the microbial quality of liquid matrices with spore-forming microorganisms. PRACTICAL APPLICATION: The developed antimicrobial-coated filters have shown remarkable removal properties against an important spore-forming bacterium in food industry. These filters may be used as a potential sterilization technique for preservation of different beverages alone or in combination with other mild-thermal or nonthermal techniques.

Caenorhabditis elegans to Model the Capacity of Ascorbic Acid to Reduce Acute Nitrite Toxicity under Different Feed Conditions: Multivariate Analytics on Behavioral Imaging.

Nitrocompounds are present in the environment and human diet and form part of vegetables and processed meat products as additives. These compounds are related to negative impacts on human and animal health. The protective effect of ascorbic acid has been demonstrated by some biological systems as regards several nitrocompounds. This work focused on studying the possibility of modeling this effect on nitrite toxicity with the model Caenorhabditis elegans. The three factors studied in this work were ascorbic acid concentration, nitrite exposure concentration, and presence/absence of food. The protective effect was evaluated by scoring lethality and its impact on behavior by means of multivariate statistical methods and imaging analytics. The effects of nitrite and the influence of food availability were evidenced. Apart from increasing lethality, nitrite had disruption effects on movements. All the observed symptoms reduced when ascorbic acid was administered, and it diminished lethality in all cases. Ascorbic acid maintained nematodes' postural capacities. The results suggest that nitrites' nonspecific toxicity in C. elegans can be mitigated by ascorbic acid, as previously evidenced in other biological systems. Thus, our results reveal the ability of C. elegans to reproduce the known protective effect of ascorbic acid against nitrite.

Evaluation of the influence of food intake on the incorporation and excretion kinetics of mesoporous silica particles in C.elegans.

The effect of the presence of food on the incorporation and excretion of silica particles was studied in this work using the biological model Caenorhabditis elegans and image analysis techniques. The experiment was based on two 24-hour phases: exposure and depuration. During exposure, nematodes were maintained for 24 h in liquid medium with silica particles, but some with and others without food. During depuration, nematodes were transferred to medium without particles. Nematodes were analysed by an image analysis in both phases to quantify the properties of particle distributions in nematodes' bodies with time. No differences were found in the proportion of nematodes carrying particles in the exposure phase when food was present. However in the depuration phase, lack of food generated a high proportion of particle carriers. Particle distribution properties were also similar in the exposure phase. Nevertheless, lack of food produced particle accumulation due to decelerated excretion because digestive tube relaxed under these conditions. Thus after the depuration phase, lack of food led particles to persist in digestive tubes. According to these results, intake of silica particles had no retention effects when a food flux was provided, but particles were not easily excreted when the food flux was interrupted.

Chia (Salvia hispanica L.) seed mucilage as a fat replacer in yogurts: Effect on their nutritional, technological, and sensory properties.

Growing consumer demand for healthy and nutritious products has motivated scientists and food manufacturers to design novel dairy products with higher fiber levels and lower fat content that are free of chemical additives. Chia seed mucilage (CSM) is a healthy natural gel extensively used as a dietary source of soluble fiber, a bulking agent, and a fat replacer in a large variety of foods. In this study, we evaluated the effect of CSM on the nutritional, technological, and sensory properties of skimmed yogurts. The addition of 7.5% CSM to a yogurt formula lowered the degree of syneresis of the resulting yogurt during storage compared with full-fat yogurts. The nutritive value of the enriched yogurts improved due to higher levels of dietary fiber compared with full-fat and skimmed yogurts. Moreover, rheological measurements revealed greater consistency, firmness, and viscosity, as well as the formation of a highly structured network and better resistance to stress in yogurts containing 7.5% CSM. The sensory acceptance of the yogurts enriched with 7.5% CSM was similar to the reference samples in acidity, creaminess, and viscosity terms. These results confirm the feasibility of using CSM as a fat replacer to design novel skimmed yogurts.

Toxicological implications of amplifying the antibacterial activity of gallic acid by immobilisation on silica particles: A study on C. elegans.

Immobilisation of natural compounds on solid supports to amplify antimicrobial properties has reported successful results, but modifications to physico-chemical properties can also imply modifications from a toxicological viewpoint. This work aimed to study the immobilising process of gallic acid in the antibacterial activity of L. innocua and its toxicological properties in vivo using Caenorhabditis elegans. The experiment was based on obtaining the minimum bactericidal concentration for free and immobilised gallic acid by comparing lethality, locomotion behaviour, chemotaxis and thermal stress resistance on C.elegans at those concentrations. The results showed a lowering minimum bactericidal concentration and modifications to nematode responses. Increased lethality and velocity of movements was observed. Immobilisation increased the repellent effect of gallic acid with a negative chemotaxis index. Thermal stress resistance was also affected, with higher mortality for immobilised gallic acid compared to bare particles and free gallic acid. Thus despite evidencing a generalised increase in the toxicity of gallic acid in vivo, lowering the minimum bactericidal concentration allowed a bacterial reduction of 99 % with less than one third of mortality for the nematodes exposed to free gallic acid.

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.

In vitro antimicrobial activity of immobilised essential oil components against Helicobacter pylori.

Available disinfection methods and therapies against Helicobacter pylori have multiple disadvantages, such as increased prevalence of antibiotic-resistant strains, which requires the search for novel effective antimicrobial agents against H. pylori. Among them, naturally-occurring antimicrobial compounds, like essential oil components (EOCs), have been reported as substances with anti-H. pylori potential. To avoid the disadvantages associated with using EOCs in their free form, including volatility, low water solubility and intense sensory properties, their immobilisation in inert supports has recently been developed. This study sought to evaluate the inhibitory properties of EOCs immobilised on silica microparticles against H. pylori and to elucidate the mechanism of action of the immobilised antimicrobials. After the preparation and characterisation of the antimicrobial supports, the susceptibility of H. pylori in the presence of the immobilised compounds was assessed by plate count, fluorescent viability staining and direct viable count-fluorescent in situ hybridisation analyses. The antimicrobial supports were found to inhibit H. pylori growth, and to induce morphological and metabolic alterations to the H. pylori membrane, with a minimum bactericidal concentration value between 25 and 50 µg/ml according to the tested EOC. These findings indicate that immobilised EOCs can be used as potential antimicrobial agents for H. pylori clearance and treatment.

New Oleic Acid-Capped Mesoporous Silica Particles as Surfactant-Responsive Delivery Systems.

A new delivery microdevice, based on hydrophobic oleic acid-capped mesoporous silica particles and able to payload release in the presence of surfactants, has been developed. The oleic acid functionalization confers to the system a high hydrophobic character, which avoids cargo release unless surfactant molecules are present. The performance of this oleic-acid capped microdevice in the presence of different surfactants is presented and its zero-release operation in the absence of surfactants is demonstrated.

Non destructive monitoring of the yoghurt fermentation phase by an image analysis of laser-diffraction patterns: Characterization of cow's, goat's and sheep's milk.

Monitoring yogurt fermentation by the image analysis of diffraction patterns generated by the laser-milk interaction was explored. Cow's, goat's and sheep's milks were tested. Destructive physico-chemical analyses were done after capturing images during the processes to study the relationships between data blocks. Information from images was explored by applying a spectral phasor from which regions of interest were determined in each image channel. The histograms of frequencies from each region were extracted, which showed evolution according to textural modifications. Examining the image data by multivariate analyses allowed us to know that the captured variance from the diffraction patterns affected both milk type and texture changes. When regression studies were performed to model the physico-chemical parameters, satisfactory quantifications were obtained (from R2 = 0.82 to 0.99) for each milk type and for a hybrid model that included them all. This proved that the studied patterns had a common fraction of variance during this processing, independently of milk type.

Antimicrobial activity of commercial calcium phosphate based materials functionalized with vanillin.

Infections represent one of the most frequent causes of arthroplasty revision. Thus, design of new antimicrobial scaffolds to reduce implant rejections, bone infections and associated medical costs is highly desired. In recent years, essential oil components (EOCs) have merged as compounds with significant antimicrobial activity that can be attached to specific surfaces to enhance and prolong their antimicrobial effect. Herein calcium phosphate CaP regenerative materials have been coated with a vanillin derivative to combine its original bone regeneration properties with antimicrobial action of EOCs. Materials in form of microparticles and blocks were prepared and fully characterized. Clonogenic viability tests demonstrated that low concentrations of material (10 mg·mL-1) resulted effective to kill 100% of E. coli DH5α bacteria. Additionally, vanillin containing scaffolds did not display any toxic effect over cells, yet they preserve the ability to express alkaline phosphatase (ALPL), collagen type 1, chain α1 (COL1A1) and bone gamma-carboxyglutamic acid-containing protein or osteocalcin (BGLAP), which are genes typically expressed by osteoblasts. These results demonstrate that commercially available scaffolds can be functionalized with EOCs, achieving antimicrobial activity and open up a new approach for the treatment and prevention of infection. STATEMENT OF SIGNIFICANCE: During the last years, the interest in bone regenerative materials with antibiotic properties has increased, since prosthesis infection is one of the most usual complications in implant surgery. In this work, we report a hybrid system composed by a calcium phosphate material (powders and scaffolds) functionalized with the derivative of an essential oil component (EOC). Our purpose was to provide the calcium phosphate material with antimicrobial activity without harming its bone regenerative capability. The obtained results were encouraging, which opens up the possibility of developing new modified materials for the prevention and treatment of bone infection.