Automatic and non-targeted analysis of the volatile profile of natural and alkalized cocoa powders using SBSE-GC-MS and chemometrics.

A total of 56 key volatile compounds present in natural and alkalized cocoa powders have been rapidly evaluated using a non-target approach using stir bar sorptive extraction gas chromatography mass spectrometry (SBSE-GC-MS) coupled to Parallel Factor Analysis 2 (PARAFAC2) automated in PARADISe. Principal component analysis (PCA) explained 80% of the variability of the concentration, in four PCs, which revealed specific groups of volatile characteristics. Partial least squares discriminant analysis (PLS-DA) helped to identify volatile compounds that were correlated to the different degrees of alkalization. Dynamics between compounds such as the acetophenone increasing and toluene and furfural decreasing in medium and strongly alkalized cocoas allowed its differentiation from natural cocoa samples. Thus, the proposed comprehensive analysis is a useful tool for understanding volatiles, e.g., for the quality control of cocoa powders with significant time and costs savings.

In vivo toxicity assessment of eugenol and vanillin-functionalised silica particles using Caenorhabditis elegans.

The toxicological properties of different silica particles functionalised with essential oil components (EOCs) were herein assessed using the in vivo model C. elegans. In particular, the effects of the acute and long-term exposure to three silica particle types (SAS, MCM-41 micro, MCM-41 nano), either bare or functionalised with eugenol or vanillin, were evaluated on different biological parameters of nematodes. Acute exposure to the different particles did not reduce nematodes survival, brood growth or locomotion, but reproduction was impaired by all the materials, except for vanillin-functionalised MCM-41 nano. Moreover, long-term exposure to particles led to strongly inhibited nematodes growth and reproduction. The eugenol-functionalised particles exhibited higher functionalisation yields and had the strongest effects during acute and long-term exposures. Overall, the vanillin-functionalised particles displayed milder acute toxic effects on reproduction than pristine materials, but severer toxicological responses for the 96-hour exposure assays. Our findings suggest that the EOC type anchored to silica surfaces and functionalisation yield are crucial for determining the toxicological effects of particles on C. elegans. The results obtained with this alternative in vivo model can help to anticipate potential toxic responses to these new materials for human health and the environment.

Safety evaluation of glucosylated steviol glycosides as a food additive in different food categories.

The EFSA Panel on Food Additive and Flavourings (FAF) assessed the safety of glucosylated steviol glycosides proposed for use as a new food additive in different food categories. Glucosylated steviol glycosides consist of a mixture of glucosylated steviol glycosides, containing 1-20 additional glucose units bound to the parent steviol glycosides. Glucosylated steviol glycosides consist of not less than 95% (on dry, dextrin-free, basis) of total steviol glycosides, comprised of glucosylated and parent steviol glycosides. Glucosylated steviol glycosides are produced via enzymatic bioconversion using cyclomaltodextrin glucanotransferase (CGTase) (EC 2.4.1.19), derived from a non-genetically modified strain of Anoxybacillus caldiproteolyticus, that catalyses the transfer of glucose from starch to steviol glycosides mixtures isolated from the dried leaves of Stevia Rebaudiana. The Panel considered that the metabolism of glucosylated steviol glycosides is sufficiently similar to the already authorised steviol glycosides, and thus, the toxicological data previously assessed by the ANS Panel for steviol glycosides (E 960) were considered to support their safety as food additive. The existing acceptable daily intake (ADI) for steviol glycosides (E 960) of 4 mg/kg body weight (bw) per day expressed as steviol can also be applied to glucosylated steviol glycosides. The Panel concluded that there is no safety concern for the use of glucosylated steviol glycosides as a new food additive at the proposed use and use levels. The Panel recommended some modifications to the specifications proposed by the applicant for glucosylated steviol glycosides with respect to the assay, the definition of the proposed new food additive and the proposed maximum limits for arsenic.

In vitro toxicological evaluation of mesoporous silica microparticles functionalised with carvacrol and thymol.

The cytotoxicity of carvacrol- and thymol-functionalised mesoporous silica microparticles (MCM-41) was assessed in the human hepatocarcinoma cell line (HepG2). Cell viability, lactate dehydrogenase (LDH) activity, reactive oxygen species (ROS) production, mitochondrial membrane potential (ΔΨm), lipid peroxidation (LPO) and apoptosis/necrosis analyses were used as endpoints. The results showed that both materials induced cytotoxicity in a time- and concentration-dependent manner, and were more cytotoxic than free essential oil components and bare MCM-41. This effect was caused by cell-particle interactions and not by degradation products released to the culture media, as demonstrated in the extract dilution assays. LDH release was a less sensitive endpoint than the MTT (thiazolyl blue tetrazolium bromide) assay, which suggests the impairment of the mitochondrial function as the primary cytotoxic mechanism. In vitro tests on specialised cell functions showed that exposure to sublethal concentrations of these materials did not induce ROS formation during 2 h of exposure, but produced LPO and ΔΨm alterations in a concentration-dependent manner when cells were exposed for 24 h. The obtained results generally support the hypothesis that the carvacrol- and thymol-functionalised MCM-41 microparticles induced toxicity in HepG2 cells by an oxidative stress-related mechanism that resulted in apoptosis through the mitochondrial pathway.

Effects of essential oil components exposure on biological parameters of Caenorhabditis elegans.

The extensive use of essential oil components in an increasing number of applications can substantially enhance exposure to these compounds, which leads to potential health and environmental hazards. This work aimed to evaluate the toxicity of four widely used essential oil components (carvacrol, eugenol, thymol, vanillin) using the in vivo model Caenorhabditis elegans. For this purpose, the LC50 value of acute exposure to these components was first established; then the effect of sublethal concentrations on nematodes' locomotion behaviour, reproduction, heat and oxidative stress resistance and chemotaxis was evaluated. The results showed that all the components had a concentration-dependent effect on nematode survival at moderate to high concentrations. Carvacrol and thymol were the two most toxic compounds, while vanillin had the mildest toxicological effect. Reproduction resulted in a more sensitive endpoint than lethality to evaluate toxicity. Only pre-exposure to carvacrol and eugenol at the highest tested sublethal concentrations conferred worms oxidative stress resistance. However, at these and lower concentrations, both components induced reproductive toxicity. Our results evidence that these compounds can be toxic at lower doses than those required for their biological action. These findings highlight the need for a specific toxicological assessment of every EOC application.

Relevant essential oil components: a minireview on increasing applications and potential toxicity.

Phenolic compounds carvacrol, thymol, eugenol, and vanillin are four of the most thoroughly investigated essential oil components given their relevant biological properties. These compounds are generally considered safe for consumption and have been used in a wide range of food and non-food applications. Significant biological properties, including antimicrobial, antioxidant, analgesic, anti-inflammatory, anti-mutagenic, or anti-carcinogenic activity, have been described for these components. They are versatile molecules with wide-ranging potential applications whose use may substantially increase in forthcoming years. However, some in vitro and in vivo studies, and several case reports, have indicated that carvacrol, thymol, and eugenol may have potential toxicological effects. Oxidative stress has been described as the main mechanism underlying their cytotoxic behavior, and mutagenic and genotoxic effects have been occasionally observed. In vivo studies show adverse effects after acute and prolonged carvacrol and thymol exposure in mice, rats, and rabbits, and eugenol has caused pulmonary and renal damage in exposed frogs. In humans, exposure to these three compounds may cause different adverse reactions, including skin irritation, inflammation, ulcer formation, dermatitis, or slow healing. Toxicological vanillin effects have been less reported, although reduced cell viability after exposure to high concentrations has been described. In this context, the possible risks deriving from increased exposure to these components for human health and the environment should be thoroughly revised.

Secreted Enzyme-Responsive System for Controlled Antifungal Agent Release.

Essential oil components (EOCs) such as eugenol play a significant role in plant antimicrobial defense. Due to the volatility and general reactivity of these molecules, plants have evolved smart systems for their storage and release, which are key prerequisites for their efficient use. In this study, biomimetic systems for the controlled release of eugenol, inspired by natural plant defense mechanisms, were prepared and their antifungal activity is described. Delivery and antifungal studies of mesoporous silica nanoparticles (MSN) loaded with eugenol and capped with different saccharide gates-starch, maltodextrin, maltose and glucose-against fungus Aspergillus niger-were performed. The maltodextrin- and maltose-capped systems show very low eugenol release in the absence of the fungus Aspergillus niger but high cargo delivery in its presence. The anchored saccharides are degraded by exogenous enzymes, resulting in eugenol release and efficient inhibition of fungal growth.

Towards the Enhancement of Essential Oil Components' Antimicrobial Activity Using New Zein Protein-Gated Mesoporous Silica Microdevices.

The development of new food preservatives is essential to prevent foodborne outbreaks or food spoilage due to microbial growth, enzymatic activity or oxidation. Furthermore, new compounds that substitute the commonly used synthetic food preservatives are needed to stifle the rising problem of microbial resistance. In this scenario, we report herein, as far as we know, for the first time the use of the zein protein as a gating moiety and its application for the controlled release of essential oil components (EOCs). The design of microdevices consist of mesoporous silica particles loaded with essential oils components (thymol, carvacrol and cinnamaldehyde) and functionalized with the zein (prolamin) protein found in corn as a molecular gate. The zein protein grafted on the synthesized microdevices is degraded by the proteolytic action of bacterial enzymatic secretions with the consequent release of the loaded essential oil components efficiently inhibiting bacterial growth. The results allow us to conclude that the new microdevice presented here loaded with the essential oil component cinnamaldehyde improved the antimicrobial properties of the free compound by decreasing volatility and increasing local concentration.

Comparative cytotoxic study of silica materials functionalised with essential oil components in HepG2 cells.

This work evaluated the cytotoxic effect of different EOCs-functionalised silica particle types. The in vitro toxicity of eugenol and vanillin-immobilised SAS, MCM-41 microparticles and MCM-41 nanoparticles was evaluated on HepG2 cells, and compared to free EOCs and pristine materials. The results revealed that free essential oil components and bare silica had a mild cytotoxic effect on HepG2 cells. However, the comparative study showed that free eugenol and vanillin had a milder cytotoxic effect than the equivalent concentrations of immobilised components on the different silica particles, while differences in cell viability between the bare and functionalised particles relied on the type of analysed material. The most cytotoxic materials were eugenol and vanillin-functionalised MCM-41 micro with IC50 values of 0.19 and 0.17 mg/mL, respectively, at 48 h exposure. Differences in cytotoxicity between functionalised particles may be attributed to the density of the functional components on their surface as a result of the functionalisation reaction performance for different materials. The study of the physico-chemical properties of particles demonstrated that cationic nature and increased hydrophobicity could be responsible for promoting cell-particle interactions for the eugenol and vanillin functionalised silica particles, enhancing their cytotoxic behaviour.

Effect of Cooking on Protein Digestion and Antioxidant Activity of Different Legume Pastes.

Legumes are protein-rich foods that can be used to prepare pastes or pureed foods suitable for babies and the elderly. The aims of this study were the characterization of different legume pastes (from soybean, lentil, and pea) subjected to three processing methods (ordinary cooking, pressure cooking, and microwave) and the evaluation of protein digestion and antioxidant activity during simulated gastrointestinal digestion (GID). The different cooking methods of legumes led to differences in the physicochemical properties of the pastes, as well as on the textural and viscoelastic characteristics, except for soybean samples, despite all the pastes presenting elastic properties and weak gel behavior. Cooking followed by GID improved the protein digestibility and antioxidant activity of the legumes, which was attributed to released peptides and amino acids more than free phenolics. However, the fate and extent at each digestion stage was different according to the legume type and cooking method, as it would be influenced by the matrix structure and interaction between components. This work has expanded knowledge about the properties, digestibility, and antioxidant activity of different cooked legumes for a future design of pastes.

Roadmap of cocoa quality and authenticity control in the industry: A review of conventional and alternative methods.

Cocoa (Theobroma cacao L.) and its derivatives are appreciated for their aroma, color, and healthy properties, and are commodities of high economic value worldwide. Wide ranges of conventional methods have been used for years to guarantee cocoa quality. Recently, however, demand for global cocoa and the requirements of sensory, functional, and safety cocoa attributes have changed. On the one hand, society and health authorities are increasingly demanding new more accurate quality control tests, including not only the analysis of physicochemical and sensory parameters, but also determinations of functional compounds and contaminants (some of which come in trace quantities). On the other hand, increased production forces industries to seek quality control techniques based on fast, nondestructive online methods. Finally, an increase in global cocoa demand and a consequent rise in prices can lead to future cases of fraud. For this reason, new analytes, technologies, and ways to analyze data are being researched, developed, and implemented into research or quality laboratories to control cocoa quality and authenticity. The main advances made in destructive techniques focus on developing new and more sensitive methods such as chromatographic analysis to detect metabolites and contaminants in trace quantities. These methods are used to assess cocoa quality; study new functional properties; control cocoa authenticity; or detect frequent emerging frauds. Regarding nondestructive methods, spectroscopy is the most explored technique, which is conducted within the near infrared range, and also within the medium infrared range to a lesser extent. It is applied mainly in the postharvest stage of cocoa beans to analyze different biochemical parameters or to assess the authenticity of cocoa and its derivatives.

Degradation of silica particles functionalised with essential oil components under simulated physiological conditions.

In this work, the biodurability of three silica particle types (synthetic amourphous silica, MCM-41 microparticles, MCM-41 nanoparticles) functionalised with three different essential oil components (carvacrol, eugenol, vanillin) was studied under conditions that represented the human gastrointestinal tract and lysosomal fluid. The effect of particle type, surface immobilised component and mass quantity on the physico-chemical properties of particles and silicon dissolution was determined. Exposure to biological fluids did not bring about changes in the zeta potential values or particle size distribution of the bare or functionalised materials, but the in vitro digestion process partially degraded the structure of the MCM-41 nanoparticles. Functionalisation preserved the structure of the MCM-41 nanoparticles after simulating an in vitro digestion process, and significantly decreased the amount of silicon dissolved after exposing different particles to both physiological conditions, independently of the essential oil component anchored to their surface. The MCM-41 microparticles showed the highest solubility, while synthetic amorphous silica presented the lowest levels of dissolved silicon. The study of these modified silica particles under physiological conditions could help to predict the toxicological behaviour of these new materials.

Effect of oregano (Origanum vulgare L. ssp. hirtum) and clove (Eugenia spp.) nanoemulsions on Zygosaccharomyces bailii survival in salad dressings.

This work aimed to evaluate the in vitro effect of encapsulated oregano and clove essential oils on oil-in-water nanoemulsions against Zygosaccharomyces bailii. The antifungal efficacy of these nanoemulsions and their sensory acceptance were tested in salad dressings. Both essential oils were effective inhibitors against the target yeast, with minimal inhibitory and fungicidal concentrations of 1.75 mg/mL. In the in vitro assay done with the nanoemulsions, no yeast growth was observed for any tested essential oil concentration. In the salad dressings, all the formulations were able to reduce Z. bailii growth compared to the control, and only those samples with 1.95 mg/g of essential oil were capable of inhibiting yeast development after 4 inoculation days. The sensory acceptance of the dressing containing the nanoemulsions was similar to the control dressing in appearance, consistency and colour terms. These results evidence the antifungal activity of oregano and clove nanoemulsions against Z. bailii.

Olive leaf extracts for shelf life extension of salmon burgers.

In this work, the effect of the addition of olive leaf extracts on the quality of vacuum-packed salmon burgers stored at 4 ℃ during 16 days has been studied. Olive leaf extract and its hydrolysate were initially characterized and then incorporated to salmon burgers. A shelf life study was conducted in three different batches (control, olive leaf extract, and hydrolyzed olive leaf extract burgers). Among the chemical indices determined, total volatile base nitrogen values were lower in hydrolyzed olive leaf extract and olive leaf extract burgers than in control samples. Lipid oxidation was lower in salmon burger with olive leaf extract. Salmon mince treated with hydrolyzed olive leaf extract showed lower microbial counts during the whole study, which extended the shelf life of the fish product. Therefore, the potential of olive leaf extracts to preserve salmon burgers during cold storage has been demonstrated.

Anchoring Gated Mesoporous Silica Particles to Ethylene Vinyl Alcohol Films for Smart Packaging Applications.

This work is a proof of concept for the design of active packaging materials based on the anchorage of gated mesoporous silica particles with a pH triggering mechanism to a packaging film surface. Mesoporous silica micro- and nanoparticles were loaded with rhodamine B and functionalized with N-(3-trimethoxysilylpropyl)diethylenetriamine. This simple system allows regulation of cargo delivery as a function of the pH of the environment. In parallel, poly(ethylene-co-vinyl alcohol) films, EVOH 32 and EVOH 44, were ultraviolet (UV) irradiated to convert hydroxyl moieties of the polymer chains into ⁻COOH functional groups. The highest COOH surface concentration was obtained for EVOH 32 after 15 min of UV irradiation. Anchoring of the gated mesoporous particles to the films was carried out successfully at pH 3 and pH 5. Mesoporous particles were distributed homogeneously throughout the film surface and in greater concentration for the EVOH 32 films. Films with the anchored particles were exposed to two liquid media simulating acidic food and neutral food. The films released the cargo at neutral pH but kept the dye locked at acidic pH. The best results were obtained for EVOH 32 irradiated for 15 min, treated for particle attachment at pH 3, and with mesoporous silica nanoparticles. This opens the possibility of designing active materials loaded with antimicrobials, antioxidants, or aromatic compounds, which are released when the pH of the product approaches neutrality, as occurs, for instance, with the release of biogenic amines from fresh food products.

Sistemas de encapsulación y liberación controlada basados en el uso de puertas moleculares / Encapsulation and controlled delivery systems based on molecular gates

Las partículas mesoporosas de sílice (PMS) son estructuras de dióxido de silicio organizadas de manera que se crean poros entre 2 y 50 nm. El alto volumen de poros y su superficie interna, convierten a las PMS en excelentes soportes para la encapsulación de moléculas bioactivas. Además, la posibilidad de incluir moléculas con función de puerta molecular en su superficie externa permite el diseño de sistemas inteligentes de liberación. Las PMS con puerta molecular muestran "liberación cero" de la molécula encapsulada, pero tras la aplicación de un estímulo externo específico son capaces de liberar su carga como respuesta específica a dicho estímulo. En este artículo se describen las características de las PMS usadas en la encapsulación de compuestos bioactivos, las puertas moleculares más importantes para crear sistemas de liberación controlada y ejemplos de aplicación de PMS para la encapsulación de ingredientes alimenticios y nutracéuticos. Estas aplicaciones incluyen la modulación de la bioaccesibilidad de ingredientes alimenticios o nutracéuticos, así como la protección de su estabilidad frente a la degradación por agentes externos

Mesoporous silica particles (MSP) are structures of silicon dioxide arranged so that they are able to create pores between 2 and 50 nm. The high volume of pores and the internal surface of the MSP make them excellent supports for the encapsulation of bioactive molecules. In addition, the possibility of including molecules acting as molecular gate onto their outer surface allows the design of smart delivery systems. Gated-MSP show "zero release" of the encapsulated molecule, but after the application of a specific external stimulus, the cargo is released as a specific response to the stimulus. This article describes the features of the MSP used in the encapsulation of bioactive compounds, the most important molecular gates to create controlled release systems, as well as examples of application of MSP for the encapsulation and controlled release of food ingredients and nutraceuticals. These applications include the modulation of the bioaccessibility of food ingredients or nutraceuticals as well as the protection of their stability against external agents degradation

[Encapsulation and controlled delivery systems based on molecular gates]. / Sistemas de encapsulación y liberación controlada basados en el uso de puertas moleculares.

Mesoporous silica particles (MSP) are structures of silicon dioxide arranged so that they are able to create pores between 2 and 50 nm. The high volume of pores and the internal surface of the MSP make them excellent supports for the encapsulation of bioactive molecules. In addition, the possibility of including molecules acting as molecular gate onto their outer surface allows the design of smart delivery systems. Gated-MSP show "zero release" of the encapsulated molecule, but after the application of a specific external stimulus, the cargo is released as a specific response to the stimulus. This article describes the features of the MSP used in the encapsulation of bioactive compounds, the most important molecular gates to create controlled release systems, as well as examples of application of MSP for the encapsulation and controlled release of food ingredients and nutraceuticals. These applications include the modulation of the bioaccessibility of food ingredients or nutraceuticals as well as the protection of their stability against external agents degradation.

Las partículas mesoporosas de sílice (PMS) son estructuras de dióxido de silicio organizadas de manera que se crean poros entre 2 y 50 nm. El alto volumen de poros y su superficie interna, convierten a las PMS en excelentes soportes para la encapsulación de moléculas bioactivas. Además, la posibilidad de incluir moléculas con función de puerta molecular en su superficie externa permite el diseño de sistemas inteligentes de liberación. Las PMS con puerta molecular muestran "liberación cero" de la molécula encapsulada, pero tras la aplicación de un estímulo externo específico son capaces de liberar su carga como respuesta específica a dicho estímulo.En este artículo se describen las características de las PMS usadas en la encapsulación de compuestos bioactivos, las puertas moleculares más importantes para crear sistemas de liberación controlada y ejemplos de aplicación de PMS para la encapsulación de ingredientes alimenticios y nutracéuticos. Estas aplicaciones incluyen la modulación de la bioaccesibilidad de ingredientes alimenticios o nutracéuticos, así como la protección de su estabilidad frente a la degradación por agentes externos.

Combination of different antifungal agents in oil-in-water emulsions to control strawberry jam spoilage.

The combination of antifungal agents (cinnamon bark oil, zinc gluconate and trans-ferulic acid) in oil-in-water emulsions to control the fungal spoilage of strawberry jams, minimising essential oil's sensory impact, was evaluated in this work. The in vitro assays of free antifungal agents were performed against five fungal strains; meanwhile, the emulsions assays were conducted against Aspergillus niger given its strong resistance and its relevance in strawberry products. The emulsion formulated with 0.08mg/g of essential oil was able to inhibit mould growth after the incubation period. The incorporation of zinc gluconate or trans-ferulic acid, independently of the concentration used, allowed to reduce a 25% the amount of essential oil needed to inhibit the microbial growth. The combination of antifungal agents in the emulsions has demonstrated to be an effective alternative to reduce the amount of essential oil employed, maintaining the hygienic quality and sensory profile of the strawberry jam.

Prevention of fungal spoilage in food products using natural compounds: A review.

The kingdom Fungi is the most important group of microorganism contaminating food commodities, and chemical additives are commonly used in the food industry to prevent fungal spoilage. However, the increasing consumer concern about synthetic additives has led to their substitution by natural compounds in foods. The current review provides an overview of using natural agents isolated from different sources (plants, animals, and microorganisms) as promising antifungal compounds, including information about their mechanism of action and their use in foods to preserve and prolong shelf life. Compounds derived from plants, chitosan, lactoferrin, and biocontrol agents (lactic acid bacteria, antagonistic yeast, and their metabolites) are able to control the decay caused by fungi in a wide variety of foods. Several strategies are employed to reduce the drawbacks of some antifungal agents, like their incorporation into oil-in-water emulsions and nanoemulsions, edible films and active packaging, and their combination with other natural preservatives. These strategies facilitate the addition of volatile agents into food products and, improve their antifungal effectiveness. Moreover, biological agents have been investigated as one of the most promising options in the control of postharvest decay. Numerous mechanisms of action have been elucidated and different approaches have been studied to enhance their antifungal effectiveness.

Encapsulation of folic acid in different silica porous supports: A comparative study.

Although folic acid is essential to numerous bodily functions, recent research indicates that a massive exposition to the vitamin could be a double-edged sword. In this study, the capacity of different caped mesoporous silica particles (i.e. Hollow Silica Shells, MCM-41, SBA-15 and UVM-7) to dose FA during its passage through the gastrointestinal tract has been evaluated. Results confirmed that the four capped materials were capable to hinder the delivery of FA at low pH (i.e. stomach) as well as able to deliver great amounts of the vitamin at neutral pH (i.e. intestine). Nevertheless, the encapsulation efficiency and the deliver kinetics differed among supports. While supports with large pore entrance exhibited an initial fast release, MCM-41, showed a sustained release along the time. This correlation between textural properties and release kinetics for each of the supports reveals the importance of a proper support selection as a strategy to control the delivery of active molecules.