Effect of Edible Onion (Allium cepa L.) Film on Quality,Sensory Properties and Shelf Life of Beef Burger Patties

The production of edible film from onion (Allium cepa L.) to be applied as packaging is attractive, due to its chemical properties and biodegradable characteristics. Thus, we tested the hypothesis that edible onion film can positively influence the sensory properties, quality and increasing shelf life of beef burgers patties. The experiment was designed in a 4 × 2 factorial scheme, with two treatments (beef burgers patties with or without edible onion film) at an interval of four storage times (0, 3, 6 and 9 days) at 4 °C. The uncoated burger patties (control) suffered the most intense color modifications during the storage (p < 0.05). The luminosity index was higher (p < 0.05) in the control at all storage times, except at day 6, and redness, yellowness and chrome were higher (p < 0.05) in the edible onion film patties at all storage times. The pH of the beef burger patties was lower (p < 0.05) at all storage times when the edible onion film was applied. For the texture profile, only the chewiness was affected, as the inclusion of the edible onion film improved the chewing of the beef burgers patties over the storage time (p < 0.05). Additionally, there was an inhibition of the microbial growth of mesophiles and psychrophiles with the application of the edible onion film in beef burgers patties. The use of edible onion film improved the perception of panelists for the variables texture, color, flavor, odor and overall appearance, and increased the preference of panelists. The edible onion film is recommended for preserving beef burgers patties, as it delays the proliferation of unwanted microorganisms, stabilizes and improves the color parameters and sensory attributes, and increases the overall acceptance of the consumer.     

Phenolic Compounds in Active Packaging and Edible Films/Coatings: Natural Bioactive Molecules and Novel Packaging Ingredients

In recent years, changing lifestyles and food consumption patterns have driven demands for high-quality, ready-to-eat food products that are fresh, clean, minimally processed, and have extended shelf lives. This demand sparked research into the creation of novel tools and ingredients for modern packaging systems. The use of phenolic-compound-based active-packaging and edible films/coatings with antimicrobial and antioxidant activities is an innovative approach that has gained widespread attention worldwide. As phenolic compounds are natural bioactive molecules that are present in a wide range of foods, such as fruits, vegetables, herbs, oils, spices, tea, chocolate, and wine, as well as agricultural waste and industrial byproducts, their utilization in the development of packaging materials can lead to improvements in the oxidative status and antimicrobial properties of food products. This paper reviews recent trends in the use of phenolic compounds as potential ingredients in food packaging, particularly for the development of phenolic compounds-based active packaging and edible films. Moreover, the applications and modes-of-action of phenolic compounds as well as their advantages, limitations, and challenges are discussed to highlight their novelty and efficacy in enhancing the quality and shelf life of food products.     

Hydrogel Emulsion with Encapsulated Safflower Oil Enriched with Açai Extract as a Novel Fat Substitute in Beef Burgers Subjected to Storage in Cold Conditions

This study evaluates the effects of using a fat substitute in beef burgers composed of a hydrogel emulsion enriched with encapsulated safflower oil and açai extract. The influences of the fat substitute on the chemical (TBARS, fatty acids, and volatile compounds profile) and physical (weight loss, cooking loss, water-holding capacity, color, and texture analyses) characteristics of the burgers were analyzed after 0, 4 and 8 days of storage at 4 ± 1 °C. The obtained results were compared with control groups (20 g of tallow or 8 g of safflower oil). The fat substitute used improved burger parameters such as chewiness, hardness and the a* color parameter remained unchanged over storage time. The addition of açai extract slowed the oxidation rate of polyunsaturated fatty acids and reduced the changes in the volatile compounds profile during the storage of burgers. The utilization of a fat substitute enriched the burgers with polyunsaturated fatty acids and lowered the atherogenic index (0.49 raw, 0.58 grilled burger) and the thrombogenicity index (0.8 raw, 1.09 grilled burger), while it increased the hypocholesterolemic/hypercholesterolemic ratio (2.59 raw, 2.09 grilled burger) of consumed meat. Thus, the application of the presented fat substitute in the form of a hydrogel enriched with açai berry extract extended the shelf life of the final product and contributed to the creation of a healthier meat product that met the nutritional recommendations.     

Nutraceutical Potential of Leaf Hydro-Ethanolic Extract of the Edible Halophyte Crithmum maritimum L.

Aromatic halophytes represent an exceptional source of natural bioactive compounds for the food industry. Crithmum maritimum L., also known as sea fennel, is a halophyte plant colonizing cliffs and coastal dunes along Mediterranean and Atlantic coasts. It is well known to produce essential oils and polyphenols endowed with antioxidant and biological effects. The present work reports the phytochemical profile, as well as antioxidant, antimicrobial and antimutagenic properties of C. maritimum leaf hydro-alcoholic extract. From LC-ESI-MS analysis, eighteen phenolic compounds were depicted in sea fennel extract and the amount of total phenolic content exceeds 3% DW. Accordingly, C. maritimum extract showed strong antioxidant activities, as evidenced by in vitro (DPPH, ORAC, FRAP) and ex vivo (CAA-RBC and hemolysis) assays. An important antimicrobial activity against pathogenic strains was found as well as a strong capacity to inhibit Staphylococcus aureus (ATCC 35556) biofilm formation. Sea fennel extracts showed a significant decrease of mutagenesis induced by hydrogen peroxide (H₂O₂) and menadione (ME) in Saccharomyces cerevisiae D7 strain. In conclusion, our results show that C. maritimum is an exceptional source of bioactive components and exert beneficial effects against oxidative or mutagenic mechanisms, and pathogenic bacteria, making it a potential functional food.     

Using freezing and drying techniques of emulsions for the microencapsulation of fish oil to improve oxidation stability

Epidemiological investigations show that n-3-polyunsaturated fatty acids (PUFA) have a protective effect with respect to coronary heart disease. For a long time fish oil has been known as a source of PUFA. The successful incorporation of fish oil into the normal food components offers an opportunity to increase the intake of PUFA, but fish oil has to be protected against oxidation preferably by microencapsulation. The high temperatures during the traditional spray-drying microencapsulation process lead to an increased oxidation of the PUFA. The authors demonstrate the application of a freeze-drying technique with respect to the production of dried microencapsulated fish oil with high quality and oxidation stability. The influence of emulsion parameters, freezing parameters and formulation on the stability of a dried fish oil emulsion is presented and illustrated. The used procedure gave a product with a good oxidation stability which is available as pellets or powder. It was found that the stability was mainly influenced by the freezing rate and the used encapsulation carbohydrate, whereby the powder showed a better shelf life than the pellets. Concluding, it can be summarized that the production of microencapsulated fish oil by freezing and subsequent freeze-drying offers an opportunity to achieve a product with a good oxidation stability.     

Carbon dots enhanced gelatin/chitosan bio-nanocomposite packaging film for perishable foods

Carbon dots(CDs) with intriguing fluorescent property, good biocompatibility, high stability, easy interaction with substrates, are burgeoning carbon nanoparticles with large potential in various applications. Incorporating CDs into the polymer matrix is becoming a popular strategy to endow the complex with new functions. Herein, the green-synthesized CDs was integrated into the mixture of gelatin(derived from waste fish scale) and chitosan, and a multifunctional bio-nanocomposite(defined as Gel...     

Irradiation in combined treatments and food safety

Irradiation combined with other processes can contribute to insuring food safety to consumers and controlling severe losses during transportation and commercialisation. We have demonstrated that using in synergy with other treatments; a lower dose could be used to eliminate pathogenic bacteria and permit a better protection of the sensorial quality and to prolong the shelf life of foods. Results indicated that some bacteria are more sensitive to irradiation under modified atmosphere (MAP) and the presence of active compound can increase the bacterial radiosensitivity by more than 4 times under air and by more than 10 times under MAP. Mild heat treatment or addition of natural antimicrobial compounds before irradiation treatment has also permitted an increase of Bacillus cereus radiosensitization. An increase of the bacterial radiosensitization of 1.5 and 1.56 was respectively observed. The effectiveness of the use of edible coating containing natural antimicrobial compounds, modified atmosphere packaging (MAP) or mild treatment before irradiation treatment was demonstrated in order to inactivate Listeria monocytogenes, Salmonella typhimurium, Escherichia coli and Bacillus cereus growth or B. cereus spore germination, to increase the bacterial sensitivity to irradiation, to reduce the water loss and to extend the shelf life of the food when stored at 4 °C. Also, the use of edible coating previously crosslinked by irradiation have permitted a better control of the active compounds release. Studies of combined treatments were used in ready to eat vegetables, fruits and meat products.     

Characterization of Plant Seeds by Phosphorus-31 Nuclear Magnetic Resonance Spectroscopy

Plant seeds accumulate and store phosphorus for the initial growth of seedlings. Phosphorus speciation by ³¹P nuclear magnetic resonance spectroscopy of NaOH–EDTA seed extracts showed that P was mainly present in organic forms such as phytate and α- and β-glycerophosphate in poppy, sesame, mustard, fennel, and cumin seeds. The inorganic P forms present included orthophosphate and pyrophosphate. The highest concentration of orthophosphate was found in NaOH–EDTA extracts of fennel seeds (41.7%) and the lowest in mustard (9.3%) and sesame seeds (6.9%). For the organic P forms, the highest concentration of phytate was found in mustard seeds (85.2%) and the lowest in fennel seeds (43.3%). Other organic P forms detected were α- and β-glycerophosphate ranging from 1.2 to 5.1% and 0.7 to 2.1%, respectively. Pyrophosphate was detected in trace amounts only in fennel (0.7%) and poppy seeds (0.5%). The only orthophosphate diester observed was in sesame seeds at a low concentration (0.7%), while phosphonates and polyphosphates were not present in any seeds. Phytate was the most dominant P form in all seeds except for fennel and cumin, which contained the lowest phytate concentration but the highest orthophosphate and glycerophosphate concentrations. These results suggest that P transferred from the plant vegetative parts to the developing seeds during maturation is converted to phytate (organic P) in addition to being stored as orthophosphate (inorganic P).     

Effect of ionizing energy on extracts of Quillaja saponaria to be used as an antimicrobial agent on irradiated edible coating for fresh strawberries

Incorporating antimicrobial compounds into edible films or coatings provides a novel way to improve the safety and shelf life of ready-to-eat foods. Diverse studies with Quillaja saponaria Mol. (popularly named quillay) extracts have demonstrated their potential as antifungal agents against phytopathogenic fungi. Crosslinking induced by ionizing radiation is an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on milk proteins. However there are few reports about the effects of γ-radiation on plant extracts. The aim of this work was to evaluate the effect of ionizing radiation (0, 5, 10, 15, 20, 25 and 35 kGy) on extracts prepared from in vitro plants of Q. saponaria to be used as antimicrobial agent in irradiated edible coating based on calcium caseinate and whey protein isolated, and also to establish the concentration of Q. saponaria extract to be added as an antifungal agent in the coating. Gamma irradiation since 15 kGy affects negatively the antimicrobial activity and metabolites composition of extract of Q. saponaria by reducing compounds of phenolic nature. Otherwise no effect on saponins profile was observed even at higher doses. It was possible to conclude that the antifungal activity of Q. saponaria extract is mainly related to phenolic compounds content. In addition, our work also shows that to obtain an efficient antifungal protection is necessary to add a minimum concentration of 6% of the extract after the coating irradiation.     

Antibacterial and Antiparasitic Activity of Propyl-Propane-Thiosulfinate (PTS) and Propyl-Propane-Thiosulfonate (PTSO) from Allium cepa against Gilthead Sea Bream Pathogens in In Vitro and In Vivo Studies

The use of phytogenic extracts is considered a sustainable strategy for the prevention of fish diseases, including Alliaceae as a potential option due to their variety of bioactive compounds. In this study, we analyzed the antibacterial and antiparasitic potential of propyl-propane-thiosulfinate (PTS) and propyl-propane-thiosulfonate (PTSO) from onions. The in vitro activity against Pseudomonas anguilliseptica, Tenacibaculum maritimum, and Photobacterium damselae of both compounds was tested. In addition, the viability of Sparicotyle chrysophrii larvae was evaluated. Moreover, a diet that consisted of a blend of PTS/PTSO (ALLIUM) was used. A total of 90 gilthead sea bream juveniles were tested against P. damselae subsp. Piscicida after 12 weeks of dietary administration. Furthermore, 150 fish with a rate of 10–15 parasites/fish were fed for 21 days and the number of gill parasites was recorded. All strains were sensitive to both compounds. PTSO showed the highest inhibitory effect against all target strains, while PTS showed higher effectiveness against S. chrysophrii. Fish from ALLIUM group presented the highest probability of survival, increasing up to 91.1%, whereas in the control group, the probability of survival was 66.7%. The number of parasites in the gilthead sea bream decreased in the ALLIUM group over time. These results suggest the inclusion of PTS and PTSO in feed as a natural strategy to prevent antibacterial and antiparasitic fish diseases.     

Propolis Integration Methods into Solutions for Highly Loaded Propolis Fibers by Needleless Electrospinning

A load-bearing matrix filled with biologically active compounds is an efficient method for transporting them to the target location. Bee-made propolis has long been known as a natural product with antibacterial and antiviral, anti-inflammatory, antifungal properties, and anti-oxidative activity. The aim of the research is to obtain stable propolis/PVA solutions and produce fibers by electrospinning. To increase propolis content in fibers as much as possible, various types of propolis extracts were used. As a result of the research, micro- and nano-fiber webs were obtained, the possible use of which have biomedical and bioprotective applications. All used materials are edible and safe for humans, and fiber webs were prepared without using any toxic agent. This strategy overcomes propolis processing problems due to limitations to its solubility. The integration of different combinations of extracts allows more than 73 wt% of propolis to be incorporated into the fibers. The spinning solution preparation method was adapted to each type of propolis, and by combining the methods, solutions with different propolis extracts were obtained. Firstly, the total content of flavonoids in the propolis extracts was determined for the assessment and prediction of bioactivity. The properties of the extracts relevant for the preparation of electrospinning solutions were also evaluated. Secondly, the most appropriate choice of PVA molecular weight was made in order not to subject the propolis to too high temperatures (to save resources and not reduce the bioactivity of propolis) during the solution preparation process and to obtain fibers with the smallest possible diameter (for larger surface-to-volume ratios of nanofibers and high porosity). Third, electrospinning solutions were evaluated (viscosity, pH, conductivity and density, shelf life) before and after the addition of propolis to predict the maximum propolis content in the fibers and spinning stability. Each solution combination was spun using a cylindrical type electrode (suitable for industrial production) and tested for a stable electrospinning process. Using adapted solution-mixing sequences, all the obtained solutions were spun stably, and homogeneous fibers were obtained without major defects.     

Development of bioactive coatings based on γ-irradiated proteins to preserve strawberries

Gamma irradiation was applied for creating cross-linked proteins to enhance the physicochemical properties of edible films made of calcium caseinate, whey protein isolate and glycerol. The characteristics of γ irradiated cross-linked proteins were analyzed by Fourier Transform Infrared spectroscopy. A second derivative spectra exhibited changes in band intensities that were correlated to an increase of β-sheet structure and a decrease of α-helix and unordered fractions of γ irradiated-cross-linked proteins as compared to the control without irradiation. Furthermore, on addition of methylcellulose to the irradiated protein matrix it was found that it has potential in enhancing the puncture strength and has no detrimental effect on water vapor permeability of protein based films. Finally, these film formulations were used as bioactive edible coatings containing natural antimicrobial agents (limonene and peppermint) to preserve the shelf life of fresh strawberries during storage. The bioactive coatings containing peppermint was found to be more efficient as preserving coatings than the formulations containing limonene. Irradiated proteins/methylcellulose/peppermint formulation had only 40% of decay at day 8 while it was 65% for the control.     

Ultrasound-Assisted Extraction of Anthocyanins Using Natural Deep Eutectic Solvents and Their Incorporation in Edible Films

Extracts rich in bioactive compounds added to edible films have allowed the development of active packaging that increases the shelf life of food. However, it is necessary to search for solvents that are nontoxic and not harmful to the environment, with natural deep eutectic solvents (NADES) being an attractive and easily synthesized alternative. This research aimed to design NADES by lyophilization to be used in the extraction of anthocyanins from the Chilean Luma chequen (Molina) A. Gray berry, and subsequently adding them to the matrix of edible ƙ-carrageenan films. For this purpose, ultrasound-assisted extraction (UAE) was used and the anthocyanin content was evaluated with the pH differential method. The antioxidant capacity of extracts was determined by DPPH assay and the antibacterial capacity by diffusion agar tests. The results obtained indicate that the designed NADES are efficient at extracting anthocyanins, reaching concentrations between 81.1 and 327.6 mg eq cyanidin 3-glucoside/100 g dw of L. chequen (Molina) A. Gray. The extracts reached inhibition diameters between 5 and 34 mm against Escherichia coli, Staphylococcus aureus, and Salmonella typhi strains. Once the extracts were incorporated into ƙ-carrageenan films, active edible films with antioxidant and antibacterial capacities were obtained.     

Impacts of Gum Arabic and Polyvinylpyrrolidone (PVP) with Salicylic Acid on Peach Fruit (Prunus persica) Shelf Life

Peaches are grown in many Egyptian orchards for local and global fresh market sales. The interior fruit tissue breakdown (IFTB), often resulting in decayed peaches, is a severe problem during marketing. Therefore, to minimize FTB of peaches, in this study, gum arabic (GA) and polyvinylpyrrolidone (PVP) were mixed with different concentrations of salicylic acid (SA) (0, 1, and 2 mM) and were applied as edible coating to extend the shelf life of peach fruits. Mature peaches were selected and harvested when peaches reached total soluble solid content (SSC: 8.5%) and fruit firmness of about 47 N. Fruits were coated and stored at room temperature (26 ± 1 °C and air humidity 51 ± 1%) for 10 days during two seasons: 2020 and 2021. Fruit coated with GA/PVP-SA 2 mM showed a significant (p < 0.05) inhibition in degrading enzyme activities (CWDEs), such as lipoxygenase (LOX), cellulase (CEL), and pectinase (PT), compared to uncoated and coated fruits during the shelf-life period. Hence, cell wall compartments were maintained. Consequently, there was a reduction in browning symptoms in fruits by inhibiting polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) activities. Thus, the fruit skin browning index showed almost no symptoms. The lipid peroxidation process and ionic permeability declined as well. The result suggests that, by applying GA/PVP-SA 2 mM as an edible coating, fruit tissue breakdown can be minimized, and the shelf life of peach can be extended up to 10 days without symptoms of tissue breakdown.     

Volatile fraction of lavender and bitter fennel infusion extracts

The relative proportions of chemical classes (hydrocarbons, oxides, alcohols/ethers, aldehydes/ketones, acids/esters/lactones) in the essential oil of lavender (Lavendula angustifolia Mill., family Lamiaceae) and bitter fennel (Foeniculum vulgare Mill. subsp. vulgare var. vulgare (Mill.) Thellung, family Apiaceae) and in the volatile fraction of infusion extracts were examined and showed remarkable differences. The volatile compounds of infusions were isolated by hydrodistillation and solid phase extraction (SPE). Their qualitative and semiquantitative compositions were compared with the essential oil isolated by hydrodistillation directly from the plant material and analyzed by GC-MS. Furthermore, quantification of the major constituents of lavender oil and of the volatile fraction obtained by hydrodistillation of the infusion was performed. Comparison of the total essential oil yield quantified by hydrodistillation of the lavender infusion (0.7% v/w, corresponding to plant material) with the essential oil yield of the blossoms (5.1% v/w) revealed that only 13.9% of the initial oil could be extracted by infusion. The main constituents of the volatile fraction of the lavender infusion were (hydrodistillation/SPE): linalool (39.3%/28.2%), 1,8 cineole (24.8%/18.9%), cis-linalool oxide (furanoid) (5.8%/8.0%), trans-linalool oxide (furanoid) (4.1%/7.1%), camphor (5.3%/4.0%) and alpha-terpineol (4.0%/3.0%). The major constituents of lavender essential oil were linalool (28.8%), 1,8-cineole (18.05%), linalyl acetate (13.9%) and alpha-terpineol (4.0%). Most intriguing, in the volatile fraction of lavender infusion a significant proportional decrease of linalyl acetate and an increase of linalool oxides was recognized. The essential oil yield of fennel fruits was 12.5% v/w, whereas 1.8% v/w volatile fraction (corresponding to plant material) was obtained by hydrodistillation of the fennel infusion, which is equivalent to 14.5% of the initial fennel essential oil. The main constituents of the volatile fraction of the fennel infusion were (hydrodistillation/SPE): trans-anethole (56.4%/54.8%), fenchone (36.2%/39.5%) and estragole (2.5%/2.2%), which were also the major compounds of the genuine bitter fennel essential oil. In infusions, the proportion of ethers vs. ketones was shifted significantly towards a higher proportion of the latter compared with the essential oil obtained from the fruits.     

Photodegradable transient bilayered poly(phthalaldehyde) with improved shelf life

Metastable poly(phthalaldehyde) (PPHA) can be triggered to depolymerize under visible light by incorporation of photosensitive compounds, such as a photoacid generator (PAG), which can generate a strong acid in situ. However, photosensitive compounds can be thermally unstable and have limited shelf life, causing inadvertent device triggering. It can also be difficult to fabricate components that are photosensitive because special lighting conditions are needed. In this paper, nonphotosensitive PPHA films were formed and made photosensitive at the point of use. This improved the material shelf life and manufacturability by adding a second, PAG‐containing layer to the original nonphotosensitive layer at an optimal point before use. The catalytic photoacid was generated rapidly by exposure of the PAG‐containing layer to radiation. Depolymerization of PPHA via the acid catalyst was followed by diffusion of the acid into the nonphotosensitive layer causing it to depolymerize. Diffusion of the photoacid into the nonphotosensitive medium was quantified at various temperatures. Photoacid diffusion in a liquid, moving‐front caused depolymerization of the nonphotosensitive PPHA layer. The fabricated bilayer structure allowed for better stability of the structural material using PPHA while still achieving transience.     

Rancimat and PDSC accelerated techniques for evaluation of oxidative stability of soybean oil with plant extracts

Taking into account the importance of natural antioxidants in the preservation of oils and fats, the present study evaluated the antioxidant action of five plant extracts in the control of soybean oil stability, by means of the accelerated techniques Rancimat and PDSC. These plants are rosemary (Rosmarinus officinalis L.), chamomile (Matricaria recutita L.), coriander (Coriandrum sativum L.), fennel (Foeniculum vulgare), and senna (Cassia angustifolia Vahl). The plant extracts and also the synthetic antioxidant BHT were added to the samples of crude soybean oil at the concentration of 1,000 mg kg^?1. The values of total phenolic contents ranged from 8.7 ± 0.4 to 63.0 ± 2.3 mg GAE g^?1 extract and a strong positive correlation was observed between the total phenolic contents and the overall antioxidant activity of the plant extracts. Such high values indicate a good protection of the analyzed soybean oil, moreover for the Rosemary extract that was superior to the remaining extracts. In the Rancimat technique the rosemary extract was more effective than the synthetic BHT antioxidant. The OIT values of Rosemary extract and the BHT antioxidant were equivalent, and the former, showed the highest phenolic contents among the extracts, for all the performed tests, confirming that it is a powerful natural source of antioxidants.     

Two-dimensional HPLC coupled to ICP-MS and electrospray ionisation (ESI)-MS/MS for investigating the bioavailability in vitro of arsenic species from edible seaweed

Edible seaweed consumption is a route of exposure to arsenic. However, little attention has been paid to estimate the bioaccessibility and/or bioavailability of arsenosugars in edible seaweed and their possible degradation products during gastrointestinal digestion. This work presents first use of combined inductively coupled plasma mass spectroscopy (ICP-MS) with electrospray ionization tandem mass spectrometry (ESI-MS/MS) with two-dimensional HPLC (size exclusion followed by anion exchange) to compare the qualitative and quantitative arsenosugars speciation of different edible seaweed with that of their bioavailable fraction as obtained using an in vitro gastrointestinal digestion procedure. Optimal extraction conditions for As species from four seaweed namely kombu, wakame, nori and sea lettuce were selected as a compromise between As extraction efficiency and preservation of compound identity. For most investigated samples, the use of ammonium acetate buffer as extractant and 1 h sonication in a water bath followed by HPLC-ICP-MS resulted in 40–61% of the total As to be found in the buffered aqueous extract, of which 86–110% was present as arsenosugars (glycerol sugar, phosphate sugar and sulfonate sugar for wakame and kombu and glycerol sugar and phosphate sugar for nori). The exception was sea lettuce, for which the arsenosugar fraction (glycerol sugar, phosphate sugar) only comprised 44% of the total extracted As. Interestingly, the ratio of arsenobetaine and dimethylarsinic acid to arsenosugars in sea lettuce extracts seemed higher than that for the rest of investigated samples. After in vitro gastrointestinal digestion, approximately 11–16% of the total As in the solid sample was found in the dialyzates with arsenosugars comprising 93–120% and 41% of the dialyzable As fraction for kombu, wakame, nori and sea lettuce, respectively. Moreover, the relative As species distribution in seaweed-buffered extracts and dialyzates was found to be very similar. Collection of specific fractions from the size-exclusion column to be analysed using anion-exchange HPLC-ESI-MS/MS enabled improved chromatographic selectivity, particularly for the less retained arsenosugar (glycerol sugar), facilitating confirmation of the presence of arsenosugars in seaweed extracts and dialyzates. Using this approach, the presence of arsenobetaine in sea lettuce samples was also confirmed.     

Application of Polyfolates in the Development of Electrochemical Glucose Biosensors

Folic acid was polymerised electrochemically at a glassy carbon electrode surface from 0.1 mol L^?1 phosphate buffer saline solution, pH 5.0, containing 0.1 mmol L^?1 monomer. The obtained thin film was porous with a pore size of 50–60 nm. Since its electrochemical stability was rather short, the polyfolate film was covered with a graphene‐chitosan composite layer which increased its stability significantly. The best strategy to immobilise the enzyme was crosslinking with glutaraldehyde. The lifetime of this glucose biosensor in use was at least 12 days, on‐shelf life time was at least 30 days. The linear range was up to 1 mmol L^?1 and the LOD was 0.6 µmol L^?1. The first polyfolate‐based biosensor was applied to analysis of natural samples.     

Oral delivery of therapeutic proteins bioencapsulated in plant cells: Preclinical and clinical advances

Oral delivery of protein drugs (PDs) made in plant cells could revolutionize current approaches to their production and delivery. Expression of PDs reduces their production cost by elimination of prohibitively expensive fermentation, purification, cold transportation/storage, and sterile injections and increases their shelf life for several years. The ability of plant cell wall to protect PDs from digestive acids/enzymes, commensal bacteria to release PDs in gut lumen after lysis of plant cell wall, and the role of gut-associated lymphoid tissue in inducing tolerance facilitate prevention or treatment of allergic, autoimmune diseases or antidrug antibody responses. The delivery of functional proteins facilitates treatment of inherited or metabolic disorders. Recent advances in making PDs free of antibiotic resistance genes in edible plant cells, long-term storage at ambient temperature maintaining their efficacy, production in Current Good Manufacturing Practice (cGMP) facilities, Investigational New Drug (IND)-enabling studies for clinical advancement, and Food and Drug Administration approval of orally delivered PDs augur well for advancing this novel drug delivery platform technology.