In Vitro Evaluation of the Adsorption Efficacy of Biochar Materials on Aflatoxin B1, Ochratoxin A, and Zearalenone.

Mycotoxin sequestration materials are important tools to reduce mycotoxin illness and enable proper handling of mycotoxin-contaminated commodities. Three food-grade bentonite clays and four generally recognized as safe (GRAS) charcoal/biochar carbon materials that are marketed as feed additives and supplements were evaluated for their ability to sequester the mycotoxins aflatoxin B1, ochratoxin A, and zearalenone. The surface area of the clays varied between 32.1 to 51.4 mg2/g, and the surface area of the carbon-based materials varied from 1.7 to 1735 mg2/g. In vitro, gastric fluid studies indicated that certain pine biochar and activated coconut charcoal could sequester high amounts (85+%) of the mycotoxins at 1 ppm levels or below. However, some biochar materials with lower surface area properties lacked binding capacity. The coconut shell charcoal and pine biochar utilize agricultural waste products in a manner that significantly reduces carbon emissions and provides valuable materials to minimize exposure to toxins found in food and feed.

Biophysical characterization of α-glucan nanoparticles encapsulating feruloylated soy glycerides (FSG).

Water insoluble α-glucans that were enzymatically synthesized using glucansucrase that was cloned from Leuconostoc mesenteroides NRRL B-1118 were previously shown to form nanoparticles via high pressure homogenization. These α-glucan nanoparticles were previously shown capable of encapsulating a small hydrophobic molecule. This work demonstrates that the same α-glucan can be formed into nanoparticles that encapsulate feruloylated soy glycerides from modified soybean oil, a product of interest to the cosmetic and skin care industries because of the UV absorbance and antioxidant properties of the feruloyl moiety. It is demonstrated that the feruloylated soy glyceride/α-glucan nanoparticles have distinct size, zeta potential and thermal profiles from that of nanoparticles made from α-glucan alone or feruloylated soy glyceride alone. Thermal analysis also demonstrates the release of feruloylated soy glycerides from the α-glucan nanoparticles.

When Machine Learning and Deep Learning Come to the Big Data in Food Chemistry.

Since the first food database was released over one hundred years ago, food databases have become more diversified, including food composition databases, food flavor databases, and food chemical compound databases. These databases provide detailed information about the nutritional compositions, flavor molecules, and chemical properties of various food compounds. As artificial intelligence (AI) is becoming popular in every field, AI methods can also be applied to food industry research and molecular chemistry. Machine learning and deep learning are valuable tools for analyzing big data sources such as food databases. Studies investigating food compositions, flavors, and chemical compounds with AI concepts and learning methods have emerged in the past few years. This review illustrates several well-known food databases, focusing on their primary contents, interfaces, and other essential features. We also introduce some of the most common machine learning and deep learning methods. Furthermore, a few studies related to food databases are given as examples, demonstrating their applications in food pairing, food-drug interactions, and molecular modeling. Based on the results of these applications, it is expected that the combination of food databases and AI will play an essential role in food science and food chemistry.

Resilience of Chemistry: An Introduction to the Agricultural and Food Chemistry Technical Program at the 262nd American Chemical Society National Hybrid Meeting & Exposition, Both Online and in Atlanta, Georgia.

This is the third special issue of the Journal of Agricultural and Food Chemistry (JAFC) based on the Agricultural and Food Chemistry Division (AGFD) technical program, at the 262nd American Chemical Society National Meeting. This was the first national meeting held in a hybrid format, both virtually and in-person in Atlanta, Georgia, U.S.A., on August 22-26, 2021. The AGFD proudly hosted 12 symposia, including three award symposia. There were 34 sessions held in total, with 143 oral presentations and 49 poster presentations. This meeting was highly successful in terms of attendance, and technology issues experienced at the previous virtual meetings were successfully resolved.

Raman spectral analysis for rapid determination of zearalenone and alpha-zearalanol.

Mycotoxins, including zearalenone, are important natural products produced by fungi that occasionally contaminate agricultural commodities and pose serious health risks to consumers of food and feed. Zearalenone and its metabolite, α-zearalanol, are of significant concern due to their estrogenic and anabolic steroid activity. Several governments have regulatory standards and advisory guidelines for zearalenone and α-zearalanol. Raman and ultraviolet spectroscopy were employed with density functional theory methods to evaluate spectroscopic properties to distinguish between zearalenone and α-zearalanol systematically. Raman bands were assigned based on vibrational frequency calculations. A portable Raman spectroscopy instrument (785 nm laser) distinguished between zearalenone and α-zearalanol in a label-free manner. Many vibrational bands of zearalenone and α-zearalanol are similar, including high-intensity peaks at 1315 cm-1 and 1650 cm-1. However, the intensities in the Raman spectra at 1465 cm-1, 1495 cm-1, and 1620 cm-1 enabled the identification of zearalenone. The Raman peak at 1450 cm-1 is associated with α-zearalanol. These vibrational bands serve as spectral indicators to differentiate between the structurally similar zearalenone and α-zearalanol.

Predictive Quantitative Structure-Activity Relationship Modeling of the Antifungal and Antibiotic Properties of Triazolothiadiazine Compounds.

Predictive models were developed using two-dimensional quantitative structure activity relationship (QSAR) methods coupled with B3LYP/6-311+G** density functional theory modeling that describe the antimicrobial properties of twenty-four triazolothiadiazine compounds against Aspergillus niger, Aspergillus flavus and Penicillium sp., as well as the bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. B3LYP/6-311+G** density functional theory calculations indicated the triazolothiadiazine derivatives possess only modest variation between the frontier orbital properties. Genetic function approximation (GFA) analysis identified the topological and density functional theory derived descriptors for antimicrobial models using a population of 200 models with one to three descriptors that were crossed for 10,000 generations. Two or three descriptor models provided validated predictive models for antifungal and antibiotic properties with R 2 values between 0.725 and 0.768 and no outliers. The best models to describe antimicrobial activities include descriptors related to connectivity, electronegativity, polarizability, and van der Waals properties. The reported method provided robust two-dimensional QSAR models with topological and density functional theory descriptors that explain a variety of antifungal and antibiotic activities for structurally related heterocyclic compounds.

Pseudoflowers produced by Fusarium xyrophilum on yellow-eyed grass (Xyris spp.) in Guyana: A novel floral mimicry system?

Pseudoflower formation is arguably the rarest outcome of a plant-fungus interaction. Here we report on a novel putative floral mimicry system in which the pseudoflowers are composed entirely of fungal tissues in contrast to modified leaves documented in previous mimicry systems. Pseudoflowers on two perennial Xyris species (yellow-eyed grass, X. setigera and X. surinamensis) collected from savannas in Guyana were produced by Fusarium xyrophilum, a novel Fusarium species. These pseudoflowers mimic Xyris flowers in gross morphology and are ultraviolet reflective. Axenic cultures of F. xyrophilum produced two pigments that had fluorescence emission maxima in light ranges that trichromatic insects are sensitive to and volatiles known to attract insect pollinators. One of the volatiles emitted by F. xyrophilum cultures (i.e., 2-ethylhexanol) was also detected in the head space of X. laxifolia var. iridifolia flowers, a perennial species native to the New World. Results of microscopic and PCR analyses, combined with examination of gross morphology of the pseudoflowers, provide evidence that the fungus had established a systemic infection in both Xyris species, sterilized them and formed fungal pseudoflowers containing both mating type idiomorphs. Fusarium xyrophilum cultures also produced the auxin indole-3-acetic acid (IAA) and the cytokinin isopentenyl adenosine (iPR). Field observations revealed that pseudoflowers and Xyris flowers were both visited by bees. Together, the results suggest that F. xyrophilum pseudoflowers are a novel floral mimicry system that attracts insect pollinators, via visual and olfactory cues, into vectoring its conidia, which might facilitate outcrossing of this putatively heterothallic fungus and infection of previously uninfected plants.

Development and Physical Characterization of α-Glucan Nanoparticles.

α-Glucans that were enzymatically synthesized from sucrose using glucansucrase cloned from Leuconostoc mesenteroides NRRL B-1118 were found to have a glass transition temperature of approximately 80 °C. Using high-pressure homogenization (~70 MPa), the α-glucans were converted into nanoparticles of ~120 nm in diameter with a surface potential of ~-3 mV. Fluorescence measurements using 1,6-diphenyl-1,3,5-hexatriene (DPH) indicate that the α-glucan nanoparticles have a hydrophobic core that remains intact from 10 to 85 °C. α-Glucan nanoparticles were found to be stable for over 220 days and able to form at three pH levels. Accelerated exposure measurements demonstrated that the α-glucan nanoparticles can endure exposure to elevated temperatures up to 60 °C for 6 h intervals.

Changing the Landscape: An Introduction to the Agricultural and Food Chemistry Technical Program at the 258th American Chemical Society National Meeting in San Diego.

This special issue of the Journal of Agricultural and Food Chemistry (JAFC) is a highlight of the Agricultural and Food Chemistry Division (AGFD) technical program at the 258th National Meeting of the American Chemical Society (ACS) in San Diego, CA, U.S.A., on August 25-29, 2019. At the conference, AGFD had 44 oral sessions at 19 symposia and 100 poster presentations with more than 400 abstract submissions. The technical program covered a broad range of current research and development topics in agricultural and food chemistry, including bioactive food components, diet and human nutrition, utilization of agricultural materials in food systems, food packaging, nanotechnology, and food safety, as well as several special award symposia. This is the first JAFC special issue that highlights an ACS national meeting program with joint efforts from AGFD.

Enzymatic Synthesis and Flash Chromatography Separation of 1,3-Diferuloyl-sn-Glycerol and 1-Feruloyl-sn-Glycerol.

Ethyl ferulate was transesterified with Enova Oil (a soy-based vegetable oil containing 80-85% diacylglycerol) using Novozym 435 at 60 °C. The resultant feruloylated vegetable oil reaction product produced a precipitate (96.4 g, 4.02 wt%) after 7 d of standing at room temperature. Preliminary characterization of the precipitate identified the natural phenylpropenoids 1,3-diferuloyl-sn-glycerol (F2G) and 1-feruloyl-sn-glycerol (FG) as the major components. A flash chromatography method was developed and optimized (e.g., mass of sample load, flow rate, binary solvent gradient slope, and separation run length) using a binary gradient of hexane and acetone mobile phase and silica gel stationary phase to separate and isolate F2G and FG. The optimized parameters afforded F2G (1.188 ± 0.052 g, 39.6 ± 1.7%) and FG (0.313 ± 0.038 g, 10.4 ± 1.3%) from 3.0 g of the transesterification precipitate, n = 10 trials. Overall, all flash chromatography separations combined, F2G (39.1 g, 40.6%) and FG (9.4 g, 9.8%) were isolated in a combined yield of 48.5 g (51.4%), relative to the 96.4 g of transesterification precipitate collected. The optimized flash chromatography method was a necessary improvement over previously reported preparative HPLC and column chromatography methods used to purify milligram to low gram quantities of F2G and FG to be able to process ~100 g of material in a timely, efficient manner.

Rapid Raman spectroscopic determination of 1-feruloyl-sn-glycerol and 1,3-diferuloyl-sn-glycerol.

Ferulic acid and its derivatives are important natural products found throughout the plant kingdom and are of special interest due to their health benefits. 1-Feruloyl-sn-glycerol (FG) and 1,3-diferuloyl-sn-glycerol (F2G) are two common bioproducts of ferulic acid that co-occur in nature and during the biocatalytic production of feruloylated lipids. In this paper, we report a comprehensive characterization of FG and F2G using Raman and UV spectroscopies and theoretical density functional theory calculations at the B3LYP/6-311+G** level. UV spectroscopy produced spectra for FG and F2G with similar peak shape, but difference intensities. The vibrational frequency calculations aided in the assignment of the Raman bands. The Raman analysis demonstrates that Raman spectroscopy is a rapid label free method to clearly distinguish between FG and F2G.

Charged phospholipid effects on AAPH oxidation assay as determined using liposomes.

The capacity of molecules to inhibit oxidation is widely tested using liposomes as host matrices of the antioxidant molecule of interest. Spectroscopic assays are readily used for this purpose, specifically assays using 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH). In this work the effect that charged lipids have on an AAPH antioxidation assay using 4,4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-undecanoic acid (C11-BODIPY® 581/591) as the reporter molecule was investigated. We measured the diameter, zeta potential and spectroscopic rate of decay and area-under-the-curve (AUC) associated with liposomes containing C11-BODIPY® 581/591 at varying molar percentages (0-10 mol%) of charged (cationic or anionic) lipids and compared the results. We showed that although increasing amounts of cationic or anionic lipids did change the diameter of the liposomes, size had little to no effect on the area-under-the-curve or decay rate of fluorescence. Increased (more positive) or decreased (more negative) zeta potentials did, on the other hand, affect the spectroscopic decay rates and area-under-the-curve. The results demonstrate the importance of considering the presence of charged lipids in the AAPH antioxidation assay.

Determination of pH Effects on Phosphatidyl-Hydroxytyrosol and Phosphatidyl-Tyrosol Bilayer Behavior.

A robust method was developed to investigate the liposomal behavior of novel enzymatically-synthesized hydroxytyrosol and tyrosol phospholipids. Bilayer characteristic obtained by this method, including bilayer formation stability and adsorption properties, were explored using dynamic light scattering, zeta-potential measurements, and quartz crystal microbalance with dissipation monitoring (QCMD), respectively. Liposome diameters were found to typically increase from pH 5.5 to pH 10. Zeta potentials values, on the other hand, were found to be well below -25 mV at all pH conditions explored, with the lowest values (and thus, the best liposome stability) at pH 5.5 or pH 10. Quartz crystal microbalance with dissipation monitoring measurements demonstrated that 100% 1,2-dioloeoylphosphatidyl-hydroxytyrosol (DOPHT) liposomes adsorbed intact onto silica in buffer conditions at pH 5.5 and with no calcium, or at pH 7.5 with calcium (no adsorption was detected at pH 10). 1,2-Dioleoylphosphatidyl-tyrosol (DOPT) liposomes were shown to adsorb intact under buffer conditions only at pH 5.5 with and without calcium. 1,2-Dioleoylphosphatidyl-2-phenolethanol (DOPPE), in comparison, readily adsorbed intact at pH 7.5 without calcium and just slightly at pH 5.5 with calcium present, but formed a supported bilayer over hours at pH 5.5 in the absence of calcium ions.

Experimental and theoretical study of the influence of water on hydrolyzed product formation during the feruloylation of vegetable oil.

BACKGROUND: Feruloylated vegetable oil is a valuable green bioproduct that has several cosmeceutical applications associated with its inherent anti-oxidant and ultraviolet-absorption properties. Hydrolyzed vegetable oil by-products can influence product quality and consistency. RESULTS: The formation of by-products by residual water in the enzymatic synthesis of feruloylated vegetable oil was investigated using chemical theory and experimental studies by monitoring the reaction over a 22-day period. The hydrolysis of vegetable oil is thermodynamically favored over the hydrolysis of the ethyl ferulate starting material. These results suggest that hydrolyzed vegetable oil products will be experimentally observed in greater concentrations compared to hydrolyzed ethyl ferulate products. CONCLUSION: Quantum chemical studies identified several reaction mechanisms that explain the formation of side products by water, suggesting that residual water influences product quality. Efforts to reduce residual water can improve product consistency and reduce purification costs. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Mycotoxin Analysis Using Imprinted Materials Technology: Recent Developments.

Molecular imprinting technology is an attractive, cost-effective, and robust alternative to address the limitations of highly selective natural receptors, such as antibodies and aptamers. The field of molecular imprinting has seen a recent surge in growth, and several commercially available products are of great interest for sample cleanup to improve mycotoxin analysis. Current research trends are in specific applications of imprinting technology for small-molecule sensing and chromatographic cleanup procedures in new commodities. The choice of components and imprinting template are critical factors for mycotoxin recovery or detection optimization. Template mimics offer a means to reduce toxic exposure during polymer synthesis and address issues of leaching template from the imprinted polymer. Recent reports of molecularly imprinted polymers for aflatoxins, ochratoxins, fumonisins, fusaric acid, citrinin, patulin, zearalenone, deoxynivalenol, and T-2 toxin are reviewed.

Feruloyl glycerol and 1,3-diferuloyl glycerol antioxidant behavior in phospholipid vesicles.

Feruloyl-sn-glycerol (FG) and 1,3-diferuloyl-sn-glycerol (F2G), the by-product of biocatalytic transesterification soybean oil and ethyl ferulate, were examined for their behavior in phospholipid vesicles. Based on absorbance and fluorescence methods, FG and F2G both were found to partition into vesicles and incorporate well into 1,2-dioleoylphosphocholine (DOPC) vesicles. FG and F2G incorporation resulted in vesicles that were as or slightly more stable than the unloaded vesicles. FG and F2G both demonstrated the ability to maintain antioxidant properties within the lipid bilayer. Bilayer depth analysis was conducted using the parallax method and molecular modeling.

Octadecyl ferulate behavior in 1,2-Dioleoylphosphocholine liposomes.

Octadecyl ferulate was prepared using solid acid catalyst, monitored using Supercritical Fluid Chromatography and purified to a 42% yield. Differential scanning calorimetry measurements determined octadecyl ferulate to have melting/solidification phase transitions at 67 and 39°C, respectively. AFM imaging shows that 5-mol% present in a lipid bilayer induced domains to form. Phase behavior measurements confirmed that octadecyl ferulate increased transition temperature of phospholipids. Fluorescence measurements demonstrated that octadecyl ferulate stabilized liposomes against leakage, maintained antioxidant capacity within liposomes, and oriented such that the feruloyl moiety remained in the hydrophilic region of the bilayer. Molecular modeling calculation indicated that antioxidant activity was mostly influenced by interactions within the bilayer.

Microwave-assisted synthesis of cyclodextrin polyurethanes.

Cyclodextrin (CD) has often been incorporated into polyurethanes in order to facilitate its use in encapsulation or removal of organic species for various applications. In this work a microwave-assisted method has been developed to produce polyurethanes consisting of α-, ß-, and γ-CD and three common diisocyanates. As compared to conventional heating, this new synthetic method saves energy, significantly reduces reaction time, and gets similar or improved yield. The reaction products have been fully characterized with (13)C, (1)H, and two-dimensional NMR spectroscopy. With suitable stoichiometry of starting CD and diisocyanate, the resulting CD polyurethane is organic-soluble and water-insoluble and is shown to remove Nile red dye and phenol from water. Possible applications include the removal of undesirable materials from process streams, toxic compounds from the environment, and encapsulation of color or fragrance molecules.

Assessment of the electronic structure and properties of trichothecene toxins using density functional theory.

A comprehensive quantum chemical study was carried out on 35 type A and B trichothecenes and biosynthetic precursors, including selected derivatives of deoxynivalenol and T-2 toxin. Quantum chemical properties, Natural Bond Orbital (NBO) analysis, and molecular parameters were calculated on structures geometry optimized at the B3LYP/6-311+G** level. Type B trichothecenes possessed significantly larger electrophilicity index compared to the type A trichothecenes studied. Certain hydroxyl groups of deoxynivalenol, nivalenol, and T-2 toxin exhibited considerable rotation during molecular dynamics simulations (5 ps) at the B3LYP/6-31G** level in implicit aqueous solvent. Quantitative structure activity relationship (QSAR) models were developed to evaluate toxicity and detection using genetic algorithm, principal component, and multilinear analyses. The models suggest electronegativity and several 2-dimensional topological descriptors contain important information related to trichothecene cytotoxicity, phytotoxicity, immunochemical detection, and cross-reactivity.

Determination of fusaric acid in maize using molecularly imprinted SPE clean-up.

A new LC method to detect fusaric acid (FA) in maize is reported based on a molecularly imprinted SPE clean-up using mimic-templated molecularly imprinted polymers. Picolinic acid was used as a toxin analog for imprinting polymers during a thermolytic synthesis. Both acidic and basic functional monomers were predicted to have favorable binding interactions by MP2 ab initio calculations. Imprinted polymers synthesized with methacrylic acid or 2-dimethylaminoethyl methacrylate exhibited imprinting effects in SPE analysis. FA levels were determined using RP ion-pairing chromatography with diode-array UV detection and tetrabutylammonium hydrogen sulfate in the mobile phase. A method was developed to detect FA in maize using molecularly imprinted SPE analysis within the range of 1-100 µg/g with recoveries between 83.9 and 92.1%.