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Highlights: [•] A highly sensitive monoclonal antibody (MAb) for tropomyosins was produced. [•] The MAb specifically recognizes allergic tropomyosin-derived peptides. [•] A sandwich ELISA based on the MAb was developed. [•] The developed sandwich ELISA were successfully applied in processed foods. [ABSTRACT FROM AUTHOR]

Abstract: The fruits of Persea americana (Avocado) are nowadays used as healthy fruits in the world. Bioassay-guided fractionation of the active ethyl acetate soluble fraction has led to the isolation of five new fatty alcohol derivatives, avocadenols A–D (1–4) and avocadoin (5) from the unripe pulp of P. americana, along with 12 known compounds (6–17). These structures were elucidated by spectroscopic analysis. Among the isolates, avocadenol A (1), avocadenol B (2), (2R,4R)-1,2,4-trihydroxynonadecane (6), and (2R,4R)-1,2,4-trihydroxyheptadec-16-ene (7) showed antimycobacterial activity against Mycobacterium tuberculosis H37RV in vitro, with MIC values of 24.0, 33.8, 24.9, and 35.7μg/ml, respectively. [Copyright &y& Elsevier]

Abstract: This study represents the first phytochemical research of phenolic components of Sercial and Tinta Negra Vitis vinifera L. The phenolic profiles of Sercial and Tinta Negra V. vinifera L. grape skins (white and red varieties, respectively) were established using high performance liquid chromatography–diode array detection–electrospray ionisation tandem mass spectrometry (HPLC–DAD–ESI-MS n ), at different ripening stages (véraison and maturity). A total of 40 phenolic compounds were identified, which included 3 hydroxybenzoic acids, 8 hydroxycinnamic acids, 4 flavanols, 5 flavanones, 8 flavonols, 4 stilbenes, and 8 anthocyanins. For the white variety, in both ripening stages, hydroxycinnamic acids and flavonols were the main phenolic classes, representing about 80% of the phenolic composition. For red variety, at véraison, hydroxycinnamic acids and flavonols were also the predominant classes (71%), but at maturity, anthocyanins represented 84% of the phenolic composition. As far as we know, 10 compounds were reported for the first time in V. vinifera L. grapes, namely protocatechuic acid-glucoside, p-hydroxybenzoyl glucoside, caftaric acid vanilloyl pentoside, p-coumaric acid-erythroside, naringenin hexose derivate, eriodictyol-glucoside, taxifolin-pentoside, quercetin-glucuronide-glucoside, malylated kaempferol-glucoside, and resveratrol dimer. These novel V. vinifera L. grape components were identified based on their MS n fragmentation profile. This data represents valuable information that may be useful to oenological management and to valorise these varieties as sources of bioactive compounds. [Copyright &y& Elsevier]

Abstract: Two types of murine monoclonal antibodies (MAbs) against American lobster (Homarus americanus) were generated and characterized. Three purified MAbs were characterized to be specific to the shellfish major allergen tropomyosin. MAbs 5G5E1 and 1A3A7 were reactive to tropomyosin from crustacean species only, whereas MAb 2A7H6 was reactive to both crustacean and mollusk tropomyosins. None of the antibodies reacted to vertebrate tropomyosins. Competitive ELISA indicated that the antigenic epitopes recognized by the two types of MAbs were different from each other. In addition, competitive immunoblot results showed that the binding of shellfish-allergic patient IgEs to lobster tropomyosin was inhibited by the MAb 2A7H6 only. This finding suggests that the antigenic epitope for the 2A7H6 antibody might be similar or close to the allergenic epitope shared by crustaceans and mollusks. Consequently, the MAbs recognizing the different common antigenic epiotopes obtained in the present study would not only facilitate the allergen characterization of shellfish, but may also be useful for the development of specific and sensitive immunoassays for allergen quantification or epitope mapping. [Copyright &y& Elsevier]

The object of this study was to trace TwHf-derived toxins in raw honey and clarify their acute toxic effect related to the addition of honey or sugars. TwHf flowers, raw honey from TwHf planting base and from beekeepers in high-risk area were detected using LC-MS/MS. The results revealed five target toxins were detected in TwHf flowers; only celastrol was detected in one raw honey sample, as a food safety risk factor, celastrol had been traced back to TwHf flowers from raw honey. In a series of acute toxic tests on zebrafish, toxification effects were observed when honey, mimic honey or sugar was mixed with toxins. The degree of toxicity varied among various sugar-based solutions. At the same mass concentration, they follow this order: raw honey/mimic honey > glucose > fructose. The main toxic target organs of triptolide and celastrol with honey were the heart and liver. [Display omitted] • A method combining QuEChERS with LC-MS/MS traced five suspicious toxins in large-scale raw honey samples. • Celastrol was linked to the flower of Tripterygium wilfordii Hook. f.(TwHf). • Mimic honey, a natural deep eutectic solvent, was firstly used to explore the interaction between honey and target toxins. • Honey, mimic honey, glucose and fructose all had synergistic effects on acute toxicity induced by triptolide or celastrol. [ABSTRACT FROM AUTHOR]

[Display omitted] • The molecular properties of Eriocheir sinensis HC were revealed for the first time. • Heat treatment induced an increase in β-sheet of HC and reduced its allergenicity. • Anti-digestibility of HC was different from allergen tropomyosin of crustaceans. • Five allergenic epitopes of HC were validated by murine sensitization model. Hemocyanin in crustaceans is an allergen for humans. However, little information was available on its molecular, structural and allergenic properties. In this study, the purified natural protein was identified as Eriocheir sinensis HC by LC-MS/MS, which was allergenic because its reaction with the serum IgE of crustacean patients. Results of the molecular properties showed that, HC was resistant to trypsin digestion, but not a heat-stable protein. Boiling (55.05 ± 3.50 %) and steaming (66.84 ± 1.65 %) induced an increase in β-sheet and decreased allergenicity of HC. By comparing the amino acid sequences of eight crustaceans, HC was found to be highly conserved. Five epitopes of HC were identified and validated by murine sensitization model, and two of them (P3 and P10) were exactly as the predicted by six types of bioinformatics. Multiple bioinformatics analysis combining with murine sensitization model seemed to be effective way for identification of allergenic epitopes. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel model, IR-CAM, was developed by infrared spectroscopic chemometrics. • TM could be identified within 10 min by shared and unique fingerprint peaks group. • Rapid species differentiation of TM at the Class/Family level was achieved by IR-CAM. • The IR-CAM was a new tool for identification and traceability of food allergens. To solve the lack of rapid and accurate methods for allergen identification and traceability, an infrared spectroscopic chemometric analytical model (IR-CAM) was established by combining infrared spectroscopy with principal component and cluster analysis. By comparing the second derivative infrared (SD-IR) spectra of 5 proteins and 14 crustaceans and shellfish tropomyosin (TM), 8 shared peaks and unique fingerprint peaks in the amide III region were found for crabs, shrimps, and shellfish. Based on the unique fingerprint peaks coexisting with shared peaks, allergen TM in crustaceans and shellfish could be identified within 10 min (cf. ELISA ∼ 4 h). Concurrently, the species differentiation of TM at the Class/Family level was achieved based on IR-CAM. Validation by fermented aquatic products TM (n = 60) demonstrated that the developed IR-CAM could simultaneously identify and differentiate TM in crustaceans and shellfish accurately. It could be applied for allergen detection and traceability of aquatic products on an antibody-free basis. [ABSTRACT FROM AUTHOR]

• Specific fingerprints were extracted by Tri-step IR for red wine authentication. • Multivariate data fusion of IR with E-nose endowed better quantitative model. • Fusion models based on extracted spectral regions rendered the best r p and RPD. A robust data fusion strategy integrating Tri-step infrared spectroscopy (IR) with electronic nose (E-nose) was established for rapid qualitative authentication and quantitative evaluation of red wines using Cabernet Sauvignon as an example. The chemical fingerprints of four types of wines were thoroughly interpreted by Tri-step IR, and the defined spectral fingerprint region of alcohol and sugar was 1200–950 cm−1. The wine types were authenticated by IR-based principal component analysis (PCA). Furthermore, ten quantitative models by partial least squares (PLS) were built to evaluate alcohol and total sugar contents. In particular, the model based on the fusion datasets of spectral fingerprint region and E-nose was superior to the others, in which RMSEP reduced by 47.95% (alcohol) and 79.90% (total sugar), r p increased by 11.95% and 43.47%, and RPD >3.0. The developed methodology would be applicable for mass screening and rapid multi-chemical-component quantification of wines in a more comprehensive and efficient manner. [ABSTRACT FROM AUTHOR]

Abstract: Seven kinds of amino acids were used to modify the non-water-soluble extracellular melanin (LEM346) from Lachnum YM-346. It was found that arginine–melanin (ALEM346) had the highest solubility, being 4.55% (gg−1) in 30°C distilled water. Elemental analysis, infrared spectrum and mass spectrum analysis revealed that LEM346 molecule contained indole quinone structure, its molecular formula speculated to be C18H8O6N2. Infrared spectrum analysis showed that ALEM346 had characteristic absorption peaks at 1672.346 and 1637.679cm−1. Mass spectrum analysis indicated that ALEM346 contained three types of arginine–melanin molecules. When the ALEM346 concentration was 500mgL−1, its total antioxidant capacity was equivalent to α-tocopherol of 46.65mmolL−1, the DPPH and O2 − scavenging rates and the Fe2+ chelating rate were 89.05%, 93.81% and 80.18%, respectively, suggesting that the antioxidant activity of ALEM346 was stronger than that of LEM346. [Copyright &y& Elsevier]

Abstract: Cinnamaldehyde has been shown to exert diverse health benefits on humans. We investigated the molecular effects of cinnamaldehyde on the growth regulation mechanism and the Janus kinase–signal transducers and activators of the transcription (JAK–STAT) signalling pathway in human hepatoma cells. We found that cinnamaldehyde caused inhibition of cellular mitogenesis, partly by promoting apoptosis in two human hepatoma cancer cell lines – HepG2 and Hep3B. Amplified changes in caspase 3 activity, Bcl-2 protein expression, and mitochondrial cytochrome c release were displayed in cinnamaldehyde treatments in these cells. The ability of cinnamaldehyde to induce growth arrest was also verified by the observation that it significantly decreased the protein levels of cyclin D1 and proliferative cell nuclear antigen (PCNA) but increased the protein levels of p27Kip1 and p21Waf1/Cip1. Especially, the JAK2–STAT3/STAT5 signalling pathway was markedly blocked by cinnamaldehyde in human hepatoma cells. Suppressor of cytokine signalling 1 (SOCS1) and SOCS3 expressions were slightly activated by cinnamaldehyde. The specific JAK2 inhibitor, AG490, significantly prevented the phosphorylation of STAT3 and STAT5 proteins and enhanced the effect of cinnamaldehyde-inhibited cellular mitogenesis. Hence, these results suggest that cinnamaldehyde has a potent inhibitory effect against human hepatoma cell growth, and the JAK2–STAT3/STAT5 and that the apoptotic pathways may be important targets of cinnamaldehyde. [Copyright &y& Elsevier]

• Morphology changes of MNPs were characterized in a quantitative braising process. • Compositions of MNPs were intrinsically rich in glycoconjugates and triglycerides. • MNPs initially formed were inclined to self-assemble into larger particles. • Mechanisms of MNP evolution were revealed from microcosmic-spatial perspectives. • A hypothesis that MNP might be a key factor of broth flavor regulation was proposed. The formation and transformation mechanisms of micro-nano particles (MNPs) in broth during meat braising were systematically investigated through a sophisticated controlled process. Dynamic changes in the morphology, composition and spatial distribution of MNPs were comprehensively characterized, and subsequently the mechanisms were visually uncovered from microcosmic-spatial perspectives. MNPs formed as circular-shape colloidal systems with an aggrandizing tendency for particle number and size and gradually stabilize eventually. Specifically, the major MNPs gradually increased the size from <400 nm to ~1500 nm and accumulated triglycerides and glycoconjugates resulting from lipid oxidation, Maillard reaction, etc. Continuous formation of MNPs in broth progressively facilitated the spatial coalescence and self-assembly of free substances driven by intermolecular interactions, and consequently principal nutrients and flavor compounds further accumulated in the MNPs by the braising process. Hence, this work not only revealed the MNP formation and transformation mechanisms but offered a foundation for investigating MNP-dependent effect on broth flavor. [ABSTRACT FROM AUTHOR]

• IRN, SVM and RF models based on IR spectra of parvalbumin were constructed and compared. • IRN model had the greatest accuracy for recognizing fish pavalbumin (up to 97.3%). • IRN model was based on highly representative featured from IR spectra of the parvalbumin allergen. • IRN model could detect parvalbumin accurately in seafood matrices. • Infrared spectroscopic IRN method was rapid (~20 min) and effective. We have developed a novel approach that involves inception-resnet network (IRN) modeling based on infrared spectroscopy (IR) for rapid and specific detection of the fish allergen parvalbumin. SDS-PAGE and ELISA were used to validate the new method. Through training and learning with parvalbumin IR spectra from 16 fish species, IRN, support vector machine (SVM), and random forest (RF) models were successfully established and compared. The IRN model extracted highly representative features from the IR spectra, leading to high accuracy in recognizing parvalbumin (up to 97.3%) in a variety of seafood matrices. The proposed infrared spectroscopic IRN (IR-IRN) method was rapid (~20 min, cf. ELISA ~4 h) and required minimal expert knowledge for application. Thus, it could be extended for large-scale field screening and identification of parvalbumin or other potential allergens in complex food matrices. [ABSTRACT FROM AUTHOR]