Microfluidic origami nano-aptasensor for peanut allergen ara h1 detection.

In this study, an origami microfluidic electrochemical nano-aptasensor was developed for the rapid detection of the peanut allergen Ara h1. Specifically, the microfluidic aptasensor was fabricated through sequential folding of a piece of chromatography paper substrate patterned with microchannel and screen-printed electrodes. Aptamer-decorated black phosphorus nanosheets (BPNSs) were electrodeposited onto the paper-based electrode surface as […]

Exploring the volatile metabolome of conventional and organic walnut oils by solid-phase microextraction and analysis by GC-MS combined with chemometrics.

It is challenging to establish a correlation between the agronomical practices and the volatile profile of high-value agricultural products. In this study, the volatile metabolome of walnut oils from conventional and organic farming type was explored by HS-SPME-GC-MS. The SPME protocol was optimized after evaluating the effects of extraction time, extraction temperature, and sample mass. […]

Phenolic profiles and antioxidant activities of free, esterified and bound phenolic compounds in walnut kernel

The free, esterified and bound forms of 37 phenolic compounds (including hydroxybenzoic acid, hydroxycinnamic acids, flavanols, flavonols and flavones) from walnut kernel (Juglans regia L.) were investigated in this study. Results showed that the majority of walnut phenolics were presented in the free form (51.1%-68.1%), followed by bound (21.0%-38.0%) and esterified forms (9.7%-18.7%). Ellagic acid, […]

Epitope mapping of the major allergen 2S albumin from pine nut.

The epitopes of the major allergen of pine nut, Pin p 1, were analyzed using a peptide library and sera from patients with clinical allergy to pine nut in order to deepen into the allergenic characteristics of Pin p 1. Analyses of epitope similarities and epitopes location in a 3D-model were also performed. Results showed […]

Discovery based high resolution MS/MS analysis for selection of allergen markers in chocolate and broth powder matrices.

Peptide marker identification is an important step in development of a mass spectrometry method for multiple allergen detection, since specificity, robustness and sensitivity of the overall analytical method will depend on the reliability of the proteotypic peptides. As part of the development of a multi-analyte reference method, discovery analysis of two incurred food matrices has […]

Removal of aflatoxin B1 from contaminated peanut oils using magnetic attapulgite

The efficient magnetic adsorbent (Fe3O4@ATP) was prepared by precipitation through the dispersion of Fe3O4 nanoparticles on the natural attapulgite (ATP) and then tested as an adsorbent for aflatoxin B1 (AFB1) removal from contaminated oils. The adsorbent characterization results revealed that the Fe3O4 were incorporated into the ATP, affording the Fe3O4@ATP composite. This magnetic composite displayed […]

Effect of hot air and infrared roasting on hazelnut allergenicity.

Roasting is known to affect the protein profile and allergenicity of hazelnuts (Corylus avellana cv TGL). The aim of the study was to investigate whether roasting techniques based on different heat transfer methods (hot air and infrared), differently affect the protein solubility and the IgE-binding capacities of both the soluble and insoluble hazelnut protein fractions. […]

An effective chromatographic fingerprinting workflow based on comprehensive two-dimensional gas chromatography-mass spectrometry to establish volatiles patterns discriminative of spoiled hazelnuts (Corylus avellana L.).

The volatile fraction of hazelnuts encrypts information about: cultivar/geographical origin, post-harvest treatments, oxidative stability and sensory quality. However, sensory features could be buried under other dominant chemical signatures posing challenges to an effective classification based on pleasant/unpleasant notes. Here a novel workflow that combines Untargeted and Targeted (UT) fingerprinting on comprehensive two-dimensional gas-chromatographic patterns is […]

Comparative study of concatemer efficiency as an isotope-labelled internal standard for allergen quantification.

Mass spectrometry-based methods coupled with stable isotope dilution have become effective and widely used methods for the detection and quantification of food allergens. Current methods target signature peptides resulting from proteolytic digestion of proteins of the allergenic ingredient. The choice of appropriate stable isotope-labelled internal standard is crucial, given the diversity of encountered food matrices […]