Hogansoelberg0172

In this study, a paper-based enzyme biosensor for hypoxanthine (Hx) was developed, enabling visual and one-step fish freshness detection. Xanthine oxidase and horseradish peroxidase were immobilized on nitrocellulose membranes with 3,3',5,5'-tetramethylbenzidine to output the colour signal. Chitosan oligosaccharide lactate-modified nitrocellulose membranes entrapped the dual-enzyme system and exhibited excellent microfluidic aggregation effect. The developed enzyme biosensor produced a linear response of 0.01-0.16 mmolL-1 with a detection limit of 8.22 μmolL-1, and was selective for Hx with recoveries of 96.13-103.11 % for fish samples. These biosensors were attached directly to the surface of fish samples and the colour was revealed within 3 min. Colour signals can be judged by the naked-eye to distinguish between fresh and spoiled fish samples and analyzed by a smartphone for quantitative analysis. The biosensor shows great potential as a powerful pattern- and reagent-free device for on-site freshness evaluation of fish.Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) is considered as a valuable wild germplasm for wheat improvement on account of its numerous outstanding traits. During this study, 7182-1Ns with higher quality was screened out, a series of experiments were conducted to clarify the reasons of quality improvement. The results indicated 7182-1Ns was carried a novel high-molecular-weight glutenin subunit (HMW-GS) from P. huashanica, designated as P. selleck kinase inhibitor huashanica' subunit in wheat (HS), which changed the HMW-GS compositions, increased the proportion of glutenins in wheat gluten protein, accelerated the accumulation speed of unextractable polymeric protein (UPP) during grain development stage accelerated, and a denser microstructure of the gluten network was formed in the dough. Therefore, the current research provides important reference on effectively utilize 7182-1Ns as an intermediate germplasm for quality breeding improvement.The modification, structure, functionality and IgE binding capacity of soybean protein (SPI) upon covalent conjugation with gallic acid (GA), caffeic acid (CA), and tannic acid (TA) under alkali treatment were assessed. SDS-PAGE showed the formation of SPI-polyphenol conjugates and the cross-linking of SPI. Protein unfolding in the conjugates was observed, characterized by a reduction in α-helix and an increase in UV ultraviolet absorption, surface hydrophobicity and free sulfhydryl groups. LC/MS-MS demonstrated that the modification of protein and major allergens varied with the types of polyphenols. Western-blot and ELISA demonstrated that SPI-polyphenol conjugates exhibited a significant reduced IgE binding capacity due to the masking or destruction of epitopes among Gly m 4, Gly m 5, Gly m 6 and P28, resulting from structural changes. Additionally, antioxidant capacity and emulsifying properties were increased in SPI-polyphenol conjugates. Therefore, polyphenol treatment may be a promising method to prepare hypoallergenic soybean products with desired functionality.Origin verification of high-value saffron is essential for fair trade and to protect consumers' interests and rights. A traceability method using elemental content (% C and % N) and stable isotopes (δ13C, δ2H, δ18O, and δ15N) combined with chemometrics was developed to discriminate saffron from Iran and China and classify major domestic production areas in China. Results showed that Iranian samples had lower % C and % N contents but higher δ13C values than Chinese origin saffron, with δ13C acting as an important variable for origin discrimination. Moreover, δ2H and δ13C isotopes were found to be important variables to classify Chinese regional saffron origin. Two supervised pattern recognition models (PLS-DA) developed to classify Iranian and Chinese saffron, and regional Chinese saffron had a discrimination accuracy of 85.0 % and 80.2 %, respectively. These models provide the basis for a new regulatory inspection procedure to verify saffron origin and label claims, minimizing fraudulent mislabeling and adding value to saffron from specific regions.This study involves the preparation of PLA/PBAT composite blend films incorporated with TiO2 and varying concentrations of cinnamon essential oil. The films were characterised for optical and mechanical properties, chemical composition, thermo-stability, surface hydrophobicity, inhibition of biofilm formation, anti-microbial efficiency against S. aureus and E. coli, and application on cheese. The thickness of the films increased with the increase in cinnamon oil concentration along with the water contact angle degree and highest UV-barrier properties with the PLA-PBAT-TiO2-7 %Cinn film. The best anti-bacterial activity was seen in the PLA-PBAT-TiO2-7 %Cinn film against S. aureus and E. coli. The cheese packed in PLA-PBAT-TiO2-7 %Cinn film has shown the least weight loss and enhanced antibacterial activity against E. coli for 12 days of storage. The use of cinnamon oil-loaded TiO2 incorporated in films showed positive effects on the shelf life, quality, and safety of a food product and has a high potential for use commercially.This study evaluated the levels of eight biogenic amines in 59 craft beers of five styles and monitored the changes during beer fermentation, showing that putrescine and tryptamine were the most abundant at maximum values of 46.14 mg/L and 89.97 mg/L, respectively. This research indicated for the first time that dark beer, such as Stout/Porter, displayed the highest total biogenic amine content due to considerable tryptamine accumulation, with a maximum value of 116.95 mg/L. The total biogenic amine level increased gradually during the segmental saccharification and main fermentation stages, representing the two critical control points for their formation during beer fermentation. This study provides a theoretical basis and technical guidance for the safe and standardized production of craft beer and the formulation of biogenic amines limit standards, which is highly significant for protecting the health of consumers.Hydrogen sulfide (H2S) has been identified as a critical gaseous signaling chemical. Herein, the effects of H2S treatment on the postharvest goji berries and antioxidant enzyme activities were determined. H2S application delayed the decay index, loss of firmness, color, flavor, and total sugars and loss of total protein, betaine and ascorbic acid in goji berries during postharvest storage. Meanwhile, H2S noticeably reduced the MDA, H2O2, and O2- accumulation. Additionally, it was shown that H2S increased the activity of catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD), glutathione reductase (GR) and superoxide dismutase (SOD) while decreased the quantity of lipoxygenase (LOX). The mRNA expression of LDC, DCD, CAT, APX, POD, GR and SOD was up-regulated but LOX, RBOH-b and RBOH-e was down-regulated in goji berries after H2S treatment. Altogether, H2S could efficiently delay the senescence, improves postharvest quality, increase the bioactive compounds accumulation, and boost the antioxidant capacity of goji berries through modulating antioxidant enzyme system.An analytical method for the determination of erythromycin A (ERY) residues in fish fillet was developed, optimized, and validated employing a modified QuEChERS procedure associated to DLLME technique as a preconcentration step. The obtained LOD and the LOQ were 0.1 µg kg-1 and 1 µg kg-1, respectively. The validated method provides linearity in the range of 1 to 20 µg kg-1, precision (CV less then 6.3 %) and accuracy (recovery ranging from 103 to 110 %). The procedure was applied in an experimental study to evaluate the residual depletion profile of ERY in fish (Piaractus mesopotamicus) after oral administration. The treatment was carried out at a daily dose of 100 mg (kg BW)-1 of ERY, for 7 consecutive days and with an average water temperature of 30 °C. A withdrawal time of 240°-day was estimated for eliminating ERY residues at concentration levels below the maximum residue limit considered (MRL 100 µg kg-1).Rice bran is rich in nutrients and bioactive components, which plays an important role in reducing dyslipidemia and regulating intestinal flora. However, due to the rice bran's instability resulting from rancidity during storage, the development is limited. E-nose, GC-MS and E-tongue were used to monitor the flavor and bitterness of different stabilized rice bran during accelerated storage, and the change of physicochemical properties in rice bran was determined. The rice bran flavor significantly changed after five stabilization treatments. The bitterness increased during storage, but the growth was small (from 7.39 to 7.62). Besides, after stabilization treatments, lipase (LA) activities gradually decreased from 10.11 to 2.03 mg/g, and lipoxygenase (Lox) activities decreased from 3.71 to 1.38 U/g. These results comprehensively elucidate changes in volatile composition, bitterness and physicochemical properties of stabilized rice bran samples during storage and lay the foundation for improving its acceptability and edibility in the future.To reveal the nature of thermal aggregation of soybean protein at subunit level, structure and physicochemical properties of αα'- and β-subunits isolated from β-conglycinin, acidic polypeptide, and basic polypeptide from glycinin, as well as β-conglycinin and glycinin, were characterized before and after heat treatment. The transmission electron microscopy (TEM) images showed that β-conglycinin, αα'-subunits and acidic polypeptide formed regular thermal aggregates, which exhibited high solubility, high ζ-potential value, and small particle size. While glycinin, β-subunit, and basic polypeptide aggregated to insoluble clusters with large particle size distribution. The results of size exclusion chromatography and non-reducing electrophoresis showed that the disulfide bond was the important force in stabilizing the protein conformation of thermal aggregates in β-conglycinin, glycinin, and their isolated subunits/polypeptides but β-subunit. The results of surface hydrophobicity and intrinsic fluorescence spectra showed that the thermal aggregations of β-subunit and basic polypeptide were mainly driven by hydrophobic interactions.Although sterols have multiple physiological functions, low solubility and weak emulsifying properties of sterols affect their application in the food industry. However, binding interaction between protein and sterol potentially enhances its biological activities and emulsifying properties. In this work, effects of two structurally different sterols, namely ergosterol (ES) and γ-oryzanol (γS) on binding interactions, emulsifying properties, and biological activities of whey protein isolate (WPI)-sterol complexes were investigated and compared. Fluorescence spectroscopies and molecular docking presented that binding affinity of WPI treated with γS was stronger than that with ES. Importantly, WPI-γS exhibited stronger absolute value of ζ-potential, surface hydrophobicity, emulsifying characteristics and biological activities than WPI-ES. Principal component analysis (PCA) showed that emulsifying characteristics and biological activities of all the samples were positively correlated. This study provided a theoretical basis for the development and practical application of protein-sterol complexes as functional ingredients in food industry.