Gliadin nanoparticles are promising carriers for hydrophobic bioactive compounds; however, their poor colloidal stability and limited control over gastrointestinal release restrict practical applications. Although gliadin-carboxymethyl chitosan (Gli-CMCS) nanoparticles have recently been developed for bioactive delivery, the molecular mechanisms by which specific intermolecular interactions contribute to nanoparticle assembly, structural evolution, and digestive release behavior remain insufficiently understood. This study aimed to develop Gli-CMCS nanoparticles as delivery carriers for quercetin and to investigate their formation mechanism, physicochemical properties, encapsulation behavior, and in vitro digestion characteristics. A combination of spectroscopic analyses, interaction force probing, and physicochemical characterization was employed to elucidate the assembly mechanism, structural evolution, stability, and delivery performance of Gli-CMCS nanoparticles. The results showed that CMCS incorporation significantly influenced nanoparticle assembly and stability. Spectroscopic and interaction force analyses revealed that gliadin interacted with CMCS through hydrogen bonding and electrostatic interactions, resulting in conformational rearrangement and nanoparticle assembly. Appropriate CMCS addition (Gli:CMCS ratios of 2:1-1:1) resulted in nanoparticles with a relatively narrow size distribution (PDI 0.30-0.37) and improved colloidal stability. Quercetin was efficiently encapsulated in the nanoparticles, achieving a maximum encapsulation efficiency of 93.92% at a quercetin concentration of 0.04 mg/mL. In vitro digestion studies demonstrated that CMCS incorporation retarded the apparent release of quercetin and improved its retention under simulated gastrointestinal conditions. These findings provide mechanistic insights into how protein-polysaccharide interactions contribute to nanoparticle assembly and are associated with digestive behavior, offering a theoretical basis for the rational design of protein-based delivery systems for hydrophobic bioactive compounds.
Red pepper (Capsicum annuum L.) is stored at low temperatures to maintain freshness; however, prolonged storage can induce chilling stress and quality deterioration. This study investigated metabolic alterations associated with chilling stress during cold storage. Chilling injury (CI) symptoms progressively intensified, became evident after 2 weeks, and were accompanied by pronounced metabolic shifts. Complementary proton nuclear magnetic resonance spectroscopy and gas chromatography-tandem mass spectrometry (GC-MS/MS) analyses revealed metabolite-specific alterations in carbohydrates, amino acids, and organic acids. Multivariate analysis clearly distinguished early (0-2 weeks) and late (4-6 weeks) storage stages, whereas GC-MS/MS profiling showed a marked increase in sucrose (log₂FC = 1.67). Changes in amino acids and tricarboxylic acid cycle-related metabolites were associated with coordinated alterations in central carbon and nitrogen metabolism. These findings provide novel insights into metabolic responses to chilling stress and a metabolic framework for future studies on postharvest management of chilling-sensitive horticultural crops.
The ferric-tripyridyltriazine: [Fe(TPTZ)2]3+ complex, the chromogenic FRAP reagent, was electrostatically attached to negatively charged Nafion membrane to manufacture a total antioxidant capacity (TAC) sensor for food. Trolox-equivalent antioxidant capacities for 19 different phenolic and thiol antioxidants were measured directly on the sensor (at 620 nm). The sensor worked well for both phenols and thiols, with high linearity. The method was also applied after reaction with 5,5'-dithiobis(2-nitrobenzoic acid): DTNB, and positive deviations observed in thiol-phenol mixtures were prevented, with quantitative recovery from fruit juices and green tea samples. TAC determination could be performed 10 months after the membrane was prepared, and the color on the sensor remained almost unchanged within 5 days. The three prominent novelties of this work are the first-time design of a colorimetric FRAP sensor, correction of negative error for simple thiols, and elimination of thiols overrating error in FRAP for thiol-phenol mixtures by preliminary reaction with DTNB.
Ultrasonic-combined pH-shifting (USCPS) is an effective strategy for reducing the allergenicity of food glycoproteins. The N-glycosylation of ginkgo seed glycoprotein isolate (GPI) allergen is closely linked to its allergenicity. However, the effect of USCPS on the allergenicity and N-glycosylation level of GPI remains unclear. In this study, the allergenicity of GPI and its USCPS-treated product (GPI-12-UPPI) were evaluated, and their N-glycans were analyzed qualitatively and quantitatively. USCPS significantly reduced allergenicity of GPI. Ten N-glycans were identified in GPI, predominantly MMX and MMXF (84.38% combined), while none were detected in GPI-12-UPPI. Molecular docking results further revealed that MMX and MMXF may bind to FcγRIIB, interfering with IgG's immune regulatory function. In summary, the decreased allergenicity of GPI after USCPS treatment may be associated with its N-glycosylation level, particularly in fucose and xylose residues. These findings provide a theoretical basis for research on ginkgo allergy mechanisms and development of low-allergenicity ginkgo foods.
This study systematically investigated the characteristic flavors of hot-brewed Yunnan specialty coffees subjected to different primary processing methods (washed, honey-processed, and sun-dried). An integrated multi-scale approach was employed, combining sensory evaluation, physicochemical analysis, chromatography-mass spectrometry (LC-MS/MS and HS-SPME-GC-MS), and computational chemistry. Twenty-three aroma-active compounds (OAV > 1) were identified as major contributors. Aroma recombination and omission experiments confirmed their sensory significance, establishing a quantitative link between chemical composition and sensory attributes. Molecular docking and dynamics simulations revealed that key aroma molecules (e.g., isopulegol, nonanal, ethyl decanoate) primarily interact with olfactory receptors OR1A1 and OR8D1 via van der Waals forces and hydrophobic interactions, elucidating their aroma presentation mechanisms. This research provides a comprehensive data chain and methodological framework for understanding and optimizing the flavor quality of Yunnan specialty coffee through targeted processing and brewing techniques.
Pumpkin exhibits excellent postharvest storability; however, cultivar-specific changes in volatile profiles during storage remain poorly understood. The total volatile compound content increased progressively in Cmo-gm, Cmo-53, and Cma-81 but increased initially and then declined in Cma-78. Aldehydes dominated volatile profile changes in C. maxima, whereas alcohols predominated in C. moschata, accompanied by continuous geraniol accumulation. Based on volatile and nonvolatile quality profiles, favorable postharvest periods were identified at 20-30 dop for C. moschata and 10-20 dop for C. maxima. A multi-scale, multi-label attention network was developed using Fourier transform near-infrared spectroscopy for rapid cultivar and postharvest stage identification, achieving a Hamming loss of 0.0065, a macro F1-score of 0.984, a micro F1-score of 0.985, and a subset accuracy of 0.956. These findings reveal postharvest changes in volatile evolution profiles and support rapid cultivar and postharvest stage identification under controlled storage conditions.
Lycium ruthenicum pomace, a juice-processing by-product, is characterized by low soluble dietary fiber (SDF) content and limited functionality, which restricts its further application. In this study, the pomace dietary fibers (LPDFs) were modified using high-pressure homogenization (HPH), complex enzymatic hydrolysis (CE), and alkaline hydrogen peroxide (AHP), and the resulting changes in physicochemical, structural, and functional properties of both SDF and insoluble dietary fiber (IDF) fractions were evaluated. Modification treatments effectively increased SDF content (from 6.89% to 15.44%) and enhanced functional attributes. AHP produced the highest SDF yield (15.44%) and crystallinity (16.54%), and improved thermal stability. In contrast, CE and HPH treatments loosened the compact structure, reduced particle size, and increased antioxidant activity and viscosity. Notably, CE treatment yielded a substantial SDF increase (12.61%) and exhibited superior overall functional performance, including higher viscosity, rehydration capacities, and antioxidant activities. Our findings suggest that CE represents a more appropriate modification approach for LPDFs.
The cultivation of crops at high altitudes is a promising strategy to face global warming. This study aimed to unravel the effect of altitude of wheat cultivation on wheat beer quality using a multi-omic approach. Common and durum wheat were cultivated at different altitudes and used to produce Blanche craft beers, which were analysed for physico-chemical parameters, volatile organic compounds (VOCs), and sensory profile. These three blocks of data were successfully processed by a sparse multi-block-based approach able to predict altitude of wheat cultivation of beers. VOCs block was the most frequently (50%) interconnected, whilst sensory attributes were most frequently (35%) correlated with altitude. Altitude positively affected Ethyl phenylacetate and floral flavour, whilst negatively affected phenolics and astringency as well as Ethyl esters, and apricot flavour. Multi-block analysis was effective in linking chemical and sensory data, and predicting quality changes related to altitude of cultivation.
