Tannins are structurally diverse food polyphenols whose behavior cannot be predicted from total tannin content alone. This review uses tannin class, linkage chemistry, degree-of-polymerization metrics, galloylation and hydroxylation, conformational flexibility, and oxidation state as a common framework for interpreting interactions with food proteins, digestive enzymes, starch, plant cell-wall polysaccharides, minerals, and salivary constituents. These descriptors explain differences in digestibility, mineral bioaccessibility, astringency, interfacial behavior, and crosslinking. Many apparently contradictory findings arise because matrix composition, dose, processing sequence, and analytical endpoint change together. The same multivalent and oxidation-prone chemistry that creates nutritional or sensory liabilities can be exploited in preservation, delivery systems, food colloids, and active packaging, provided that benefits are balanced against binding, color, migration, and sensory costs. Digestive fate should be evaluated at the level of free tannins, soluble complexes, precipitated or cell-wall-bound fractions, and transformed products. A phase-resolved framework integrating INFOGEST digestion, Caco-2 testing, colonic fermentation, animal studies, and human interventions is proposed. Minimum methodological requirements are provided for structural characterization, complex preparation, mass balance, microbiota experiments, and cross-model validation. Structure-resolved reporting should improve comparability and support selective processing and rational food design.

To improve the utilization value of summer tea resources, fresh summer tea leaves with different plucking standards were processed into four tea types (green, yellow, white, and black teas) to elucidate the effects of plucking maturity and processing methods on tea quality. Sensory evaluation, physicochemical analysis, electronic tongue, and metabolomics were employed to comprehensively characterize tea quality attributes. The tea samples made from one bud and one leaf showed superior sensory quality, especially in aroma, freshness, and sweetness. Processing significantly shaped flavor profiles: black tea reduced bitterness, white and yellow tea enhanced sweetness and umami, and green tea exhibited stronger umami and astringency characteristics. White and black tea processing also promoted key metabolite accumulation. Based on TAV (taste activity value) and rOAV (relative odor activity value), 10 key taste compounds (e.g., Asp, Glu, Thea, EGCG) and 10 key volatile metabolites (e.g., geraniol and dihydro-2-methyl-3(2H)-furanone) were identified, providing insights into the chemical mechanisms underlying tea quality development. The differential accumulation of taste compounds influenced taste characteristics, while variations in volatile metabolitescontributed to aroma diversity induced by different processing methods.

Oenological tannins are widely used in winemaking to enhance clarification, stabilize color, modulate mouthfeel, and prevent oxidation. Among emerging sources, tannins extracted from pomegranate peel (PPE), a food industry by-product rich in ellagitannins characterized by the distinctive gallagyl group, represent a promising alternative. This study evaluated the effect of adding PPE during pre-fermentation of Sangiovese grapes, compared with commercial nutgall tannin (NGT), oak tannin (OKT), and control without tannins. Polyphenol content, antioxidant activity, and color parameters (including CIELab coordinates) were monitored throughout vinification and after six months of bottle aging, alongside sensory evaluation. PPE wines showed the highest polyphenol content (2585 mg/L) and enhanced antioxidant activity, comparable to NGT. PPE significantly increased color intensity and polymeric pigment concentration, improving long-term color stability. Bitterness was reduced and stabilized without affecting astringency or sourness. These findings highlight pomegranate tannin as an effective and sustainable oenological coadjutant, supporting circular economy approaches in winemaking.

Diabetes mellitus (DM) is a chronic metabolic disease characterized by hyperglycemia, and the diaphragm-the primary respiratory muscle-is adversely affected by this diabetic process. The aim of this study is to investigate the effects of zinc sulfate (ZnSO4) treatment on diaphragm muscle contractile dynamics, calcium homeostasis, apoptosis, and fibrosis in an 18-month-old female Type 2 diabetic rat model. Thirty-two 18-month-old female Wistar rats were randomly divided into four groups: Control (CON), CON + ZnSO4, Diabetes Mellitus (DM), and DM + ZnSO4. The DM model was induced by a high-fat diet and administration of 30 mg/kg streptozotocin (STZ); after the disease was confirmed, ZnSO4 was administered intraperitoneally at a daily dose of 10 mg/kg to the treatment groups. The mechanical functions of the diaphragm muscle were evaluated using a post-rest potentiation protocol in an isolated organ bath; qPCR analyses (Caspase-3, TGF-β1, SERCA2a) were performed to investigate cellular apoptosis, fibrosis, and calcium regulation. Compared with the CON group, the DM group exhibited a severe ~90% reduction in diaphragmatic contraction force (CF) and a ~97% decline in maximal contraction/relaxation velocities (±dF/dtmax) (p < 0.0001), which strongly correlated with a 30% suppression of SERCA2a gene expression (p < 0.01). Concomitantly, apoptotic Caspase-3 (~2.6-fold) and profibrotic TGF-β1 (~3.1-fold) mRNA levels were significantly elevated (p < 0.0001). In the DM + ZnSO4 group, daily zinc treatment (10 mg/kg/day, i.p. for 6 weeks, initiated 4 weeks after diabetes confirmation) did not reverse the elevated Caspase-3 and TGF-β1 expressions (p > 0.05). However, SERCA2a expression was fully preserved back to control levels (p < 0.05 vs. DM), leading to a substantial ~3-fold improvement in CF and velocities (p < 0.05 to p < 0.0001 vs. DM). On the other hand, the healthy CON + ZnSO4 group exhibited a physiological slowing of contractility (~53% decrease in CF), without histological damage, likely due to a competitive antagonism between excess divalent zinc (Zn[2+]) and calcium (Ca[2+]) on myofilaments. Although zinc cannot reverse the structural apoptotic and fibrotic remodeling in the aged diabetic diaphragm, it successfully rescues functional contractility by preserving SERCA2a transcriptional expression.

Cultivar-specific characteristics and fermentation potential are key factors influencing both fresh blueberry consumption and blueberry wine production. Aroma and phenolic profiles of nine blueberry cultivars and their corresponding wines were analyzed using GC-MS, UHPLC-MS/MS, and sensory evaluation. Fresh fruit showed pronounced cultivar-dependent differences in aroma intensity and complexity, mainly driven by esters and terpenes, with aldehydes and ketones contributing synergistically. Fermentation reshaped aroma and phenolics, weakening ester-fruit linkages while enhancing the influence of aromatics, aldehydes, and C13-norisoprenoids. Phenolic composition determined mouthfeel and color, with body, astringency, and visual attributes closely linked to anthocyanin-derived pigments, flavonols, and flavanols in a cultivar-dependent manner; Vitisin contributed notably to color development. 'L25', 'Misty', and 'Liaolan 503'exhibited high aroma intensity and complexity, indicating their potential for fresh consumption and distinctive wine styles. These findings establish a chemical-sensory framework connecting cultivar composition with sensory expression in blueberry fruit and wine.

Fermentation by food microorganism provides an effective approach for transforming plant-based substrates, yet the microbial mechanisms underlying these biochemical processes remain insufficiently understood. In this study, Eurotium cristatum-mediated solid-state fermentation of Apocynum venetum L. tea (AVL) was investigated at 2, 4 and 6 days using an integrated multi-omics approach and sensory-related analyses. Fermentation decreased bitterness and astringency of AVL infusions, accompanied by reductions in total polyphenols and flavonoids. Untargeted metabolomics identified 41 core differential non-volatile metabolites, predominantly fatty acyls, glycerophospholipids, steroids, phenolics, and terpenoids. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment highlighted phenylpropanoid-, flavonoid-, and isoflavonoid-related pathways. Volatile profiling identified 16 aroma-active compounds. Changes in aldehydes, ketones, alcohols, and esters contributed to fermentation-associated aroma characteristics. Metaproteomic analysis identified 4614 E. cristatum proteins, including 1838 differential proteins enriched in functional categories related to catalytic activity, oxidoreductase activity, glycosyl bond hydrolase activity, carbohydrate metabolism, and secondary metabolism. Integrated multi-omics analysis showed that non-volatile metabolite remodeling was associated with multiple microbial functional modules related to carbon metabolism, redox reactions, and secondary metabolism while fatty acid and amino acid metabolism were associated with the formation of characteristic aroma-active compounds. Overall, E. cristatum-mediated fermentation of AVL represents a growth-coupled, enzyme-associated biotransformation process in which coordinated microbial metabolic activities contribute to metabolites remodeling and the development of characteristic taste and aroma properties. These findings provide a mechanistic basis for understanding E. cristatum-mediated transformation of plant substrates and offer insights into the formation of characteristic quality attributes during fermented tea production.

This study aimed to determine the effect of lactoferrin (LF) fortification of bovine milk on yogurt flavor and volatile compound profiles during the 21-day storage period. Experimental yogurt samples containing 750.6 mg/L of LF were produced. LF fortification increased viscosity on the first day of storage and reduced syneresis, while a* and b* showed only minor fluctuations without perceptible color differences. Flavor profile analysis revealed that the "sweet" taste was perceived at a higher intensity in LF-fortified yogurt compared to the control on the first day of storage (control: 2.89; LF-fortified: 3.75). Furthermore, the incorporation of LF influenced the textural properties of the yogurt, resulting in increased astringency during storage. The increased astringency can be explained by LF's interactions with milk proteins, which strengthen the gel network. The volatile compound profiles were generally similar between the control and LF-fortified yogurt samples. In LF-fortified yogurt samples, 2-butanone decreased by the end of storage (from 11.51 to 9.06 μg/kg), whereas benzaldehyde was detected only on day 1 (9.37 μg/kg). LF fortification of A2 yogurt is feasible and subtly improves properties while preserving quality, suggesting for value-added dairy products; further studies should assess formulations and bioactivity.

Quinoa (Chenopodium quinoa Willd.) seedlings are nutrient-dense leafy vegetables, but their inherent bitterness and astringency limit consumer acceptance. The chemical basis underlying these sensory attributes remains largely unclear. In this study, four quinoa seedling varieties differing in seed coat colour were evaluated using electronic tongue analysis in combination with comprehensive metabolomics. Among the detected flavor attributes, bitterness and astringency were the most prominent in the four identified quinoa seedling varieties. Meanwhile, 2060 metabolites were identified across the four varieties, with differential metabolites predominantly enriched in flavonoids. Correlation analysis revealed significant associations between flavonoids and bitter, astringent sensory traits of quinoa seedlings vegetables, indicating a potential connection to unpleasant taste perception. Among these flavonoids, quercetin and kaempferol glycoside derivatives showed the strongest correlation with bitter and astringent sensory attributes. This study deepens our knowledge of flavor-related metabolites and offers correlational references for breeding low-bitterness quinoa varieties.

Fermentative skin contact is increasingly applied in white winemaking, yet its compositional and sensory consequences remain underexplored. This study evaluated Arneis and Erbaluce wines produced under four maceration regimes (0, 2, 7, and 14 days), as well as the effect of post-fermentative oxygenation for each wine obtained. Phenolic composition was quantified by LC-MS/MS and spectrophotometry, volatile compounds by GC-MS, and sensory attributes through a trained panel using a Rate-All-That-Apply (RATA) approach. Extended maceration substantially increased proanthocyanidins, flavan-3-ols, hydroxycinnamates, and flavonols, reaching levels comparable to red wines, while color shifted toward deeper yellow hues. Oxygenation reduced monomeric flavanols and esters and amplified oxidative notes. Sensory evaluation revealed heightened astringency and dryness in long-macerated samples, alongside diminished fruity aromas. These findings demonstrate that fermentative maceration strongly modulates the phenolic and aroma profiles of white wines, with oxygen exposure further refining their sensory expression.

The bitter and astringent properties of plant-derived chalcone compounds result in lower sweet taste purity compared to that of sugars such as sucrose, thereby limiting their applications. To elucidate the relationship between the structure of chalcones and their sweet taste purity, a 3D-QSAR model was established according to the sensory experiments that evaluated the sweetness and aftertaste of 22 chalcone compounds. Based on Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Index Analysis (CoMSIA), key sites and functional groups affecting the sweet taste purity of chalcones were identified. The model indicated that the sweet taste purity of chalcone compounds can be enhanced by introducing negative charges and hydrophilic groups at the C2 position of ring A, hydrophilic groups at positions C3 and C4 of ring A, and small-volume groups at position C6 of ring A, as well as introducing hydrophilic groups on ring B and large-volume groups at positions C4' and C5' of ring B. Furthermore, the chalcones compatible with the model were selected for sensory evaluations of the sweet taste purity. The results were consistent with model predictions, thereby validating the efficacy of the 3D-QSAR model. Molecular docking studies further corroborated the model's reliability. This study establishes a 3D-QSAR model for evaluating sweet taste purity scores, thereby enhancing the sensory profile of chalcone compounds. It provides novel design concepts for developing sweeteners with high sweet taste purity and offers the food industry access to high-performance sweetener options.

Phenolic compounds constitute a broad family of secondary metabolites synthesized by plants responsible for their color, flavor, and astringency, as well as being very important in the human diet as the main source of antioxidants. This work describes a simple and disposable microfluidic paper-based analytical device (μPAD) for the determination of total phenolic content in different beverages. The detection was based on the colorimetric reaction between the Fast Blue BB reagent and the active hydroxyl groups of the phenolic compounds in an alkaline medium. The developed μPAD enabled TPC determination for gallic acid equivalents in the range of 5-200 mg/L and catechin equivalents of 25-125 mg/L, with a detection limit below 5.5 mg/L. Tea and wine samples were analyzed with the developed μPAD and compared to the conventional spectrophotometric method, with no significant differences (p > 0.05). The device remained stable for 7 days under a vacuum atmosphere.

The role of the main apple compositional parameters (sugars, organic acids, polyphenols, and volatile organic compounds) and their interactions on the perceived sensory attributes of Sweetness, Sourness, and Astringency was investigated in apple juice. Bivariate correlations and Support Vector Machine Regression (SVMR) analyses were used to examine the relationships between all the analyzed features and their relative importance in an interactive mode. By analyzing the contribution of the features to the SVMR models using Shapley values, we found that sweetness was strongly influenced by sucrose and by a few volatile organic compounds (VOCs), including acetate and butyl esters associated with fruity odors and flavors. For sourness, as expected, a strong contribution is given by malic acid, while VOCs associated with fruity odor contribute negatively. Regarding astringency, the major contributions were given by malic acid, procyanidins, sorbitol, and chlorogenic acid; the VOCs (few esters, hexanol, and (E)-2-hexenal) show a suppressing effect on astringency. In our investigation, SVMR confirms the role and the importance of the evidenced compositional parameters in driving the perception of the three analyzed sensory attributes in apple juices. PRACTICAL APPLICATIONS: This research could help provide apple breeders with new varieties with more predictable flavor, such as sweeter apples for juice or more tannic apples for cider. It could also help juice and cider producers select, blend, and process apples more consistently by using chemical measurements to estimate how a product may taste. The work may support better quality control, reduces variability, and strengthen product differentiation in markets where flavor consistency and clean-label formulations are increasingly important.