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22 pages, 1353 KB

Open AccessArticle

Near-Infrared Spectroscopy-Based Discriminant Analysis for the Classification of Coffee Quality in Dry Parchment and Green Coffee

by Claudia Rocio Gómez Parra, Aristófeles Ortiz and Valentina Osorio Pérez

Molecules 2026, 31(9), 1395; https://doi.org/10.3390/molecules31091395 - 23 Apr 2026

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Abstract

This study evaluates the potential of near-infrared spectroscopy (NIRS) combined with discriminant analysis to classify coffee quality based on sensory defects in dry parchment coffee (DPC) and green coffee. Spectral data were used to develop classification models, which were validated using both cross-validation [...] Read more.

This study evaluates the potential of near-infrared spectroscopy (NIRS) combined with discriminant analysis to classify coffee quality based on sensory defects in dry parchment coffee (DPC) and green coffee. Spectral data were used to develop classification models, which were validated using both cross-validation and independent external datasets. Model performance was assessed using classification accuracy and Cohen’s kappa coefficient. The results demonstrate high classification accuracy for DPC (93.5%), with a Kappa coefficient indicating almost perfect agreement (κ = 0.90). In contrast, green coffee showed lower predictive performance (82.4%) and moderate agreement (κ = 0.55), reflecting the greater physicochemical complexity of this matrix. Importantly, the findings demonstrate that coffee quality can be reliably classified at the dry parchment stage, enabling early quality assessment without additional processing steps. This represents a significant advancement compared to previous studies, which have mainly focused on green or roasted coffee. Overall, these results highlight the potential of NIRS as a rapid, non-destructive, and objective tool for coffee quality assessment, with strong applicability in quality control and decision-making processes along the coffee production chain. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

28 pages, 4145 KB

Open AccessArticle

GC-MS Analysis of Volatile Differences in Rice and Qingke Noodles Formulated with Functional Root Plant Flours

by Essam ElShamey, Jiazhen Yang, Jiachun Jiang, Xiaoying Pu, Li Xia, Li’e Yang, Xiaomeng Yang and Yawen Zeng

Molecules 2026, 31(8), 1348; https://doi.org/10.3390/molecules31081348 - 20 Apr 2026

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Abstract

The integration of rooted plant flour into traditional noodle matrices, such as rice noodles and qingke noodles, represents a novel approach to enhancing the nutritional and sensory profiles of staple foods. This study investigates the volatile flavor components and functional compounds derived from [...] Read more.

The integration of rooted plant flour into traditional noodle matrices, such as rice noodles and qingke noodles, represents a novel approach to enhancing the nutritional and sensory profiles of staple foods. This study investigates the volatile flavor components and functional compounds derived from rooted plant flours, including Gongmi “tribute rice”, qingke “highland barley” flour, kudzu vine flour, Gastrodia elata blume flour, dried ginger flour, and fishwort root flour, when incorporated into rice and qingke noodles. The novelty of this research lies in its comprehensive analysis of how these flours influence not only the nutritional and textural properties but also the volatile organic compounds (VOCs) that define sensory acceptance and health benefits. Using advanced gas chromatography mass spectrometry (GC-MS), we identified key VOCs, such as esters, aldehydes, and terpenes, which contribute to unique flavor profiles like umami, sweetness, and earthy notes in fortified noodles. Additionally, the study highlights the best functional compounds for health, including polyphenols, resistant starch, and polysaccharides, which demonstrate significant antioxidants, anti-inflammatory, and cholesterol-lowering properties. For instance, highland barley enriched flour exhibited high levels of phenolic compounds and carotenoids, which correlated with improved antioxidant activity and a reduced glycemic index. Similarly, Gongmi flour contributed elevated levels of γ-aminobutyric acid (GABA) and rutin, enhancing the rice noodles’ potential to manage metabolic diseases and support cardiovascular health. Molecular docking analyses predicted strong interactions between key volatile compounds (e.g., 3-dihydro-1, 3-trimethyl-33-phenyl-1H-indene) and metabolic targets like ACE and SGLT1, suggesting mechanisms for their cardioprotective and anti-diabetic effects. This research provides a groundbreaking framework for developing next generation functional foods by leveraging rooted plant flours to bridge the gap between sensory appeal and health efficacy, offering strategic insights for personalized nutrition and sustainable food production. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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14 pages, 2843 KB

Open AccessArticle

Fabrication of Fluorinated Magnetic Covalent Organic Frameworks for the Extraction of Fluoroquinolone Residues Coupled with HPLC Detection

by Jichao Liu, Xiuzhuang Li and Jiaojiao Yu

Molecules 2026, 31(6), 1025; https://doi.org/10.3390/molecules31061025 - 19 Mar 2026

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Abstract

Fluoroquinolones (FQs) are a kind of antibiotics, which are widely used in animal husbandry and aquaculture. However, the abuse of FQs can result in residues in foodstuffs of animal origin. Therefore, it is essential to establish a sensitive and accurate detection method for [...] Read more.

Fluoroquinolones (FQs) are a kind of antibiotics, which are widely used in animal husbandry and aquaculture. However, the abuse of FQs can result in residues in foodstuffs of animal origin. Therefore, it is essential to establish a sensitive and accurate detection method for determination of FQs in food samples. An effective sample pretreatment method is a crucial procedure for enrichment of trace target compounds from complex matrix before HPLC analysis. As an emerging kind of sample pretreatment methods, magnetic solid-phase extraction (MSPE) has attracted much interest due to its characteristics including low cost, simplicity, and rapidity. In this study, a novel fluorinated magnetic covalent organic framework (Fe₃O₄@PDA@COF) was fabricated, which was used as an adsorbent in MSPE as well as coupled with HPLC to determine FQs in food samples. Under optimal conditions, the developed Fe₃O₄@PDA@COF-MSPE-HPLC-UV method possessed a wide linear range (1–250 µg·kg⁻¹) and low limits of detection (0.5–0.7 µg·kg⁻¹) with good linearity (R² ≥ 0.9938). Additionally, the method has been used to adsorb FQs from chicken samples. The recoveries of target FQs in spiked samples were 84.2–106.7% with relative standard deviations (RSDs) below 7.8%. These results demonstrated that the established method provides an efficient and sensitive solution for monitoring FQ residues in foodstuffs. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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14 pages, 1057 KB

Open AccessArticle

FTIR-ATR Spectroscopy and Chemometrics for Varietal Screening of PDO Douro Monovarietal Wines: An Exploratory Feasibility Study

by Ângela Vieira, Amanda Priscila Silva Nascimento, Maria Zélia Branco, Paula Martins-Lopes, José Eduardo Eiras-Dias, João Brazão, Luís Ferreira, Nelson Machado and Ana Novo Barros

Molecules 2026, 31(6), 1004; https://doi.org/10.3390/molecules31061004 - 17 Mar 2026

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Abstract

The authentication of wines with Protected Designation of Origin (PDO) status is a key requirement for quality assurance, traceability, and consumer trust, particularly in traditional wine-producing regions such as the Douro Demarcated Region (Portugal). Among the certification criteria, the reliable identification of grape [...] Read more.

The authentication of wines with Protected Designation of Origin (PDO) status is a key requirement for quality assurance, traceability, and consumer trust, particularly in traditional wine-producing regions such as the Douro Demarcated Region (Portugal). Among the certification criteria, the reliable identification of grape varieties remains technically challenging, especially when rapid and non-destructive analytical approaches are required. In this study, Fourier-transform infrared spectroscopy coupled with chemometric analysis was evaluated as a rapid screening approach for the differentiation of monovarietal Douro wines produced under standardized microvinification conditions. Twenty-one monovarietal wines were analyzed using mid-infrared spectra (1800–1000 cm⁻¹) and classification models were developed using Partial Least Squares Discriminant Analysis (PLS-DA). The PLS-DA models showed preliminary discriminatory capacity, with apparent error rates of 10.2% for calibration and 19.3% under leave-one-out cross-validation. The results indicate that FTIR-ATR spectroscopy combined with chemometrics captures chemically relevant spectral variability associated with grape varietal differences and shows potential as a rapid exploratory screening approach within PDO traceability frameworks. Although the study is based on a limited number of biological replicates from a single vintage and sub-region, the findings provide a methodological baseline for future multi-vintage and multi-region investigations aimed at consolidating FTIR-based approaches for varietal authentication of Douro wines. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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16 pages, 1913 KB

Open AccessArticle

Effect of Storage Duration on Amylase, Protease, and Lipase Activities in Ultrasound-Assisted Extracted Bovine Pancreatin

by Gulmira Kenenbay, Urishbay Chomanov, Gulzhan Zhumaliyeva and Alibek Alashevich Tursunov

Molecules 2026, 31(6), 980; https://doi.org/10.3390/molecules31060980 - 15 Mar 2026

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Abstract

Long-term stability of multienzyme protein systems is governed by preservation of conformational integrity and resistance to thermally induced structural destabilization. This study evaluated bovine pancreatin (BP) obtained by conventional extraction (CM) and ultrasound-assisted extraction (UAM) during 0–930 days of storage at 10–40 °C. [...] Read more.

Long-term stability of multienzyme protein systems is governed by preservation of conformational integrity and resistance to thermally induced structural destabilization. This study evaluated bovine pancreatin (BP) obtained by conventional extraction (CM) and ultrasound-assisted extraction (UAM) during 0–930 days of storage at 10–40 °C. Amylolytic (AA), proteolytic (PA), and lipolytic activities (LA), representing the functional enzymatic activity (EA) of the multienzyme protein system, were monitored to characterize degradation kinetics and activity loss associated with conformational destabilization. After 930 days at 20 ± 1 °C, UAM retained 76% of initial AA compared with 58% for CM, corresponding to a 31% higher residual activity in UAM. LA demonstrated comparatively high stability in both preparations (~84% retention), whereas PA exhibited delayed degradation and significantly higher residual values in UAM samples. Two-way ANOVA confirmed significant effects of extraction method, storage duration, and their interaction (p < 0.001), indicating method-dependent kinetic behavior. Elevated temperatures (35–40 °C) accelerated inactivation, consistent with increased molecular mobility and reduced conformational stability. The smoother degradation trajectories and lower apparent inactivation rates observed in UAM preparations suggest kinetic stabilization, potentially associated with improved conformational preservation and reduced extraction-induced structural stress. Both preparations complied with pharmacopoeial microbiological limits. These findings support the hypothesis that UAM enhances long-term functional stability of complex multienzyme systems through mechanisms related to conformational resilience. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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18 pages, 620 KB

Open AccessArticle

Volatile Compound Profiling and Quality Assessment of Sweet Fermented High-Amylose Rice: A Comparative GC-MS Analysis with Traditional Glutinous Rice Fermentation

by Kamonwan Chucheep, Nongnuch Siriwong, Zee Wei Lai and Naree Phanchindawan

Molecules 2026, 31(6), 937; https://doi.org/10.3390/molecules31060937 - 11 Mar 2026

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Abstract

High-amylose Lueang Patew Chumphon (LPC) rice, a Thai geographical indication variety, represents an underutilized resource for functional food development. This study investigated sweet fermented LPC rice (SFLPC) compared to conventional sweet fermented glutinous rice (SFGR) through comprehensive microbial, chemical, and nutritional characterization. Starter [...] Read more.

High-amylose Lueang Patew Chumphon (LPC) rice, a Thai geographical indication variety, represents an underutilized resource for functional food development. This study investigated sweet fermented LPC rice (SFLPC) compared to conventional sweet fermented glutinous rice (SFGR) through comprehensive microbial, chemical, and nutritional characterization. Starter cakes contained Aspergillus sp., Rhizopus stolonifer, and Pediococcus pentosaceus (>99% similarity by ITS/16S rRNA sequencing and MALDI Biotyper). Both varieties demonstrated comparable fermentation with pH reductions to ~3.5 and lactic acid production (~6 g/L). GC-MS analysis with mass spectral library matching and Linear Retention Index (LRI) comparison tentatively annotated twelve volatile compounds. Absolute peak area analysis revealed distinct variety-specific profiles: SFGR was characterized by significantly higher ethyl palmitate (75.89 ± 19.30 vs. 16.80 ± 7.21 × 10⁶, p = 0.008) and isobutyl alcohol (33.09 ± 3.56 vs. 23.53 ± 1.71 × 10⁶, p = 0.014), exclusive ethyl dodecanoate (44.87 ± 20.60 × 10⁶), and exclusive 2,4-di-tert-butylphenol, while SFLPC showed exclusive ethyl acetate formation. Isoamyl alcohol was the dominant volatile in both varieties, with comparable absolute peak areas (273.91 ± 22.65 vs. 267.54 ± 28.78 × 10⁶, ns). SFLPC demonstrated superior mineral retention (2.1-fold phosphorus, 1.9-fold potassium and magnesium) and enhanced antioxidant capacity (IC₅₀: 3.30 vs. 5.20 μg/mL, representing 36% improvement). Degree of gelatinization analysis validated comparable starch gelatinization (32.5–40.1%) despite different cooking methods, confirming volatile differences arose from rice variety rather than processing. These findings demonstrate high-amylose LPC rice as a promising fermented food substrate offering enhanced nutritional properties and volatile compound profiles through traditional fermentation. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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20 pages, 2394 KB

Open AccessArticle

Comparative Metabolomics and Transcriptomics Analysis of Rosa roxburghii Tratt and Rosa kweichonensis var. sterilis

by Xiaohui Wu, Yi Yuan, Yu Yang, Min Yan, Qiong Yang, Jun Zha, Guoshun Pei, Yali Wei and Li Tang

Molecules 2026, 31(5), 831; https://doi.org/10.3390/molecules31050831 - 2 Mar 2026

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Abstract

Rosa roxburghii Tratt (RR) and Rosa kweichonensis var. sterilis (RS) are both edible medicinal plants. However, they are often confused due to their similar phenotypic characteristics, which may limit their targeted development and utilization. Here, we integrated targeted metabolomics (UPLC-MS/MS) and transcriptomics (Illumina [...] Read more.

Rosa roxburghii Tratt (RR) and Rosa kweichonensis var. sterilis (RS) are both edible medicinal plants. However, they are often confused due to their similar phenotypic characteristics, which may limit their targeted development and utilization. Here, we integrated targeted metabolomics (UPLC-MS/MS) and transcriptomics (Illumina HiSeq) to systematically dissect the metabolic and transcriptional differences between the two species. Metabolomic profiling identified 558 differentially accumulated metabolites (DAMs), defined as metabolites with significantly different abundance between RS and RR, predominantly classified as flavonoids and phenolic acids. Among these, vitamin C (L-ascorbic acid) and argininosuccinic acid were prioritized as key DAMs based on their significant fold changes, high abundance, and functional relevance to bioactivity and stress tolerance. Transcriptomic analysis further revealed that vitamin C synthesis is primarily driven by the coordinated up-regulation of USP and GME genes in the L-ascorbic acid metabolic pathway, while argininosuccinic acid production, as an intermediate in the urea cycle, is mainly mediated by the up-regulated glnA gene. These findings not only clarify the molecular basis of metabolic divergence between RR and RS but also provide potential biomarkers for their identification, laying a solid foundation for their development as distinct functional foods. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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21 pages, 3944 KB

Open AccessArticle

Chitosan Electrospun Membranes Possess Natural pH-Responsive Indicators for Smart Real-Time Spoilage Detection of Shrimp

by Jing Wei, Abdul Qayum, Qingmin Chen, Qiangqiang Xiao, Zhenghong Hao, Chengzhi Xiang and Jianxin Fu

Molecules 2026, 31(5), 820; https://doi.org/10.3390/molecules31050820 - 28 Feb 2026

Viewed by 447

Abstract

Ensuring the simple, rapid, and real-time monitoring of the freshness of fresh food items is essential for maintaining food safety. By reacting with characteristic substances generated during spoilage, pH-responsive indicators can effectively reveal the degree of food freshness. In this study, a mixture [...] Read more.

Ensuring the simple, rapid, and real-time monitoring of the freshness of fresh food items is essential for maintaining food safety. By reacting with characteristic substances generated during spoilage, pH-responsive indicators can effectively reveal the degree of food freshness. In this study, a mixture of hydroxypropyltrimethyl ammonium chloride chitosan (HACC), polyvinyl alcohol (PVA), and blueberry anthocyanins (BAs) was adopted and, via an electrospinning strategy, changed into a membrane coupled with a pH-responsive ability to assess the freshness of shrimp. The results showed that HACC/PVA-BA membranes with a HACC: PVA ratio of 1:4 exhibited enhanced hydrophobicity, better WVP properties (4.32 × 10⁻⁹ g m⁻¹ s⁻¹ Pa⁻¹), a rapid pH-response ability within 5 s and super radical scavenging capacity (56.34% for DPPH and 54.74% for ABTS radicals). HACC’s immutable positive charge creates a strong electrostatic field that pre-concentrates spoilage-generated ammonia and intensifies the protonation state of BAs, which dramatically enhances colorimetric sensitivity and rapid response to volatile amines. Moreover, a satisfactory antibacterial ability for S. aureus and E. coli were also evidenced: HACC/PVA-BA (1:4) membranes achieved a maximum inhibition rate of 64.9% for E. coli and 62.2% for S. aureus. Once applied to monitor the freshness of shrimp stored at 4 °C, the HACC/PVA-BA (1:4) membranes were able to indicate shrimp freshness through visually recognizable color changes within 3 h, which correlated strongly with the spoilage indicators of total volatile basic nitrogen, total viable count, and pH value. It is suggested that the intelligent pH-responsive membranes show great potential for practical application in monitoring food freshness. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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13 pages, 1031 KB

Open AccessArticle

Origin Identification of Scutellariae radix Based on Multidimensional Quality Indicators and Machine Learning Algorithms

by Xiao-Lu Liu, Tong Zhu, Ming-Yue Zhang, Jun-Xuan Yang, Hua Li and Bin Yang

Molecules 2026, 31(4), 680; https://doi.org/10.3390/molecules31040680 - 15 Feb 2026

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Abstract

This study aims to establish an origin identification method for Scutellariae radix that integrates multidimensional quality indicators and machine learning algorithms, enabling accurate and rapid traceability of Scutellariae radix medicinal materials from four production areas: Hebei (HB), Shanxi (SX), Shaanxi (SAX), and Chengde [...] Read more.

This study aims to establish an origin identification method for Scutellariae radix that integrates multidimensional quality indicators and machine learning algorithms, enabling accurate and rapid traceability of Scutellariae radix medicinal materials from four production areas: Hebei (HB), Shanxi (SX), Shaanxi (SAX), and Chengde (CD). The study collected a total of 43 batches of Scutellariae radix samples from the aforementioned origins. It systematically measured 12 key quality indicators covering flavonoids, physicochemical parameters, chromaticity values, and biological activity. These specifically include four flavonoid components: baicalin, wogonoside, baicalein, and wogonin; three physicochemical parameters: moisture content, ash content, and alcohol-soluble extract; four chromaticity values: L*, a*, b*, and ΔE; and in vitro anti-inflammatory activity (IC₅₀ value for NO clearance). On the basis of these parameters, in this study there were five machine learning models constructed based on the following algorithms and methods: Random Forest (RF), Extreme Learning Machine (ELM), Backpropagation Neural Network (BP), and Radial Basis Function Neural Network (RBF). A comparative analysis was conducted to evaluate the origin identification performance of each model. The results indicate significant differences (p < 0.05) in the contents of baicalin, wogonoside, L*, a*, b*, ΔE, and alcohol-soluble extract among Scutellariae radix from different origins. The comparative analysis of four machine learning models reveals that RF outperforms ELM, BP, and RBF in multiclass classification, achieving a test accuracy of 75% and consistent precision, recall, and F1-score of 79.17%. In contrast, the three neural networks attain only 66.67% test accuracy, with RBF showing high precision but low recall, ELM delivering moderate performance, and BP performing poorly. These results underscore the strength of ensemble methods like RF in small-sample settings, where they mitigate overfitting and enhance generalization, whereas neural networks struggle with limited data. We therefore recommend RF for deployment under current data constraints and suggest future work should focus on data expansion, especially for under-performing classes, along with hyperparameter tuning to further improve classification. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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29 pages, 2297 KB

Open AccessArticle

Integrated Nutritional, Spectroscopic and Technological Evaluation of Black Oat (Avena strigosa) and White Oat (Avena sativa L.) Cultivars

by Bogdan Cozma, Sylvestre Dossa, Antoanela Cozma, Daniela Stoin, Dacian Lalescu, Isidora Radulov, Ilinca Imbrea, Georgeta Pop, Laura Crista, Mariana Suba, Ersilia Alexa and Florin Imbrea

Molecules 2026, 31(4), 639; https://doi.org/10.3390/molecules31040639 - 12 Feb 2026

Viewed by 527

Abstract

Oat is increasingly recognized as a valuable cereal due to its favorable nutritional profile and potential application in functional foods. This study aimed to provide an integrated nutritional and technological evaluation of black oat (Avena strigosa) and white oat (Avena [...] Read more.

Oat is increasingly recognized as a valuable cereal due to its favorable nutritional profile and potential application in functional foods. This study aimed to provide an integrated nutritional and technological evaluation of black oat (Avena strigosa) and white oat (Avena sativa L.) cultivars Ovidiu, Jeremy, and Sorin, grown under uniform conditions. The chemical composition was assessed by determining proteins, lipids, total mineral and polyphenol contents. Macro- and microelement profiles (Ca, Mg, K, Na, Fe, Mn, Cu, Ni, and Zn) were quantified by atomic absorption spectrometry (AAS), while the technological suitability of black oat flour for bakery applications was evaluated using Mixolab analysis and bread quality parameters. Additionally, Fourier-transform infrared (FTIR) spectroscopy was applied to investigate structural features associated with β-glucans in the oat samples. The results showed that protein content ranged from 12.39 to 13.48%, while lipid content varied between 3.24 and 4.64%. Significant differences were observed in mineral composition among the analyzed samples. Black oat showed a balanced mineral profile, characterized by high levels of K, Mg, Mn, Zn, and Ni, confirming its classification as a mineral-rich cereal, while the Ovidiu cultivar generally presented the lowest concentrations for most elements. Mixolab results revealed that the partial substitution of wheat flour with black oat flour significantly influenced dough rheological behavior, particularly in terms of protein weakening and starch gelatinization, without severely affecting dough stability when applied at moderate inclusion levels. Bread quality evaluation demonstrated acceptable crumb elasticity, porosity, and height-to-diameter ratios, supporting the feasibility of incorporating black oat in bakery products. FTIR analysis revealed characteristic absorption bands associated with β-glucans, supporting their presence and structural integrity in both black oat and cultivated varieties. Overall, this study demonstrates that both black oat and selected oat cultivars represent valuable raw materials for functional food applications, offering enhanced nutritional profiles and suitable technological performance. The combined use of compositional, rheological, and spectroscopic analyses provides a comprehensive approach for evaluating oat-based ingredients in the context of modern cereal science. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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15 pages, 730 KB

Open AccessArticle

Optimizing the Flavor Profile of Brazilian Spirits: Torrefaction Modeling of Native Woods for Cachaça Maturation

by Amanda F. Reitenbach, Adriana Sturion Lorenzi, Nicole P. Catibe, Renata P. I. Tormena, Diego C. B. D. Santos, Ana Carolina Broch, Edgar A. Silveira, Talita Souza Carmo, Paulo Anselmo Z. Suarez and Grace F. Ghesti

Molecules 2026, 31(4), 633; https://doi.org/10.3390/molecules31040633 - 12 Feb 2026

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Abstract

Cachaça, a traditional Brazilian spirit, undergoes significant sensory refinement through barrel aging. In this study, we investigated how heat treatment of Brazilian woods (Balsam, Jaqueira, Jequitibá, Amburana, and Ipê) affects the sensory profile of cachaça, using Oak as a benchmark. Physicochemical [...] Read more.

Cachaça, a traditional Brazilian spirit, undergoes significant sensory refinement through barrel aging. In this study, we investigated how heat treatment of Brazilian woods (Balsam, Jaqueira, Jequitibá, Amburana, and Ipê) affects the sensory profile of cachaça, using Oak as a benchmark. Physicochemical characterization, toasting assessments, sensory analysis, and artificial intelligence (AI) were integrated to develop a predictive model for optimizing wood selection and heat-treatment conditions to achieve targeted sensory profiles. Applying this model, we produced a five-wood cachaça, a novel spirit distinguished by its complexity and customized sensory attributes. This approach reveals that each wood species develops distinct characteristics depending on toasting parameters such as time and temperature, challenging the current Brazilian practice where a single toasting condition is applied to all woods without prior physicochemical analysis. Linking wood composition with sensory outcomes through AI, this work introduces an unprecedented product innovation and demonstrates the potential of multi-criteria analysis to guide spirit maturation, enhance product design, and reshape the beverage industry. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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16 pages, 493 KB

Open AccessArticle

Functional Properties of Chitosan Conjugated with Oleic Acid and Caffeic Acid and Its Application in Oil-in-Water Emulsions

by Tsung-Shi Yang, Tzu-Ying Ho and Tai-Ti Liu

Molecules 2026, 31(3), 505; https://doi.org/10.3390/molecules31030505 - 2 Feb 2026

Viewed by 378

Abstract

The objective of this study was to develop multifunctional chitosan (CT) derivatives by conjugating oleic acid (OLA) and caffeic acid (CAF) to improve water solubility at neutral pH, enhance interfacial activity, and provide antioxidant protection in oil-in-water emulsions. Two CAF-incorporation strategies—1-(3-dimethylaminopropyl)-3-ethylcarbodiimide·HCl/N-hydroxysuccinimide (EDC/NHS)-mediated amide [...] Read more.

The objective of this study was to develop multifunctional chitosan (CT) derivatives by conjugating oleic acid (OLA) and caffeic acid (CAF) to improve water solubility at neutral pH, enhance interfacial activity, and provide antioxidant protection in oil-in-water emulsions. Two CAF-incorporation strategies—1-(3-dimethylaminopropyl)-3-ethylcarbodiimide·HCl/N-hydroxysuccinimide (EDC/NHS)-mediated amide coupling and ascorbic acid/H₂O₂-initiated free radical grafting—were employed to functionalize the CT–OLA backbone. The CT–OLA–CAF conjugates generated via the free radical pathway exhibited markedly lower viscosity and interfacial tension than those produced through EDC/NHS coupling, thereby highlighting the respective advantages and limitations associated with these two synthesis approaches. Chemically, CAF incorporation substantially enhanced the antioxidant capacity of the conjugates—surpassing that of both CT and CT—OLA and conferred excellent protection to photo-oxidatively labile β-carotene in o/w emulsions. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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16 pages, 1767 KB

Open AccessArticle

Unveiling Fermentation Effects on the Functional Composition of Taiwanese Native Teas

by Wei-Ting Hung, Chih-Chun Kuo, Jheng-Jhe Lu, Fu-Sheng Yang, Yu-Ling Cheng, Yi-Jen Sung, Chiao-Sung Chiou, Hsuan-Han Huang, Tsung-Chen Su, Hsien-Tsung Tsai and Kuan-Chen Cheng

Molecules 2026, 31(1), 171; https://doi.org/10.3390/molecules31010171 - 1 Jan 2026

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Abstract

Tea’s chemical composition is influenced by cultivar, harvest maturity, and growing environment; however, processing remains the dominant factor shaping final quality. Despite the diversity of Taiwanese native teas, systematic comparisons of functional components across multiple manufacturing stages remain limited. In this study, nine [...] Read more.

Tea’s chemical composition is influenced by cultivar, harvest maturity, and growing environment; however, processing remains the dominant factor shaping final quality. Despite the diversity of Taiwanese native teas, systematic comparisons of functional components across multiple manufacturing stages remain limited. In this study, nine representative Taiwanese teas were evaluated at four key processing stages—green tea (G), enzymatic fermentation (oxidative fermentation, F), semi-finished tea prior to roasting (S), and completed tea (C)—to clarify how enzymatic oxidation, rolling, and roasting alter major bioactive constituents. Green-tea-stage samples exhibited clear cultivar-dependent profiles: large-leaf cultivars contained higher catechins and gallic acid, whereas bud-rich small-leaf teas showed elevated caffeine and amino acids, with amino acids further enhanced at higher elevations. Fermentation intensity governed the major chemical transitions, including catechin depletion, gallic acid formation, accumulation of early stage catechin-derived paired oxidative polymerization compounds (POPCs), and pronounced increases in theasinensins in heavily fermented teas. L-theanine decreased most markedly in teas subjected to prolonged withering. Roasting further reduced amino acids but had minimal influence on caffeine, while rolling effects varied by tea type. Overall, this study provides the first stage-resolved chemical map of Taiwanese native teas, offering practical insights for optimizing processing strategies to enhance functional phytochemical profiles. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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20 pages, 2159 KB

Open AccessArticle

¹H-NMR Analysis of Wine Metabolites: Method Development and Validation

by Guillaume Leleu, Rémi Butelle, Daniel Jacob, Lou-Ann Kurkiewicz, Jean-Claude Boulet, Catherine Deborde, Matthieu Dubernet, Laetitia Gaillard, Antoine Galvan, Karen Gaudin, Alexandra Gossé, Markus Herderich, Annick Moing, Sophie Rosset, Flynn Watson, Gregory Da Costa and Tristan Richard

Molecules 2026, 31(1), 65; https://doi.org/10.3390/molecules31010065 - 24 Dec 2025

Viewed by 988

Abstract

Wine, as a high-value product, is vulnerable to counterfeiting. To tackle increasingly sophisticated fraud, innovative analytical approaches are required. However, they must undergo rigorous validation. Proton nuclear magnetic resonance spectroscopy (¹H-NMR) is intrinsically quantitative, reproducible, and fast, making it a promising [...] Read more.

Wine, as a high-value product, is vulnerable to counterfeiting. To tackle increasingly sophisticated fraud, innovative analytical approaches are required. However, they must undergo rigorous validation. Proton nuclear magnetic resonance spectroscopy (¹H-NMR) is intrinsically quantitative, reproducible, and fast, making it a promising tool for official control. This study presents the development and validation of a standardised and fully automated workflow for the quantification of 20 oenologically relevant compounds, including organic acids, sugars, alcohols, esters, phenolics, and an alkaloid. The method combines optimised sample preparation, external quantification standards, spectrometer calibration, and a dedicated R package (RnmrQuant1D) for fully automated spectral processing, enabling high-throughput and operator-independent analysis. Validation was performed under intermediate precision according to OIV metrological standards, evaluating accuracy, precision, robustness, limits of quantification, and measurement uncertainty. The results demonstrated excellent linearity, trueness, and reproducibility, matching the targeted analytical performance. Measurement uncertainties were estimated both by conventional linear modelling and by a dynamic approach better suited to detection limits. The workflow is easy to implement, requires minimal sample consumption, and substantially reduces operator bias. Beyond validating a robust method, this study provides a framework for harmonised, transferable ¹H-NMR workflows that could support large-scale databases, integration with chemometric models, and ultimately, ¹H-NMR’s recognition as a relevant method for wine authentication and quality control. This work fills a crucial gap in wine analysis by uniting practical application and rigorous methods, enabling broader adoption in control laboratories worldwide. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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14 pages, 16405 KB

Open AccessArticle

Influence of Arabic Gum/Gelatin/Ascorbyl Palmitate Coating on Quality Parameters of Hazelnut Kernels Stored in Plastic Boxes

by Dariusz Kowalczyk, Katarzyna Niedźwiadek, Tomasz Skrzypek, Emil Zięba and Jaromir Jarecki

Molecules 2025, 30(20), 4126; https://doi.org/10.3390/molecules30204126 - 19 Oct 2025

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Abstract

Edible coatings enriched with antioxidants offer a promising approach to prolong the shelf life of oxidation-sensitive foods such as nuts. Nonetheless, not all formulations provide the expected protection, and understanding why is equally important. The aim of this study was to assess the [...] Read more.

Edible coatings enriched with antioxidants offer a promising approach to prolong the shelf life of oxidation-sensitive foods such as nuts. Nonetheless, not all formulations provide the expected protection, and understanding why is equally important. The aim of this study was to assess the effect of an Arabic gum/gelatin/ascorbyl palmitate (GAR/GEL/AP) coating on the quality of hazelnut kernels during storage at 23 °C and ~40% relative humidity. The coating was applied by dipping hazelnuts in a 20% ethanolic solution containing GAR/GEL 75/25 blend (10% w/w), glycerol (1% w/w), Tween 80 (0.25% w/w), and AP (2% w/w), followed by drying. Control (uncoated) and coated hazelnuts were stored in plastic containers and evaluated at 1, 2, 4, 8, and 16 weeks for weight loss, moisture content, hardness, color, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH*) scavenging activity, acid and peroxide values, and thiobarbituric acid reactive substances (TBARS) level. Coated hazelnuts showed higher initial moisture content (8.17%), stabilizing at 4.80% after one week, compared to 3.35% in uncoated samples. This increased moisture led to greater storage-related weight loss. The coating darkened the nuts and reduced their yellow hue. It had no significant effect on hardness, peroxide value, or TBARS index, but notably enhanced the antiradical potential. After 16 weeks, coated nuts had an acid value ~10 mg KOH/g lower than the control. In conclusion, the coating improved antioxidant capacity and reduced hydrolytic, but not oxidative, rancidity in hazelnuts. Therefore, further optimization of the coating formulation or application method is necessary to more effectively improve the shelf life of hazelnuts. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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11 pages, 1368 KB

Open AccessArticle

Ionizing Radiation-Induced Structural Modification of Isoegomaketone and Its Anti-Inflammatory Activity

by Euna Choi, Chang Hyun Jin, Trung Huy Ngo, Jisu Park, Joo-Won Nam and Ah-Reum Han

Molecules 2025, 30(17), 3466; https://doi.org/10.3390/molecules30173466 - 23 Aug 2025

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Abstract

Isoegomaketone [(E)-1-(furan-3-yl)-4-methylpent-2-en-1-one; 1] is abundant in the essential oil of Perilla species and exhibits various biological activities, such as anticancer and anti-inflammatory effects. In order to discover compounds with reduced toxicity or enhanced biological activity through structural modification of natural [...] Read more.

Isoegomaketone [(E)-1-(furan-3-yl)-4-methylpent-2-en-1-one; 1] is abundant in the essential oil of Perilla species and exhibits various biological activities, such as anticancer and anti-inflammatory effects. In order to discover compounds with reduced toxicity or enhanced biological activity through structural modification of natural product-derived components, isoegomaketone was irradiated with an electron beam at five different doses, and (±)-8-methoxy-perilla ketone (2) was obtained with the highest yield of 3.8% (w/w) at 80 kGy. Its structure was identified by one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy and high-resolution chemical ionization mass spectrometry. Compound 2 inhibited nitric oxide production and inducible nitric oxide synthase mRNA expression in a dose-dependent manner in lipopolysaccharide-stimulated RAW 264.7 cells. It also dose-dependently suppressed the mRNA expression of pro-inflammatory mediators such as IL-1β, IFN-β, and MCP-1, while having no significant effect on IL-6 mRNA levels. Furthermore, ELISA analysis demonstrated that 2 reduced MCP-1 protein expression but did not affect the protein level of TNF-α or IL-6. This study provides a reference for the structural analysis of compounds related to 2 by presenting NMR data acquired with chloroform-d, and is the first to report the anti-inflammatory properties of 2. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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Review

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16 pages, 1297 KB

Open AccessReview

Strategies for Metabolic Engineering of Escherichia coli for β-Carotene Biosynthesis

by Jiali Liu, Yilin Shi, Daxin Zhao, Minghao Lin, Ping Wang, Ying Zhou and Xiaohui Yan

Molecules 2026, 31(4), 611; https://doi.org/10.3390/molecules31040611 - 10 Feb 2026

Viewed by 1085

Abstract

β-Carotene has extensive applications in the food, pharmaceutical, and cosmetics industries. Traditional chemical synthesis methods face challenges such as byproduct residues and high costs, whereas natural extraction is constrained by low yields and complex processes. Recent advancements in synthetic biology and metabolic engineering [...] Read more.

β-Carotene has extensive applications in the food, pharmaceutical, and cosmetics industries. Traditional chemical synthesis methods face challenges such as byproduct residues and high costs, whereas natural extraction is constrained by low yields and complex processes. Recent advancements in synthetic biology and metabolic engineering have paved the way for the heterologous biosynthesis of β-carotene in microorganisms. Owing to its rapid growth, convenience of genetic manipulation, and suitability for producing apocarotenoids, Escherichia coli is an ideal host for the production of β-carotene and its derivatives, as exemplified by the record production of multiple apocarotenoids in engineered E. coli strains. Here, we summarize the metabolic engineering strategies employed to produce β-carotene in E. coli, including manipulation of the endogenous MEP pathway, introduction of the hybrid MVA pathway, modulation of central carbon metabolism, modification of the cell membrane, and fermentation process optimization. As β-carotene acts as a biosynthetic hub for many carotenoids and apocarotenoids, we also highlighted the importance of efficient β-carotene production for the sustainable preparation of these compounds. This review aims to provide theoretical insights for designing talented β-carotene producers and laying the foundation for the sustainable manufacturing of valuable carotenoids and apocarotenoids. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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17 pages, 1956 KB

Open AccessReview

Cork By-Products as Bioactive Ingredients: From Waste Valorization to Pharmaceutical Prototypes

by Nuno Miguel Silva, Ana Colette Maurício, Ruben Fernandes and Ana Novo Barros

Molecules 2026, 31(1), 95; https://doi.org/10.3390/molecules31010095 - 25 Dec 2025

Cited by 1 | Viewed by 1074

Abstract

The pharmaceutical sector has evolved toward innovation-driven and sustainability-oriented development, driven by increasing regulatory pressure and global health challenges. In this context, cork (Quercus suber L.) has emerged as a promising bio-based resource due to its renewable nature, near-zero-waste processing chain, and [...] Read more.

The pharmaceutical sector has evolved toward innovation-driven and sustainability-oriented development, driven by increasing regulatory pressure and global health challenges. In this context, cork (Quercus suber L.) has emerged as a promising bio-based resource due to its renewable nature, near-zero-waste processing chain, and growing evidence of biological activity. Cork by-products are rich in phenolic compounds, triterpenes, lignin derivatives, and other secondary metabolites exhibiting antioxidant, anti-inflammatory, and anti-aging properties, with relevance for pharmaceutical and dermocosmetic applications. These bioactivities are associated with the modulation of oxidative stress, inhibition of pro-inflammatory signaling pathways, and support of skin barrier function. This review provides an updated and focused overview of the chemical composition, bioactive potential, and valorization pathways of cork by-products, with particular emphasis on their translation into pharmaceutical and dermocosmetic formulations. Key challenges related to extraction standardization, bioavailability, safety, and clinical validation are critically discussed, highlighting future directions for the sustainable development of cork-derived bioactive ingredients within circular bioeconomy frameworks. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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22 pages, 1814 KB

Open AccessReview

Microalgae and Macroalgae as Advanced Sources of Tyrosinase Inhibitors

by Joanna Harasym and Katarzyna Hałdys

Molecules 2026, 31(1), 20; https://doi.org/10.3390/molecules31010020 - 20 Dec 2025

Cited by 1 | Viewed by 1034

Abstract

Tyrosinase (EC 1.14.18.1) is the primary enzyme responsible for melanogenesis in mammals and enzymatic browning in food, creating a high demand for potent, safe inhibitors of this enzyme in the cosmetic, medical, and agricultural sectors. Conventional synthetic inhibitors often face limitations concerning their [...] Read more.

Tyrosinase (EC 1.14.18.1) is the primary enzyme responsible for melanogenesis in mammals and enzymatic browning in food, creating a high demand for potent, safe inhibitors of this enzyme in the cosmetic, medical, and agricultural sectors. Conventional synthetic inhibitors often face limitations concerning their cytotoxicity and stability, necessitating the exploration of marine natural products (MNPs). Marine algae, comprising macroalgae (seaweeds) and microalgae (including cyanobacteria), represent an underexploited source of structurally diverse bioactives. Macroalgae, particularly brown species, yield complex phlorotannins, such as the non-competitive oligomer dieckol, which exhibits an IC50 of 2.16 µg/mL. Conversely, microalgae deliver high-potency, low-molecular-weight compounds, notably the synthesizable scytonemin monomer (ScyM) with an IC50 of 4.90 µM—significantly stronger than kojic acid. Mechanistic analysis, supported by molecular docking, reveals diverse modes of action, from the two-step slow binding of complex phlorotannins to the highly specific competitive binding of red algal bromophenols. Translational success requires the consistent application of green extraction techniques, such as Natural Deep Eutectic Solvents (NADESs), and advanced delivery systems, like Nanostructured Lipid Carriers (NLCs), to ensure the stability and bioavailability of these compounds for future cosmeceutical and medical applications. Full article

(This article belongs to the Special Issue 30th Anniversary of Molecules—Recent Advances in Food Chemistry)

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