Chemistry and Materials Science

Abstract: Anaerobic fermentation has emerged as an increasingly important post-harvest processing strategy in specialty coffee production, offering opportunities to modify the biochemical composition of coffee cherries and influence the sensory characteristics of the resulting beverage. Unlike conventional fermentation approaches, oxygen-restricted processing can create distinct microbial and physicochemical environments that affect substrate utilization, metabolite production, and the development of aroma-related compounds. This review examines the biochemical and chemical mechanisms underlying anaerobic fermentation in specialty coffee, with particular emphasis on microbial ecology, carbohydrate metabolism, organic acid production, amino acid transformations, and the formation of volatile and non-volatile metabolites. The metabolic contributions of yeasts and bacteria are considered in relation to changes in the chemical composition of coffee during fermentation. Particular attention is given to esters, higher alcohols, aldehydes, ketones, and other volatile compounds associated with aroma development, as well as the potential role of fermentation-derived metabolites as precursors of roasting-related flavor compounds. The influence of fermentation parameters, including temperature, duration, pH, oxygen availability, and microbial composition, is also critically discussed. Furthermore, analytical approaches such as gas chromatography–mass spectrometry, liquid chromatography, and metabolomics are examined for their contributions to chemical characterization and process evaluation. Finally, current knowledge gaps concerning microbial interactions, metabolic pathways, process reproducibility, and sensory outcomes are identified. A more integrated understanding of microbial metabolism and chemical transformations is essential for developing controlled, reproducible, and scientifically optimized anaerobic fermentation strategies for specialty coffee.

Abstract: A survey of multi-mycotoxin contamination was conducted in processed cereal-based foods intended for children and infants/toddlers in Tirana, Albania. Fourteen mycotoxins were quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Mycotoxins were detected in all cornflakes and maize flour samples, as well as in all infant cereals. Aflatoxin B1 (AFB1, 100%) and AFB2 (50.0%) frequently co-occurred in cornflakes, with the highest concentrations observed in cornflakes (0.469 µg/kg) and maize flour (4.469 µg/kg); both commodities exhibited 100% contamination. AFB1 was the most prevalent mycotoxin (88.2%), followed by deoxynivalenol (DON, 76.5%), fumonisin B1 (58.8%), fumonisin B2 (52.9%), and zearalenone (ZEA, 23.5%). ZEA, a phytoestrogenic mycotoxin, reached 97.5 µg/kg in maize flour, exceeding the European Union (EU) maximum level of 75 µg/kg for maize milling products placed on the market for the final consumer. Although AFB1 was detected in 50.0% of infant cereal samples, the mean concentration was low (0.005 µg/kg), and DON, although detected in all samples, remained low (mean 11.6 µg/kg). T-2, DAS, 3-AcDON, 15-AcDON, and OTA were not detected. The findings showed a matrix-dependent contamination pattern, with AFB1 and DON as the most frequently detected analytes. While most toxin concentrations were below EU regulatory limits, the observed exceedances of AFB1, fumonisins and ZEA in maize flour point out the necessity for intensified monitoring, stricter raw material controls, and risk reduction measures within cereal supply chains.

Abstract: Representative sampling for microbiological testing is limited because contamination is rare and heterogeneously distributed. Conventional excision and grab methods consume product, cover limited surface area, and require substantial labor. Rinse samples, such as those used for poultry carcasses and parts, are difficult to aggregate across a lot. Cloth-based sampling uses a sterile porous polymeric material to transfer microorganisms from food or environmental surfaces into a sample suitable for culture, enrichment, enumeration, or molecular analysis. This review describes the physical and statistical principles of cloth sampling, distinguishes localized collection from aggregated sampling, and examines applications in beef, poultry, fresh produce, and environmental monitoring. Beef studies and U.S. regulatory implementation provide the strongest evidence base, demonstrating the efficacy of cloth-based sampling for the validated raw-beef-trim application. Poultry comparisons support cloth sampling as a nondestructive alternative to rinse collection under specified conditions. Recent commercial produce work indicates that time-integrated cloth collection can match or exceed grab-sample detection frequencies for selected microbial index targets, while penetrative formats may improve access to difficult-to-sample leafy-green surfaces. Performance depends on cloth material, moisture, contact mechanics, product geometry, target location, transport, and laboratory recovery. Cloth sampling should therefore be validated as a complete sampling system rather than assumed to be universally equivalent across matrices. Future work should quantify transfer and release kinetics, effective sampled surface or mass, uncertainty, lot boundaries, and compatibility with quantitative and culture-independent analyses.

Abstract: Bitter melon (Momordica charantia L.) is widely used as an antidiabetic food and traditional remedy, but the causes of variation in its bioactive content remain unclear. This study aimed to investigate whether genotype or growing conditions are the primary determinants of this variation. ITS barcoding identified all ten accessions as M. charantia, but genetic relationships only partly corresponded to agricultural classification and did not predict chemotypes. The native Pathum Thani genotype was grown at four sites, and charantin content varied ninefold (2.56–23.73 mg/100 mg extract), exceeding the range observed among the ten accessions and showing a negative correlation with soil pH. In addition, fertilizer form affected the two markers in opposite ways: manure alone maximised charantin, whereas manure plus 15-15-15 fertilizer maximised momordicine, suggesting a potential trade-off between the sterol and cucurbitane biosynthetic pathways. Charantin was as potent as acarbose in inhibiting α-glucosidase and α-amylase, extract potency correlated with charantin content, and consensus docking predicted that the glucosyl moiety was positioned near the catalytic residues. In streptozotocin-injured β-cells, charantin conferred stronger cytoprotection, whereas momordicine induced the highest insulin release. The native Pathum Thani extract was consistently the most active, including in assays of myotube glucose uptake. Standardised bitter melon products therefore require both charantin and momordicine as quality-control markers, together with controlled cultivation practices, rather than selection based solely on agricultural classification.

Abstract: Resveratrol is a phenolic compound with recognized antioxidant activity; however, its application is limited by its low stability and poor gastrointestinal bioavailability. This study investigated the functionalization of zein with resveratrol through a free radical-mediated grafting reaction using an ascorbic acid/hydrogen peroxide redox system and evaluated the effect of dialysis on the resulting conjugates. The materials were characterized by UV–Vis, FTIR, XPS, XRD, SEM, DSC, and TGA. Protein and total phenolic contents were determined using the Bradford and Folin–Ciocalteu assays, antioxidant activity was evaluated by ABTS and DPPH, and stability was assessed under simulated gastrointestinal digestion. Spectroscopic, structural, morphological, and thermal analyses indicated modifications in the zein matrix after functionalization, with dialysis producing a more homogeneous surface morphology. The functionalized materials exhibited significantly higher antioxidant activity than native zein, reaching ABTS and DPPH inhibition values of 87–93% and 84–86%, respectively, comparable to free resveratrol. During simulated gastrointestinal digestion, the conjugates maintained resveratrol contents between 885.9 and 1115.0 μmol GAE/g, although significant time-dependent variations were detected within each treatment (p < 0.05). Overall, free radical-mediated functionalization provided zein–resveratrol conjugates with improved physicochemical stability while preserving the antioxidant properties of resveratrol, supporting their potential application as protein-based delivery systems for phenolic bioactive compounds.

Abstract: The persistence Postharvest losses of Tomato and other perishable fruits rise an urgenet need biodegradable and environmentally benign preservation methods. Polysaccharide-based edible coatings have shown great potential as alternatives to conventional synthetic methods for postharvest treatments due to their film-forming ability, biodegradability, biocompatibility, antimicrobial, and antioxidant carrier capabilities. This review examines the application of polysaccharide edible coatings as a sustainable preservation technique for tomatoes and other selected perishable fruits by considering their sources, functional and structural properties, in edible coating applications, focusing on their concentrations and preservation outcomes. Findings from published studies reveal that polysaccharide-based coatings reduce physiological weight loss, respiration rate, softening, ethylene production, colour change, and microbial damage, while enhancing nutritional constituents, hence extending the overall postharvest shelf life. Depending on the polymer concentration, molecular properties, fruit species, storage temperature, and coating formulation, it further demonstrated that, incorporating coatings with two or more polysaccharides, essential oils, plant extracts, and nanoparticles show improved preservative properties. The study suggests further studies on the development of low-cost, multifunctional, food-safe, polysaccharide-based coatings, especially those sourced from agricultural waste and other locally available resources. Such innovations could significantly contribute to sustainable postharvest control, food security, and environmentally benign food packaging systems.

Abstract: Phenylketonuria (PKU) requires lifelong adherence to a strict low phenylalanine (Phe) diet. However, PKU friendly foods remain limited in variety and sensory appeal, contributing to poor dietary compliance, especially in children. Objective: This study aimed to develop innovative, personalized snacks using 3D food printing and casein glycomacropeptide (CGMP)—a naturally low Phe protein source—to improve dietary diversity and palatability for individuals with PKU. Methods: Two snack prototypes were formulated: (1) a short-crust pastry shell filled with a CGMP based gel, and (2) a 3D printed chocolate shell filled with a CGMP based mousse. Functional ingredients included tagatose (a low glycemic sweetener) and glucomannan (a hydrocolloid stabilizer). Sensory evaluation was conducted with 40 panelists using a five point hedonic scale assessing appearance, smell, taste, flavour, texture, and overall liking. Results: All prototypes contained very low phenylalanine levels (approximately 3 mg per serving), contributing to the expansion of available low‑Phe food options. Although the amino acid profile is not complete, the formulations provide relevant amounts of several essential amino acids—particularly threonine, isoleucine, and valine—and can be further optimized in future development. Sensory evaluation indicated high overall liking, with the peanut‑flavored mousse and the short‑crust pastry achieving the highest scores.. Conclusion: Combining CGMP based formulations with 3D food printing offers a promising strategy for developing safe, palatable, and customizable PKU snacks. Precise portioning, personalized shapes, and improved sensory quality may help address current market limitations and support long term dietary adherence.

Abstract: Stevia (Stevia rebaudiana) is processed industrially mainly for steviol glycosides, whereas its co-occurring chlorogenic acids—especially dicaffeoylquinic acids (diCQAs)—are emerging value-added food and feed ingredients. The stability of a commercial stevia chlorogenic acid product (total acids 61.39%; diCQAs 53.79%) was evaluated in the solid state and in 80% aqueous methanol under heat (80–180 °C), light, oxygen, metal-ion (Fe³⁺, Cu²⁺), pH (3.0–8.0), and solvent conditions. In solids, total acid loss remained below 10% at ≤140 °C (≤4 h) and was 2.12% at ≤100 °C for 24 h, but rose to 45.45% (160 °C) and 93.21% (180 °C) after 4 h; LC–MS revealed degradation, methylation, acetylation, and diCQA lactonization products that accumulated below 160 °C and degraded above 180 °C. In solution, total acid content was conserved at 60–80 °C, as acyl migration converted 4,5-diCQA and 5-CQA to more stable isomers. Fe³⁺ and Cu²⁺ formed reversible insoluble diCQA complexes (98.36–99.81% recovery after EDTA) that accelerated light- and oxidation-induced loss, Cu²⁺ more strongly. Hydrolytic loss predominated at pH 3.0–4.0 and was buffered by monomer interconversion at pH 5.0–8.0. These findings define a safe processing/storage window (≤140 °C solids; ≤80 °C, metal-ion-free, sealed opaque liquids) and provide a mechanistic basis for quality control.

Abstract: Osmunda japonica sporophyll is a medicinal food source in China and Southeast Asia. However, its functional components are still unknown and its spores are not utilized. This study aims to analyze the main functional compounds of its sporophylls and spores. Selenium-enrichment cultivation of O. japonica was conducted and the main components of sporophylls and spores were comparatively analyzed using ultraviolet-visible spectrum, high performance liquid chromatagraphy and mass spectrum. The common phenolics of spores and sporophylls were chlorogenic acid, caffeic acid and kaempferol-3-rutinoside; sporophylls contained one more component as caffeic acid-3-O-(2’-O-butenyl) rahmnoside; caffeic acid was the main phenolic component in spores (2.15±0.09 g/100g, dried weight); contents of caffeic acid (2.36±0.1 g/100g, dried weight), kaempferol-3-rutinoside (2.69±0.15 g/100g, dried weight), polysaccharides (3.53±0.23 g/100g, dried weight), carotenoids (364±34.9 mg/100g, fresh weight) and chlorophylls (437±40.2 mg/100g, fresh weight) of spores were all significantly higher than those of sporophylls (P＜0.05). The organic selenium components of spores were Se-Cys(selenocysteine) and Se-Met (selenomethoine); Se-Cys, Se-Met, chlorogenic acid, carotenoids and chlorophylls were all significantly increased by selenium enrichment (R²＞0.9). In conclusion, selenium-enriched japonica spores showed highly nutritional and medicinal values and should be developed as a new medicinal food source and selenium supplementation food source.

Abstract: Polycyclic aromatic hydrocarbons (PAHs) are toxic thermal contaminants which accumulate in meat products during high-temperature culinary operations. With the aim of evaluating the chemical variation and regional distribution of these carcinogenic compounds, published concentration profiles of 16 EPA-priority PAHs in cooked meat and sausage samples originating from Iran, Nigeria and Poland were used to perform a meta-analysis. Following data preprocessing and variable reduction, the sparse reporting was refined, reducing the dataset to 12 representative PAH variables followed by multivariate outlier diagnostic screening. Principal component analysis (PCA) was then executed on standardized correlation matrices which revealed that the first two principal components accounted for 66.2% of the total dataset variance. Distinct geographical clustering was observed with PC1 primarily discriminating Iranian samples from Polish and Nigerian products, while PC2 further separated Iranian and Nigerian groups. These patterns reflect differences in regional preparation techniques, such as high-temperature direct-flam grilling compared to traditional smoking processes. These results thus, demonstrate that multivariate chemometric modeling effectively classifies meat contamination patterns across international origins and highlights the significant influence of regional cooking methods on PAH accumulation.

Abstract: Toxic element impurities in food additives may contribute to the dietary exposure to arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg). This study aimed to quantify these toxic elements in selected food additives available on the Belgian market and to assess their contribution to dietary exposure and associated health risks. Seventeen food additives were analysed using ICP-MS/MS, direct mercury analysis, and LC-ICP-MS. Dietary exposure to toxic elements originating from food additives was estimated for different age groups using probabilistic modelling based on occurrence data and EFSA intake estimates for the food additives. The highest element concentra-tions were measured in algae-based additives, notably sodium alginate and carragee-nan. Arsenic speciation showed predominantly organic forms in sodium alginate, while carrageenan contained up to 32% inorganic arsenic. Mineral additives and pec-tin also contributed to toxic element occurrence, whereas additives produced via a purification process showed negligible levels. The exposure to Pb through the com-bined intake of multiple food additives may reach up to ~18% of total dietary Pb ex-posure in adults. For children, margins of exposure for Pb and inorganic As were low (≈2–6), indicating that a health concern cannot be excluded. Exposure to Cd and Hg remained well below health-based guidance values.

Abstract: Green coffee defects are evaluated worldwide as visible abnormalities, physical damage, foreign matter or off-odor, yet the relationship between a grading label and cup quality is neither direct nor uniform. This review integrates international and national classification systems with evidence on defect formation, green-bean composition, roasting chemistry and sensory consequences. It shows that standards differ fundamentally in sample mass, counting basis, legal status and intended purpose, so their values cannot be converted into a common sensory scale. Defects are best understood as disturbances to precursor pools or as processing and safety risks rather than as fixed flavor entities. The strongest chemical evidence concerns black, sour/brown, immature, insect-damaged and aged beans; many other visible categories lack defect-specific odor-active or dose–response data. The term quaker illustrates the central nomenclature problem: standards commonly join it to immature beans, whereas a differentiated physiological position treats emaciated beans as a separate pathway. Rio flavor and potato taste defect provide more specific chemical signatures than most visual defects. A precursor-centered framework is proposed to connect grading with analytical and roasting practice while retaining uncertainty where the evidence chain is incomplete.

Abstract: Purple rice (Oryza sativa L.) is a pigmented plant-based food whose starch is rich in the anthocyanins cyanidin-3-glucoside (C3G) and peonidin-3-glucoside (P3G), yet is largely rapidly digestible and confers a high glycemic index that limits its dietary use. Converting native starch into resistant starch type III (RS3) via dual autoclav-ing-retrogradation treatment (DART) or dual enzyme treatment (DET) lowers digesti-bility, but the conditions required compromise anthocyanin stability. This study tracked how these two food-processing routes govern phenolic and anthocyanin fate, structure and digestibility. RS3 content rose from 5.35% (native) to 34.13% (DART) and 51.34% (DET), while total phenolic content fell by 76.1% and 71.4% and the starch darkened (L* 68.27 to 43.49 and 28.25); free C3G became undetectable after DART but was partly retained (11.86 mg/100 g) after DET. X-ray diffraction showed A-type to B-type conversion after DART, whereas DET gave a mixed B+V-type pattern with a diagnostic peak near 2θ ≈ 19°, coinciding with greater phenolic retention. Both RS3 products resisted simulated digestion, with DET-RS3 limiting intestinal hydrolysis to 12.72% versus 30.71% for native starch. Processing thus entails a nutritional trade-off, partly offset in DET by amylose-phenolic complexation, positioning purple-rice RS3 as a candidate colon-targeted antioxidant delivery vehicle.

Abstract: Improving the efficiency of pelleted compound feed production requires optimizing process parameters while considering the use of new protein components that provide high nutritional value without compromising technological properties. The aim of the study was to optimize the parameters for producing pelleted compound feed using a feed enrichment concentrate (FEC) based on natural, multi-protein raw materials of animal origin. The study examined the effects of mixing duration, feed mixture moisture content before pelleting, and the FEC addition rate on pelleted feed quality. Process efficiency was assessed based on feed mixture homogeneity, pellet strength and crumbliness, and key chemical composition indicators. The optimal mixing duration was 9 minutes, while the most favorable moisture content before granulation was 16%, ensuring high mixture homogeneity, maximum pellet strength, and minimal crumbling. The introduction of FEC did not negatively affect production processes or the physical and mechanical properties of pelleted feed compared to the control. At the same time, FEC increased crude and digestible protein and crude fiber content while maintaining high energy value. The 20% FEC treatment was the most effective, confirming the feasibility of its industrial application.

Abstract: Inappropriate concentrations of elements in formulae for infants may lead to adverse health effects. Selenium (Se) is a trace element essential for the proper development of infants. It is naturally present in human milk and is also added to infant formulae. However, both insufficient and excessive Se intake may be harmful. The aim of this study was to determine the Se concentrations and chemical forms in all formulae for infants available on the Polish market and to assess their nutritional safety. Se concentrations were determined using inductively coupled plasma mass spectrometry (ICP‑iCRC‑MS). Se speciation was performed using a HPLC system coupled to ICP‑iCRC‑MS. The Se concentrations in most analyzed formulae were in good agreement with the recommended EU limits (median 4.5 µg/100 kcal, range 0 – 15.6 µg/100 kcal). However, the estimated daily intake for 6‑month‑old infants exceeded the tolerable upper intake level in six formulae, indicating a potential health risk. Speciation analysis showed that the dominant Se forms were sodium selenite and sodium selenate, and their levels were mostly consistent with the manufacturers’ declarations. Additionally, trace amounts of selenometionine (SeMet) and methyloselenocysteine (MeSeCys) were detected. Therefore, regular monitoring of the composition of infant formulae remains necessary. The detection of SeMet and MeSeCys provides new avenues for research on Se content and Se speciation in formulae intended for infants.

Abstract: Psidium guajava L. leaves are a valuable source of phenolic compounds, particularly glycosylated flavonoids, with possible applications as standardized nutraceutical ingredients. However, the intrinsic variability of botanical matrices requires reproducible production processes integrating extraction optimization, phytochemical characterization, and biological validation. This study aimed to develop an integrated workflow for obtaining a standardized P. guajava leaf extract from a pilot cultivation in southeastern Sicily. A Design of Experiments (DoE) approach, implemented by MODDE software, was used to optimize the aqueous extraction process. The optimal extraction conditions were a drug-to-solvent ratio of 1:30 (w/v) and an extraction temperature and time of 95 °C and 24 min., respectively. The optimized crude extract yielded a dry residue of 0.81% w/v, with total polyphenol contents of 0.253% w/v and a total flavonoid content of 0.052% w/v. Comparative HPLC-DAD screening of two macroporous resins identified Resin B as the most effective material for flavonoid enrichment, mainly targeting avicularin, guaijaverin, and hyperoside, three biomarker compounds highly characteristic of this plant species. The resulting enriched extract showed a dry residue of 3.22% w/w and a total flavonoid content of 11.071% w/v, including 3.019% w/v avicularin, 2.845% w/v guaijaverin, and 1.196% w/v hyperoside. The enriched extract was subsequently formulated on a maltodextrin carrier to obtain a standardized ingredient with a total flavonoid content of 7.75% w/v. The final formulation exhibited strong antioxidant activity in cell-free assays and significantly reduced nitric oxide production in LPS-stimulated RAW264.7 macrophages, supporting its possible use as a reproducible botanical ingredient for nutraceutical applications.

Abstract: The increasing demand for functional beverages has stimulated interest in developing non-alcoholic beers with enhanced nutritional and health-promoting properties. This study investigated the effect of replacing 20–30% of barley malt with wheat bran enriched with linseed or sunflower seeds on the antioxidant activity, polyphenol content, vitamin composition, mineral profile, and selected physicochemical properties of non-alcoholic beer. The impact of adding oak chips (2% or 4% of the grist) during the third or fourth stage of mashing was also evaluated. Eight beer formulations were produced using different proportions of wheat bran, linseed, and sunflower seeds. The experimental beers were compared with a commercial Polish non-alcoholic beer, Żywiec 0%. The results demonstrate that partial substitution of barley malt with wheat bran enriched with linseed or sunflower seeds is an effective approach for producing non-alcoholic beer with enhanced antioxidant capacity and improved nutritional value, offering potential for the development of functional beer products.

Abstract: Phytosterols are key minor constituents of olive oil, contributing not only to its nutritional and bioactive properties but also to authenticity assessment, quality control, and regulatory classification. In Greek olive oils, particularly extra virgin olive oils produced from the dominant Koroneiki cultivar, sterolic composition represents a critical yet complex compositional marker, as total sterol content and specific sterol fractions may naturally approach regulatory thresholds without necessarily indicating adulteration or quality deterioration. This review critically synthesizes current knowledge on phytosterol profiling in Greek olive oil, emphasizing sterolic composition, analytical methodology, stability, and the principal biological, geographical, technological, and methodological factors governing sterolic variability. Particular attention is given to the characteristic sterolic fingerprint of Greek olive oils, dominated by β-sitosterol, Δ⁵-avenasterol, campesterol, stigmasterol, and Δ⁷-sterols, and to cultivar-dependent variation that may influence regulatory interpretation. The review further evaluates the official GC–FID analytical methodology, the complementary role of GC–MS and chemometric approaches, and the limitations of interpreting sterolic composition exclusively through fixed regulatory thresholds. This review proposes a context-dependent framework for interpreting phytosterol composition in authentic Greek olive oils and introduces the concept of the Near-Threshold Sterolic Space, describing the natural clustering of authentic oils close to regulatory decision limits as a consequence of cultivar- and terroir-driven biological variability. We argue that phytosterol data should be interpreted through an integrated framework combining regulatory thresholds, conditional verification criteria, cultivar-specific baselines, analytical methodology, and complementary compositional evidence. Overall, this review argues that phytosterol interpretation should evolve from a purely threshold-based regulatory exercise toward a biologically informed, method-aware and cultivar-sensitive framework that better reflects the natural complexity of Greek olive oils.

Abstract: This study looked at the distribution of major and minor volatile components in distillates created by combining two plum types, Stanley and Požegača. Two methods of blending were used: (i) during fermentation and (ii) by macerating fresh Požegača in raw Stanley distillate and then redistilling the mixture. Plums were combined in three different ratios: 90:10, 70:30, and 50:50. The blending was done to enhance the plum aroma of the drinks. Major volatile components were measured by GCxFID analysis, while minor components were measured using GCxGCxMS. All produced distillates had the usual values of the main volatile components. Compared to the blending procedure, the distribution of minor volatile components in the samples varied more according to the plum variety and its ratio in the blend. Nevertheless, samples made by fermentation mixing had higher concentrations of α-terpineol, heptanal, benzaldehyde, and γ-dodecalactone. Fresh plum maceration yielded significantly higher concentrations of benzyl alcohol, 2-phenylethanol, octanoic acid, and (E)-β-damascenone. The sensory perception of spirits is significantly influenced by terpenes. Stanley spirits are distinguished for myrcene, which gives them a pleasing mouthfeel. Geraniol α-terpeneol and γ-dodecalactone, which are more typical for Požegača spirit, have a positive impact on the plum like odour of spirits. Isopentyl acetate, ethyl octanoate, 2-phenylethyl acetate, ethyl dodecanoate, heptanol, and octanoic acid were other positive aromatic compounds. Blending different plum varieties is a successful way to improve the flavour profile of spirits.

Abstract: Octopus maya is a fast-growing species from the Yucatán Peninsula with high economic relevance, accounting for a major share of regional fishery production. However, a sig-nificant fraction of the organism, rich in type I collagen, is discarded as by-products, representing a promising and underutilized source for sustainable biomaterials. This study evaluated, through a 3² factorial design, the effect of two factors: (1) the type of food-grade polysaccharide, chitosan (Ch), hydroxypropyl methylcellulose (H), or starch (S), and (2) its proportion in blendings with Octopus maya insoluble collagen (CIPM), obtained by ultrasound-assisted extraction, using polysaccharide:collagen ratios of 30:70, 50:50, and 70:30 (w/w), and using rheological and dynamic mechanical properties of film-forming solutions (FFS) as response variables. This approach aims to valorize oc-topus by-products through the recovery and functional utilization of collagen. Rheo-logical properties were determined by rotational and oscillatory rheometry at 25 °C, with flow curves fitted to the Carreau-Yasuda model. All formulations exhibited pseu-doplastic behavior (n < 1), with viscosity decreasing as shear rate increased. Pure CIPM showed high viscosity (190.36 Pa·s at 1 s⁻¹), which decreased (0.3-10.44 Pa·s) in HPMC and chitosan systems, favoring applications requiring fluidity, such as spray coatings or film-forming solutions. In contrast, starch-based systems exhibited higher viscosities (33.54-197.53 Pa·s) and a more structured viscoelastic profile (G′ > G″), forming networks suitable for thick coatings or gels requiring structural stability. These results demonstrate that CIPM-polysaccharide systems enable tunable rheological properties, supporting the use of Octopus maya collagen as a sustainable functional material for advanced food and biomaterial design.