Search Results (359)

Euonymus maackii is an important ornamental tree species valued for its autumn foliage in northern China. To precisely elucidate the molecular mechanisms underlying the distinct leaf coloration types in E. maackii during autumn, this study aimed to identify the optimal reference genes for qRT-PCR normalization across different tissues, developmental stages, and autumn leaf coloration types. Using 10 different tissues of E. maackii as experimental materials, 10 candidate reference genes were comprehensively evaluated for expression stability using three software tools, including geNorm, and the RefFinder online platform, with structural genes of the pigment biosynthesis pathway employed for validation. The comprehensive evaluation revealed that TIP41 was the most stable reference gene across different tissues, developmental stages, and the full sample set; EF-1α exhibited the highest stability among samples representing different autumn leaf coloration types; and GAPDH was the least stable in all sample groups. Quantitative validation of target genes demonstrated that when EF-1α and TIP41 were used in combination for normalization, the expression patterns of pigment biosynthesis structural genes were highly consistent with the phenotypic changes observed in autumn leaf coloration. In summary, this study recommends TIP41 as a universal reference gene for expression analysis across different tissues and developmental stages of E. maackii; for studies involving different autumn leaf coloration types, a dual-reference normalization approach combining EF-1α and TIP41 is recommended. Full article

Cauliflower by-products represent a valuable source of bioactive compounds that can be valorized as functional ingredients within circular food systems; however, their stability is strongly influenced by processing conditions. This study evaluated the combined effects of plant section (leaves and stems) and drying method (freeze-drying, hot-air drying at 40 °C and solar drying at approximately 30–45 °C) on the nutritional composition, pigment content, antioxidant activity and colour of cauliflower by-product flours. Proximate composition, chlorophylls, carotenoids, total polyphenols, total flavonoids, glucosinolates, sulforaphane and antioxidant activity (ABTS and DPPH assays) were determined, and colour was assessed using CIELAB parameters (L*, a*, b*, chroma, hue angle and browning index). Freeze-drying showed the highest preservation of pigments, phenolic compounds, sulforaphane and antioxidant activity, followed by hot-air drying, while solar drying resulted in the lowest retention. Leaf-derived flours consistently presented higher pigment and phenolic contents and more favorable colour attributes than stem-derived flours. Antioxidant activity was strongly associated with matrices richer in pigments and phenolics. Although leaves exhibited higher glucosinolate contents, sulforaphane levels showed only minor differences between plant sections, suggesting that stem-derived fractions may also represent a valuable raw material considering their greater biomass availability and industrial scalability. Overall, these findings demonstrate that both plant section and drying method significantly influence the techno-functional quality of cauliflower by-product flours and should be jointly considered to optimize the development of stable, functional and sustainable food ingredients. Full article

Natural microbial pigments offer important advantages and are widely studied for food applications. We investigated the biosynthetic pathways, characteristics, and bioactivities of the orange–red pigment produced by Bacillus velezensis YM–3, a strain isolated from the traditional Pixian Douban condiment. Whole-genome sequencing revealed complete pathways for melanin, phytoene, and heme biosynthesis. The purified extracellular pigment was characterized using ultraviolet–visible spectroscopy, Fourier-transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and ultra-performance liquid chromatography–high-resolution mass spectrometry; it was preliminarily characterized as melanin-like pigment. The pigment was highly soluble in alkaline solutions, moderately soluble in water, and insoluble in common organic solvents. It exhibited strong photostability and remained stable at low temperature, precipitated under acidic conditions, and showed high stability under alkaline environments. Furthermore, the pigment demonstrated in vitro free radical scavenging activity. Hence, this study provides a scientific foundation for exploring the potential utility of B. velezensis YM–3 and its pigment metabolites as functional agents. Full article

The growing demand for clean-label products has intensified the search for natural and sustainable alternatives to synthetic colorants. Anthocyanins stand out as promising pigments due to their coloring capacity and bioactive properties. This study evaluated the efficiency of natural deep eutectic solvents (NADES) in extracting anthocyanins from agro-industrial by-products—molasses grass, black corn cobs, and grape skins—and their application in food and cosmetic matrices. A simplex-centroid mixture design with Response Surface Methodology was used to optimize solvent composition based on sorbitol, citric acid, and glycine. NADES showed high extraction efficiency, especially for black corn cobs, reaching 54.20 mg/100 g under optimized conditions. Although conventional extraction performed better for grape skins, NADES demonstrated competitive efficiency and superior environmental performance (AGREE index 0.73 vs. 0.58). The extracts were successfully incorporated into yogurt and moisturizing gel formulations. Yogurts maintained stable physicochemical properties and color, while gels showed good homogeneity and chromatic stability. These findings support the use of NADES as green solvents for recovering natural colorants from agro-industrial residues, with potential applications in sustainable food and cosmetic products. Full article

The biological treatment risk associated with wastewater containing the novel pigment intermediate N,N′-(1,4-phenylene)bis(acetoacetamide) has not been previously characterized. This study systematically evaluated the tolerance and performance of a laboratory-scale anaerobic–anoxic–oxic (AAO) system subjected to progressively increasing loadings of high-concentration (COD > 10,000 mg·L⁻¹) wastewater. During a 39-day trial, the influent proportion was incrementally increased from 0.57% to 52.14% without system collapse. Complete microbial adaptation required approximately seven days. The anaerobic unit exhibited the highest sensitivity to shock loads, followed by the oxic unit, while the anoxic unit remained stable. GC-MS analysis confirmed the degradation of complex organic intermediates throughout the treatment stages, and TEST-based predictions indicated that the effluent exhibited lower predicted toxicity than the influent. Notably, cessation of mother liquor addition resulted in system self-recovery, further demonstrating robust shock resistance. This study provides the first experimental evidence of (i) unit-specific shock sensitivity (anaerobic > oxic > anoxic), (ii) a quantified adaptation period of approximately seven days, (iii) an operational threshold of 52.14% mother liquor without causing system collapse, and (iv) self-recovery following load cessation in an AAO system treating wastewater containing N,N′-(1,4-phenylene)bis(acetoacetamide). These findings extend previous AAO toxicity studies on industrial wastewater and present a practical, cost-effective mitigation strategy for full-scale applications. Full article

A newly isolated red-pigmented yeast, Sporobolomyces reniformis EMCC1691, was evaluated for its biotechnological potential in an integrated case study aimed at developing an efficient microbial cell factory for the valorization of delactosed whey. Fermentation trials in 5 L bioreactors demonstrated robust yeast growth on this dairy by-product, with complete consumption of glucose (21.86 g/L) and galactose (20.36 g/L), leading to the accumulation of approximately 6172 mg/L of lipids and 5634 µg/L of total carotenoids. Fatty acid analysis revealed a final concentration of 3924 mg/L, mainly represented by oleic (2037 mg/L), palmitic (779 mg/L), stearic (403 mg/L), and linoleic (362 mg/L) acids. HPLC analysis showed a pigment profile dominated by torularhodin, torulene, γ-carotene, and β-carotene. To complement downstream processing, the fermented culture was spray-dried into a stable powder and subsequently subjected to a simple, cost-effective, and unconventional mechanical pretreatment using a hydraulic press. This post-drying operation ensured extensive cell-wall disruption without the use of chemical agents or specialized equipment, thereby significantly enhancing the recoverability of intracellular lipids and carotenoids through supercritical CO₂ extraction. Under optimized conditions, SFE-CO₂ with ethanol recovered 92.18 ± 1.61 µg/g of total carotenoids, achieving an extraction efficiency of 84% relative to organic solvent extraction (109.17 ± 2.10 µg/g). Importantly, fermentation also reshaped the fatty acid composition of delactosed whey, shifting it toward a profile enriched in monounsaturated and polyunsaturated fatty acids, thereby further highlighting the metabolic impact and bioconversion potential of S. reniformis EMCC1691. Overall, this work highlights the technological relevance of a recently characterized yeast species and its potential to convert dairy by-products into high-value compounds within a proof-of-concept microbial cell factory framework, paving the way for future scale-up investigations. Full article

Amaranthin is a major red-violet betacyanin of Amaranthaceae and an increasingly relevant natural pigment for food, cosmetic, nutraceutical, and biotechnological applications. This review integrates knowledge from over 100 studies, addressing amaranthin as a chemically defined betalain, distinguishing it from other scientific uses of the term, and evaluates its natural sources, analytical methods, extraction strategies, in vitro production systems, biosynthetic regulation, and biological activity. Cultivated Amaranthus species are among the richest plant sources, with total betacyanins of 46.1–199 mg/100 g fresh weight and amaranthin comprising, on average, 80.9% of the pigment fraction. Reliable identification and quantification rely on high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and ultraviolet–visible (UV–Vis) spectrophotometry. Microwave- and ultrasound-assisted extraction can improve pigment recovery under optimized conditions, although its stability depends strongly on pH, temperature, solvent, time and storage parameters. While plant in vitro cultures, including callus, suspension, and shoot systems, have clarified biosynthetic regulation and offer controlled production platforms, engineered yeast systems have recently expanded production options, with Yarrowia lipolytica reaching 2.97 ± 0.029 g L⁻¹ amaranthin in fed-batch fermentation. Amaranthin-rich extracts and amaranthin-type pigments show antioxidantand anti-inflammatory potential, while antimicrobial and antiviral activities have mainly been reported for mixed betacyanin fractions; direct mechanistic, bioavailability, and in vivo evidence for purified amaranthin remains limited. Standardized analytical protocols, further investigation of stable high-yield sources, physicochemical stability assessment, and structure–activity studies are identified as priorities for advancing future application-oriented research on this multipotential pigment. Full article

Highbush blueberry (Vaccinium corymbosum L.) is widely cultivated in southern Chile on acidic Andisols, where aluminum (Al³⁺) toxicity and water deficit frequently occur simultaneously and limit plant performance. However, the integrated physiological responses to these stresses and the potential protective role of methyl jasmonate (MeJA) remain poorly understood. This study evaluated the physiological, biochemical, and hormonal responses of two cultivars with contrasting resistance, Legacy (Al-resistant) and Star (Al-sensitive), exposed to Al³⁺ stress, water deficit, and their combination, with or without MeJA application. Plants were grown in Andisol soil under greenhouse conditions and subjected to eight treatments, with measurements performed at 7, 14, and 21 days. Exposure to stress conditions resulted in decreased growth, reduced leaf water status, diminished photosynthetic performance, lower pigment stability, and decreased auxin concentration as estimated by Salkowski-reactive indolic compounds. Conversely, stress conditions led to increased aluminum (Al) accumulation, elevated proline levels, enhanced lipid peroxidation, and heightened antioxidant responses. Water deficit produced the strongest reductions in photosynthesis, about 48% in Legacy and 65% in Star, whereas Al accumulated mainly in the roots of Star (14-fold). The combined stress intensified physiological limitations and oxidative damage, particularly in the Star cultivar (4-fold), which showed stronger reductions in photosynthetic parameters, higher Al accumulation, and greater lipid peroxidation. In contrast, Legacy maintained more stable physiological performance. Exogenous MeJA mitigated stress effects by reducing Al accumulation (30–35%) and oxidative damage, improving photosynthetic performance (40–60%) and water status, and partially restoring auxin levels and growth in both cultivars, being more evident in the resistant cultivar Legacy. These results indicate that MeJA contributes to the regulation of physiological and antioxidant responses associated with resistance to combined Al toxicity and water deficit in highbush blueberry. Full article

Grafting is a widely used technique to improve stress tolerance in horticultural plants. However, little is known about how grafting affects citrus growth under low-nitrogen (N) stress. To investigate the responses of different grafting combinations to low N availability, we examined root morphology, photosynthesis, chlorophyll fluorescence and semi-quantitative mineral profiles in grafted and ungrafted citrus plants subjected to two N levels (10 and 0.15 mM NO₃⁻ -N) under potted conditions. Analyses were performed on roots and leaves of six plant combinations: ungrafted Trifoliate orange (Poncitrus trifoliata L. Raf., Pt) and red tangerine (Citrus reticulata Blanco, Cr); self-grafted combinations (Pt/Pt and Cr/Cr); and reciprocal heterografts (Pt/Cr and Cr/Pt). Under low-N stress, plant height decreased by 12.3–36.8%, stem diameter by 2.9–31.8%, leaf area by 18.2–26.3%, and SPAD by 11.6–24.5% across the six combinations, with the Cr/Cr combination showing the largest reductions in all parameters. The highest net photosynthetic rate (P_n), intercellular CO₂ concentration (C_i), stomatal conductance (Gs), electron transport rate (ETR), maximum quantum efficiency of PSII (Fv/Fm) and effective quantum efficiency of PSII (Fv’/Fm’) were observed in the Pt and Pt/Pt plants. Low-N stress reduced chloroplastid pigment contents and limited photosynthetic rates. Under 10 mM N treatment, the Fv/Fm values of Pt, Cr, Pt/Pt, and Cr/Pt were approximately 0.82, whereas those of Pt/Cr and Cr/Cr were below 0.82, suggesting lower maximal PSII efficiency in combinations with Cr rootstock. Regarding mineral elements, under low-N stress, the relative levels of P, K, Ca, Mg, and Fe in leaf and root sap increased, while those of N, Cu, Zn, B, and Mn decreased. Overall, combinations with Pt rootstock (Pt/Pt and Cr/Pt) showed better growth and photosynthetic performance, and more stable mineral profiles under low-N stress than combinations with Cr rootstock (Cr/Cr and Pt/Cr). These findings provide a physiological basis for understanding rootstock-specific responses to low-N stress under controlled conditions. Full article

A comprehensive multiregional characterization of the spectral response of cassava leaves across different ontogenetic stages was performed. For this, ultraviolet (UV), visible (VIS) and shortwave near-infrared (UV-VIS-NIR; 200–900 nm) regions were used to identify spectral signatures and indices for their potential use as biomarkers of leaf development and physiological status of plants under induced senescence conditions. Manihot esculenta Crantz (HMC-1 variety) was used as a model. Spectral signatures were obtained from leaves at two phenological stages (4 and 6 months after planting) using UV-VIS-NIR spectroscopy by the diffuse reflectance technique. Classical and experimental spectral indices were evaluated, and their discriminatory power through different ontogenies was assessed using ANOVA/Kruskal–Wallis and post hoc tests. Senescence effects were further examined by postharvest monitoring (1–20 days), with temporal, ontogenetic, and interaction effects validated using linear mixed models (LMMs), while multivariate structure and spectral convergence were explored via principal component analysis and hierarchical clustering (PCA-HCA). Functionally Enhanced Derivative Spectroscopy (FEDS), comparative analysis, and spectral correlation mapping allowed signal’s selective enhancement and the identification of phenolic compounds, photosynthetic pigments, and structural molecular components. Results showed high ontogenetic stability of UV-associated phenolic signals (~210–220 nm), whereas the VIS region (420–600 nm) clearly differentiated young leaves. The NIR region was stable across ontogeny but highly sensitive to temporal degradation, reflecting changes in water status and internal structure. UV-VIS-NIR indices effectively differentiated young leaves and changes by stress. It is concluded that multiregional characterization of the spectral response supported by FEDS allows the extraction of robust indices with strong potential as biomarkers of leaf maturation and senescence in cassava. Full article

This study investigated the impact of conventional chlorhexidine (CHX) and anti-discoloration system (ADS)-containing CHX mouthrinses on the color stability of diverse dental polymers, both alone and in combination with coffee. Specimens (n = 180) were prepared from a nanohybrid composite (Charisma Diamond; Kulzer GmbH, Hanau, Germany), a monochromatic composite (Vittra Unique APS; FGM Dental Group, Joinville, Brazil), and a dual-cure alkasite (Cention Forte; Ivoclar Vivadent, Schaan, Liechtenstein). Following a 14-day cycle of mouthrinse immersion (2 min/daily) and coffee exposure (15 min/daily at 85 °C), color changes (ΔE₀₀) were analyzed using the CIEDE2000 system. All materials exhibited significant discoloration across all protocols (p < 0.001). Cention Forte showed the highest susceptibility to staining, particularly in the CHX + coffee group (ΔE₀₀ = 21.10), while Charisma Diamond remained the most stable (0.95–8.60). Conventional CHX (Kloroben; Drogsan Pharmaceuticals, Ankara, Turkey) induced significantly higher staining than ADS-CHX (Curasept ADS; Curasept S.p.A., Saronno, Italy) across all materials (p < 0.05). Notably, ADS technology significantly inhibited coffee-induced pigmentation in Cention Forte (p = 0.003) and Charisma Diamond (p = 0.046), effectively reducing the synergistic staining layer. In conclusion, while coffee consumption dramatically increases discoloration following CHX use, ADS technology serves as a protective barrier, reducing pigment adhesion. For patients with high dietary pigment intake, ADS-containing mouthrinses offer a significant clinical advantage in preserving the aesthetic longevity of polymeric restorations. Full article

Macular pigment optical density (MPOD) is widely measured by dual-wavelength autofluorescence imaging (AFI) because the method is noninvasive, image-based, and clinically practical. AFI-derived MPOD and macular pigment optical volume (MPOV) are increasingly used as retinal biomarkers in clinical research, supplementation studies, disease-risk interpretation, and population-based comparisons. However, conventional dual-wavelength AFI assumes that posterior absorbers other than macular pigment (MP), particularly melanin, are negligible or sufficiently stable not to bias the measurement. This assumption may limit the diagnostic and biomarker reliability of AFI-derived MP metrics. This manuscript presents a focused biological, optical, and mathematical analysis of AFI-based MP quantification. The foundational AFI literature, the melanin imaging literature, retinal pigment epithelium (RPE) pigment biology, and related optical modeling concepts were examined to evaluate where melanin enters the AFI signal pathway, how it may confound MPOD and MPOV, and how a melanin-sensitive baseline could improve quantitative specificity within the AFI domain. Conventional dual-wavelength AFI estimates MP indirectly from attenuation of RPE lipofuscin autofluorescence under excitation wavelengths that differ in MP absorption. Because melanin is located in the RPE and choroid, varies with retinal location, age, and pigmentation, and can influence the same excitation and detection pathway, unmeasured melanin can become embedded in the apparent MPOD signal. Under these conditions, reported MPOD and derived MPOV are better understood as model-dependent estimates whose quantitative specificity may vary across subjects, retinal locations, devices, and studies. This has direct implications for diagnostic interpretation, normative databases, cross-subject comparison, supplementation-response studies, and biomarker-based retinal assessment. Melanin correction is not a minor refinement of AFI-based MP quantification. It is likely necessary when AFI-derived MP metrics are intended to be interpreted as quantitatively specific retinal biomarkers rather than conditionally approximate optical estimates. A melanin-corrected AFI framework, based on introducing a melanin-sensitive baseline wavelength outside the principal MP absorption range, offers a path toward more reliable MPOD and MPOV interpretation in clinical, diagnostic, and supplementation-related studies. Full article

Enormous genetic diversity exists in rice germplasm, including wild and weedy relatives, though they remain unexplored within in situ or ex situ collections. Characterisation and utilisation of the available biodiversity in plant breeding is essential for the detection of novel traits or genes for climate resilience. In this study, 97 rice genotypes, including 90 rice accessions belonging to various Oryza species and 7 check cultivars with an O. sativa background, were characterised for quantitative morphological characters following the guidelines based on distinctiveness, uniformity and stability (DUS) test by the Protection of Plant Varieties and Farmers’ Rights Authority (PPVFRA), India. Characterisation of the genotypes based on 39 important DUS morphological descriptors revealed polymorphism in 35 traits, confirming high morphological diversity among wild rice accessions and distinguishing and unique traits from other wild accessions for the utilisation in pre-breeding programmes. Genotypes such as WD5_6, WD10_4, and WD3_3 consistently expressed a favourable combination of broad and long leaves, extended panicle length, and well-branched panicles with higher panicle number. In addition, these genotypes showed purple pigmentation across multiple vegetative and reproductive organs, indicating stable and enhanced anthocyanin accumulation. Accessions WD10_4 and WD3_3 also represent valuable donors for panicle architecture and yield component enhancement, while genotypes such as WD17_15 and WD12_8 may serve as specific donors for panicle length and branching traits. Characterisation studies and detection of unique traits provide the empirical foundation for conservation decisions, taxonomic clarity, and pre-breeding applications. Interspecific crosses in the genetic background of elite cultivars with donor species viz., O. barthii, O. glaberrima and O. rufipogon were developed as pre-breeding materials for further crop improvement as well as for the identification of novel genes of agronomic importance. Full article

Controlled-release fertilizer (CRF) improves fertilizer-use efficiency through sustained nutrient release, but its rate-dependent effects on the growth and physiology of Paeonia delavayi seedlings remain unclear. In this study, germinated seeds of P. delavayi with radicles 3–4 cm in length were grown under container nursery conditions with four CRF application rates: control (CK, 0 kg·m⁻³), treatment 1 (T1, 0.6 kg·m⁻³), treatment 2 (T2, 1.2 kg·m⁻³), and treatment 3 (T3, 2.4 kg·m⁻³). Morphological traits, root characteristics, biomass accumulation, physiological parameters, and chlorophyll fluorescence were evaluated, and Pearson correlation and fuzzy membership analyses were used to compare overall treatment performance within the tested range. CRF significantly promoted seedling height, leaf number, petiole length, and biomass accumulation, although the promoting effect did not increase continuously with fertilizer rate. By June, seedling height in T2 was 160% greater than that in CK, while aboveground biomass increased by 552% and 574% in T2 and T3, respectively. Root morphological traits were not significantly affected, suggesting that CRF primarily promoted aboveground development and biomass production. Medium and high CRF rates increased leaf superoxide dismutase (SOD) activity by 42% and 103%, respectively, and peroxidase (POD) activity by 163% and 250%, respectively. Aboveground starch content was 45% higher in T2 than in CK. In contrast, photosynthetic pigment contents and the chlorophyll a/b ratio were not significantly affected by CRF. Chlorophyll fluorescence analysis showed that Fv/Fm remained stable among CRF treatments (0.78–0.82) and was significantly higher than that in CK (0.65), whereas the actual quantum yield of PSII [Y(II)] did not differ significantly among treatments. Relative to CK, the quantum yield of non-photochemical quenching [Y(NPQ)] increased from 0.20 to 0.40 in T2, while the quantum yield of non-regulated energy dissipation in PSII [Y(NO)] decreased from 0.37 to 0.24–0.22 in T2–T3. Pearson correlation and fuzzy membership analyses ranked the treatments as T2 > T3 > T1 > CK, indicating that T2 performed most favorably within the tested range, although its advantage over T3 was small. Overall, an appropriate CRF rate promoted P. delavayi seedling growth and was associated with changes in biomass accumulation, antioxidant enzyme activity, carbon assimilate storage, and chlorophyll fluorescence parameters. Full article

Physicochemical transformations in wine aging are strongly influenced by storage environment and scale. While kinetic modeling has been extensively applied to bulk aging systems, bottle aging is often treated as a continuation of cellar evolution despite representing a different physicochemical regime. A reaction-kinetics framework was applied to assess whether wine aging in bulk and bottle environments can be described by a unified model or instead requires divergent quantitative descriptions. A Sangiovese red wine was aged for six months under controlled conditions in inert bulk systems (stainless steel and a non-porous composite material), a porous bulk system (raw earthenware), and glass bottles. Key physicochemical parameters, including dissolved oxygen, oxidation–reduction potential, free sulfur dioxide, anthocyanins, polymerized pigments, and colorimetric indices, were monitored through non-invasive and laboratory analysis. Exploratory multivariate analysis showed that inert systems follow overlapping compositional trajectories, indicating stable chemical evolution, whereas bottle-aged wines exhibited greater variability. Kinetic analysis revealed comparable oxygen-limited behavior and buffered oxidation–reduction evolution in inert bulk systems, whilst bottle aging displayed different oxygen and sulfur dioxide dynamics, consistent with scale effects and altered oxygen partitioning. Overall, bottle aging cannot be reliably predicted by extrapolation of bulk storage kinetics and requires boundary-condition-aware descriptors accounting for scale and environmental constraints. Full article