Anthocyanins In Flowers Research Articles

Multifunctional fish gelatin film incorporated with chitosan carbon dots and butterfly pea flower anthocyanins for active/smart packaging of Pacific white shrimp

Multifunctional fish gelatin film incorporated with chitosan carbon dots and butterfly pea flower anthocyanins for active/smart packaging of Pacific white shrimp

Valorization of Hibiscus Flower (Hibiscus sabdariffa L.) Anthocyanins to Produce Sustainable Spray-Dried Ingredients

The recent increase in sustainability awareness has triggered the industry to establish novel, eco-friendly sources of plant-based ingredients. In the present study, hibiscus flowers (Hibiscus sabdariffa L.) were investigated as a sustainable source of anthocyanins for use in spray-dried ingredients with antioxidant capacity. To this end, the extraction and spray-drying microencapsulation of hibiscus flower anthocyanins were optimized and the final products were evaluated for their oxidative stability index. Initially, preliminary experiments were carried out to evaluate the effects of selected processing parameters on anthocyanin extraction. Next, the extraction was optimized through a 22 central composite design, considering ethanol concentration (44–56% v/v) and extraction time (1.6–6.4 h) as independent factors. The optimum extraction conditions (8 h, 41.6% v/v ethanol concentration) were used to produce anthocyanin-rich extracts, which were microencapsulated by spray drying using a 22 central composite design with the carrier addition rate (1–3% w/v) and inlet temperature (160–192 °C) as factors. Maximum values of solids recovery (60.8%) and anthocyanin retention (96.0%) were reached when 3.2% w/v of starch–alginate carrier blend and a 170.7 °C inlet temperature were used. Finally, when hibiscus microcapsules were added to soybean oil, higher oxidative stability was achieved compared to the control. Overall, we demonstrate an industrially friendly and scalable approach that takes advantage of abundant hibiscus flowers as a viable source of anthocyanins for multiple applications.

Identification of novel flower anthocyanins of Delphinium grandiflorum cultivars

Flower color is one of the most important properties of ornamental flowers. Information on the kinds of pigments that flowers can biosynthesize is useful for breeding cultivars focused on flower colors. The flower colors of regular ornamental delphinium cultivars are blue, violet, purple, pink, and white. The pigments of these flowers are delphinidin-based anthocyanins. It has been reported that the typical modification in delphinium anthocyanins involves the transfer of glucose and p-hydroxybenzoic acid molecules to the 7-position of delphinidin one by one, and it was predicted that other unidentified anthocyanins are present in addition to the already reported ones. Recently, light pink flowers that accumulate pelargonidin-based anthocyanins were reported from cultivars derived from Delphinium grandiflorum. Converting delphinidin-based anthocyanins to pelargonidin-based ones is considered key to producing red flowers in delphinium. Hence, we investigated anthocyanins of blue, mauve, light pink, and white flowers of D. grandiflorum cultivars. We isolated anthocyanins and analyzed them using HPLC, TLC, UV–vis spectra, FABMS, and NMR. Using these methods, we identified two novel delphinidin-based anthocyanins and three novel pelargonidin-based anthocyanins: delphinidin 3-O-[6-O-(α-rhamnopyranosyl)-β-glucopyranoside]-7-O-[6-O-(p-hydroxybenzoyl)-β-glucopyranoside] (2), pelargonidin 3-O-[6-O-(α-rhamnopyranosyl)-β-glucopyranoside]-7-O-[6-O-(4-O-(6-O-(p-hydroxybenzoyl)-β-glucopyranosyl)-p-hydroxybenzoyl)-β-glucopyranoside] (5, rubrodelphin), pelargonidin 3-O-[6-O-(α-rhamnopyranosyl)-β-glucopyranoside]-7-O-[3-O-(β-glucopyranosyl)-6-O-(4-O-(6-O-(p-hydroxybenzoyl)-β-glucopyranosyl)-p-hydroxybenzoyl)-β-glucopyranoside] (6), delphinidin 3-O-[6-O-(α-rhamnopyranosyl)-β-glucopyranoside]-7-O-[3-O-(3-O-(6-O-(p-hydroxybenzoyl)-β-glucopyranosyl)-β-glucopyranosyl)-6-O-(4-O-(6-O-(p-hydroxybenzoyl)-β-glucopyranosyl)-p-hydroxybenzoyl)-β-glucopyranoside] (7), and pelargonidin 3-O-[6-O-(α-rhamnopyranosyl)-β-glucopyranoside]-7-O-[3-O-(3-O-(6-O-(4-O-(6-O-(p-hydroxybenzoyl)-β-glucopyranosyl)-p-hydroxybenzoyl)-β-glucopyranosyl)-β-glucopyranosyl)-6-O-(4-O-(6-O-(p-hydroxybenzoyl)-β-glucopyranosyl)-p-hydroxybenzoyl)-β-glucopyranoside] (9, rosedelphin), along with four known anthocyanins. The flowers of five blue cultivars accumulated cyanodelphin (8) as the dominant pigment. The shapes of visible absorption spectra of these five blue flowers were similar, indicating that the color and the absorption spectra were the typical ones for delphinium blue color produced by 8. The mauve flower color was due to a mixture of delphinidin-based anthocyanins in various polyacylated levels at the 7-position. The light pink flowers accumulated pelargonidin-based anthocyanins 5, 6, and 9. These pigment structures showed that the pelargonidin-based anthocyanins modified in the same way as in the originally biosynthesized delphinidin-based anthocyanins even though aglycone was replaced by pelargonidin in these anthocyanins.

Application of anthocyanins from blue pea flower in yoghurt and fermented milk: An alternate natural blue colour to spirulina

Studies investigating the application of blue pea flower anthocyanins in fermented dairy products are limited. In this study, the application of anthocyanin extracts from blue pea flower (Clitoria ternatea) in yoghurt and fermented milk at 1 and 2% (w/v) concentrations was investigated and compared to a commercial blue colourant from spirulina. The total anthocyanin content (TAC), antioxidant activity (DPPH free radical and ferric reducing antioxidant power assays), pH, titratable acidity, syneresis, colour, and viable cell count were measured at 6 days intervals for 30 days at 4 °C storage. The TAC of yoghurt with blue pea flower anthocyanin extract demonstrated high stability, but the TAC of fermented milk with blue pea flower anthocyanin extract decreased significantly. The yoghurt and fermented milk with blue pea flower anthocyanin extract demonstrated higher antioxidant activity than the negative control and samples containing spirulina. The total colour change (ΔE) of yoghurt with blue pea flower anthocyanin extract was less than that of yoghurt containing spirulina during storage. However, the colour of fermented milk with blue pea flower anthocyanin extract was less stable than samples containing spirulina. The average colour acceptability of yoghurt and fermented milk containing 2% (w/v) blue pea flower anthocyanin extracts and those containing spirulina colourant was not significantly different. Therefore, an anthocyanin extract from blue pea flowers at 2% (w/v) concentration was a better blue colourant than spirulina in yoghurt. Spirulina was a better colourant compared to blue pea flower anthocyanins for fermented milk.

Essential oil composition, morphological characterization, phenolic content and antioxidant activity of Iranian populations of Hymenocrater longiflorus Benth. (Lamiaceae)

The study focused on the morphological and chemical characteristics of 200 Hymenocrater longiflorus Benth. genotypes found in natural habitats of eight regions in west of Iran. The primary objective of the study was to assess the morphological and phytochemical variability within populations grown in their natural habitats, with the aim of identifying their potential for domestication and utilization in pre-breeding programs. The plant height (PH) ranged from 50.32 to 69.65 cm, with the highest observed in population P8. The internode distances ranged from 4.7 to 6.47 cm, with the maximum distance found in P4. Flower lengths varied from 1.95 to 2.45 cm, with the minimum and maximum values observed in P4 and P3, respectively. The highest leaf length (5.20 cm) and width (3.87 cm) were recorded in P2. The aerial parts of the plant were utilized to extraction and determine the essential oil (EO) content and composition, which ranged from 0.40 to 0.78% (v/w). The analysis of EO by gas chromatography (GC) and gas chromatography mass spectrometry (GC/MS) identified 26 compounds, constituting 99–99.5% of the EOs. The main compounds in the EO and their percentage range (v/w DW) were tau-cadinol (0.62–55.56), mono (2-ethylhexyl) phthalate (8.10–94.70), elemol (0.21–19.11), β-spathulenol (0.08–14.39), 4-terpineol (0.23–10.19), and β-eudesmol (0.21–9.94). The main chemical groups found in EOs included oxygenated sesquiterpenes (1.12–68.43), and phthalates (9.73–94.72). Cluster analysis revealed three distinct chemotypes: chemotype I (populations 1 and 2) with major components of mono (2-ethylhexyl) phthalate, tau-cadinol, and α-elemol; chemotype II (population 5) rich in mono (2-ethylhexyl) phthalate; and chemotype III (populations 3, 4, 6–8) containing tau-cadinol, β-eudesmol, and 4-terpineol. The study also evaluated total phenolic, total flavonoid, and DPPH free radical scavenging activity in the fifty percent inhibitory concentration (IC50) in leaf and flower samples of the genotypes, along with estimating total anthocyanin content in the flower samples. The total phenolic content (TPC) in leaf and flower samples ranged from 7.89 to 107.18 mg GAE/g DW and 39.98 to 86.62 mg gallic acid equivalent (GAE)/g DW, respectively. Total flavonoid content (TFC) ranged from 81.04 to 143.46 mg QUE/g DW in leaf samples and from 94.82 to 133.26 mg quercetin equivalent (QUE)/g DW in flower samples. DPPHsc IC50 (µg/mL) ranged from 0.65 to 78.74 in leaf samples and from 4.38 to 7.71 in flower samples. Anthocyanin content ranged from 1.89 to 3.75 mg cyanidin-3-glucoside equivalent (C3GE)/g DW among populations. Canonical correspondence analysis and simple correlation demonstrated a strong association and correlations among the studied attributes. The negative correlations between leaf DPPH (DPPH L) IC50 and TFC (− 0.73), TPC (− 0.63), Elemol (− 0.90), and EO (− 0.85) indicate that these compounds have a significant impact on the antioxidant activity of the leaves. Furthermore, Fruit DPPH (DPPH F) IC50 showed a negative correlation with TPC (− 0.79) and TFC (− 0.78), but a positive correlation with flower anthocyanins (0.51), (Z)-β-Farnesene (0.66), and 4-Terpineol (0.57). Circular cluster analysis categorized the genotypes of all individuals in the eight studied populations into three main categories based on all the studied traits, indicating significant variation in phytochemical and morphological traits among populations, surpassing the within-populations variation.

Properties of Gelatin-based Films Incorporated with Anthocyanins and Curcuminoids and Stability of Antioxidant Activity during In Vitro Digestion

In this study, gelatin-based films incorporated with two plant pigments; butterfly pea flower anthocyanins (BPA) and turmeric rhizome curcuminoids (TRC) were prepared. Their physical and antioxidant properties were investigated. The results showed that addition of BPA and TRC at different concentrations (10%, 20%, and 30% of gelatin weight) significantly affected the visible color and color values (L*, a*, b*, hue and chroma) of the obtained films. With increasing pigment concentrations, lower % light transmittance was observed (p<0.05). The improved light barrier property corresponded with the increased opacity of the two films (p<0.05). Compared with the control films, the addition of either BPA or TRC slightly increased thickness of films (p<0.05). The moisture content of films increased with increasing BPA concentration but decreased with increasing TRC concentration (p<0.05). However, water solubility was not significantly different among films with varying concentrations of BPA or TRC (p>0.05). Total anthocyanin content (TAC), total curcuminoid content (TCC), total phenol content, and antioxidant activities by FRAP and DPPH increased with increasing pigment concentration in films (p<0.05). Based on in vitro digestion, the film forming solution containing 30% (w/w) plant pigment significantly improved the stability of pigment compounds, TPC, and antioxidant activities during the intestinal phase. Compared to the pigment extract alone, film forming solution containing gelatin and glycerol showed protecting effects against biological conditions during intestinal digestion of the two pigments, BPA and TRC, and therefore, offered greater stability of antioxidant activity (p<0.05).

Integrated Metabolomic and Transcriptomic Profiles Provide Insights into the Mechanisms of Anthocyanin and Carotenoid Biosynthesis in Petals of Medicago sativa ssp. sativa and Medicago sativa ssp. falcata.

The petals of Medicago sativa ssp. sativa and M. sativa ssp. falcata are purple and yellow, respectively. Free hybridization between M. sativa ssp. sativa and M. sativa ssp. falcata has created hybrids with various flower colors in nature. Moreover, the flower colors of alfalfa are closely correlated with yield, nutritional quality, stress tolerance and other agronomic characteristics. To elucidate the underlying mechanisms of flower color formation in M. sativa ssp. sativa and M. sativa ssp. falcata, we conducted an integrative analysis of the transcriptome and metabolome of alfalfa with three different petal colors (purple, yellow and cream). The metabolic profiles suggested that anthocyanins and carotenoids are the crucial pigments in purple and yellow flowers, respectively. A quantitative exploration of the anthocyanin and carotenoid components indicated that the accumulations of cyanidin, delphinidin, peonidin, malvidin, pelargonidin and petunidin derivatives are significantly higher in purple flowers than in cream flowers. In addition, the content of carotenes (phytoene, α-carotene and β-carotene) and xanthophylls (α-cryptoxanthin, lutein, β-cryptoxanthin, zeaxanthin, antheraxanthin and violaxanthin derivatives) was markedly higher in yellow flowers than in cream flowers. Furthermore, we found that delphinidin-3,5-O-diglucoside and lutein were the predominant pigments accumulated in purple and yellow flowers, respectively. The transcriptomic results revealed that twenty-five upregulated structural genes (one C4H, three 4CL, twelve CHS, two CHI, one F3H, one F3'H, one F3'5'H and four DFR) are involved in the accumulation of anthocyanins in purple flowers, and nine structural genes (two PSY, one ZDS, two CRTISO, two BCH, one ZEP and one ECH) exert an effect on the carotenoid biosynthesis pathway in yellow flowers. The findings of this study reveal the underlying mechanisms of anthocyanin and carotenoid biosynthesis in alfalfa with three classic flower colors.

Soybean flower-specific R2R3-MYB transcription factor gene GmMYB108 induces anthocyanin production in Arabidopsis thaliana

R2R3-MYB transcription factors (TFs) are known to play a key role in regulating the expression of structural genes involved in plant flavonoid biosynthesis. However, the regulatory networks and related genes controlling isoflavonoid biosynthesis in soybean are poorly understood. We previously reported that ethephon application increases the production of isoflavonoids in soybean leaves. In this study, we attempted to identify a potential regulatory gene that positively controls isoflavonoid production in response to ethephon treatment in soybean (Glycine max L.). RNA sequencing (RNA-seq) revealed that ethephon application led to the upregulation of 22 genes, including the genes for R2R3-MYB TFs, related to isoflavonoid biosynthesis in soybean plants. Ethephon treatment highly induced the expression of GmMYB108, and its expression was exclusively enriched in flowers as determined using in silico and real-time quantitative PCR analyses. Furthermore, GmMYB108 overexpression resulted in an intense accumulation of anthocyanins as well as total flavonoid production in the leaf tissues of transgenic Arabidopsis plants. In addition, GmMYB108 overexpression increased the transcript levels of several genes involved in the biosynthesis of anthocyanins and their regulatory pathways in Arabidopsis. These results suggest that GmMYB108 is a potential positive regulator of the biosynthesis of flavonoids and anthocyanins in soybean flowers.

Butterfly Pea Flower Anthocyanin Immobilized pH Sensitive Intelligent Nanocomposite Films of Starch/Chitin with Improved Thermal and Mechanical Properties

AbstractThin films with pH sensitivity have been a trendsetter in the current research scenario. Edible films for packaging are comparatively newer ones, where the study uses conventional food materials as a source or precursor to fabricate the films. Starch(S) is one such material that is not much exploited in packaging and pH sensing. Here, the study presents the preparation of a new type of sensitive, intelligent film from starch‐chitin(CHN) composites and adds the anthocyanin pigment extracted from the Butterfly Pea flower (BPE). The combination films are much more sensitive to ammonia and formalin and thus suggested for the detection of adulteration in fish. All the films (S, S/BPE, S/CHN, and S/BPE/CHN) are fabricated by the solution casting method. The addition of 10 wt% CHN results in the enhancement of the thermal and mechanical properties of pH indicator films. Owing to the presence of anthocyanin pigment, the films can change their color changes in pH. The developed starch‐based intelligent films display wide color differences from bright red to green over the 1–12 pH range, which is discriminated by the naked eye.

Development of Semolina Starch/Agar-Based Intelligent Films by Incorporating Butterfly Pea Flower Anthocyanins to Monitor the Freshness of Prawns

The natural plant-derived pH indicator film which monitors food freshness during storage has gained attention among researchers due to consumer awareness of food quality, freshness, and food safety. This study aims to develop a semolina/agar-based film (S/A) incorporated with anthocyanins from butterfly pea flower extract (BPE) as a freshness indicator for tiger prawns and freshwater prawn during 4 days of storage at 4±1 °C. The semolina/agar-based butterfly pea extract (S/A/BPE) films were developed with different concentrations of BPE (3, 6, and 9%) by casting method. Increasing BPE up to 9% in the S/A film increased the thickness and moisture content, lowering the films’ water permeability. The film also had a smoother surface structure with a darker colour. Different pH solutions (pH 2.0-12.0) also changed the colour of films, depending on the BPE concentrations. The application of S/A/BPE films on tiger prawns and freshwater prawns caused colour changes from dark blue at day 0 (fresh stage) to intense green at day 2 (beginning of spoilage) indicating the spoilage of samples. The pH values of both prawns were gradually increased. However, no major changes were observed in the texture profile analysis. These results indicate that S/A/BPE film has the potential to be used as a pH indicator film to detect the freshness of prawn samples.

Potential use of red hibiscus flower extract for the production of spray-chilled microparticles: Characterization, stability, and bioaccessibility in vitro of anthocyanins

Microparticles (MLP) containing red hibiscus flower (Hibiscus rosa-sinensis) anthocyanins were produced by spray chilling, and characterized for physicochemical parameters, accelerated stability, and gastrointestinal release profile. Fully hydrogenated palm oil and cocoa butter were used as wall materials, at a lipid blend to hibiscus extract ratio of 70:30 (w/w). The lipid blends containing fully hydrogenated palm oil (FHPO) and cocoa butter (CB) were produced by ultrasound-assisted technique in the following FHPO to CB ratios: 100:0 (Control), 75:25, 50:50, 60:40, and 40:60. Increasing the cocoa butter content reduced the melting temperature and increased the unstable polymorphic behavior of the microparticles, resulting in amorphous characteristics. The microparticles exhibited higher viscosity, more agglomerates, and holes on the surface, and greater diameters. Characteristic peaks corresponding to the hibiscus extract were observed in the infrared spectra of the spray-chilled microparticles, indicating that the microencapsulation did not affect the anthocyanins. The antioxidant capacity of the red hibiscus anthocyanins ranged from 75 % to 79 %, with the best result observed for the treatment MLP_75:25. Higher antioxidant activities were observed for the lipid blends containing lower cocoa butter concentrations. Concerning the release profile of anthocyanins, the simulated GI digestion in vitro showed reduced release in the gastric tract and more intense release in the intestinal tract for an effective absorption of the antioxidant compounds in the small intestine. Furthermore, the treatment MLP_75:25 showed the highest encapsulation retention and lower total color difference in the accelerated stability study. Overall, the microparticles from all treatments were light-sensitive and thermosensitive at 35 °C. Thus, it is recommended to store the particles in a dark environment at temperatures below 35 °C for an effective use of the microparticles as natural food colorants.

An intelligent chitosan/gelatin film via improving the anthocyanin-induced color recognition accuracy for beef sub-freshness differentiation monitoring

A novel volatile amine-responsive food freshness smart film, CG-BAE, has been developed utilizing chitosan (CS) and gelatin (GL) as film substrates and butterfly pea flower anthocyanin extract (BAE) as the indicator. The pH value of the film-forming solution was found to significantly impact the physical properties, biogenic amine response sensitivity, and initial color of the film. The hydrogen bonding interaction between anthocyanins and the film matrix was identified as the main binding force, as confirmed by FT-IR spectroscopy and molecular docking simulation analysis. Notably, CG-BAE-2.0 films have demonstrated excellent color stability, antioxidant activity, and color responsiveness. The performance of the film in monitoring beef freshness was evaluated and proved clear differentiation between four stages: freshness, sub-freshness, onset of spoilage, and complete spoilage. The color change of the film was assessed using RGB values obtained from a smartphone App, reducing the difference in color recognition by individual naked eyes. Therefore, this work addresses the limitation that BAE-based intelligent films cannot be distinguished at the starting point of meat spoilage, and presents a promising approach to sub-freshness indication, opening new possibilities for food freshness differentiation monitoring.

Metabolic perturbations and key pathways associated with the bacteriostatic activity of Clitoria ternatea flower anthocyanin fraction against Escherichia coli.

Clitoria ternatea flowers are rich in anthocyanins and possess various biological activities. Specifically, the antibacterial mechanism of action of C. ternatea anthocyanins remains unknown and was investigated in Escherichia coli . A time-kill assay was used to assess the antibacterial activity and the metabolic perturbations in E. coli were investigated utilizing liquid chromatography-mass spectrometry (LC-MS)-based metabolomics. Pathway analyses were carried out for metabolites showing ≥2-fold changes. The anthocyanin fraction remarkably reduced the growth of E. coli at 4 h by 95.8 and 99.9 % at minimum inhibitory concentration (MIC) and 2× MIC, respectively. The anthocyanin fraction (MIC) had a bacteriostatic effect and was shown to have perturbed glycerophospholipids (1-acyl-sn-glycero-3-phosphoethanolamine, phosphatidylglycerol, diacylglycerol and cardiolipin), amino acids (valine, tyrosine and isoleucine) and energy (ubiquinone and NAD) metabolites at 1 and 4 h. This study demonstrated significant metabolic perturbations of the glycerophospholipid, amino acid and energy metabolism, with these being the key pathways involved in the bacteriostatic activity of anthocyanins from C. ternatea, which may have promise as bacteriostatic agents for E. coli -related infections.

A comparative metabolomics investigation of flavonoid variation in faba bean flowers

IntroductionFaba bean (Vicia faba L.) flowers are edible and used as garnishes because of their aroma, sweet flavor and attractive colors. Anthocyanins are the common plant pigments that give flowers their vivid colors, whereas non-anthocyanin flavonoids can serve as co-pigments that can modify the color intensity of flowers.ObjectivesTo explore the polyphenol diversity and differences in standard and wing petals of faba bean flowers; and identify glycosylated flavonoids that contribute to flower color.MethodsFlower standard and wing petals from 30 faba bean genotypes (eight color groups with a total of 60 samples) were used for polyphenol extraction. Samples were analyzed using a targeted method and a semi-untargeted analysis using liquid chromatography–high resolution mass spectrometry (LC–HRMS) combined with photodiode array (PDA) detection. Compound Discoverer software was used for polyphenol identification and multivariate analysis.ResultsThe semi-untargeted analysis guided by the PDA detected 90 flavonoid metabolites present in faba bean flower petals. Ten anthocyanins largely influenced the flower colors, but other flavonoids (63 flavonols and 12 flavones) found with variable levels in different flower color groups appeared to also influence color, especially in mixed colors.ConclusionAnalysis of the different colored faba bean flowers confirmed that the color variation between the flowers was mainly controlled by anthocyanins in brown, red and purple-red flowers. Of the other flavonoids, multiglycosylated kaempferols were abundant in white and brown flowers, monoglycosylated kaempferols were common in red and purple-red flowers, and quercetin and apigenin glycosides were abundant co-pigments in purple-red flowers.

Systematic analysis of MYB transcription factors and the role of LuMYB216 in regulating anthocyanin biosynthesis in the flowers of flax (Linum usitatissimum L.)

Anthocyanin is an important pigment that affects plant color and nutritional quality. MYBs play an important role in plant anthocyanin synthesis and accumulation. However, the regulatory function of MYB transcription factors in anthocyanin synthesis in flax flowers is still unclear. In this study, 402 MYB transcription factors were identified in the flax genome. These MYB members are unevenly distributed on 15 chromosomes. The R2R3-LuMYB members were divided into 32 phylogenetic subfamilies. qRT-PCR analysis showed that seven R2R3-LuMYB genes in the adjacent subfamily of the evolutionary tree had similar expression patterns, among which LuMYB216 was highly expressed in the petals of different colors. Moreover, gene editing of LuMYB216 in flax showed that the petal color, anther color and seed coat color of mutant plants were significantly lighter than those of wild-type plants, and the anthocyanin content of lumyb216 mutant plants was significantly reduced. Correlation analysis indicated that LuMYB216 was significantly positively correlated with the upstream regulator bHLH30. This study systematically analyzed the MYB gene family in flax, laying a foundation for studying the regulation of LuMYB216 in flax flower anthocyanin synthesis.

Utilising N‐glutaryl chitosan‐based film with butterfly pea flower anthocyanin as a freshness indicator of chicken breast

AbstractA novel indicator film was produced with N‐glutaryl chitosan (ChGA) as a matrix and butterfly pea flower anthocyanin (BPA) as a dye. The synthesis of ChGA was achieved by the reaction of chitosan (Ch) and glutaric anhydride (GA), which resulted in the structural alteration of Ch, with carboxylic groups being present in ChGA. The ChGA–BPA film demonstrated higher sensitivity to changes in pH, a more compact structure, and more hydrophilic properties compared with Ch‐BPA film. The ChGA–BPA film demonstrated antioxidant and antimicrobial activity, as well as an enhanced biodegradable property. Further characterisation showed ChGA–BPA film possessed ultraviolet visible (UV–Vis) light barrier properties and was non‐toxic to cells. Lastly, when tested as packaging, the films underwent a visible colour changes from blue to yellowish‐green as chicken breast was stored at various temperatures, which correlated with an increase in nitrogen compounds, indicating the potential of this film as a smart packaging solution to monitor the freshness of chicken breast.

A visual bi-layer sensor based on Agar/TiO2/butterfly bean flower anthocyanin/κ-carrageenan with photostability for monitoring Penaeus chinensis freshness

Visual indicator bi-layer films were manufactured incorporating κ-carrageenan, butterfly pea flower anthocyanin, varying Nano‑titanium dioxide (TiO2) content and agar for Penaeus chinensis (Chinese white shrimp) freshness detection. The κ-carrageenan-anthocyanin (CA) layer served as indicator, while the TiO2-agar (TA) layer functioned as the protective layer to improve the photostability of film. The bi-layer structure was characterized by scanning electron microscopy (SEM). The TA2-CA film had the best tensile strength with a value of 17.8 MPa and the lowest water vapor permeability (WVP) value of bi-layer films was 2.98 × 10−7 g.m−1.h−1.pa−1. The bi-layer film protected anthocyanin against exudation when immersed in aqueous solution of varying pH. The TiO2 particles filled the pores of the protective layer, increasing the opacity from 1.61 up to 4.49 significantly improving the photostability with a consequent slight color change under illumination of UV/visible light. Under UV irradiation, the TA2-CA film had no significant color change with a ΔE value of 4.23. Finally, the TA2-CA films showed an obvious color change from blue to yellow green in the early stages of Penaeus chinensis putrefaction (≤48 h) then the color change and Penaeus chinensis freshness were well correlated (R2 = 0.8739).

Combined analysis of multi-omics reveals the potential mechanism of flower color and aroma formation in Macadamia integrifolia.

Macadamia integrifolia Maiden & Betche is a domesticated high-value nut crop. The development of nut flower affects the fruit setting rate, yield and quality of nuts. Therefore, in this experiment, two varieties with different flower color, flowering time, flowering quantity and nut yield (single fruit weight) were selected as the research objects. Transcriptome (RNA-Seq) and metabolome (LC-MS/MS, GC-MS) analyses were performed to study the regulatory mechanisms of nut flower development, color and aroma. The results indicated that plant hormone signal transduction, starch sucrose metabolism, phenylpropanoid metabolism, flavonoid biosynthesis, and anthocyanin biosynthesis pathways were related to nut flower development and flower color formation. In the early stage of flowering, most of the differentially expressed genes (DEGs) are involved in the IAA signal transduction pathway, while in the later stage, the brassinolide signal pathway is mainly involved. In starch and sugar metabolism, DEGs are mainly involved in regulating and hydrolyzing stored starch into small molecular sugars in flower tissues. In the phenylpropanoid biosynthesis pathway, DEGs are mainly related to the color and aroma (volatile organic compounds, VOCs) formation of nut flowers. Four color formation metabolites (anthocyanins) in nut flowers were found by LC-MS/MS detection. In addition, the VOCs showed no significant difference between red nut flowers (R) and white nut flowers (W), which was mainly reflected in the aroma formation stage (flowering time). And 12 common differentially accumulation metabolites (DAMs) were detected by GC-MS and LC-MS/MS. At the same time, the DEGs, AAT, LOX and PAL genes, were also identified to regulate key metabolite synthesis during nut flower development. These genes were further verified by qRT-PCR. Our results provide insights to clarify the molecular mechanism of color and aroma formation during M. integrifolia flower development that pave the way for nut quality and yield breeding.

Comparative transcriptome analysis reveals an insight into the candidate genes involved in anthocyanin and scent volatiles biosynthesis in colour changing flowers of Combretum indicum.

Combretum indicum is a widely cultivated ornamental species displaying the distinct phenomenon of floral colour change. Flowers display a gradual colour change from white to red, attributed to increased cyanidin 3-O glucoside in petal tissues. The differently coloured flowers also emanate a complex blend of VOCs with trans-linalool oxide (furanoid) as the major compound in the emission profile. To understand molecular mechanisms regulating floral colour shifts and scent biosynthesis, we performed Illumina transcriptome sequencing, including de novo assembly and functional annotation, for the two stages of floral maturation (white and red). Homology analysis with functional classification identified 84 and 42 candidate genes associated with pigment and scent biosynthesis, respectively. Genes encoding transcription factors, such as MYB, ERF, WD40, WRKY, NAC, bHLH and bZIP, that play critical roles in regulating specialized metabolism were also identified in the transcriptome data. Differences in expression of genes were consistent with accumulation patterns of anthocyanins in the two different flower colours. A clear upregulation of flavonoid biosynthesis genes in red flower tissue is associated with increased pigment content. RT-qPCR-based expression analyses gave results consistent with the RNA-Seq data, suggesting the sequencing data are consistent and reliable. This study presents the first report of genetic information for C. indicum. Gene sequences generated from RNA-Seq, along with candidate genes identified by pathway mapping and their expression profiles, provide a valuable resource for subsequent studies towards molecular understanding of specialized metabolism in C. indicum flowers.

Development of Shrimp Freshness Indicating Films by Embedding Anthocyanins-Rich Rhododendron simsii Flower Extract in Locust Bean Gum/Polyvinyl Alcohol Matrix.

Freshness indicating films containing anthocyanins are one type of smart packaging technology. Anthocyanins in the films can show visual color changes when food spoilage occurs, thereby indicating the freshness degree of food in real-time. Rhododendron simsii is a landscape plant with attractive flowers that are abundant in anthocyanins. In this study, smart packaging films were prepared by embedding 2% and 4% R. simsii flower anthocyanins (RA) in locust bean gum- (LBG) and polyvinyl alcohol- (PVA) based matrices. The micro-structure, barrier, mechanical, thermal, antioxidant, and color-changeable properties of the films were determined. The potential application of the films in indicating the freshness of shrimp at 4 °C was also investigated. Results showed that the RA interacted with the LBG/PVA matrices through hydrogen bonds, which significantly improved the barrier, mechanical, thermal, antioxidant, pH-sensitive, and ammonia-sensitive properties of the films. Meanwhile, the performance of the films was remarkably influenced by the content of the RA. The film containing 4% RA had the highest light blocking ability, tensile strength (38.32 MPa), elongation at break (58.18%), and antioxidant activity, and also showed the lowest water vapor permeability (22.10 × 10-11 g m-1 s-1 Pa-1) and oxygen permeability (0.36 cm3 mm m-2 day-1 atm-1). The films containing 2% and 4% RA could effectively change their colors when the level of total volatile basic nitrogen in the shrimp exceeded the safe value, which demonstrated the suitability of the films for indicating the freshness degree of shrimp.