Silver/bacterial cellulose/Clitoria ternatea composite film for packaging application: synthesis, characterization and antibacterial properties

This study aimed to develop novel composite films made of Ag, bacterial cellulose (BC), and Clitoria ternatea flower extract for food packaging applications. The films were synthesized using varying concentrations of Ag ion (10-3-10-1 M) and flower extract (0-2x104 µg/ml), followed by characterization using scanning electron microscopy-energy dispersive X-ray (SEM-EDX), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy. The antibacterial activity of the films was assessed against five bacteria, including Escherichia coli, Salmonella Typhimurium, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. The composite films appeared opaque and slightly dark. A porous network of microfibrils was observed under SEM, and higher Ag concentrations resulted in a rougher film surface. Higher Ag+ and extract concentrations resulted in higher percentages of Ag deposited on the surface, as confirmed by EDX (up to 34.7% at 2x104 µg/ml extract and 10-1 M Ag+). Ag/BC/C. ternatea extract combinations generally exhibit higher antibacterial activity than pure BC film. The highest inhibition of S. Typhimurium, P. aeruginosa, and B. subtilis was achieved by a composite film made with 10-1 M Ag+ and 2x104 µg/ml extract with inhibition values of 7.78 mm, 8.12 mm, and 8.25 mm, respectively. All tested composite films also had lower water vapor sorption capacity (2.31-6.71%, depending on the compositions) than BC (6.93%), enabling better protection of the preserved food from surrounding moisture. The Ag/BC/C. ternatea extract composite films are promising, sustainable packaging materials for preserving food quality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-025-04284-8.

Optimization of Ultrasound-Assisted Obtention of Bluish Anthocyanin Extracts from Butterfly Pea (Clitoria ternatea) Petal Powders Using Natural Deep Eutectic Solvents

This study focused on improving the extraction of anthocyanins from medicinal plants using green solvents, which is important for the food, pharmaceuticals, and cosmetics industries. The goal was to optimize the time (15-50 min), temperature (40-80 °C), and petal/solvent ratio (2.5/7%) for the ultrasound-assisted extraction of anthocyanins from Butterfly Pea (Clitoria ternatea), using a natural deep eutectic solvent (choline chloride/glycerol, ChCl:Gly). The extraction was compared with a simple water extraction. To assess stability, we analyzed the anthocyanin content, antioxidant capacity, and color changes over 21 days. The optimal results were achieved using a temperature of 80 °C for 50 min and a 7% petal/solvent ratio. The CHCl:Gly solvent resulted in higher anthocyanin levels (374.65 mg DGE/L) compared to water (211.63 mg DGE/L). After storing the CHCl:Gly extract at 5 °C, only 16% of anthocyanins were lost, while the water extract lost 38%. The CHCl:Gly extract also showed better antioxidant capacity (156.43 µmol/mL). Color changes were less noticeable in the CHCl:Gly extract, especially when refrigerated. These findings demonstrate the method's effectiveness for producing bioactive extracts, with potential for the food, pharmaceutical, and cosmetic industries.

Antioxidant, Physicochemical and Rheological Properties of White and Milk Chocolate Compounds Supplemented with Plant-Based Functional Ingredients

Product development must be continuously done by the chocolate industry to face a high level of competitiveness in the market industry. This study investigates the effect of powdered sappan wood and butterfly pea flower incorporation in milk and white chocolate compounds. Four concentrations of each additional ingredient were used (0, 5, 10 and 15%). The results show that incorporating powdered sappan wood and butterfly pea flower significantly improved the total phenolic and flavonoid content and antioxidant activity of milk and white compounds. This study clearly shows that the selected plant could be an alternative to improve the health-promoting properties of milk and white chocolate compounds. However, supplementation also has some drawbacks, particularly in increasing the moisture content and the degree of colour difference between the milk and white compounds containing additional ingredients and the control. Also, powdered sappan wood and butterfly pea flower caused a higher viscosity of milk and white chocolate compounds. The results obtained in this study create a new strategy for using sappan wood and butterfly pea flower in various food products.

Clitoria ternatea L. (Butterfly Pea) Flower Against Endometrial Pain: Integrating Preliminary In Vivo and In Vitro Experimentations Supported by Network Pharmacology, Molecular Docking, and Molecular Dynamics Simulation Studies

Clitoria ternatea L. (CT) is a perennial herbaceous plant with deep blue flowers native to tropical Asia. This work explores the endometrial pain (EP) regulation of CT flower through a multifaceted approach. Phytochemical screening unveiled the presence of alkaloids, steroids, flavonoids, glycosides, and tannins in CT flower methanolic extract (ME). In the in vitro membrane stabilizing experiment, the ME demonstrated 91.47% suppression of heat-induced hemolysis. Upon carrageenan-induced paw edema assay conducted on male Swiss albino mice at doses of 200 mg/kg and 400 mg/kg, 65.28% and 81.89% inhibition rates, respectively, of paw edema were reported. For the same doses, upon acetic acid-induced-writhing assay, 75.6% and 76.78% inhibition rates, respectively, were observed. For network pharmacology analyses, a protein-protein interaction network was constructed for 92 overlapping gene targets of CT and EP, followed by GO and KEGG pathway enrichment analyses. Network pharmacology-based investigation identified the anti-EP activity of CT to be mostly regulated by the proteins SRC homology, ESR1, and PI3KR1. Physicochemical, pharmacokinetic, and toxicity property predictions for the compounds with stable ligand-target interactions and a molecular dynamics simulation for the highest interacting complex further validated these findings. This work affirmed the anti-EP role of CT flower against EP, suggesting a probable molecular mechanism involved.

Biogenic silver nanoparticles incorporated hydrogel beads for anticancer and antibacterial activities

Green nanotechnology is an effective treatment approach being used in cancer research with less adverse effects. This work describes the incorporation of silver nanoparticles synthesized from clitoria ternatea plant extract (Ag@CT NPs) into sodium alginate and gelatin polymer blends (SA/GEL) to produce Ag@CT-SA/GEL polymer beads using calcium chloride (CaCl2) crosslinking agent. Both the formation and the effective incorporation of Ag@CT NPs into polymer blend have been proven by various spectroscopic analysis, surface morphology study and energy dispersive X-ray analysis. Ag@CT NPs and Ag@CT-SA/GEL demonstrate good antibacterial and antioxidant activities comparable to commercially available drug. Dimethyl thiazolyl tetrazolium bromide (MTT) anticancer assay and apoptosis study of plant extract and Ag@CT NPs against lung cancer cell lines clearly indicate that Ag@CT-SA/GEL polymer bead can serve as an effective anticancer agent.

Unveiling kaempferol glycosides as the key antiglycative components in butterfly pea (Clitoria ternatea) flower

Edible flowers have been used in dietary practices since ancient times. In recent years, they have garnered increasingly more attentions for their potentials in the prevention and amelioration of pathological conditions. The present study employed in vitro BSA models to evaluate the antiglycative effect of some edible flowers. Results showed that butterfly pea flower (BFPF) exhibited the highest potential in preventing advanced glycation end products (AGEs) formation, which had an inhibition rate of 92.11% at 1 g/mL, 56.99% at 0.1 g/mL, and 9.94% at 0.01 g/mL, respectively. Moreover, the antiglycative components in BFPF were identified as four flavonol glycosides through chromatographic and spectral analyses, which were manghaslin (quercetin 3-2″-rhamnosylrutinoside, QCT-Rh), clitorin (kaempferol 3-2″-rhamnosylrutinoside, KFR-Rh), rutin (quercetin 3-rutinoside), and kaempferol 3-neohesperidoside (KFR-Ne). Notably, KFR-Rh and KFR-Ne were presented in higher concentrations in BFPF (764.31 mg/kg and 1135.10 mg/kg dry matter) and significantly contributed to the antiglycative activity (IC50 = 182.17 μM and IC50 = 131.03 μM). Molecular docking (MD) and nuclear magnetic resonance (NMR) analyses revealed that KFR-Rh and KFR-Ne formed hydrogen bonds and hydrophobic interactions with BSA, while KFR-Ne demonstrating a stronger interaction than KFR-Rh. Collectively, our findings highlight the beneficial effects of BFPF with clearly identified active components, which might further promote its application in functional food and medical industry.

Biocolorants in food: Sources, extraction, applications and future prospects

Color of a food is one of the major factors influencing its acceptance by consumers. At presently synthetic dyes are the most commonly used food colorant in food industry by providing more esthetically appearance and as a means to quality control. However, the growing concern about health and environmental due to associated toxicity with synthetic food colorants has accelerated the global efforts to replace them with safer and healthy food colorants obtained from natural resources (plants, microorganisms, and animals). Further, many of these biocolorants not only provide myriad of colors to the food but also exert biological properties, thus they can be used as nutraceuticals in foods and beverages. In order to understand the importance of nature-derived pigments as food colorants, this review provides a thorough discussion on the natural origin of food colorants. Following this, different extraction methods for isolating biocolorants from plants and microbes were also discussed. Many of these biocolorants not only provide color, but also have many health promoting properties, for this reason their physicochemical and biological properties were also reviewed. Finally, current trends on the use of biocolorants in foods, and the challenges faced by the biocolorants in their effective utilization by food industry and possible solutions to these challenges were discussed.

Increases of Lipophilic Antioxidants and Anticancer Activity of Coix Seed Fermented by Monascus purpureus

Lipophilic tocols, γ-oryzanol, and coixenolide in coix seed before and after fermentation by Monascus purpureus were determined. Antioxidant and anticancer activities of raw and fermented coix seed were evaluated using free-radical-scavenging assays and polyunsaturated fatty acid oxidation model, and human laryngeal carcinoma cell HEp2, respectively. Compared to the raw seed, the tocols, γ-oryzanol, and coixenolide contents increased approximately 4, 25, and 2 times, respectively, in the fermented coix seed. Especially, γ-tocotrienol and γ-oryzanol reached 72.5 and 655.0 μg/g in the fermented coix seed. The lipophilic extract from fermented coix seed exhibited higher antioxidant activity in scavenging free radicals and inhibiting lipid oxidation. The inhibitory concentrations for 50% cell survival (IC₅₀) of lipophilic extract from fermented coix seed in inhibiting HEp2 cells decreased by 42%. This study showed that coix seed fermented by M. purpureus increased free and readily bioavailable lipophilic antioxidants and anticancer activity. Therefore, fermentation could enhance the efficacy of the health promoting function of coix seeds.

Extraction methods of butterfly pea (Clitoria ternatea) flower and biological activities of its phytochemicals

Clitoria ternatea or commonly known as 'Butterfly pea' has been used traditionally in Ayurvedic medicine in which various parts of the plants are used to treat health issues such as indigestion, constipation, arthritis, skin diseases, liver and intestinal problems. The flowers of C. ternatea are used worldwide as ornamental flowers and traditionally used as a food colorant. This paper reviews the recent advances in the extraction and biological activities of phytochemicals from C. ternatea flowers. The application of maceration or ultrasound assisted extraction greatly increased the yield (16-247% of increase) of phytochemicals from C. ternatea flowers. Various phytochemicals such as kaempferol, quercetin and myricetin glycosides as well as anthocyanins have been isolated from C. ternatea flowers. Clitoria ternatea flower extracts were found to possess antimicrobial, antioxidant, anti-inflammatory, cytotoxic and antidiabetic activities which are beneficial to human health. Clitoria ternatea flower is a promising candidate for functional food applications owing to its wide range of pharmacotherapeutic properties as well as its safety and effectiveness.

Neglected treasures in the wild - legume wild relatives in food security and human health

The legume family (Fabaceae) is the third-largest flowering family with over 18 000 species worldwide that are rich in proteins, oils, and nutrients. However, the production potential of legume-derived food cannot meet increasing global demand. Wild legumes represent a large group of wild species adaptive to diverse habitats and harbor rich genetic diversity for the improvement of the agronomic, nutritional, and medicinal values of the domesticated legumes. Accumulating evidence suggests that the genetic variation retained in these under-exploited leguminous wild relatives can be used to improve crop yield, nutrient contents, and resistance/tolerance to environmental stresses via the integration of omics, genetics, and genome-editing technologies.

Clitoria ternatea Flower Petal Extract Inhibits Adipogenesis and Lipid Accumulation in 3T3-L1 Preadipocytes by Downregulating Adipogenic Gene Expression

Clitoria ternatea (commonly known as blue pea) flower petal extract (CTE) is used as a natural colorant in a variety of foods and beverages. The objective of study was to determine the inhibitory effect of CTE on adipogenesis in 3T3-L1 preadipocytes. The phytochemical profiles of CTE were analyzed by liquid chromatography and tandem mass spectrometry (LC-MS/MS). Anti-adipogenesis effect of CTE was measured by using Oil Red O staining, intracellular triglyceride assay, quantitative real-time PCR and western blot analysis in 3T3-L1 adipocytes. Cell cycle studies were performed by flow cytometry. Lipolysis experiments were performed using a colorimetric assay kit. In early stages, CTE demonstrated anti-adipogenic effects through inhibition of proliferation and cell cycle retardation by suppressing expression of phospho-Akt and phospho-ERK1/2 signaling pathway. The results also showed that CTE inhibited the late stage of differentiation through diminishing expression of adipogenic transcription factors including PPARγ and C/EBPα. The inhibitory action was subsequently attenuated in downregulation of fatty acid synthase and acetyl-CoA carboxylase, causing the reduction of TG accumulation. In addition, CTE also enhanced catecholamine-induced lipolysis in adipocytes. These results suggest that CTE effectively attenuates adipogenesis by controlling cell cycle progression and downregulating adipogenic gene expression.

Impact of ultrasound and conventional extraction techniques on bioactive compounds and biological activities of blue butterfly pea flower (Clitoria ternatea L.)

The present study was conducted to evaluate the influence of ultrasound on bioactive compounds and biological activities of blue butterfly pea flower (Clitoria ternatea L.). For this purpose, optimized conditions (temperature 50 °C, time 150 min, solid to liquid ratio 1 g:15 ml, 70% amplitude and 240 W, 20 kHz frequency, 3 s on and 3 s off) of ultrasound (US) and conventional extraction (AGE: Agitation, water bath for 150 min, 50 °C at 150 rmp) were used. The results showed significant (p < 0.05) effect of US and AGE on total phenolics (TPCs), flavonoids (TFCs) and antioxidant activities (DPPH, ABTS, FRAP, reducing activity, Cu²⁺ and H₂O₂) of butterfly pea flower extract (BPFE). The results showed an increased trend in yield, TPCs, TFCs and antioxidant activities of US treated BPFE with comparison to AGE. However, insignificant (p > 0.05) effect of US and AGE over TFlaCs and PACs were observed. Moreover, the results of Fourier-transform infrared spectroscopy (FTIR) showed little changes in spectrum and US does not affect the functional group of bioactive compounds structure. Additionally, extracts (500-2000 µg/ml) protect pBR322 plasmid DNA damage induced by (1 mM H₂O₂ and 1 mM FeSO₄), plasma oxidation (induced by 250 µM CuCl₂) and inhibit erythrocyte hemolysis (induced by 200 mM AAPH, 34.6 to 66.73%). Sonication can be applied successfully for the extraction of bioactive compounds from plant materials with high biological activities.