A reverse micellar microemulsion combined with magnetic solid phase extraction (RMM-MSPE) technology was developed for the extraction and purification of juglone from Juglans mandshurica . Reverse micellar microemulsion (RMM) (Tween 80: n-propanol: n-hexane: 0.05 mol/L KCl aqueous solution = 27:13.5:4.5:55; w/w/w/w) was used to extract juglone based on microwave. The optimum conditions were a pH of 5.6, a liquid-solid ratio of 20:1 (mL/g), temperature of 40 °C, time of 63 s, and power of 400 W. Graphene oxide/nano diamonds/ Fe 3 O 4 (GO/ND/Fe 3 O 4 ) was prepared as adsorbent and applied to purify juglone by magnetic solid-phase extraction (MSPE). The optimum adsorption conditions were time of 14 h, solid to liquid ratio of 30 mg/mL, pH of 5.5 and shaker speed of 200 r/min. Anhydrous methanol provided the best desorption of juglone and the optimum conditions were a desorption time of 16 h, pH of 8, and the solid-liquid ratio of 40 mg/mL. The purity of juglone was 69.08% and the recovery yield was 78.67%. RMM and GO/ND/Fe 3 O 4 could be reused three times and eight times after the first use, respectively. The proposed RMM-MSPE is a green and efficient alternative method for extraction and purification of juglone.
Succinate cyclodextrin/chitosan nanoparticles (SCC NPs) loaded with resveratrol (Res) were successfully synthesized by self-assembly. Nanocomposite films were prepared by adding R-SCC NPs to sodium alginate (SA). The structure, physical and chemical properties, and antioxidant, antibacterial and biodegradability properties of the nanocomposite films were characterized. Scanning electron microscopy (SEM) results revealed that R-SCC NPs in 1–6 % were uniformly distributed in the SA film matrix. FTIR analysis revealed that the R-SCC NPs formed intermolecular hydrogen bonds with SA. The maximum tensile strength of the nanocomposite film was 44.24 ± 0.82 MPa, which was 153.50 % of that of the SA film. The addition of R-SCC NPs markedly enhanced the UV absorption capacity, antioxidant stability, and antibacterial activity of the nanocomposite films. In addition, because Res was encapsulated in the SCC NPs, control over the release from the composite film was achieved. This film has excellent biodegradability in soil and can regulate the soil microbial community. Furthermore, the developed film package can effectively prolong the expiry date of blueberries, so the SA film containing R-SCC NPs as active packaging has significant potential for maintaining food quality.
Jing Chen,Jin Zhang,Rundong Liang,Mingyue Ma,Yan Cui
The work established a new method combining MILs with ultrasound to effectively extract naphthoquinone pigments from green walnut husk. With the yield of juglone as the index, some parameters were optimized by single factor experiment with UV. Optimal extraction conditions were determined to be as follows: extraction solvent of [C 4 MIM] [FeCl 4 ], ratio of liquid to material of 10 mL/g, extraction temperature of 60 °C and extraction time of 60 min. Based on this method, the extraction yield of green walnut husk pigment was as high as 85.52% (g/g), which was a lot higher than that of heat-reflux extractions with ethanol and NaOH. Subsequently, the extracted pigment was used as a colorant in the hair dyeing combined with eugenol and tea polyphenol as natural accelerating agent and mordant. The process was optimized by orthogonal experiment, and the hair treated with the extracts got by MB-UA-E was the darkest when pH was kept at 5.0, the pigment concentration was 60%, the dyeing temperature was kept at 70 °C, and the dyeing time was 40 min. Compared to two products obtained by reflux extraction, the extracts got by MB-UA-E showcased superior black dyeing capacity, higher tensile strength, less damage to hair scales or α-keratin and greater UV protection property. It caused less damage to structural of hair fiber than commercial oxidative dye despite participation of conditioner in the oxidative dye. Our study could open new possibilities for using recycled walnut waste in the field of hair dyeing with an eco-friendly and efficient method.
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