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BACKGROUND: Chitosan (CS) and tripolyphosphate (TPP) can be combined in the development of a material with synergistic properties and promising potential for the conservation of food products. In this study, ellagic acid (EA) and anti‐inflammatory peptide (FPL)‐loaded CS nanoparticles (FPL/EA NPs) were prepared using the ionic gelation method and optimal preparation conditions were obtained through a single factor design. RESULTS: The synthesized nanoparticles (NPs) were characterized using a scanning electron microscope (SEM), Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), and differential scanning calorimetry (DSC). Nanoparticles were spherical, with an average size of 308.33 ± 4.61 nm, a polydispersity index (PDI) of 0.254, a zeta potential of +31.7 ± 0.08 mV, and a high encapsulation capacity (22.16 ± 0.79%). An in vitro release study showed that EA/FPL had a sustainable release from FPL/EA NPs. The stability of the FPL/EA NPs was evaluated for 90 days at 0, 25, and 37 °C. Significant anti‐inflammatory activity of FPL/EA NPs was verified by nitric oxide (NO) and tumor necrosis factor‐α (TNF‐α) reduction. CONCLUSION: These characteristics support the use of CS nanoparticles to encapsulate EA and FPL and improve their bioactivity in food products. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) has been widely used in food packaging due to its excellent comprehensive properties, but has relatively low barrier properties towards small molecules. In this study, whey protein isolate (WPI)/chitosan (CS)/microcrystalline cellulose (MCC) solution was sprayed evenly on PET which pretreated by corona discharge (CD) and uniform glow discharge (UGD) plasma to prepare WPI/CS/MCC/PET bilayer film, and the properties, structure, and morphology of films were characterized. The water contact angle of UGD treated PET was significantly decreased by 79.01% due to increased polar functional groups. After coated with WPI/CS/MCC film, the reduced oxygen and carbon dioxide transmission rates of untreated and pretreated PET was in the range of 71.74–94.64%, and UGD pretreatment was more efficient to improve gas barrier properties than CD, but the mechanical and water vapor barrier properties of pretreated bilayer film weakened a little. There was a high intermolecular interaction between hydroxyl and amino groups of WPI/CS/MCC film and polar groups, such as COC and CH bonds, carbonyl, and methyl groups, of UGD‐pretreated PET, as verified by Fourier transform infrared with attenuated total reflection. In conclusion, UGD‐pretreated WPI/CS/MCC/PET bilayer film was significantly efficient to enhance the gas barrier properties of single‐layer PET. Practical Applications: Polyethylene terephthalate (PET) has relatively low barrier properties and its application has been limited in food high air tightness packaging. The present study aimed to develop biopolymer‐based high barrier bilayer film using surface‐pretreated PET substrate. The thermogravimetric analysis, mechanical, and barrier properties were investigated, and the structural characterization and morphology of bilayer films were investigated by Fourier transform infrared with attenuated total reflection analysis, environmental scanning electron microscopy, and atomic force microscope. This work provides a foundation for enhancing the gas barrier properties of single‐layer PET using the combination of biopolymer‐based coating and surface pretreatment. [ABSTRACT FROM AUTHOR]

BACKGROUND Spirulina platensis is rich in β-carotene, which possesses many important biological activities. This study investigated the ultrasound-assisted extraction and purification of β-carotene from Spirulina platensis by using response surface methodology ( RSM), determined its antioxidant capacity in vitro and explored its hypoglycaemic effect in diabetic mice. RESULTS The raw β-carotene extract with a concentration of 1942.14 ± 10.03 µg mL−1 was obtained at the optimised condition by RSM (0.40 of the solid-liquid ratio, 51% of the extraction power, and 17 min of the extraction time), and the purity of evaporated β-carotene extract reached 816.32 ± 10.57 mg g−1 after purified by a NKA-9 resin with a sampling and elution rate of 1 mL min−1. The β-carotene extract scavenged 1,1-diphenyl-2-picrylhydrazyl and hydroxyl free radicals with the highest ratios of 44 ± 0.26% and 35 ± 0.45% respectively, and exhibited strong inhibiting capacity on anti-lipid peroxidation. The blood glucose level of streptozotocin-induced diabetic mice was significantly reduced from 15.81 ± 1.71 mmol L−1 to 8.10 ± 0.88 mmol L−1 after 10 d administration of the β-carotene extract [100 mg kg−1 body weight ( BW)], and the increased food and water intakes in the diabetic mice were also significantly relieved after β-carotene treatment. CONCLUSION Our results suggested that extraction of β-carotene from Spirulina platensis had potential prospects in scaled-up industrialisation and healthcare applications. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]