No abstract

SummaryThis study investigated the effects of adding different concentrations of virgin coconut oil (VCO) on the optical, mechanical, thermodynamic and antimicrobial properties, as well as water vapour permeability and morphology of potato starch‐based biodegradable films. Increasing VCO concentrations caused a rise in the light transmittance of the films from 2.13 to 4.79 mm−1 and a decrease in water vapour transmittance from 6.77 to 2.12 (10−5 GPa−1 h−1 m−1). At a VCO concentration of 14 wt% (based on potato starch), the tensile strength reached its highest value (19.98 MPa). Scanning electron microscopy showed that the surface of the film became smoother as VCO concentration increased. The addition of VCO inhibited the growth of Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. In conclusion, VCO supplementation improved the mechanical, antibacterial and water barrier properties of starch‐based films. These results could expand the scope of the application of starch‐based films in food packaging.

Summary The effects of xylanase–cellulase hydrolysis, ultrasonic modification and enzymatic‐ultrasonic treatment on the physicochemical properties, morphological structures and adsorption capacities in vitro of purified fibre (PF) from tea seed were determined. The results showed the ultrasonically treated fibre (UTF) had a higher water‐holding capacity (60.15 g g−1), oil‐binding capacity (30.42 g g−1), swelling capacity (29.93 mL g−1), emulsification activity (381.36 m2 g−1) and emulsification stability (20.20) than PF, enzymatically hydrolysed fibre (EHF) and enzymatic‐ultrasonic treated fibre (EUF). The structures of PF, UTF, EHF and EUF were characterised by scanning electron microscope, Laser particle size analyzer, X‐ray diffraction, thermogravimetric analysis and Fourier transform infrared spectra. Furthermore, compared with PF, the adsorption capacity of UTF, EHF and EUF for cholesterol, glucose and nitrite ions during simulative gastrointestinal tract was improved to different degrees. This study can provide guidance for the comprehensive utilisation of byproduct of tea seed and designing novel functional dietary fibre.

For patients with extensive full-thickness burns who do not have sufficient autologous split-thickness skin for skin grafts, the application of biological skin substitutes may be considered. The aim of this study was to find an optimal new type method for the production of a biovital skin substitute based on acellular dermal matrix (ADM) and preclinical evaluations. In this work, 25 methods of ADM production were assessed. The proposed methods are based on the use of the following enzymes: papain, Carica papaya lipase (CPL), and purification using a polymer/salt aqueous two-phase system. The obtained ADM samples were characterized via scanning electron microscopy (SEM), porosity measurement and water vapor transmission test. Results showed that the collagen bundles of ADM microparticles were intact and orderly. Through differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA) and biocompatibility tests, the results indicated that the proportion of papain and CPL was the same and 5 h processing time are the optimum conditions for ADM preparation and the material showed good biocompatibility. Our results suggested that the potential of developing this kind of decellularization process to manufacture ADM scaffolds for clinical application.

Fish oil is beneficial to health and its quality is significantly impacted by the extraction method. To determine the effect of various methods used to extract the oil on its chemical composition and thermal properties, tilapia oil extracted by dilute alkali hydrolysis, enzymatic hydrolysis, and microwave-assisted methods were investigated in this study. Nutrient analyses showed that freeze-dried tilapia contained fat (36.69 g/100 g freeze-dried tilapia), protein (49.95 g/100 g freeze-dried tilapia), ash (12.04 g/100 g freeze-dried tilapia) and moisture (1.21 g/100 g freeze-dried tilapia). Chemical analysis showed that the fish oil extracted by dilute alkali hydrolysis had the lowest acid value (AV) and peroxide value (POV) (AV: 0.77 mg KOH/g oil and POV: 3.76 mmol/kg oil) compared to the oil extracted using the other methods. The main fatty acid components were palmitic acid (22.78-23.16%), oleic acid (25.73-26.19%), and linoleic acid (15.69-15.98%). Furthermore, the oil extracted by dilute alkali hydrolysis showed significantly higher content of DHA+ EPA (2.30%). The thermal behaviors indicated that the aforementioned oils had significantly different crystal structures. The main endothermic peaks of fish oil extracted by dilute alkali hydrolysis, enzymatic hydrolysis and microwave-assisted methods were located at −2.03℃, −3.20℃ and −4.37℃, respectively. However, infrared spectroscopic analyses indicated them had the same characteristic functional groups. Consequently, different extraction methods significantly affect the oil's physical and chemical properties without affecting spectral characteristics. Furthermore, these results advocated the use of alkali hydrolysis for fish oil extraction.