Effect of film-forming solution pH on the mechanical, barrier, and biological characteristics of chitosan/Piper betel L. leaf extract coating film for mango preservation.

The present work aimed to investigate the effect of film-forming solution pH on characteristics of chitosan (CH) - Piper betel L. leaf extract (PBe) coating films and their potential applications in mango preservation. The coating films were fabricated from CH-PBe solutions in the pH range of 3-5 using a solvent evaporation technique. The analysis results (DSC and FTIR) demonstrate higher miscibility, better compatibility, and tighter intermolecular interactions between CH and active compounds in the film matrix prepared at low pH. The mechanical and barrier properties of the CH-PBe film significantly decreased with increasing pH value. Varying the film-forming pH insignificantly affected the antioxidant activity and antibacterial inhibition against Staphylococcus aureus (Gram-positive) of the resultant films. However, Escherichia coli (Gram-negative) was less vulnerable to the blend film prepared at the higher pH medium. The coating solution at pH 4 proved suitable for preserving 'Tu Quy' mangoes, according to the observation of color changes, accumulated decay rate, respiration rate, ripening index, and other related factors. The findings of this work reveal the importance of pH control in producing CH-PBe coating films for mango preservation and provide more insights into pH-affected interactions between CH matrix and polyphenols in PBe.

Enhancement of zein-based films for mango preservation using high-intensity ultrasound and castor oil plasticization.

Zein-based films exhibit high efficiency in ethylene adsorption. However, its brittleness limits the practical applications. To address this issue, this study synergizes the plasticizing effects of high-intensity ultrasound (HIU) and castor oil (CO) to reduce the brittleness of zein-based films. The plasticizing mechanism was demonstrated through the formation of new intermolecular hydrogen bonds and electrostatic interactions, as evidenced by fourier transform infrared spectroscopy (FTIR) and zeta potential measurements. The tensile strength of 6 % CO-zein film increased eightfold. Additionally, the freshness of mangoes stored with 6 % CO-zein film significantly improved, extending their shelf life from 5 days to 15 days. Therefore, this study investigated the synergistic plasticization of zein-based films through the addition of CO, based on HIU. It also provides a theoretical basis for fruit packaging.

Preparation and characterization of carvacrol/ε-polylysine loaded antimicrobial nanobilayer emulsion and its application in mango preservation.

Carvacrol is well-known natural antimicrobial compounds. However, its usage in fruit preservation is restricted owing to poor water solubility. Our study aims to address this limitation by combining carvacrol with whey protein isolate (WPI) to form nanoemulsion and enhancing antimicrobial properties and stability of nanoemulsion through ε-polylysine addition, thereby improving their application in fruit preservation. The results indicated that the nanoemulsion exhibited a double-layer structure. The physicochemical properties and storage stability were found to be favorable under the conditions of WPI (0.3 wt% v/v), Carvacrol (0.5 % v/v), and ε-polylysine (0.3 wt% v/v). In addition, the nanoemulsion had inhibitory effects on Staphylococcus aureus, Escherichia coli, and Aspergillus niger at concentrations of minimal inhibition concentration (32, 32, and 200 µg/mL, respectively). In addition, during a 7-day storage period, the nanoemulsion effectively preserved mangoes. Therefore, nanoemulsion could serve as a candidate for control of postharvest mangoes spoilage and extend its period of storage.

Preparation and Characterization of a Novel Artemisia Oil Packaging Film and Its Application in Mango Preservation.

In this work, a new food packaging film was synthesized via blending Artemisia oil (AO) into soybean protein isolate (SPI) and gelatin (Gel) for the postharvest storage of mango. The morphological architecture and mechanical properties of the films were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), and other technologies. The results show that the prepared films had relatively flat surfaces with good mechanical properties. AO enhanced the light-blocking ability of the film, increased the hydrophobicity, and affected the moisture content and water solubility of the film to a certain extent. Furthermore, the antioxidant performance and antifungal (Colletotrichum gloeosporioides) capacity of the films increased with higher AO concentration due to the presence of the active components contained in AO. During mango storage applications, the films showed good freshness retention properties. The above results indicate that SPI-Gel films containing AO have excellent physicochemical and application properties and have great potential in the field of food packaging.

Chitosan-cinnamon essential oil/sodium alginate-TiO2 bilayer films with enhanced bioactive retention property: Application for mango preservation.

The bilayer anti-ultraviolet preservation films were developed successfully by incorporating the cinnamon essential oil (CEO) to chitosan (CH) as the bioactive layer, and incorporating the TiO2 to sodium alginate (SA) as the protective layer. The addition of CEO improved the antibacterial and antioxidant properties of the films. The addition of TiO2 enhanced the bioactive retention property of the films. Remarkably, CS-0.6 film had better water vapor permeability (WVP) and mechanical properties, but CS-1.2 film had better antioxidant and antibacterial properties. After 10 d of storage, the CS-0.6 group of mangoes maintained the highest firmness of 17.62 ± 0.85 N and the highest total phenol content of 254.40 ± 4.14 mg/100 g. It also had the lowest lipoxygenase activity of 5.00 ± 1.66 10-3 U/kg. The obtained research results revealed that the developed CH/SA based bilayer film incorporated with CEO and TiO2 could be used as a multifunctional packaging material to maintain the freshness of harvested mangoes.

Biodegradable Cellulose Film Prepared From Banana Pseudo-Stem Using an Ionic Liquid for Mango Preservation.

The excessive use and disposal of plastic packaging materials have drawn increasing concerns from the society because of the detrimental effect on environment and ecosystems. As the most widely used fruit packing material, polyethylene (PE) film is not suitable for long-term preservation of some tropical fruits, such as mangos, due to its inferior gas permeability. Cellulose based film can be made from renewable resources and is biodegradable and environmental-friendly, which makes it a promising alternative to PE as a packaging material. In this study, cellulose film synthesized from delignified banana stem fibers via an ionic liquid 1-Allyl-3-methylimidazolium chloride ([AMIm][Cl]) were evaluated as packing material for mangos preservation. The moisture vapor transmission rate and gas transmission rate of the synthesized cellulose film were 1,969.1 g/(m2⋅24 h) and 10,015.4 ml/(m2⋅24 h), respectively, which are significantly higher than those of commercial PE films. The high permeability is beneficial to the release of ethylene so that contribute to extend fruit ripening period. As a result, cellulose film packaging significantly decreased the disease and color indexes of mangos, while prolonged the storage and shelf life of marketable fruits. In addition, the cellulose film was decomposed in soils in 4 weeks, indicating an excellent biodegradability as compared to the PE plastic film.

Carboxymethyl chitosan-pullulan edible films enriched with galangal essential oil: Characterization and application in mango preservation.

This study aimed to develop an active edible film based on carboxymethyl chitosan (CMCS) and pullulan (Pul) incorporated with galangal essential oil (GEO) by the casting method. And their physical properties, structural and preservation effect on mangoes were characterized. The CMCS/Pul ratio was determined to be 2.5:2.5 after the optimization of physical properties, mechanical properties and barrier properties of the blend film. The results of FT-IR and XRD showed that hydroxyl groups of Pul interacted with the carboxyl groups of CMCS and the blend films had good compatibility. Good thermal stability of CMCS/Pul-GEO films was further proven by TGA curves. The CMCS/Pul-8 %GEO film showed effective preservations on mango fruits during 15 days of storage at 25 ± 1 °C, based on the characterization by fruits weight loss, firmness, titratable acidity, soluble solids. Consequently, CMCS/Pul-GEO blend films may be a promising eco-friendly packaging material for the industrial application of fruit preservation.