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In this study, we prepared sodium alginate (SA) and montmorillonite (MMT) composite films for application in coatings for strawberry preservation. SA and MMT were used as the matrix and glycerol was used as a plasticizer. Six types of composite films with different MMT contents were compared by analyzing their mechanical properties, permeability, and preservation effects. The results show that the mechanical properties of the 10 and 20% MMT composite films were superior, with tensile strength and fracture elongation values reaching 63.09 and 48.06 MPa and 5.75 and 6.47%, respectively. Increased MMT content caused the water vapor permeability to decrease, while the effect on oil permeability was the opposite. A comparison of the preservation effect provided by the coatings showed that, on day 12, the weight loss, malondialdehyde content, and respiratory intensity of strawberries treated with the 20% MMT coating liquid decreased by 43.3, 25.8, and 57.1%, respectively, compared with the control. The contents of titratable acid, soluble sugar, total phenols, and soluble solids decreased by 25.8, 37.7, 25.9, and 14.5%, respectively. The results provide data support for the application of these new composite films as edible coatings for fruit preservation. [ABSTRACT FROM AUTHOR]

The antibacterial effects of clove essential oil, cinnamon essential oil and peppermint essential oil on strawberry Botrytis cinerea were compared, and the preservation effects of three kinds of plant essential oils on postharvest strawberry were explored. The inhibition zone and minimum inhibitory concentration of the three essential oils against Botrytis cinerea were determined by filter paper method and agar dilution method, respectively. The strawberry was sprayed and stored at 25 °C for 4 days. The texture, nutrient composition and oxidation related indexes of the fruits during storage were determined. The results showed that clove essential oil, cinnamon essential oil and mint essential oil could significantly inhibit the growth of Botrytis cinerea, and the minimum inhibitory concentrations were 0.50, 0.25, 1.00 µL/mL, respectively. The antibacterial effect of cinnamon essential oil was better than that of clove essential oil and mint essential oil. During storage, the decay index (39.85%), weight loss rate (2.24%) and total colony number of strawberry in cinnamon essential oil treatment group on the 4th day of storage were significantly lower than those in clove essential oil treatment group and peppermint essential oil treatment group (P<0.05), the hardness (105.2 g/cm²) was significantly higher than that in clove essential oil treatment group and peppermint essential oil treatment group (P<0.05), and the contents of soluble solids and VC in nutrient components index were significantly higher than those in clove essential oil treatment group and peppermint essential oil treatment group (P<0.05). The malondialdehyde (MDA) content and polyphenol oxidase (PPO) activity in the oxidation-related indicators were lower than those in the clove essential oil treatment group and the peppermint essential oil treatment group, and the superoxide dismutase (SOD) and peroxidase (POD) activity were higher than those in the other two essential oil treatment groups. This study showed that the antibacterial preservation effect of cinnamon essential oil was better than that of clove essential oil and peppermint essential oil, which provided a theoretical basis for the application of strawberry preservation. [ABSTRACT FROM AUTHOR]

This study investigated the effects of adding different amounts of sesame oleosomes on the properties of polysaccharide edible films, and explored the application of the film incorporated with sesame oleosomes in strawberry preservation in terms of sensory evaluation and physicochemical indexes. The results showed that the extracted sesame oleosomes contained 72.3% fat, which could maintain good oxidative stability for 8 days. Adding an appropriate amount of sesame oleosomes to edible films could effectively improve the softness, water vapor barrier, solubility and elongation. However, adding excess sesame oleosomes (≥ 5.6%) decreased the mechanical properties and transparency. Taken together, the optimal proportion of oleosome addition was 1.2%. Compared with the blank and oleosome-free control groups, the oleosome-incorporated film effectively delayed the rotting and softening of strawberry fruits as well as the decrease in moisture, soluble solids and titratable acids, and extended the shelf life by at least 1 day. This study showed that a certain amount of oleosomes can be used as lipid derivatives in lipid-based edible films to extend the shelf life of fruits and vegetables.

Fungal infestations, particularly from Rhizopus stolonifer, pose significant post-harvest challenges for strawberries, compromising their shelf life and quality. Traditional preservation methods, including refrigeration, offer limited protection against such pathogens. This study introduces an innovative approach, utilizing edible films infused with Bacillus subtilis strains GOS 01 B-67748 and HFC 103, known for their antifungal properties. We demonstrate that these bioactive films not only inhibit fungal growth effectively but also enhance the preservation of strawberries at varying temperatures. The inclusion of Bacillus subtilis in edible films represents a significant advancement in extending the viability of strawberries, surpassing the efficacy of conventional methods. Our findings suggest a promising avenue for natural, safe food preservation techniques, aligning with current consumer preferences for additive-free products. This research contributes to the broader understanding of microbial-based food preservation strategies, offering potential applications across a range of perishable commodities. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Perilla frutescens L. essential oil (PLEO) has antibacterial and antioxidant properties, which can effectively maintain the quality of fruits and extend their shelf life. In this study, sodium alginate and chitosan were used as wall materials, and PLEO microcapsule powder was used as the core materials to prepare PLEO hydrogel beads. The best results were obtained by using 2%w/v sodium alginate and 1.5%w/v chitosan as wall materials, with a core-to-wall ratio of 2:1 and homogenized for 15 min producing PLEO hydrogel beads with encapsulation efficiency of 82.61 %. For strawberries preservation, PLEO hydrogel beads preservation group had a better effect after 5 d of storage, showing a lower decay rate (15.71 %), better maintaining the hardness of 1.75 kg/cm2, and a weight loss of 3.29 %. Furthermore, organic acids and total phenols were retained more in this group, the number of microorganisms was significantly reduced, and sensory qualities were improved, especially taste and color. This study provides important insights into the application of natural preservatives in the food industry and promotes sustainable practices in food preservation.

As an antioxidant and broad-spectrum antibacterial agent, thymol has some disadvantages such as poor solubility, low stability and strong irritating odor, restricting its application in food preservation. In order to overcome these shortcomings, thymol-containing microcapsules were prepared by the saturated aqueous solution method using thymol as the core material and β-cyclodextrin as the wall material, and the sustained release performance, antibacterial and antioxidant capacity of the microcapsules were evaluated. Meanwhile, its structure was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric (TG) analysis, and its efficacy in preserving strawberry quality was analyzed. The results showed that thymol was successfully embedded in β-cyclodextrin and the thermal stability of the microcapsules was significantly improved. The maximum cumulative amount of thymol released from the microcapsules was 41.16% after 360 min. When used at a dosage of 25 mg, the microcapsules had the strongest antibacterial effect on Escherichia coli and Staphylococcus aureus. At a concentration of 10 mg/mL, it scavenged 81.40% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The microcapsules reduced the decay incidence and loss rate by 26.34% and 19.63%, respectively on the 10th day of storage compared with the control group, slowed the decrease in hardness and soluble solids content (SSC), and better maintained the appearance, color, texture and flavor. Thymol-containing microcapsules could delay the spoilage, effectively maintain the quality, and prolong the shelf life of strawberry at room temperature.

Strawberries rich nutrition, flavor, and aroma profiles make them popular. Many studies have tried to extend strawberries shelf life. In the current study, grape pomace extract (GPE) was combined with polyvinyl alcohol (PVA) and used to extend the shelf life of strawberries. Ascorbic acid content, total phenolic content, total anthocyanin content, and antioxidant activity determinations showed that PVA/GPE-coated strawberries were superior to the uncoated fruits during storage. Total mesophilic aerobic bacteria (TMAB) and yeast/mold counts in the uncoated strawberries were 2 and 2.68 log cfu/g at the start of storage, respectively, and 9.8 and 14.00 log cfu/g after 16 days of storage, respectively. Strawberries coated with the PVA solution with 2.5% ( w/v ) GPE showed 32% and 25% less TMAB and yeast/mold counts, respectively, at the end of storage. The PVA/GPE-coated strawberries showed significantly higher firmness compared to the control fruit. The PVA/GPE coating improved strawberry shelf life and functional properties.

Copyright of Journal of Henan University of Technology Natural Science Edition is the property of Henan University of Technology Journal Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Currently, food saving, a circular economy, and zero environmental fingerprints are of major interest. Scientific efforts for enhanced food preservation using "green" methods have been intensified. Even though chemicals could achieve such targets effectively, the global trend against the "greenhouse effect" suggests the use of environmentally friendly biobased materials for this purpose. In this study, the promising biopolymer chitosan is incorporated with the promising biodegradable polymer polyvinyl alcohol to produce an improved biopolymeric matrix. This biodegradable biopolymer was further mixed homogeneously with 15% thymol/nano-zeolite nanohybrid material. The properties of the final developed film were improved compared to the relevant values of chitosan/polyvinyl alcohol film. The mechanical properties were enhanced significantly, i.e., there was a 34% increase in Young's modulus and a 4.5% increase in the ultimate tensile strength, while the antioxidant activity increased by 53.4%. The antibacterial activity increased by 134% for Escherichia coli, 87.5% for Staphylococcus aureus, 32% for Listeria monocytogenes, and 9% for Salmonella enterica. The water vapor diffusion coefficient and the oxygen permeability coefficient decreased to −51% and −74%, respectively, and thus, the water vapor and oxygen barrier increased significantly. The active pads were used in strawberries, and the antimicrobial activity evaluation against the mold of fungi was carried out. The visual evaluation shows that the active pads could extend the shelf life duration of strawberries. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Strawberries rich nutrition, flavor, and aroma profiles make them popular. Many studies have tried to extend strawberries shelf life. In the current study, grape pomace extract (GPE) was combined with polyvinyl alcohol (PVA) and used to extend the shelf life of strawberries. Ascorbic acid content, total phenolic content, total anthocyanin content, and antioxidant activity determinations showed that PVA/GPE-coated strawberries were superior to the uncoated fruits during storage. Total mesophilic aerobic bacteria (TMAB) and yeast/mold counts in the uncoated strawberries were 2 and 2.68 log cfu/g at the start of storage, respectively, and 9.8 and 14.00 log cfu/g after 16 days of storage, respectively. Strawberries coated with the PVA solution with 2.5% (w/v) GPE showed 32% and 25% less TMAB and yeast/mold counts, respectively, at the end of storage. The PVA/GPE-coated strawberries showed significantly higher firmness compared to the control fruit. The PVA/GPE coating improved strawberry shelf life and functional properties. [ABSTRACT FROM AUTHOR]

Fungal infestations, particularly from Rhizopus stolonifer, pose significant post-harvest challenges for strawberries, compromising their shelf life and quality. Traditional preservation methods, including refrigeration, offer limited protection against such pathogens. This study introduces an innovative approach, utilizing edible films infused with Bacillus subtilis strains GOS 01 B-67748 and HFC 103, known for their antifungal properties. We demonstrate that these bioactive films not only inhibit fungal growth effectively but also enhance the preservation of strawberries at varying temperatures. The inclusion of Bacillus subtilis in edible films represents a significant advancement in extending the viability of strawberries, surpassing the efficacy of conventional methods. Our findings suggest a promising avenue for natural, safe food preservation techniques, aligning with current consumer preferences for additive-free products. This research contributes to the broader understanding of microbial-based food preservation strategies, offering potential applications across a range of perishable commodities.

This research presents the effect of combining UV‐C irradiation and vacuum sealing on the shelf life of strawberries and quartered tomatoes and compares it with the effect of the sole use of UV‐C irradiation or vacuum sealing. A constant UV‐C dose of 360 J/m2 was used for the samples' irradiation, and all the vacuum‐sealed samples were stored at a reduced pressure of 40 kPa. Organoleptic analysis, microbial population quantification of yeast and mold, Pseudomonas sp., weight loss, and pH measurements were obtained to identify the spoilage occurrence, monitor the samples' quality, and quantify the shelf life. Sensory evaluation was conducted by 12 consumer panelists to evaluate the aroma, taste, color, texture, and the overall acceptance of the samples. The results revealed that the combination of UV‐C irradiation and vacuum sealing prolongs the shelf life of perishables more than the sole use of UV‐C irradiation or vacuum sealing. The achieved shelf‐life increase using this combination was 124.41% and 54.41% for strawberries and quartered tomatoes, respectively, while acceptable sensory characteristics were maintained throughout the storage period. Hence, this food preservation method can be further improved and integrated in the daily life of modern consumers and the operations of fresh produce retailers, as it could effectively reduce the spoilage rates of fresh produce and help achieve the UN SDG 12.3, which aims to reduce food loss and waste by 50% by 2030 at the consumer and retail levels. Practical Application: The system can be further developed and introduced to the market as a kitchen appliance for households or as a predistribution step for fresh produce distribution centers. The shelf‐life extension capability of this system, which does not involve any use of chemical substances, would make it an attractive solution for households and food retailers. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • CNF-based packaging film was synergistically reinforced by lignin and tea polyphenols. • The composite film exhibited excellent mechanical and barrier performances. • The composite film possessed remarkable antibacterial and antioxidant properties. • The composite film could significantly extend the shelf life of strawberry. Developing biomass-based food packaging materials could alleviate resource scarcity and environmental pollution. This study successfully fabricated cellulose nanofibrils-based packaging films synergistically reinforced by lignin and tea polyphenols for fruit preservation. Thanks to the abundant carboxyl and hydroxyl groups in modified lignin and tea polyphenol, the composite film delivered the highest tensile strength and Young's modulus of 230.7 MPa and 11.9 GPa, respectively. The water vapor permeability (WVP) and oxygen permeability (OP) of composite film were as low as 2.53 × 10−11 g m−1 s−1 Pa−1 and 1.69 × 10−16 cm m−2 s−1 Pa−1, respectively, demonstrating excellent barrier performance. Furthermore, the composite film possessed remarkable antibacterial (100 % antibacterial activity against two types of bacteria), antioxidant (DPPH free radical scavenging activity of 90 %), and UV shielding properties (impressive UV shielding rate of 99.0 %). Strawberry preservation experiments showed that these composite films could significantly extend shelf life, owing to the excellent barrier and antimicrobial properties. Our research indicated that these composite films could be promising food packaging material compared with traditional plastic and showed great application potential in fruit preservation. [ABSTRACT FROM AUTHOR]

As an emerging non-contact cold chain preservation technology, the impact of the DENBA+ on plant cell wall metabolism and its mechanism of inhibiting softening have not been addressed. In this study, strawberries were used as an experimental model to investigate the effect of space electric field storage on cell wall metabolism. Compared with the control, 500 V DENBA+ treatment was able to reduce the firmness loss of strawberries by 18.3 % on 18 d. Additionally, the DENBA+ exhibited a pronounced ability to suppress fruit softening enzyme (FaPG1 and FaβGal4) expression, delay the rise in polygalacturonates (PG), pectin methyl esterase (PME), cellulase (Cx), and β-galactosidase (β-Gal) activities, postpone the decline in cell wall matrix (CWM), insoluble solid pectin (ISP), and colloidal soluble pectin (CSP) content along with hemicellulose and cellulose levels while attenuating water-soluble pectin (WSP) accumulation during cold storage period. These findings contribute to the maintenance of fruit cell wall structural integrity with the aim of sustaining strawberry firmness and retarding the progression of aging. • DENBA+ delayed the degradation of strawberry cell walls. • DENBA+ inhibited the cell wall-modifying enzymes activities of strawberry. • DENBA+ keeps the strawberries from softening. • DENBA+ affected the expression levels of FAPG1，FaPME1 and FaβGAL4. [ABSTRACT FROM AUTHOR]

Bio-enzymatic grafting phenolic acid to chitosan derivative is an efficient and environmentally friendly molecular synthesis technology. In the present study, N-carboxymethyl chitosan (CMCS) was grafted with gallic acid (GA) using recombinant bacterial laccase from Streptomyces coelicolor as a catalyst. GA and CMCS were successfully grafted as determined by measuring amino acid content, Fourier transform infrared (FTIR) spectroscopy and ultraviolet-visible (UV-Vis) spectroscopy. Then, the effect of GA-g-CMCS coating on the freshness of strawberries at 20 ± 2 °C was explored. The physiological and biochemical quality indicators of strawberries during storage were monitored. The 1.5% GA-g-CMCS coating helped to protect the antioxidant properties and nutrients of strawberries and extend the shelf life. Specifically, it reduced the weight loss of strawberries during preservation (originally 12.7%) to 8.4%, maintained titratable acidity content (TA) residuals above 60% and reduced decay rate from 36.7% to 8.9%. As a bioactive compound, GA-g-CMCS has the potential to become an emerging food packing method. These results provide a theoretical basis and reference method for the subsequent synthesis and application of CMCS derivatives. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chlorine dioxide (ClO 2) exhibits promising potential for the application in food preservation. However, the large-scale production of controlled-release ClO 2 films faces challenges. The sodium chlorite microcapsules (Micro-SC) were successfully prepared in this study using polyvinyl alcohol (PVA) as the wall material through the spray drying method. Furthermore, A large-scale preparation of temperature and humidity dual-responsive ClO 2 controlled-release films (Micro-SC@EVA) was achieved using melt extrusion. The film could release ClO 2 triggered by water vapor for 36 days. The antibacterial effects were significantly enhanced with the increase of microcapsule ratio from 4 % to 8 %. The Micro-SC@EVA film reduced the total viable count and wight loss of strawberries, inhibits ethylene production, and extended the shelf life of by 150 % compared with the control group at 25 °C. The application evaluation results show that the novel approach for the large-scale preparation of ClO 2 controlled-release film holds significant implications for food packaging. [Display omitted] • The prepared Micro-SC could generate ClO 2 without adding extra acid. • The production of ClO 2 controlled-release films stably in large-scale. • The controlled-release ClO 2 film could release for 36 days and exhibits a dual-response to temperature and humidity. • The controlled-release ClO 2 film could extends the shelf life of strawberries by 150 %. [ABSTRACT FROM AUTHOR]

In this study, an antimicrobial component, silk protease inhibitors (SPIs), was extracted from discarded silkworm cocoons, and a suitable degumming method for obtaining regenerated silk fibroin (SF) was screened. An edible antimicrobial coating was prepared by mixing SPIs with SF for evaluation of potential in strawberries preservation. Results demonstrated that SPI could effectively inhibit mycelial growth and spore germination. The alkaline protease method exhibited the highest degumming rate of 24.4 %. The SPI-SF coating exhibited excellent mechanical properties, high water vapor permeability, and easy washability. Within 10 days, seedlings treatment with SPI-SF coating solution showed a germination rate of 94.3 %, and exhibited good biocompatibility with HepG2 cells. Coating with SPI-SF led to increase in the storage period of strawberries to 10–14 days, concurrent with considerable reduction in decay rate at room temperature. Conclusively, this study demonstrates the potential of SPI-SF edible coating in strawberries preservation. [Display omitted] • Silk protease inhibitors (SPI) effectively inhibited Botrytis cinerea. • Silk fibroin (SF) degummed by alkaline protease had superior film-forming property. • SPI-SF benefited the fresh keeping of strawberries as antifungal coating materials. [ABSTRACT FROM AUTHOR]

Fresh strawberries are easily contaminated by microorganisms after picking. Therefore, how to effectively store and keep fresh strawberries has been a hot topic for scientists to study. In this study, we prepared a leaf shaped metal organic framework nanomaterial loaded with quercetin (Quercetin@ZIF-L) at first, which can achieve effective loading of quercetin (96%) within 45 min and has a controlled release effect under acidic conditions. In addition, by cleverly combining satellite graphene oxide @ silver nanoparticles (GO@AgNPs) with slow precipitation performance, Quercetin@ZIF-L/GO@AgNPs nanocomposite film with larger pore size and larger specific surface area was prepared by scraping method. The characterization data of water flux, retention rate, flux recovery rate and water vapor permeability show that the composite film has good physical properties. The experiment of film packaging showed that the fresh life of strawberry could be extended from 3 to 8 days, which significantly improved the storage and freshness cycle of strawberry. At the same time, the metal migration test proved that the residual amount of silver ion in strawberry met the EU standard and zinc ions are beneficial to the health, enriching the types of high-performance fresh-keeping materials and broadening the application. [Display omitted] • Rapid and efficient adsorption and stimulated release of natural active substances-quercetin by MOFs. • MOFs composite nano cling film significantly prolongs the shelf life of strawberries. • Collaborative antibacterial preservation performance of MOFs and GO @ Silver Nanoparticles. [ABSTRACT FROM AUTHOR]

Incorporating polysaccharide-based composite films with nanobiotechnology offers a new strategy for food preservation. This study initially focuses on the preparation of tea polyphenol nanoparticles (TPNP), novel and derived from natural antibacterial agents, which serve to improve stability. Afterwards chitosan-based composite films loaded with TPNP (CTN film) were developed using solution casting method. The incorporation of TPNP significantly improved the UV/water/oxygen barrier properties, mechanical properties and thermal stability, alongside notable physical properties including water contact angle (93.65 ± 0.04°), low water vapor permeability (33.72 ± 3.32 g/m2h) and oxygen permeability (0.11 ± 0.02 g/m2h), tensile strength (61.83 ± 0.70 %), and elongation at break (31.60 ± 6.12 %). The CTN film not only exhibited exceptional biodegradability and nontoxicity, but also demonstrated remarkable antimicrobial efficacy against Escherichia coli and Bacillus subtilis. Additionally, it showcased potent antioxidant activity, boasting DPPH and ABTS radical scavenging rates up to 89.25 ± 0.18 % and 93.84 ± 0.42 %. The CTN film was successfully formed on the surface of strawberries through dip-coating process and their shelf life was extended from 4 to 6 days at 20 °C without side-effect on the weight loss, harness, pH and total soluble solids, illustrating its potential for enhancing food preservation. [ABSTRACT FROM AUTHOR]

In this study, multifunctional green carbon dots (CDs) have been synthesized using Galla chinensis waste (GCW) via hydrothermal method for the first time. An active packaging film has been developed in this work by combining CDs and pullulan (PL), using the solution-casting method. The microscopic morphology revealed that the CDs that were prepared using GCW exhibited good compatibility with PL. In addition, it also led to improvement in the toughness of the PL film (14.01 % to 20.26 %), along with its water vapor permeability value [1.31 to 0.53 (g·mm)/(kPa·h·m2)]. The composite films consisting of CDs exhibited good UV blocking rates for the UVA (90.41 %–7.87 %), UVB (87.76 %–0.08 %), and UVC (83.39 %–0 %) spectral ranges. The composite films exhibited strong antioxidant activity, and the clearance of ABTS and DPPH were obtained to be 93.61 % and 86.30 %, respectively. In addition, the composite films showed good antibacterial activity for E. coli and S. aureus , with a high antibacterial rate of up to 99.99 %. Finally, the non-contact preservation of strawberries over a duration of 10 d at room temperature confirmed that the prepared composite film can help preserve the quality of strawberries, as well as extended their shelf-life. [Display omitted] [ABSTRACT FROM AUTHOR]

• Pectin coatings enriched with WLE improved strawberry shelf-life. • WLE significantly reduced strawberry weight loss during storage. • Pectin-based coatings effectively preserved strawberries' bioactive compounds. Fruits that are characterized by their fragile architecture are less durable and are a major source of waste. Thus, research on increasing the durability of such foods remains relevant. Pectin is an inexpensive and edible coating material derived from natural resources that can be used to preserve strawberries. The aim of the current research was to fortify pectin with grape pomace extract (GPE) and wine lees extract (WLE) that are rich in bioactive components. Physicochemical, microbiological and functional properties of coated and uncoated strawberries were investigated during the storage period (0, 5, 10, 15, and 20th day). GPE and WLE-supported pectin coatings helped preserve the antioxidant capacity, phenolic, anthocyanin and ascorbic acid contents of strawberries. Coated samples WLE-enriched exhibited significantly less weight loss compared to other samples. WLE coating was effective in inhibiting yeast mould populations on strawberries. WLE-enriched coatings acted as a wall material to preserve bioactive components and delayed quality changes compared to GPE, allowing them to reach a storage period of 20 days at 4 °C. [Display omitted] [ABSTRACT FROM AUTHOR]

The novel exopolysaccharide EPS-E8, secreted by Pediococcus pentosaceus E8, was obtained by anion-exchange and gel filtration chromatography. Structural analyses identified EPS-E8 as a heteropolysaccharide containing mannose, glucose, and galactose. Its major backbone consists of →2)-α-D-Man p -(1→2,6)-α-D-Glc p -(1→6)-α-D-Man p -(1→, and its molecular weight is 5.02 × 104 g/mol. Using atomic force microscopy and scanning electron microscopy, many spherical and irregular reticular-like shapes were observed in the microstructure of EPS-E8. EPS-E8 has outstanding thermal stability (305.7°C). Both the zeta potential absolute value and average particle diameter increased gradually with increasing concentration. Moreover, at a concentration of 10 mg/ml, the antioxidant capacities of, 1-Diphenyl-2-picrylhydrazyl (DPPH), ABTS and hydroxyl radical were 50.62 ± 0.5%, 52.17 ± 1.4%, and 58.91 ± 0.7%, respectively. EPS-E8 possesses excellent emulsifying properties against several food-grade oils, and its activity is retained under various conditions (temperature, pH, and ionic strength). Finally, we found that EPS-E8 as a polysaccharide-based coating could reduce the weight loss and malondialdehyde (MDA) content of strawberry, as well as preserving the vitamin C and soluble solid content during storage at 20°C. Together, the results support the potential application of EPS-E8 as an emulsifier, and a polysaccharide-based coating in fruit preservation. [ABSTRACT FROM AUTHOR]

The novel exopolysaccharide EPS-E8, secreted by Pediococcus pentosaceus E8, was obtained by anion-exchange and gel filtration chromatography. Structural analyses identified EPS-E8 as a heteropolysaccharide containing mannose, glucose, and galactose. Its major backbone consists of →2)-α-D-Manp-(1→2,6)-α-D-Glcp-(1→6)-α-D-Manp-(1→, and its molecular weight is 5.02 × 104 g/mol. Using atomic force microscopy and scanning electron microscopy, many spherical and irregular reticular-like shapes were observed in the microstructure of EPS-E8. EPS-E8 has outstanding thermal stability (305.7°C). Both the zeta potential absolute value and average particle diameter increased gradually with increasing concentration. Moreover, at a concentration of 10 mg/ml, the antioxidant capacities of, 1-Diphenyl-2-picrylhydrazyl (DPPH), ABTS and hydroxyl radical were 50.62 ± 0.5%, 52.17 ± 1.4%, and 58.91 ± 0.7%, respectively. EPS-E8 possesses excellent emulsifying properties against several food-grade oils, and its activity is retained under various conditions (temperature, pH, and ionic strength). Finally, we found that EPS-E8 as a polysaccharide-based coating could reduce the weight loss and malondialdehyde (MDA) content of strawberry, as well as preserving the vitamin C and soluble solid content during storage at 20°C. Together, the results support the potential application of EPS-E8 as an emulsifier, and a polysaccharide-based coating in fruit preservation.

Biodegradable composite films based on pullulan/carboxymethyl cellulose/nano-TiO2 were prepared using a solution casting method. In this study, the composite films were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM), and their physical, mechanical and antimicrobial properties were investigated. FTIR and XRD results confirmed that the presence of nano-TiO2 could enhance the interaction between the film matrix. SEM analysis revealed that the composite films had a homogeneous network structure, and good particle dispersion could be obtained when the nano-TiO2 particle content was low. DSC results indicated that the composite films possessed good thermal stability. The incorporation of nano-TiO2 increased the thickness and contact angle while significantly decreasing the water solubility (p < 0.05). As the content of nano-TiO2 increased, the water vapor and ultraviolet visible (UV–Vis) light barrier properties of composite films were significantly improved (p < 0.05). Mechanical analysis demonstrated that the tensile strength of the composite films first increased and then decreased, whereas the elongation at break decreased significantly (p < 0.05). In addition, the composite films exhibited excellent activity against Escherichia coli and Staphylococcus aureus mainly due to the inactivation of bacteria by nano-TiO2 photocatalysis. Preservation experiments showed that the composite films could decrease the weight loss significantly and maintain the firmness, titratable acidity, vitamin c and skin color of strawberries, thereby improving the overall quality of strawberries and extending their shelf life. This finding suggested that pullulan/carboxymethyl cellulose/nano-TiO2 composite films possessed excellent potential for application in food packaging. [ABSTRACT FROM AUTHOR]

A stronger and dimension-stabilized film was obtained using κ-carrageenan and sodium carboxymethyl starch (CMS) with carboxylated cellulose nanocrystals (C-CNC) as a reinforcing agent and anti-shrinkage agent. C-CNC endowed the films with better mechanical properties as well as excellent dimensional stability. The film solutions showed shear thinning and acted as a pseudoplastic fluid. When C-CNC content was increased from 0% to 12%, the tensile strength and elongation at break of the films improved from 23.89 MPa to 38.37 MPa and 21.00% to 27.31%, respectively. The films maintained good thermal stability and barrier performance. The Zeta potential of the film suspension can reach below −30 mV, indicating C-CNC enhanced the electrostatic repulsion in the film-forming system, which favored the network structure more continuous and stable. By virtue of the excellent mechanical properties and dimensional stability, strawberries can be tightly wrapped without cracks by the coatings to delay the deterioration greatly. By comparing the weight loss rate, Vc, total soluble solid, hardness, titratable acid and pH, CCC12-coated strawberries were closer to fresh ones. Therefore, this study has developed a feasible, low-cost and green fruit coating that can be potentially utilized on a large-scale. [Display omitted] • Sodium carboxymethyl starch and κ-carrageenan based films were prepared. • Carboxylated cellulose nanocrystals endowed films highly mechanical properties. • The film-forming solution could form a dimensional stable coating on strawberries. • The CCC12 showed a higher preservation for the strawberries obviously. [ABSTRACT FROM AUTHOR]

Bio-enzymatic grafting phenolic acid to chitosan derivative is an efficient and environmentally friendly molecular synthesis technology. In the present study, N-carboxymethyl chitosan (CMCS) was grafted with gallic acid (GA) using recombinant bacterial laccase from Streptomyces coelicolor as a catalyst. GA and CMCS were successfully grafted as determined by measuring amino acid content, Fourier transform infrared (FTIR) spectroscopy and ultraviolet-visible (UV-Vis) spectroscopy. Then, the effect of GA-g-CMCS coating on the freshness of strawberries at 20 ± 2 °C was explored. The physiological and biochemical quality indicators of strawberries during storage were monitored. The 1.5% GA-g-CMCS coating helped to protect the antioxidant properties and nutrients of strawberries and extend the shelf life. Specifically, it reduced the weight loss of strawberries during preservation (originally 12.7%) to 8.4%, maintained titratable acidity content (TA) residuals above 60% and reduced decay rate from 36.7% to 8.9%. As a bioactive compound, GA-g-CMCS has the potential to become an emerging food packing method. These results provide a theoretical basis and reference method for the subsequent synthesis and application of CMCS derivatives.

To improve the preservation of strawberries during storage, an edible coating was prepared using a layer-by-layer self-assembly electrostatic deposition technology. Sodium polyacrylate (PAAS) was used as polyanion solution, and chitosan (CS) was used as polycation solution. The obtained coating was characterised to determine its self-repairing ability and its effect on the preservation of strawberries. The results showed that CS (9 mg/mL) and PAAS (5 mg/mL) could assemble, by hydrogen and ionic bonding, to form a new coating with no obvious pores and had a tight cross-sectional structure. The PAAS/CS self-assembled coating displayed high water resistance (water vapor transmission rate, 31.22 x 10-11 g* m/m²*s*Pa*), transparency (light transmittance, 87.5%), and excellent mechanical properties (tensile strength, 17.31 MPa; elongation at break, 13.72%). The self-repairing ability of the PAAS/CS coating upon scratching was manifested by the repair of the coating's morphology (repair rate, 81.05%), and the restoration of its mechanical properties. When compared with uncoated strawberries, PAAS/CS coating significantly reduced the weight loss rate, the rot rate during storage (p < 0.05), and the loss of anthocyanin and vitamin C. In conclusion, the PAAS/CS coating greatly improved the fresh-keeping of strawberries. [ABSTRACT FROM AUTHOR]

Perilla frutescens L. essential oil (PLEO) has antibacterial and antioxidant properties, which can effectively maintain the quality of fruits and extend their shelf life. In this study, sodium alginate and chitosan were used as wall materials, and PLEO microcapsule powder was used as the core materials to prepare PLEO hydrogel beads. The best results were obtained by using 2%w/v sodium alginate and 1.5%w/v chitosan as wall materials, with a core-to-wall ratio of 2:1 and homogenized for 15 min producing PLEO hydrogel beads with encapsulation efficiency of 82.61 %. For strawberries preservation, PLEO hydrogel beads preservation group had a better effect after 5 d of storage, showing a lower decay rate (15.71 %), better maintaining the hardness of 1.75 kg/cm 2 , and a weight loss of 3.29 %. Furthermore, organic acids and total phenols were retained more in this group, the number of microorganisms was significantly reduced, and sensory qualities were improved, especially taste and color. This study provides important insights into the application of natural preservatives in the food industry and promotes sustainable practices in food preservation., Competing Interests: There are no conflicts of interest to declare., (© 2024 The Authors. Published by Elsevier Ltd.)

Edible coatings and films have gained interest because of their benefits to increase shelf life of fresh produce such as fruit and vegetables, while organic residues may constitute alternative sources to extract film-forming materials. Therefore, this research aimed to characterize coatings and films based on an innovative type of pectin obtained from the byproducts of Hibiscus sabdariffa L. (HsL) of the Sudan cultivar, to preserve strawberries. Coatings and films were prepared with HsL pectin (0.8–1.8%) and glycerol (0.5–1.5%) as plasticizer, at different casting volumes (10–20 mL). The characteristic color of HsL calyces remained in film formulations, and the intensity of this was proportional to the amount of pectin. Solutions with pectin percentages as low as 1.3% yielded coatings with high viscosities of 2500.0 ± 35.6 cP, whereas 1.8% pectin notably increase viscosity up to 6707.5 ± 126.5 cP. Films displayed different values of solubility (52.0–90.7%), water vapor permeability (4.0–14.5 × 10–12 g m−1 s−1 Pa−1), and mechanical properties (tensile strength, 1.0–10.6 MPa, elongation at break, 2.8–18.7%, and elastic modulus, 2.3–21.8 MPa), as a function of factors combination. Further, an optimized coating formulation was evaluated on strawberries, which showed a significant (p < 0.05) reduction of weight loss (39.1%) compared to the control (43.8%), during storage for 21 days. Other significant (p < 0.05) parameters were total soluble solids, total anthocyanins, color, and ascorbic acid. On coated fruit, the aerobic plate count decreased, Enterobacteriaceae and coliforms were not significant, and Escherichia coli was below the detection limit; only yeast and mold counts were higher compared with those of the uncoated fruit. [ABSTRACT FROM AUTHOR]

Recently, chitosan film has been widely used to extend the shelf life of food. In this study, high, medium and low molecular weight of chitosan were used as raw materials to prepare a series of films (C1–C27) by controlling the content of chitosan and glycerol, and their mechanical properties, water vapor permeability (WVP), oxygen transmittance (OP), morphology and antibacterial properties were characterized as well. The results indicated that all films had film-forming properties. Among them, the film C16 with high molecular weight, high chitosan content and 50% glycerol/chitosan (w/w) exhibited the excellent transparency (91.2%), elongation at break (28.948%), tensile strength (77.963 MPa), WVP (1.46 × 10−12gcm/cm2·sPa), smooth morphology, denser structure and antibacterial property (Staphylococcus aureus and Escherichia coli). Meanwhile, the preservation properties of chitosan films were evaluated by strawberry preservation. Almost all the studied films had better preservation effect than the commercially available PE films, especially of which the film C16 was the best compared with others. It maintained the physical and chemical parameters (weight loss ratio, total soluble solids, titratable acidity, total ascorbic acid and color change) of strawberry most obviously. Hence, chitosan films had great potential for the industrial application of fruit preservation. [ABSTRACT FROM AUTHOR]

Active food packaging with controlled release behavior of volatile antimicrobials is highly desirable for enhancing the quality of fresh produce. In this study, humidity-responsive antimicrobial aerogels were developed using chitosan and dialdehyde nanocellulose, loading with cyclodextrin-cinnamaldehyde inclusion complexes (ICs) for achieving humidity-triggered release of the encapsulated antimicrobial agent. Results showed that the prepared aerogels had capable water absorption ability, which could be served as absorbent pads to take in excessive exudate from packaged fresh produce. More importantly, the accumulative release rate of cinnamaldehyde from the antimicrobial aerogels was significantly improved at RH 98 % compared to that at RH 70 %, which accordingly inactivated all the inoculated Escherichia coli, Staphylococcus aureus and Botrytis cinerea. Additionally, strawberries packaged with the antimicrobial aerogels remained in good conditions after 5 d of storage at 22 ± 1 °C. The prepared composite aerogels had the potential to extend the shelf life of fresh strawberries. [Display omitted] • Bio-based aerogels were developed based on Schiff base reaction • Humidity-triggered release of volatile compound was achieved. • Changes in RH affected the crystal structure of ICs. • Packages loaded with antibacterial aerogel extended the shelf life of strawberries [ABSTRACT FROM AUTHOR]

Cinnamon essential oil (CEO) was emulsified by hydroxypropyl-β-cyclodextrin/ ethyl lauroyl arginate (HPCD/LAE) complex to make nanoemulsions, which were then incorporated into maltodextrin (MD) to prepare HPCD/LAE/CEO/MD microcapsules by spray drying. The starch/polybutylene adipate terephthalate (starch/PBAT, SP) based extrusion-blowing films containing above microcapsules were developed and used as packaging materials for strawberry preservation. The morphology, encapsulation efficiency, thermal and antibacterial properties of microcapsules with different formulations were investigated. The effects of microcapsules on the physicochemical and antimicrobial properties of SP films were evaluated. When the formula was 4 % HPCD/LAE-3% CEO-10% MD (HL-3C-MD), the microcapsule had the smallest particle size (3.3 μm), the highest encapsulation efficiency (84.51 %) of CEO and the best antibacterial effect. The mechanical and antimicrobial properties of the SP film were enhanced while the water vapor transmittance and oxygen permeability decreased with the incorporation of HL-3C-MD microcapsules. The films effectively reduced the weight loss rate (49.03 %), decay rate (40.59 %) and the total number of colonies (2.474 log CFU/g) and molds (2.936 log CFU/g), thus extending the shelf life of strawberries. This study revealed that the developed SP films containing HPCD/LAE/CEO microcapsules had potential applications in degradable bioactive food packaging materials. • Cinnamon essential oil (CEO) nanoemulsions were stabilized by HPCD/LAE complex. • The nanoemulsions were spray dried into microcapsules and incorporated into SP films. • The microcapsule addition significantly improved antibacterial property of SP films. • The films with microcapsules effectively extended the shelf life of strawberry. [ABSTRACT FROM AUTHOR]

In this work, a multifunctional preservative film of ZnO/carboxymethyl starch/chitosan (ZnO/CMS/CS) with the unique "Steel Wire Mesh" structure is fabricated by the chemical crosslinked of ZnO NPs, CMS and CS. Unlike traditional nano-filled polymer film, the formation of the "Steel Wire Mesh" structure of ZnO/CMS/CS film is based on the synergistic effect of ZnO NPs filled CMS/CS and the coordination crosslinked between CMS/CS and Zn2+ derived from ZnO NPs. Thanks to the "Steel Wire Mesh" structure, the tensile strength and water vapor barrier of 2.5ZnO/10CMS/CS film are 2.47 and 1.73 times than that of CS film, respectively. Furthermore, the transmittance of 2.5ZnO/10CMS/CS film during antifogging test is close to 89 %, confirming its excellent antifogging effects. And the 2.5ZnO/10CMS/CS film also exhibits excellent long-acting antibacterial activity (up to 202 h), so it can maintain the freshness and appearance of strawberries at least 5 days. More importantly, the 2.5ZnO/10CMS/CS film is sensitive to humidity changes, which achieves real-time humidity monitoring of the fruit storage environment. Note that the preparation method of the film is safe, simple and environmentally friendly, and its excellent degradation performance will not bring any problems of food safety and environmental pollution. [Display omitted] [ABSTRACT FROM AUTHOR]

This study used electrostatic spraying (ES) system as an efficient technique for strawberry preservation with chitosan (CH) coating. The effects of CH deacetylation degree (DD, 81.0, 88.1 and 95.2%) on the qualities (weight loss, pH, total soluble solids (TSS), firmness, flavonoids content, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity and mold growth) of strawberry during cold storage were investigated. Results showed that CH coating by ES formed more continuous and uniform protective layer compared with conventional spraying (CS). CH coating effectively enhanced the overall quality and extended shelf life of strawberry at least 2 days. CH coating with 81.0% and 88.1% DD were more effective in reducing weight loss of strawberry, and CH coating with 88.1% DD could better maintain TSS content, while CH coating with 95.2% DD delayed the decline in flavonoids more obviously. However, DD had no significant impact on pH, firmness, SOD activity, MDA and mold growth of coated samples. The evaluation criteria indicated CH coating with 88.1% DD had better preservation performance with the highest synthetic value (6.17) during storage. These findings suggest that CH coating especially with 88.1% DD by ES, as a safe, cheap and efficient technique, has great potential for industrial application of fruit preservation. [ABSTRACT FROM AUTHOR]

The carrageenan oligosaccharides (COS) possessed versatile biological activities such as antibacterial, antioxidant, anti-inflammatory activities. Herein, we aimed to explore the effects of carrageenan oligosaccharides (COS) on the preservation of strawberries (Fragaria×ananassa Duch) and factors including decay percentage, hardness, soluble solids, titratable acids, vitamin C (VC) content, the activity of peroxidase (POD), polyphenol oxidase (PPO) were judged as criteria. Also, the expression of genes related to fruit-softening enzymes were detected by real-time qPCR. Soaking treatment of oligosaccharides could significantly (P < 0.05) improve the physical and chemical factors compared with the control group. As for the preservation mechanism of strawberries, the Real-time qPCR results showed that COS coating treatment significantly prolonged the shelf life of strawberries by suppressing the gene expression of cell wall degraded enzymes and ethylene biosynthesis enzymes, with the most obvious effects observed in the 10 mg/mL concentration group. This experiment explores the possibility of COS as a strawberry preservative, which lays a theoretical foundation for future practical application. • Carrageenan oligosaccharides soaking treatment reduced the decay percentage of strawberries. • The activity of POD was promoted and that of PPO was inhibited during storage. • The expression of genes related to fruit softening enzymes were suppressed by carrageenan oligosaccharides treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrospun PVA/CS films loaded with 1,8-cineole/HP-β-CD ICs were developed. • The incorporation of ICs improved physicochemical properties of films. • PVA/CS/40% ICs film achieved the sustained release of 1,8-cineole. • PVA/CS/40% ICs film showed excellent antibacterial and antioxidant activity. • PVA/CS/40% ICs film extended the shelf-life of strawberries to 6 days. Development of food packaging systems containing essential oils (EOs) has gained increased attention recently. However, the instability of EOs restricts their application. Therefore, effective encapsulation of EOs is demanded for their protection and controlled release. In this work, 1,8-cineole, the major component in Eucalyptus globulus essential oil, was encapsulated into hydroxypropyl-β-cyclodextrin to form an inclusion complex, which was then incorporated into polyvinyl alcohol and chitosan composite polymer to fabricate nanofibrous film via electrospinning. The film with 40% (w/w) of inclusion complexes showed enhanced barrier and mechanical properties, and the release of 1,8-cineole from the film was sustained and dominated by the non-Fick diffusion. Moreover, this film could extend the shelf life of strawberries to 6 days at 25 ℃. This work suggested dual encapsulation of EOs by cyclodextrin and electrospun nanofibers is an ideal strategy to improve the availability of EOs, and the produced film is promising for food preservation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Date palm fruit waste extract (DPFW) loaded chitosan (Cs)/polyethylene glycol (PEG) biofilm was prepared. • DPFW extract displayed an impressive suppression effect against the identified pathogens in antimicrobial experiments. • As fresh strawberries were preserved using Cs/PEG packaging loaded with extract for 10 days. • The present findings imply that DPFW-3@Cs/PEG material can be successfully used to pack perishable fruits and vegetables. In light of the global concern that calls for the safe disposal of waste polluting the environment and its exploitation in adding many distinctive products that can be used practically, this study was conducted to clarify how to make the best use of such waste. Therefore, the presented research aims to eliminate these residues and use their extracts as antimicrobial materials that can be used for films/membranes preparation for food and fruit preservations with low economic feasibility. Based on that, the aim of our work was planned to prepare films of date palm fruit waste extract (DPFW) loaded chitosan (Cs)/polyethylene glycol (PEG) composite. The extract was added to the polymers mentioned above with three different concentrations to prepare three film samples (DPFW-1@Cs/PEG), DPFW-2@Cs/PEG and DPFW-3@Cs/PEG). All these films were compared with those prepared without DPFW (DPFW-0@Cs/PEG). The film solutions films were cross-linked using glyoxal as a crosslinker before films formation. The finding illustrated that, the surface structure of DPFW-loaded Cs/PEG became rough, and the extract was remarkably seen on the surface of Cs/PEG films. In addition, the water contact angle for all fabricated films revealed that the films are hydrophobic in nature. The thermal stability of Cs/PEG films were enhanced with the addition of DPFW. The DPFW extract displayed an impressive suppression effect against the identified pathogens in antimicrobial experiments. As fresh strawberries were preserved using Cs/PEG film loaded with DPFW for 10 days, it was discovered that the strawberry wrapped in the extract-containing films maintained their freshness superior to those wrapped in unloaded material. Such films have a wide range of potential applications in food packaging to extend the longevity of freshly prepared goods due to their simplicity and solid biocidal ability. The present research's findings imply that DPFW-3@Cs/PEG material can be successfully used to pack perishable fruits and vegetables. [ABSTRACT FROM AUTHOR]

In this study, we fabricated polyvinyl alcohol (PVA)/chitosan (CS) bilayer films by casting and investigated the effects of preparation conditions and CS content (2, 2.5, or 3 wt.%) on the ability of these films to preserve packaged strawberries. The best performance was achieved at a CS loading of 2.5 wt.% (ultrasound time, 25 min); the strain and stress values were 143.15 ± 6.43% and 70.67 ± 0.85 MPa, respectively, oxygen permeability was 0.16 ± 0.08 cm2·m2·day−1·MPa−1, water vapor permeability was 14.93 ± 4.09 g·cm−1·s−1·Pa−1, and the shelf life of fresh strawberries packaged in the PVA/CS 2.5 wt.% bilayer film was determined to be 21 days at 5 ± 2 °C and a relative humidity of 60 ± 5%. Treatment with PVA/CS bilayer films prevented the decrease in the firmness of strawberries during storage (21 days). The evaluated physicochemical parameters (weight loss, decay, firmness, titratable acidity, soluble solid content, ascorbic acid content, and color) indicated that treatment with PVA/CS bilayer films led to better maintenance of the fruit quality. We believe that our study makes a significant contribution to literature because it paves the way to the fabrication of smart packaging materials and facilitates the commercialization of fresh strawberries as an important health food.

The polymeric wall material of microcapsules has the function of encapsulation, protection, and controlled release of the active core material. In this study, sodium alginate (SA)-NaClO 2 solution was encapsulated in ethylcellulose (EC) microcapsules using an emulsion-solvent evaporation method. The EC/SA-NaClO 2 microcapsules were doped into polyvinyl alcohol (PVA) solution containing HCl, and an antimicrobial film was prepared using the solution casting method. Water vapor drives HCl into the interior of the microcapsules and reacts with NaClO 2 in the microcapsules to release ClO 2 gas to achieve antimicrobial properties. ClO 2 gas can effectively inhibit the growth and reproduction of bacteria and molds on strawberry surfaces. The antimicrobial film inhibited the growth of E. coli by 99.9% and reduced the area of B. cinerea to <10%. Storage bags prepared from antimicrobial films could extend the shelf life of strawberries and maintain their sensory characteristics such as color, hardness, and moisture. [Display omitted] • The antibacterial film can release ClO 2 gas at low humidity. • The antibacterial film was continuously released at 25 °C and 55% RH for about 200 h. • The film has excellent antibacterial properties against E. coli and B. cinerea. • The antibacterial film was used for packaging and storage of fruits and vegetables. • The antimicrobial film can extend strawberry shelf-life. [ABSTRACT FROM AUTHOR]

Phytochemical nanoencapsulation for nutrient delivery and edible coatings for perishable food preservation are two emerging technologies. Leveraging the strong antimicrobial function of phytochemical nutrients, we propose convergent research to integrate the two technologies by embedding phytochemical-encapsulated nanoparticles in an edible coating on fresh fruits to achieve multiple functions. In particular, we report the study of an edible coating on strawberries that is composited of trans -resveratrol (R)-encapsulated nanoparticles (RNPs) embedded in a chitosan (CS) matrix. The biodegradable and biocompatible RNPs significantly increased the aqueous solubility of R by 150-fold and bioavailability by 3.5-fold after oral administration. Our results demonstrated the abilities of the RNP-embedded CS edible coating to diminish dehydration, prevent nutrient loss, inhibit microbe growth, increase nutraceutical value, preserve strawberry quality, and extend shelf life during storage at both 22 and 4 °C. Such a phytochemical nanoencapsulation-based edible coating is promising for the dual purposes of enhancing nutrient delivery and preserving perishable foods.

Water loss is a significant factor in fruit deterioration, and edible films offer a promising method to prevent this. Herein, a silk fibroin (SF)-based edible film reinforced by cellulose nanocrystals (CNCs) and chlorogenic acid (CGA) was developed. CNCs and CGA promote the formation of hydrogen bonds and β-sheets, thereby enhancing hydrophobicity and minimizing water vapor permeability (WVP). Compared with those of pure SF film (water contact angle: 80.3°; WVP: 2.235 × 10−10 g Pa−1 s−1 m−1), the water contact angle of the composite film increased to 90.1° and its WVP decreased to 1.246 × 10−10 g Pa−1 s−1 m−1. Moreover, the tensile strength (27.05 MPa) and Young's modulus (836.53 MPa) of the composite film also increased. Additionally, the antimicrobial activities of the composite film against Escherichia coli and Staphylococcus aureus were 99.66% and 91.07%, respectively. Furthermore, it inhibited the germination of fungal spores (Rhizopus stolonifer). Accordingly, the composite film increased the shelf life of strawberries to 15 d, which is longer than that with other reported films. This study provides an excellent strategy for producing antimicrobial fruit preservation films with high hydrophobicity and low WVP. • The prepared film has high hydrophobicity and low water vapor permeability. • The prepared film has great antimicrobial properties. • The prepared film can effectively prolong the shelf life of strawberries. [ABSTRACT FROM AUTHOR]

Strawberries are a widely consumed fruit that contains a variety of antioxidant metabolites. However, postharvest strawberries are highly perishable and susceptible to a variety of fungal pathogens. In this study, a chitosan-based coating containing turmeric (TU) and green tea (GT) extracts was developed and evaluated for the preservation of strawberries. Both TU and GT extracts contained high phenolic contents (>5.8 g kg−1 dry weight), but only TU extract showed strong antifungal activity. SEM observations revealed that high concentrations of extract (3–5% v/v) caused the formation of agglomerates within the films, reduced elongation at break and increased tensile strength. The postharvest treatment of strawberries with chitosan coating containing TU extract inhibited the proliferation of Botrytis cinerea during 7 d of storage at 20 °C, whereas the coating containing GT extract extended the antioxidant properties of postharvest strawberries from 4 to 8 d at 20 °C. Sensory analysis indicated that the coatings did not significantly affect flavor and taste. Overall, TU extract was used for the first time for food packaging purposes and proved to be a great complement to the antioxidant properties of GT to extend the shelf-life of postharvest strawberries. • Chitosan-based films containing turmeric and green tea extracts were evaluated. • Turmeric extract addition improved the antifungal activity against B. cinerea. • Green tea extract addition enhanced the antioxidant capacity of the film. • The tensile strength of the film increased after adding the extracts. • The developed films extended the shelf-life of postharvest strawberries. [ABSTRACT FROM AUTHOR]

The underutilized by-products of hydrophilicity olive mill wastewater phenols (OPs) have great antimicrobial potential. ZnO NPs is one of most wildly used nano material with anti-bacterial function as well. This study aimed to prepare the detoxified and antimicrobial-enhanced OPs capping ZnO nanoparticles (OPs-ZnO NPs) containing metal core of ZnO NPs and organic shell of OPs, respectively. The OPs-ZnO NPs was chemically coordinated/chelated driven by Lewis bases (NaOH) in aqueous solution. The results obtained by SEM and TEM showed that those irregular sphere OPs-ZnO NPs were ranged from 58 to 92 nm, with an OPs caption of 35.40% (w/w). Importantly, the in vitro results showed that the strategy of capping OPs in ZnO NPs decreased the toxicity of ZnO NPs (< 0.02 g/L). Moreover, OPs-ZnO NPs presented a higher stability in simulated gastrointestinal digestion (Zn2+ < 0.07 g/L after 12 h). The results also showed that the protective coating of OPs-ZnO NPs and OPs-ZnO NPs/CMC (carboxymethyl cellulose) enhanced the antimicrobial activity of Escherichia coli , Staphylococcus aureus and Aspergillus niger. Furthermore, the coating of OPs-ZnO NPs/CMC decreased the weight loss and the rotting ratio of fresh strawberry, and ultimately prolonged its shelf-life at least 4 days under 25 ºC. Therefore, this study provided a biosafety strategy for the preparation of detoxified and antimicrobial enhanced OPs-ZnO NPs and its CMC protective coating for fresh produce throughout storage. • OPs-ZnO NPs is prepared via olive phenols from olive mill wastewater. • The cytotoxicity to L929 and Caco-2 of OPs-ZnO NPs is decreased versus ZnO NPs. • The OPs-ZnO NPs exhibits stability in the simulated gastrointestinal digestion. • Nanocoating of OPs-ZnO NPs/CMC prolongs strawberry's shelf-life at room storage. [ABSTRACT FROM AUTHOR]