Fresh-cut Apple Slices Research Articles

Zein film loaded with Fructus Ligustri Lucidi essential oil: Preparation, characterization and application in fresh-cut apple preservation

Fresh-cut fruits and vegetables are a type of convenient, ready-to-use food that offers consumers a healthy choice. However, the peeling and slicing operations make them susceptible to microbial contaminations and oxidation. In this study, zein was used as the film-forming substrate, and Fructus Ligustri Lucidi essential oil (FEO), a natural bacteriostatic agent, was incorporated into zein film to prepare a film with antibacterial and antioxidant properties to prolong the shelf life of fresh-cut fruits and vegetables. Polyethylene glycol 400 (PEG400) and glucose were used as plasticizers, and the optimal formulation of the film (FZF) was obtained by orthogonal experiment: 10% PEG400, 5% glucose and 10% FEO. The films were characterized by scanning electron microscope (SEM), Fourier transform infrared spectrum (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), and the influence of FEO on the physical, chemical, and biological characteristics of the films was explored. The results demonstrated that FEO was successfully loaded into zein film and distributed evenly. The FZF film exhibited excellent antioxidant activity, when the concentration of FEO was 200 μg/mL, the scavenging rate of DPPH and ABTS was 81.63 ± 0.69% and 91.44 ± 0.55% respectively. Furthermore, the FZF film showed antibacterial properties against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and low cytotoxicity in vitro. Moreover, the FZF film demonstrated anti-browning capabilities, effectively prolonging the shelf life of fresh-cut apple slices. Thus, the FZF film possesses considerable potential for utilization in food packaging.

Bioactive chitosan films: Integrating antibacterial, antioxidant, and antifungal properties in food packaging

In this work, chitosan was combined with bio-vanillin (BV) and kaolin clay (KC) to create a novel antifungal and biodegradable food packaging film. The chitosan/KC/BV film exhibited an antioxidant capacity of 80 % as measured by DPPH assay, which was significantly higher than that of the chitosan film which has 55.6 %). The film also demonstrated strong antimicrobial activity with a reduction of 90 % in the growth of E. coli and S. aureus compared to the control. Additionally, the chitosan/KC/BV film showed a 75 % reduction in fungal growth compared to chitosan film. Furthermore, the water vapor permeability of the chitosan film was reduced as 5.38 with the addition of KC/BV. The degradation study revealed that the chitosan/KC film degraded by 88 % within 20 days under composting conditions. Additionally, fresh-cut apple slices were used to examine the effectiveness of chitosan/KC/BV film as a packaging material. The fruit's weight loss and browning index showed satisfactory food preservation. Our research suggests that the chitosan/KC/BV film has great potential for use in the food sector due to its strong antioxidant, antimicrobial, and biodegradable properties.

Lycopene extract as an antibrowning agent for edible coating of fresh cut apples.

Edible coatings have been utilized for fresh fruit and vegetable preservation to ensure their safety and freshness. The present study reported the effect of edible coatings incorporated with Lycopene extract and Ascorbic Acid on fresh cut Apple slices (Red Delicious) during storage at refrigeration temperature for 12days. The dipping treatments include Lycopene extract (LC-100mg), Ascorbic acid (AAC-100mg) and a combination of both LC + AAC (100mg lycopene extract and 100mg Ascorbic acid). Quality parameters (color, physicochemical and enzymatic activities) were studied up to 12days at refrigeration temperature. Dipping treatments of LC and LC + AAC significantly showed lowest enzymatic activity than AAC treatment. However, color was not preserved in LC + AAC treatments due to high concentration of olive oil in these treatments. Furthermore, physicochemical quality was better preserved in LC + AAC treatments.

Cellulose nanocrystals reinforced chitosan/titanium dioxide bionanocomposite with enhanced interfacial compatibility: Fabrication, characterization, and application in fresh-cut apple slices

This research aimed to investigate the feasibility of using a bionanocomposite made of chitosan, CNC, and TiO2 nanoparticles to package freshly sliced apples. At the outset, the effect of varying concentrations of CNC (1, 5, and 10 %) and TiO2 (1, 3, and 5 %) on the mechanical, thermal, and water sensitivity characteristics of the chitosan bionanocomposite was studied. Among different combinations, the bionanocomposite containing 10 % CNC and 3 % TiO2 displayed significant enhancements compared to neat chitosan film. Notably, it exhibited a substantial increase in tensile strength (78.2 %), glass transition temperature (26.7 %), and melting temperature (30.0 %) compared to neat chitosan film. Additionally, it demonstrated reduced WVP (27.8 %), FWS (44.4 %), and SR (50.7 %). These improvements were attributed to the synergistic interactions among chitosan, CNC, and TiO2 nanoparticles through hydrogen and oxygen bonding, corroborated by spectral changes in the material. The photocatalytic degradation of ethylene and microbes by UV-A (intermittent) activated TiO2 contained in the developed bionanocomposite was confirmed by the retention of acceptable quality and radical scavenging activity (70 % retention) of fresh-cut apple slices up to 11 days. The developed bionanocomposite can thus preserve the quality of ethylene-producing horticultural produce.

Development of biobased multifunctional films incorporated with essential oils@polydopamine nanocapsules for food preservation applications

A novel multifunctional soy protein isolate-carboxymethyl cellulose (SPI-CMC) based nanocomposite film was successfully prepared by introducing the polydopamine encapsulated essential oils (EOs@PDA) nanocapsules for food packaging. The EOs@PDA nanocapsules possessed smooth spherical morphology with good dispersion, and the particle size was about 283 nm. The influence of EOs@PDA nanocapsules on the physical, chemical and biological properties of EOs@PDA/SPI-CMC nanocomposite film was investigated. The EOs@PDA nanocapsules were crosslinked with SPI-CMC matrix and distributed uniformly in the matrix. The nanocomposite film with 1 wt% nanocapsules (EP/S-C) also showed excellent antioxidant activity (66.6 ± 0.3 % on DPPH and 98.6 ± 0.1 % on ABTS), superior UV-blocking properties (100 %), advanced antibacterial ability against E. coli and S. aureus, favorable biodegradability (>90 %) and relatively low In vitro cytotoxicity. Also, the EP/S-C nanocomposite film displayed potential to extend the shelf life of fresh cut apple slices (>24 h), perishable cherry tomatoes and blueberries (>6 days). The results suggested that the EOs@PDA/SPI-CMC nanocomposite film had a great possibility in the field of biodegradable and antimicrobial materials for food packaging.

Pre-cut L-cysteine treatment inhibited the browning of fresh-cut apples by regulating enzyme activities and amino acid levels

This work investigated the effect of pre-cut L-cysteine treatment on the browning of fresh-cut apple slices. The results showed that 1% L-cysteine pre-cut treatment for 15 min could significantly inhibit the browning and extend the shelf life of fresh-cut apple slices. Pre-cut L-cysteine treatment was found to significantly inhibit polyphenol oxidase (PPO) activity and its gene expression, and increased superoxide dismutase (SOD) and catalase (CAT) activity as well as DPPH radical scavenging rate. In addition, pre-cut L-cysteine treatment improved the content of total and individual phenolics, particularly the content of chlorogenic acid and epicatechin in pulp. Pre-cut L-cysteine treatment also increased the cysteine, glutamic acid, serine and leucine level in pulp and peel. Therefore, pre-cut L-cysteine treatment is an effective method to control the browning of fresh-cut apple by inhibiting PPO activity, improving antioxidant ability and regulating the synthesis of phenolics and free amino acids.

Antioxidant effects of phenolic extract from sugarcane straw and mannan extract from brewer's spent yeast on fresh-cut apples.

Fresh-cut fruit are convenient ready-to-eat products increasingly demanded by consumers, but highly susceptible to oxidation. To increase the shelf life of these products, this industry is currently facing the challenge of finding sustainable natural preservatives capable of maintaining fresh-cut fruit quality while meeting consumers expectations regarding health and environmental concerns. In this work, fresh-cut apple slices were treated with two antioxidant extracts derived from industrial by-products, a phenolic rich extract produced from sugarcane straw (PE-SCS) and applied at 15 g L-1 , and a mannan rich extract obtained from brewers' spent yeast (MN-BSY) applied at two concentrations, 1 and 5 g L-1 . The PE-SCS, having a brown color, imparted a brownish hue to the fruit and increased the browning rate during storage, and neither the initial robust antioxidant response (high SOD, CAT, APX and POX activities), prevented oxidation. The fruit treated with MN-BSY extract at 5 g L-1 showed lower color loss rate and higher PPO inhibition while at 1 g L-1 , it showed lower firmness loss rate and lower lipid peroxidation after 6 days of storage. The results showed that the PE-SCS triggers a potent antioxidant response in fresh-cut fruit and despite at 15 g L-1 it imparted a brown color to the fruit, it may have potential for application at lower concentrations. Regarding MN-BSY, it generally decreased oxidative stress, but its effect on quality maintenance was dependent on the concentration and, thus, to conclude about its potential as a fruit preservative more concentrations must be tested. This article is protected by copyright. All rights reserved.

Comparison of two strategies enhancing the antagonistic effect of lactic acid bacteria in edible coating against Listeria monocytogenes on fresh-cut apple slices

Listeria monocytogenes is a psychrotrophic pathogen and could be associated with ready-to-eat fresh-cut fruits stored at chilled temperatures. This study explored two different strategies in enhancing the antagonistic effect of lactic acid bacteria (LAB) against L. monocytogenes on fresh-cut apple slices. First, it was shown that pre-fermentation of a probiotic LAB, Lactiplantibacillus plantarum 299v with glucose and yeast extract exhibited remarkable enhancement in L. monocytogenes inhibition on fresh-cut apples. Second, psychrophilic LAB (pLAB) which are metabolically active at low temperatures were screened and one isolate named I29, identified as Leuconostoc gelidum subsp. gelidum, showed remarkable anti-Listeria effect. As a comparison, a pre-fermentation of L. plantarum 299v (LAB counts 7.7 ± 0.1 log CFU/g) with glucose (2% w/v) and yeast extract (0.06% w/v) showed equivalent inhibition effect on L. monocytogenes (a cocktail of SSA151, LM24, LM44, and BAA-839) with L. gelidum I29 cells (pLAB counts 6.7 ± 0.1 log CFU/g). In conclusion, both strategies were potential in inhibiting L. monocytogenes on fresh-cut apple slices, with respective advantages of accomplishing additional health beneficial effect from using the probiotic L. plantarum 299v and being economical and less laborious from using L. gelidum I29.

Food packaging composite film based on chitosan, natural kaolinite clay, and Ficus. carica leaves extract for fresh-cut apple slices preservation

The problem of environmental plastic contamination is one of the most serious issues facing our world today. The majority of the packaging materials used to preserve food are made of plastic which is considered an environmental issue. Natural kaolinite clay (KC) and Ficus leaf extract (FLE) were combined with chitosan in this work to create a novel antioxidant and biodegradable food packaging film. Chitosan/KC/FLE film was compared to chitosan film, Chitosan/KC, and Chitosan/FLE films in terms of structural, physical, and functional aspects. The addition of FLE and/or KC significantly improved the light and moisture barrier characteristics, mechanical properties, and antioxidant capabilities of chitosan film. Moreover, KC addition had a remarkable impact on the water vapor permeability and the biodegradability of the chitosan film. Because of the synergistic action of FLE and KC, the Chitosan/KC/FLE film delivered strong barrier and antioxidant capabilities. Furthermore, Chitosan/KC/FLE film was tested as packaging material on fresh-cut apple slices and demonstrated good food preservation regarding the weight loss, browning index, and total phenolic content of the fruit. According to our findings, Chitosan/KC/FLE film might be employed as a possible food packaging material in the food industry.

Development of Bioactive Opuntia ficus-indica Edible Films Containing Probiotics as a Coating for Fresh-Cut Fruit.

Bioactive edible films have received more attention in recent years as a method for food preservation with value-added functions. The aim of this study was to develop a bioactive edible film containing mucilage of cactus (Opuntia ficus-indica) and incorporating the probiotic strain Enterococcus faecium FM11-2 as an active component to promote consumer health benefits. Opuntia ficus-indica is rich in nutritional and bioactive compounds and the abundance of this cactus makes it attractive for food applications. Mucilage of Opuntia ficus-indica contained 0.47 ± 0.06 mg/g total sugar, 0.33 ± 0.06 mg AGE/mL phenolic content, 0.14 mg/ mL vitamin C, and possessed 35.51 ± 1.88% DPPH scavenging activity. The edible film that was developed exhibited the following characteristics: thickness of 0.02-0.11 mm, percent moisture content 0.19-0.24%, water solubility 30.66-59.41% and water vapor permeability of 0.15-1.5 g·mm/m2·min·kpa, while the range of the variation depended on the type of plasticizer used (either sorbitol or glycerol). The addition of sorbitol in the film provided the maximum mechanical strength based on the evaluation of tensile strength, Young's modulus and elongation at break (44.71 ± 0.78 MPa, 113.22 ± 0.23 MPa and 39.47 ± 0.61%, respectively). The optimal formulation of the edible film, according to the physicochemical, physical and maintenance of fresh-cut apple slices, contained cactus mucilage, gelatin, glycerol and a probiotic. The incorporation of a probiotic into the cactus film created a bioactive edible film that could provide a health benefit. While improvement is needed to maintain the survival rate of the probiotic, this work presents an exciting method for furthering the study of food preservation with edible films.

Characterization, Stability, and Antibrowning Effects of Oxyresveratrol Cyclodextrin Complexes Combined Use of Hydroxypropyl Methylcellulose.

Oxyresveratrol (Oxy) has attracted much attention by employing it as an antibrowning agent in fruits and vegetables. In this study, the formation of cyclodextrin (CD) inclusion exhibited a certain protective effect on Oxy oxidative degradation, while hydroxypropyl-β-cyclodextrin (HP–β-CD) inclusion complex showed stronger stabilizing effects than those of β-cyclodextrin (β-CD). The combined use of CD and hydroxypropyl methylcellulose (HPMC) greatly improved the stability of Oxy–CD inclusion complexes, with approximately 70% of the trans-Oxy retained after 30 days of storage under light conditions at 25 °C. The results of the interaction between CD and Oxy determined by phase solubility studies and fluorescence spectroscopic analysis showed that the binding strength of CD and Oxy increased in the presence of HPMC. Moreover, Oxy combined with ascorbic acid and HPMC showed an excellent antibrowning effect on fresh-cut apple slices during the 48 h test period, indicating that adding HPMC as the third component will not influence the antibrowning activity of Oxy.

The combined effect of lactic acid and natural plant extracts from guava leaves and pomegranate peel on the shelf life of fresh-cut apple slices during cold storage

Freshly-cut or minimally processed fruits have a shorter shelf life than unprocessed ones. The present study was conducted to investigate the effect of natural plant extracts from guava leaves (GE 0.1%), pomegranate peel (PE 0.1%), and lactic acid (LA 1%) on the shelf life of fresh-cut apple slices (FAS) during storage. Microbiological quality, physicochemical properties, and sensory characteristics of FAS samples were monitored during cold storage (4±1oC). Samples treated with natural antimicrobials showed lower psychrotrophic bacterial and yeasts and moulds count compared to the control at day 0 and during the storage. All treated samples were free of Enterobacteriaceae up to the end of storage periods. During storage, moisture content and titratable acidity decreased while pH and soluble solids increased in all samples. Generally, the changes in the physicochemical properties of treated samples were lower compared to control. Sensory scores of all samples decreased throughout the storage, treated samples retained higher scores compared to the control. The treatments of LA 1% + PE 0.1% and LA 1% + GE 0.1% were effective in keeping the quality and prolonging the shelf life of FAS. Such treatments showed better microbial, physiochemical, and sensorial quality over a storage period of 18 days under refrigerated conditions. Our findings suggested the potential use of these natural plant extracts to retain the quality and prolong the shelf life of a fresh-cut apple

Influence of plasma activated water treatment on enzyme activity and quality of fresh-cut apples

Plasma activated water (PAW) is a new approach to disinfecting surfaces including fresh-cut foods while maintaining their quality attributes. The aim of this study was to evaluate the effect of PAW on enzyme activity, microbial and physicochemical quality of fresh-cut apples. PAW was produced at different production activation times of 10 min, 20 min, 30 min, 45 min and 60 min and the fresh-cut apple slices were washed with PAW for 5 min and stored at 4 °C for 12 days. Results showed that PAW treatments reduced the polyphenol oxidase activity immediately after treatment and the lowest activity was recorded in PAW-20 min (5.10 ± 0.16 U/g FW) after 12 days. Conversely, peroxidase activity of the samples increased immediately after PAW treatment and the samples treated with PAW activated for 30 min had the lowest peroxidase activity at the end of 12 days of storage. No significant changes in the total phenolic content and FRAP antioxidant activity of the fresh-cut apple samples after PAW treatments. The results from firmness, membrane permeability, respiration rate and microstructural imaging showed that at higher PAW activation times (45 min and 60 min) had adverse effects on the quality of fresh-cut apples. Significant reductions in the total aerobic bacteria and total yeast and molds were observed in all PAW treatments except PAW activated for 10 min. The results suggests that plasma activated water could maintain the quality of the fresh-cut apples during storage for plasma activation times of 20 min and 30 min for up to 12 days of storage.

A pilot plant scale testing of the application of seaweed‐based natural coating and modified atmosphere packaging for shelf‐life extension of fresh‐cut apple

Codium tomentosum hydroethanolic extract was obtained using a pilot solid–liquid extractor to validate the anti-browning functionality of the extract under industrial conditions. Fresh-cut apple slices were coated by immersion in: (1) a seaweed extract solution (0.5% w/v) and (2) a commercial coating, and the two sets of samples were compared with a control (immersion in water). Packaged samples were stored, under ambient and modified atmosphere conditions at 4°C. After 30 days of storage, the samples that were coated with the seaweed extract and packaged under modified atmosphere, demonstrated lower peroxidase activity and polyphenol oxidation when compared with the samples treated with the commercial additive. These results confirm, at pilot scale and under industrial production conditions, the efficacy of the seaweed extract as a bio-based substitute for the synthetic coatings, which are currently used to prevent browning in fresh-cut apples. Novelty impact statement Fresh-cut fruits are subjected to processing operations leading to a decrease in nutritional and organoleptic properties. It is therefore necessary to adopt strategies to delay the degradative processes. In this study, the efficacy of a pilot-scale production and industrial application of a coating formulated with Codium tomentosum seaweed extract has been established for the first time. This seaweed extract possesses the potential to prevent browning development in fresh-cut apples under industrial operating conditions.

UV‐C irradiation delays browning of fresh‐cut “Fuji” apples

In order to explore the effect and the corresponding physiological mechanisms of UV-C irradiation on browning of fresh-cut apples, both whole and sliced apple were irradiated with UV-C (254 nm) for 5 min before or after processing. The browning index (BI) of slices was immediately measured, while other relevant physiological parameters were evaluated on quick-frozen samples during refrigerated storage. Results indicated that both pre- and post-processing UV-C treatments effectively delayed browning of apple slices; nevertheless, post-processing UV-C treatment was more efficient. BI significantly negatively correlated with non-enzymatic capacities, and activities of catalase, ascorbate peroxidase, and glutathione reductase (GR). BI was positively correlated with the contents of H2O2 and malondialdehyde (MDA). These findings suggested that UV-C treatment delayed browning of apple slices during cold storage by improving the antioxidant system. Post-processing UV-C treatment was more efficient than pre-processing. Practical applications UV-C treatment is a technique of preservation for fresh-cut fruits. It is widely applied in food processing and many other fields due to its convenience, safety, low cost, etc. In the present study, both pre- and post-processing UV-C (254 nm) irradiation for 5 min could (1) delay the browning of fresh-cut apple, (2) improve the polyphenol oxidase activity and reduce the phenylalanine ammonia-lyase (PAL) activity and total phenolic content (TPC), and (3) reduce the accumulation of H2O2 and malondialdehyde, and increase the antioxidant activities of fresh-cut apples. Thus, UV-C treatments maintain the fresh-cut quality of fresh-cut apple slices and extend their shelf life.

Composite Films of Thermoplastic Starch and CaCl2 Extracted from Eggshells for Extending Food Shelf-Life

Calcium chloride (CaCl2) has been widely used to maintain the quality of fresh-cut fruits and vegetables because it stabilizes and strengthens the membrane system against fungal attacks. It is mainly applied via spray coating and dip coating techniques. This study explored a method of incorporating calcium chloride extracted from eggshells in a packaging material, thermoplastic starch (TPS), via a hot-melt extrusion process. The composites were characterized by FTIR, DSC, SEM-EDX and tensile testing. FTIR confirmed the chemical reactions between CaCl2 and TPS. DSC results showed a significant decrease in the heat of fusion by adding 20 wt% of CaCl2 content in TPS, indicating a drop in the degree of crystallinity. The Young’s modulus of TPS was not significantly affected by the incorporation of 10 wt% CaCl2 (P = 0.968), but reduced notably with the addition of 20 wt% CaCl2 (P = 0.05), indicating the plasticizer effect of the CaCl2. Physiochemical analysis of fresh-cut apple slices was assessed. Samples placed on the surface of the TPS/CaCl2 composites displayed less pH reduction, reduced antioxidant activity, more weight loss and increased reducing sugar compared to the samples placed on the surface of virgin TPS films. CaCl2 released from the TPS/CaCl2 films was measured and their antimicrobial activity was confirmed by bacterial inhibitory growth assessment. Fungal growth was observed on apple slices placed on virgin TPS film by day 21 while apple slices placed on TPS/CaCl2 20 wt% composites did not support any fungal growth for 28 days. In summary, TPS and eggshell-extracted CaCl2 showed the ability to maintain the quality of fresh-cut apples, and TPS/CaCl2 10 wt% composite could be a good option as a packaging material for fresh-cut fruits due to active antimicrobial activity and maintained Young’s modulus.

Bilayer edible coating with stabilized Lactobacillus plantarum 299v improved the shelf life and safety quality of fresh-cut apple slices

In this study, a bilayer probiotic edible coating was developed for fresh-cut apple slices. Lactobacillus plantarum 299v-containing carboxymethyl cellulose solution was applied to the apple slices as the primary coating, followed by a secondary coating with zein. As a result, the probiotic bacteria L. plantarum 299v remained stable on the coated apple slices during 7 days storage at 4 °C (>6 log CFU/g) and only manifested a drop of 2.24 ± 0.08 log CFU/g during simulated digestion. The bilayer probiotic edible coating was able to induce significantly less weight loss of the apple slices, suppress yeasts and moulds, and inhibit the proliferation of spiked Listeria monocytogenes during the chilled storage (P < 0.05). Taken together, our results demonstrated that the bilayer probiotic edible coating with stabilized L. plantarum 299v as developed in this study was able to improve the shelf life and safety quality of fresh-cut apple slices.

Low molecular weight fucoidan prepared by fucoidanase degradation – A promising browning inhibitor

Low molecular weight (MW) fucoidans have been proved with excellent tyrosinase inhibitory activity, which may proposed as a potential anti-browning ingredient for fruit and vegetable fresh-keeping agent. This study was conducted to obtain a low MW fucoidan fraction with high tyrosinase inhibitory capacity from Laminaria japonica crude fucoidan by fucoidanase degradation and to preliminary explore its type of tyrosinase inhibition and the application in browning inhibition of fresh-cut fruit. Firstly, the wild fucoidan-degrading strain, Flavobacteriaceae RC2-3, was mutated by UV irradiation and the fucoidanase production was improved by 40.5%. Fucoidan, which degraded by purified fucoidanase for 2 h, presented favourable tyrosinase inhibitory ability and were then separated by ultrafiltration. The fucoidan fraction with MW below 5 kDa (FF5) demonstrated the best tyrosinase inhibitory effect and shown obvious browning inhibition of fresh-cut apple slices. The inhibitory kinetics revealed that FF5 was a quite effectively competitive inhibitor of tyrosinase. The results of this study suggested that FF5 could be used as a promising browning inhibitor in the preservation of fruits and vegetables.

Development of anacardic acid incorporated biopolymeric film for active packaging applications

Biodegradable films with functional characteristics are finding several applications in the active packaging of foods and fresh-cut horticultural produce in particular, as effective alternatives to single-use plastics. In this study, anacardic acid (AA) was extracted from cashew nut shell liquid oil (CNSL) and characterized using GC–MS and HPLC. Further, the extract showed anti-microbial activity against foodborne pathogens such as Escherichia coli, Listeria monocytogenes, Streptococcus faecalis, Salmonella typhi, and Shigella boydii, apart from potent anti-oxidant behavior. With the hypothesis to exploit its food preservation capabilities, packaging films of AA-chitosan blends were prepared; these showed remarkable anti-browning effects on fresh-cut apple slices, superior to chitosan alone. The physical properties of these films were evaluated and the developed film showed around 60 % biodegradability in 30 days. This study highlights a unique application scope for underutilized CNSL.

Characterization of sodium alginate-based films incorporated with thymol for fresh-cut apple packaging

The non-antibacterial and relatively poor mechanical properties of sodium alginate film limit its application for fresh-cut fruit packaging. The phenolic compound thymol has prominent antioxidant and antibacterial activities. The physical and functional properties of thymol/sodium alginate composite films and their ability to preserve fresh-cut apples were investigated. Thymol/sodium alginate composite films were observed to have high tensile strength, elongation at break and UV–vis light blocking capability, but low water vapor permeability, water solubility, and swelling ratio compared with standard sodium alginate film without thymol. The composite films also showed notable scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radicals. In addition, the composite films exhibited remarkable inhibition of the growth of Staphylococcus aureus and Escherichia coli. Furthermore, thymol/sodium alginate films could effectively reduce weight loss, retain nutrition and surface color of fresh-cut apple slices. Therefore, sodium alginate films with thymol have strong potential as a cling wrap material used in the packaging of fresh-cut fruits.