Effect of nanocomposite-based packaging on storage stability of mushrooms ( Flammulina velutipes )

A review of physical, chemical and biological synthesis methods of bimetallic nanoparticles and applications in sensing, water treatment, biomedicine, catalysis and hydrogen storage

This article provides an in-depth analysis of various fabrication methods of bimetallic nanoparticles (BNP), including chemical, biological, and physical techniques. The review explores BNP's diverse uses, from well-known applications such as sensing water treatment and biomedical uses to less-studied areas like breath sensing for diabetes monitoring and hydrogen storage. It cites results from over 1000 researchers worldwide and >300 peer-reviewed articles. Additionally, the article discusses current trends, actionable recommendations, and the importance of synthetic analysis for industry players looking to optimize manufacturing techniques for specific applications. The article also evaluates the pros and cons of various fabrication methods, highlighting the potential of plant extract synthesis for mass production of capped BNPs. However, it warns that this method may not be suitable for certain applications requiring ligand-free surfaces. In contrast, physical methods like laser ablation offer better control and reactivity, especially for applications where ligand-free surfaces are critical. The report underscores the environmental benefits of plant extract synthesis compared to chemical methods that use hazardous chemicals and pose risks to extraction, production, and disposal. The article emphasizes the need for life cycle assessment (LCA) articles in the literature, given the growing volume of research on nanotechnology materials. This article caters to researchers at all stages and applies to various fields applying nanomaterials.

Variations of quality and volatile components of morels (Morchella sextelata) during storage

The postharvest senescence of morels was observed to be easily affected by temperature fluctuations. The objective of this study was to examine the influence of various storage temperatures on the postharvest senescence of morels. The study evaluated the variations of water content, respiration, nutrients substances, cell membrane permeability, and volatile compounds in morels stored at 20 °C and 4 °C. Results showed that low-temperature storage suppressed the loss of water and firmness, delayed the time of respiration and ethylene peak, and reduced the loss of nutrients and cell membrane permeability. Furthermore, the content of volatile compounds increased and then decreased during storage. The characteristic aroma substances of 1-octen-3-ol were identified using odor activity values and OPLS-DA analysis. The study observed a decrease in the content and changes of aroma compounds during low-temperature storage. This decrease may be attributed to the decreased activities of lipoxygenase (LOX) and alcohol dehydrogenase (ADH).

Pullulan-stabilized Soybean Phospholipids/Cinnamaldehyde emulsion for Flammulina velutipes preservation

Fresh mushrooms (Flammulina velutipes) are very perishable and easily brown; also they undergo postharvest loss of nutritive constituents. In this study, cinnamaldehyde (CA) emulsion was prepared by using soybean phospholipids (SP) as emulsifier and pullulan (Pul) as stabilizer. The effect of emulsion on the quality of mushroom during storage was also studied. The experimental results indicated that the emulsion obtained by adding 6 % pullulan was found to the most uniform and stable, which is beneficial to its application. Emulsion coating maintained the storage quality of Flammulina velutipes. The incorporation of CA emulsion into the coating system showed a positive effect on inhibiting the accumulation of reactive oxygen species, resulting from improving the effectiveness of delaying active free radical scavenging enzymes. The shelf life of mushrooms coated with emulsion was significantly prolonged, which indicates its potential application in food preservation.

Effect of nanopackaging on the quality of edible mushrooms and its action mechanism: A review

With higher demands for food packaging and the development of nanotechnology, nanopackaging is becoming a research hotspot in the field of food packaging because of its superb preservation effect, and it can effectively resist oxidation and regulates energy metabolism to maintain the quality and prolong the shelf life of mushrooms. Furthermore, under the background of SARS-CoV-2 pandemic, nanomaterials could be a potential tool to prevent virus transmission because of their excellent antiviral activities. However, the investigation and application of nanopackaging are facing many challenges including costs, environmental pollution, poor in-depth genetic research for mechanisms and so on. This article reviews the preservation effect and mechanisms of nanopackaging on the quality of mushrooms and discusses the trends and challenges of using these materials in food packaging technologies with the focus on nanotechnology and based on recent studies.

New preservation and detection technologies for edible mushrooms: A review

Edible mushrooms are nutritious, tasty, and have medicinal value, which makes them very popular. Fresh mushrooms have a high water content and a crisp texture. They demonstrate strong metabolic activity after harvesting. However, they are prone to textural changes, microbial infestation, and nutritional and flavor loss, and they therefore require appropriate post-harvest processing and preservation. Important factors affecting safety and quality during their processing and storage include their quality, source, microbial contamination, physical damage, and chemical residues. Thus, these aspects should be tested carefully to ensure safety. In recent years, many new techniques have been used to preserve mushrooms, including electrofluidic drying and cold plasma treatment, as well as new packaging and coating technologies. In terms of detection, many new detection techniques, such as nuclear magnetic resonance (NMR), imaging technology, and spectroscopy can be used as rapid and effective means of detection. This paper reviews the new technological methods for processing and detecting the quality of mainstream edible mushrooms. It mainly introduces their working principles and application, and highlights the future direction of preservation, processing, and quality detection technologies for edible mushrooms. Adopting appropriate post-harvest processing and preservation techniques can maintain the organoleptic properties, nutrition, and flavor of mushrooms effectively. The use of rapid, accurate, and non-destructive testing methods can provide a strong assurance of food safety. At present, these new processing, preservation and testing methods have achieved good results but at the same time there are certain shortcomings. So it is recommended that they also be continuously researched and improved, for example through the use of new technologies and combinations of different technologies. © 2023 Society of Chemical Industry.

Recent advances in quality preservation of postharvest golden needle mushroom (Flammulina velutiper)

The golden needle mushroom (Flammulina velutiper) is one of the most productive mushrooms in the world. However, F. velutiper experiences continuous quality degradation in terms of changes in color and textural characteristics, loss of moisture, nutrition and flavor, and increased microbial populations due to its high respiratory activity during the postharvest phase. Postharvest preservation techniques, including physical, chemical and biological methods, play a vital role in maintaining postharvest quality and extending the shelf life of mushrooms. Therefore, in this study, the decay process of F. velutiper and the factors affecting its quality were comprehensively reviewed. Additionally, the preservation methods (e.g., low-temperature storage, packaging, plasma treatment, antimicrobial cleaning and 1-methylcyclopropene treatment) for F. velutiper used for the last 5 years were compared to provide an outlook on future research directions. Overall, this review aims to provide a reference for developing novel, green and safe preservation techniques for F. velutiper. © 2023 Society of Chemical Industry.

Advances in Postharvest Storage and Preservation Strategies for Pleurotus eryngii

The king oyster mushroom (Pleurotus eryngii) is a delicious edible mushroom that is highly prized for its unique flavor and excellent medicinal properties. Its enzymes, phenolic compounds and reactive oxygen species are the keys to its browning and aging and result in its loss of nutrition and flavor. However, there is a lack of reviews on the preservation of Pl. eryngii to summarize and compare different storage and preservation methods. This paper reviews postharvest preservation techniques, including physical and chemical methods, to better understand the mechanisms of browning and the storage effects of different preservation methods, extend the storage life of mushrooms and present future perspectives on technical aspects in the storage and preservation of Pl. eryngii. This will provide important research directions for the processing and product development of this mushroom.

Improving the nutritional quality and bio-ingredients of stored white mushrooms using gamma irradiation and essential oils fumigation

Mushrooms are highly perishable in nature and deteriorate within a few days after harvesting due to their high respiration rate and delicate epidermal structure. Consequently, the shelf-life of freshly harvested mushroom is limited to 1–3 days at ambient condition. Hence, the current investigation was carried out to study γ-irradiation effects (1.5 and 2.0 kGy) and essential oils (EOs) fumigation including geranium (60 and 80 μL/L) and lemongrass (40 and 60 μL/L) on nutritional quality (Vitamins C and D2) as well as bio-ingredients such as total soluble proteins, phenolic and flavonoids contents, antioxidant activity were determined as an origin of potential natural antioxidant plus the profile of phenols and flavonoids identified by HPLC. As well as activities of some enzymes (PPO, SOD, PAL, and APX) of Agaricus bisporus mushroom at 4 °C during storage time for twelve days. The findings showed that there was a reduction in the contents of Vit. C and vitamin D2 in all mushroom samples during storage, where the essential oil treatment especially 60 μL/L of geranium and 40 μL/L of lemongrass gave the least decrease (3.42 and 3.28 mg/100 g FW, respectively) of ascorbic acid content compared to the other treatments while the irradiated samples (1.5, and 2.0 kGy) gave the lowest decrease of vitamin D2 (106.30 and 114.40 mg/kg DW, respectively) at the end of storage time. The content of the bio-ingredients content was affected by the storage periods, and the samples treated with oil fumigation gave the best content and the same trend happened with the antioxidant activity. The enzymes activity increased by the storage period, especially after 4 days of storage, and then the activity decreased after that. Quantification of phenolic and flavonoid compounds affected by storage periods in all treatments and the EO-treated mushrooms gave the best amount of them. Thus, samples of mushrooms treated with oil fumigation especially 60 μL/L of geranium and 40 μL/L of lemongrass can successfully increase the nutritional value plus maintain the value of the mushrooms during storage time.

Storage Quality Variation of Mushrooms (Flammulina velutipes) after Cold Plasma Treatment

Flammulina velutipes is susceptible to mechanical damage, water loss, microbial growth, and other factors that lead to postharvest deterioration, thereby shortening the storage period. The purpose of this study was to analyze the effects of cold plasma treatment on the physicochemical properties and antioxidant capacity of F. velutipes during storage at 4 °C for 21 days. Compared to the control group, cold plasma cold sterilization (CPCS) treatment (150 Hz, 95 kV for 150 s) effectively inhibited the growth and multiplication of microorganisms on the surface of F. velutipes, with no significant effect on the fresh weight change and the superoxide anion generation rate, but with a higher postharvest 1,1-dephenyl-2-picrylhydrzyl (DPPH) clearance rate. Moreover, CPCS increased antioxidant enzyme activities, delayed both malondialdehyde (MDA) accumulation and vitamin C loss, inhibited the browning reaction and polyphenol oxidases (PPO) activity and protected F. velutipes cell membrane from disruption. In general, CPCS not only achieved bacteriostatic effects on F. velutipes during storage, but also reduced cell damage from free radical oxidation, resulting in better postharvest quality and longer shelf life.

Low-density polyethylene based nanocomposite packaging films for the preservation of sugarcane juice

Low density polyethylene (LDPE) based nanocomposite films made from different levels of nanoclay, compatibilizer and thickness were evaluated for the storage stability of sugarcane juice for 60 days under ambient condition. During the storage period, important physico-chemical properties such as pH, total sugars, total soluble solids and overall acceptability were decreased with respect to increased level of nanoclay and compatibilizer as well as decreased thickness of film. Total plate count was nil till the storage period of 15 days and then there was an increase in microbial population. Similarly, the overall color difference was also increased during the storage period. The better storage stability with respect to biochemical characteristics, overall acceptability and microbial load was recorded in the 100 µm thick LDPE nano composite films developed from 93 percent LDPE, 2 percent nanoclay and 5 percent compatibilizer.

Metallic Nanoparticles in the Food Sector: A Mini-Review

Nanomaterials, and in particular metallic nanoparticles (MNPs), have significantly contributed to the production of healthier, safer, and higher-quality foods and food packaging with special properties, such as greater mechanical strength, improved gas barrier capacity, increased water repellency and ability to inhibit microbial contamination, ensuring higher quality and longer product shelf life. MNPs can also be incorporated into chemical and biological sensors, enabling the design of fast and sensitive monitoring devices to assess food quality, from freshness to detection of allergens, food-borne pathogens or toxins. This review summarizes recent developments in the use of MNPs in the field of food science and technology. Additionally, a brief overview of MNP synthesis and characterization techniques is provided, as well as of the toxicity, biosafety and regulatory issues of MNPs in the agricultural, feed and food sectors.

Effects of ultrasound and gamma irradiation on quality maintenance of fresh Lentinula edodes during cold storage

Microbial infection, senescence and water losses result in serious quality deterioration of postharvest mushrooms. The aim of this study was to investigate the impact of ultrasound treatment (US), gamma irradiation treatment (GI) and their combination on quality maintenance of fresh Lentinula edodes during storage. The results showed that US + GI was the most effective approach to maintaining the quality of mushrooms. US + GI reduced natural microflora present on L. edodes, such as total number of colonies, molds, yeasts, Pseudomonas and Enterobacteriaceae. Furthermore, US + GI stimulated phenylalanine ammonia lyase, maintained the highest level of total phenolic content (733.63 mg GAE/kg on Day 4), and postponed the occurrence of reduced ascorbic acid (33.7% retention relative to the control), which contributed to strengthening the antioxidant capacity. Additionally, US + GI retarded water mobility and loss. In brief, the US + GI in this study is an effective hurdle technology for preserving the quality of fresh L. edodes during storage.

Metal-based nanoparticles, sensors, and their multifaceted application in food packaging

Due to the global rise of the human population, one of the top-most challenges for poor and developing nations is to use the food produces safely and sustainably. In this regard, the storage of surplus food (and derived products) without loss of freshness, nutrient stability, shelf life, and their parallel efficient utilization will surely boost the food production sector. One of the best technologies that have emerged within the last twenty years with applications in the packaging of food and industrial materials is the use of green mode-based synthesized nanoparticles (NPs). These NPs are stable, advantageous as well as eco-friendly. Over the several years, numerous publications have confirmed that these NPs exert antibacterial, antioxidant, and antifungal activity against a plethora of pathogens. The storage in metal-based NPs (M-NPs) does not hamper the food properties and packaging efficiency. Additionally, these M-NPs help in the improvement of properties including freshness indicators, mechanical properties, antibacterial and water vapor permeability during food packaging. As a result, the nano-technological application facilitates a simple, alternate, interactive as well as reliable technology. It even provides positive feedback to food industries and packaging markets. Taken together, the current review paper is an attempt to highlight the M-NPs for prominent applications of antimicrobial properties, nanosensors, and food packaging of food items. Additionally, some comparative reports associated with M-NPs mechanism of action, risks, toxicity, and overall future perspectives have also been made.

Comparative transcriptome and proteome provide new insights into the regulatory mechanisms of the postharvest deterioration of Pleurotus tuoliensis fruitbodies during storage

The Pleurotus tuoliensis (Pt), a precious edible mushroom with high economic value, is widely popular for its rich nutrition and meaty texture. However, rapid postharvest deterioration depreciates the commercial value of Pt and severely restricts its marketing. By RNA-Seq transcriptomic and TMT-MS MS proteomic, we study the regulatory mechanisms of the postharvest storage of Pt fruitbodies at 25 ℃ for 0, 38, and 76 h (these three-time points recorded as groups A, B, and C, respectively). 2,008 DEGs (Differentially expressed genes) were identified, and all DEGs shared 265 factors with all DEPs (Differentially expressed proteins). Jointly, the DEGs and DEPs of two-omics showed that the category of the metabolic process contained the most DEGs and DEPs in the biological process by GO (Gene Ontology) classification. The top 17 KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways with the highest sum of DEG and DEP numbers in groups B/A (38 h vs. 0 h) and C/A (76 h vs. 0 h) and pathways closely related to energy metabolism were selected for analysis and discussion. Actively expression of CAZymes (Carbohydrate active enzymes), represented by laccase, chitinase, and β-glucanase, directly leads to the softening of fruitbodies. The transcription factor Rlm1 of 1,3-β-glucan synthase attracted attention with a significant down-regulation of gene levels in the C/A group. Laccase also contributes, together with phenylalanine ammonia-lyase (PAL), to the discoloration reaction in the first 76 h of the fruitbodies. Significant expression of several crucial enzymes for EMP (Glycolysis), Fatty acid degradation, and Valine, leucine and isoleucine degradation at the gene or protein level supply substantial amounts of acetyl-CoA to the TCA cycle. Citrate synthase (CS), isocitrate dehydrogenase (ICDH), and three mitochondrial respiratory complexes intensify respiration and produce high levels of ROS (Reactive oxygen species) by significant up-regulation. In the ROS scavenging system, only Mn-SOD was significantly up-regulated at the gene level and was probably interacted with Hsp60 (Heat shock protein 60), which was significantly up-regulated at the protein level, to play a dominant role in antioxidation. Three types of stresses - cell wall stress, starvation, and oxidative stress - were suffered by Pt fruitbodies postharvest, resulting in cell cycle arrest and gene expression disorder.

Isolation and Molecular Identification of the Native Microflora on Flammulina velutipes Fruiting Bodies and Modeling the Growth of Dominant Microbiota (Lactococcus lactis)

The objectives of this study were to isolate and identify the dominant microorganism in Flammulina velutipes fruiting bodies (FVFB) and to develop kinetic models for describing its growth. The native microflora community on FVFB was isolated and identified using morphological examination and high-throughput sequencing analysis. FVFB presented complex microbial communities with dominant microorganisms being Lactococcus lactis. Irradiated FVFB were inoculated with the isolated strain of L. lactis and cultivated at various temperatures (4, 10, 16, 20, 25, 32, and 37°C). Three primary models, namely the Huang, Baranyi and Roberts, and reparameterized Gompertz models, and three secondary models, namely the Huang square-root, Ratkowsky square-root, and Arrhenius-type models, were developed and evaluated. With the lowest values of mean square error (MSE, 0.023–0.161) and root mean square error (RMSE, 0.152–0.401) values, the reparameterized Gompertz model was more suitable to describe the growth of L. lactis on FVFB than both Huang and Baranyi and Roberts models. The Ratkowsky square-root model provided more accurate estimation for the effect of temperature on the specific growth rate of L. lactis. The minimum growth temperature predicted by the Ratkowsky square-root model was −7.1°C. The kinetic models developed in this study could be used to evaluate the growth behavior of L. lactis on FVFB and estimate the shelf-life of FVFB.

Microflora and umami alterations of different packaging material preserved mushroom (Flammulina filiformis) during cold storage

In order to clarify the effect of nanocomposite-based packaging (NP) on umami and microflora characteristics of F. filiformis during cold storage, the contents of umami amino acids and 5'-nucleotides, equivalent umami concentration (EUC), and microflora succession were investigated. Results showed that NP could delay the degradation of umami components and inhibit bacterial growth in F. filiformis. At the initial stage, the dominant bacteria were Lactobacillus, Thermus and Acinetobacter. After 15 days of storage, the bacteria count in NP reached 7.63 lg cfu/g, which was significantly (P < 0.05) lower than that in control, and the major bacterial communities of packaged F. filiformis were Ewingella, Serratia and Pseudomonas. Moreover, the correlation analysis showed that Lactobacillus, Brevibacillus and Okibacterium were negatively correlated with AMP and IMP 5-nucleotides. Present work suggested that NP could enhance the umami flavor formation and improve the microbial community structure of F. filiformis, resulting in a better commercial quality. The results provided theoretical basis for large-scale applications of NP.

Effect of simulated transport vibration on the quality of shiitake mushroom (Lentinus edodes) during storage

The quality and shelf life of mushrooms are critical to their commercial viability. In this study, the effects of simulated transport vibration on postharvest quality of shiitake mushrooms (Lentinus edodes) were assessed over 12 days of storage. Furthermore, the protective performance of foam cushion material used in packaging during simulated transport was evaluated. Changes in respiration rate, weight loss, browning index, firmness, and malondialdehyde content were measured following vibration treatment. The results revealed that simulated transport vibration contributed to the deterioration of quality of shiitake mushrooms during storage, and the foam cushion material had a protective influence on the maintenance of shiitake mushroom quality. Taken together, our findings suggest that the foam cushion material used in packaging has the potential to improve the quality of shiitake mushrooms and extend their shelf life.

Active Carbon-Based Nanomaterials in Food Packaging

Carbon-based nanomaterials (CBN) are currently used in many biomedical applications. The research includes optimization of single grain size and conglomerates of pure detonated nanodiamond (DND), modified nanodiamond particles and graphene oxide (GO) in order to compare their bactericidal activity against food pathogens. Measurement of grain size and zeta potential was performed using the Dynamic Light Scattering (DLS) method. Surface morphology was evaluated using a Scanning Electron Microscope (SEM) and confocal microscope. X-ray diffraction (XRD) was performed in order to confirm the crystallographic structure of detonation nanodiamond particles. Bacteriostatic tests were performed by evaluating the inhibition zone of pathogens in the presence of carbon based nanomaterials. Raman spectroscopy showed differences between the content of the diamond and graphite phases in diamond nanoparticles. Fluorescence microscopy and adenosine-5′-triphosphate (ATP) determination methods were used to assess the bactericidal of bioactive polymers obtained by modification of food wrapping film using various carbon-based nanomaterials. The results indicate differences in the sizes of individual grains and conglomerates of carbon nanomaterials within the same carbon allotropes depending on surface modification. The bactericidal properties depend on the allotropic form of carbon and the type of surface modification. Depending on the grain size of carbon-based materials, surface modification, the content of the diamond and graphite phases, surface of carbon-based nanomaterials film formation shows more or less intense bactericidal properties and differentiated adhesion of bacterial biofilms to food films modified with carbon nanostructures.

Biopolymers-Based Materials Containing Silver Nanoparticles as Active Packaging for Food Applications-A Review

Packaging is an integral part of food products, allowing the preservation of their quality. It plays an important role, protecting the packed product from external conditions, maintaining food quality, and improving properties of the packaged food during storage. Nevertheless, commonly used packaging based on synthetic non-biodegradable polymers causes serious environmental pollution. Consequently, numerous recent studies have focused on the development of biodegradable packaging materials based on biopolymers. In addition, biopolymers may be classified as active packaging materials, since they have the ability to carry different active substances. This review presents the latest updates on the use of silver nanoparticles in packaging materials based on biopolymers. Silver nanoparticles have become an interesting component of biodegradable biopolymers, mainly due to their antimicrobial properties that allow the development of active food packaging materials to prolong the shelf life of food products. Furthermore, incorporation of silver nanoparticles into biopolymers may lead to the development of materials with improved physical-mechanical properties.

Nanocomposite-based packaging affected the taste components of white Hypsizygus marmoreus by regulating energy status

The effects of nanocomposite-based packaging material (Nano-PM) on the taste components and mitochondrial energy metabolism of postharvest white Hypsizygus marmoreus (WHM), as well as the underlying influence mechanism were investigated. The results showed that the major taste components, including succinic acid and mannitol, remained at higher level in Nano-PM. The flavor 5'-nucleotides (5'-GMP and 5'-IMP) of WHM in Nano-PM were significantly higher (p < 0.05) compared with that in the normal packaging material (Normal-PM). Principal component analysis indicated that there was a distinction of flavor compounds (6 organic acids, 3 soluble sugars and 5 5'-nucleotides) of WHM between Nano-PM and Normal PM treatments during storage. Moreover, Nano-PM delayed the mitochondrial microstructure breakdown and the reduction of ATPase activity, and it maintained a higher ATP content and higher level of energy charge. Our results demonstrated that Nano-PM could affect the taste components of postharvest WHM partially by regulating the energy metabolism.

Nanocomposite packaging regulates extracellular ATP and programed cell death in edible mushroom (Flammulina velutipes)

Our previous study indicated that nanocomposite packaging material (Nano-PM) containing nano-Ag, nano-TiO₂, nano-SiO₂ and nanoattapulgite alleviated postharvest senescence of Flammulina velutipes by regulating respiration and energy metabolism. In this study, extracellular ATP (eATP) and programmed cell death (PCD) were employed as critical factors to further investigate the senescence mechanism of postharvest F. velutipes. Results demonstrated that Nano-PM delayed apyrase activity decrease and stimulated critical oxidative phosphorylation-related gene expression to inhibit eATP content increase, which is a crucial signaling molecule related to delaying senescence. The regulation of eATP resulted in alleviating PCD including chromosomal concentration, DNA fragmentation, Ca²⁺ influx, high caspase-1 activity and cytochrome c content and leading to high cell viability. Overall, Nano-PM alleviated PCD and postharvest senescence of F. velutipes by regulating extracellular ATP.

The Effect of Nanofillers on the Functional Properties of Biopolymer-based Films: A Review

Waste from non-degradable plastics is becoming an increasingly serious problem. Therefore, more and more research focuses on the development of materials with biodegradable properties. Bio-polymers are excellent raw materials for the production of such materials. Bio-based biopolymer films reinforced with nanostructures have become an interesting area of research. Nanocomposite films are a group of materials that mainly consist of bio-based natural (e.g., chitosan, starch) and synthetic (e.g., poly(lactic acid)) polymers and nanofillers (clay, organic, inorganic, or carbon nanostructures), with different properties. The interaction between environmentally friendly biopolymers and nanofillers leads to the improved functionality of nanocomposite materials. Depending on the properties of nanofillers, new or improved properties of nanocomposites can be obtained such as: barrier properties, improved mechanical strength, antimicrobial, and antioxidant properties or thermal stability. This review compiles information about biopolymers used as the matrix for the films with nanofillers as the active agents. Particular emphasis has been placed on the influence of nanofillers on functional properties of biopolymer films and their possible use within the food industry and food packaging systems. The possible applications of those nanocomposite films within other industries (medicine, drug and chemical industry, tissue engineering) is also briefly summarized.

Nanosilver-Enabled Food Storage Container Tradeoffs: Environmental Impacts Versus Food Savings Benefit, Informed by Literature

Globally, thousands of tons of food are lost each year due to spoilage and degraded quality. This loss is a current critical issue that must be addressed to ensure adequate food supply for the growing world population; the use of technology and regulatory practices are avenues to a solution. One considered approach is the reduction of the microorganism population on the surface of food products to delay spoilage through the use of antimicrobials. One current method is the use of the antimicrobial properties of nanoscale silver (nAg) particles to prolong the freshness of stored food by reducing the bacteria present. Nanoscale silver-enabled food storage containers present a potential solution to the food loss problem; nevertheless, their environmental and human health effects have been questioned by the scientific community. Literature is used to generate data for the life cycle impact assessment of these types of products and their corresponding environmental effects. The benefits of nAg-enabled food storage containers are considered with respect to their potential to extend the shelf life of stored food and prevent food spoilage. The results illustrate that the environmental effects of nano-enabling food storage containers with silver is small (when the initial silver concentration is relatively low, less than 1% by mass) compared with the overall environmental effects of food storage containers and also relatively small compared with the environmental effects of producing the stored food. This finding suggests that the added environmental burden of nano-enabling food storage containers may be small when compared with the environmental burden of food losses. Integr Environ Assess Manag 2018;14:769-776. © 2018 SETAC.

TiO₂-KH550 Nanoparticle-Reinforced PVA/xylan Composite Films with Multifunctional Properties

In order to improve the strength of polyvinyl alcohol (PVA)/xylan composite films and endow them with ultraviolet (UV) shielding ability, TiO₂-KH550 nanoparticles was synthesized and added into the PVA/xylan matrix. The TiO₂-KH550 nanoparticle dispersed well in the 0.04% sodium hexametaphosphate (SHMP) solution under ultrasonic and stirring treatments. Investigations on the properties of the films showed that TiO₂-KH550 had the positive impact on improving the strength, moisture, and oxygen barrier properties of the composite films. The maximum tensile strength (27.3 MPa), the minimum water vapor permeability (2.75 × 10⁻¹¹ g·m⁻¹·s⁻¹·Pa⁻¹), and oxygen permeability (4.013 cm³·m⁻²·24 h⁻¹·0.1MPa⁻¹) were obtained under the addition of 1.5% TiO₂-KH550. The tensile strength of TiO₂-KH550 reinforced composite film was increased by 70% than that of the pure PVA/xylan composite film, and the water vapor and oxygen permeability were decreased by 31% and 41%, respectively. Moreover, the UV transmittance of the film at the wavelength of 400 nm was almost zero when adding ≈1.5~2.5% (weight ratio, based on the total weight of PVA and xylan) of TiO₂-KH550, which indicated the PVA/xylan composite films were endowed with an excellent UV light shielding ability.