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[Display omitted] • β -sitosterol oleogel-based emulsion loaded with astaxanthin was designed. • Astaxanthin encapsulation in SM emulsion improve bioaccessibility. • Both network structure and composition affect lipolysis and bioavailability. In this study, three types of β -sitosterol-based oleogels (β -sitosterol + γ -oryzanol oleogels, β -sitosterol + lecithin, oleogels and β -sitosterol + monostearate oleogels), loaded with astaxanthin, were employed as the oil phase to create oleogel-based emulsions (SO, SL, and SM) using high-pressure homogenization. The microstructure revealed that fine-scale crystals were dispersed within the oil phase of the droplets in the β -sitosterol oleogel-based emulsion. The bioaccessibility of astaxanthin was found to be 58.13 %, 51.24 %, 36.57 %, and 45.72 % for SM, SL, SO, and the control group, respectively. Interestingly, the release of fatty acids was positively correlated with the availability of astaxanthin (P = 0.981). Further analysis of FFAs release and kinetics indicated that the structural strength of the oil-phase in the emulsions influenced the degree and rate of lipolysis. Additionally, the micellar fraction analysis suggested that the nature and composition of the oleogelators in SM and SL also impacted lipolysis and the bioaccessibility of astaxanthin. Furthermore, interfacial binding of lipase and isothermal titration calorimetry (ITC) measurements revealed that the oleogel network within the oil phase of the emulsion acted as a physical barrier, hindering the interaction between lipase and lipid. Overall, β-sitosterol oleogel-based emulsions offer a versatile platform for delivering hydrophobic molecules, enhancing the bioavailability of active compounds, and achieving sustained release. [ABSTRACT FROM AUTHOR]

The effects of different dosages of roselle flour (0 %, 4 %, and 8 %) and purple rice flour (5 %, 10 %, and 15 %) on the properties of the dough, the quality of the bread, the phenolic compounds contained, the anthocyanin content and the aroma profile were investigated by adding roselle flour and purple rice flour to the wheat flour. The results showed that the addition of purple rice flour elevated the G′ and G″ of the dough and improved the viscoelasticity of the bread. The addition of roselle flour disrupted the gluten network structure in the bread, resulting in an increase in chewiness and hardness, but within acceptable limits. The color of the bread also changed significantly. In addition, increased polyphenol content in the bread, roselle flour, and purple rice flour significantly (p < 0.05) increased the aroma profile of bread, giving it a richer odor. In particular, the presence of more acids, alkanes and heterocyclic compounds associated with fruity flavors also adds a distinctive burnt and 'roasted' note. Therefore, the addition of moderate amounts of roselle flour and purple rice flour was beneficial in improving the baking quality of bread, especially positively affecting the flavor. • Purple rice flour/roselle flour replaces wheat flour in some bread. • Purple rice flour improves dough viscoelasticity. • Too much roselle flour disrupts the gluten network. • Purple rice flour/roselle flour enriches the smell of the bread. • Purple rice flour/roselle flour makes bread produce acid and alkane VOCs. [ABSTRACT FROM AUTHOR]

Enzymatic hydrolysis lignin residues (EHLRs) of lignocellulose usually adsorbs cellulase, which can be recycled and used to replace parts of cellulase in the hydrolysis process. To understand this phenomenon during enzymatic hydrolysis (EH) of sugarcane bagasse (SCB) treated with sulfite (SPORL) and dilute acid (DA), the adsorption characteristics between lignin and cellulase in EHLRs were investigated, focusing on interaction force at molecular level and enzymatic activity. The results revealed that SPORL-EHLR adsorbed more β-glucosidases (β-GLs) through the stronger electrostatic attraction and hydrogen bond force, causing higher cellulase adsorption amount compared to DA-EHLR. Further exploration demonstrated that the cellobiose's catalytic and binding sites on β-GLs were separated from the binding site of SPORL-EHLR on β-GLs, resulting in minimal inhibition of β-GLs activity when bound to SPORL-EHLR. Furthermore, adding SPORL-EHLR in SCB hydrolysis saved 40% cellulase. This study deepens the understanding of the adsorption behavior between lignin and cellulase. [Display omitted] • Adsorption amount of cellulase on SPORL-EHLR was higher than DA-EHLR. • SPORL-EHLR adsorbed almost total β-glucosidase (β-GL). • Electrostatic and hydrogen bond force dominated β-GL adsorption on SPORL-EHLR. • SPORL-EHLR did not inhibit catalytic activity of β-GL. • Recycled SPORL-EHLR could save 40% cellulase. [ABSTRACT FROM AUTHOR]

The tilapia (Orechromis niloticus) surimi gels were prepared with high hydrostatic pressure (0, 100, 200, 300, and 400 MPa for 15 min) treatments to investigate the changes in water‐holding capacity, color, gel strength, microstructure, texture, and proteins of the gels. Compared it with cooked gel (40°C/30 min + 90°C/30 min). The whiteness of heat‐induced and HHP‐induced gels were significant (p <.05) higher than that of untreated samples. The gels formed by pressurization were dense and flexible, and formed by cross‐linking based on hydrogen bonding. SDS‐PAGE patterns showed no major change in the actin and tropomyosin protein profiles of gels induced by HHP‐300. Raman spectroscopy confirmed disulfide bonds played an important role in gel formation. A lower intensity ratio observed in HHP‐induced protein supported the tyrosine residues involved in hydrogen bond formation. The changes of secondary structure suggested decreased α‐helix content and increased β‐sheet. [ABSTRACT FROM AUTHOR]

An active packaging film based on poly(lactic acid) (PLA) incorporated with 9 wt% bergamot, lemongrass, rosemary, or clove essential oils was developed. The influence of essential oils on the properties of the PLA/essential oil blends was studied. The mechanical and antimicrobial properties of PLA/essential oil blends were found to be superior to pure PLA. The WVP of PLA/essential oil blend films was significantly ( p < 0.05) higher than that of pure PLA film. All FTIR spectra of PLA/essential oil blends displayed the characteristic bands of PLA-based materials. The addition of essential oils in the polymer matrix resulted in a two-step degradation process of TGA. Furthermore, essential oils led to the decrease of the glass transition temperature according to the DSC results. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nine new highly oxygenated meroterpenoids were identified based on the guidance of molecular networking and OSMAC approach. • Compound 14 showed good cytotoxicity against HepG2, MCF-7, HL-60, A549, HCT116 and H929 cell with IC 50 values of 6.6, 14.8, 3.2, 5.7, 6.9 and 3.0 μM, respectively. • The proposed biogenetic pathways of different types of (DMOA)-derived meroterpenoids allowed us to propose peniciacetals A−D (1–4) to be the important intermediate products. • The plausible biosynthetic pathway of new compounds were also proposed. • The discovery of these meroterpenoids with fascinating frameworks brings a new insight of (DMOA)-derived meroterpenoids chemodiversity from fungal origin. Nine new highly oxygenated meroterpenoids, peniciacetals A−I (1 – 9), along with five known analogues (10 – 14) were isolated from the mangrove-derived fungus Penicillium sp. HLLG-122 based on the guidance of molecular networking and OSMAC approach. Peniciacetals A−B (1 – 2) were characterized with a unique 6/6/6/6/5 pentacyclic system possessing an unusual 4,6-dimethyl-2,5-dioxohexahydro-6-carboxy-4 H -furo[2,3- b ]pyran moiety. Peniciacetals C−D (3 – 4) possessed an uncommon 3,6-dimethyldihydro-4 H -furo[2,3- b ]pyran-2,5-dione unit with 6/6/6/5/6 fused pentacyclic skeleton. The structures and absolute configurations of new compounds were elucidated by HR-ESI-MS, 1D and 2D NMR spectroscopic data, X-ray diffraction analysis, and quantum chemical electronic circular dichroism (ECD) calculation. The plausible biosynthetic pathway of 1 – 9 were also proposed. Compound 14 showed good cytotoxicity against HepG2, MCF-7, HL-60, A549, HCT116 and H929 cell with IC 50 values of 6.6, 14.8, 3.2, 5.7, 6.9 and 3.0 μM, respectively. Further research showed that the compound 14 induced necrosis or late apoptosis contributes to the HL-60 cells toxicity. [ABSTRACT FROM AUTHOR]

The effect of poly(lactic acid) (PLA)/poly(ε-caprolactone) (PCL)/thymol(TH) composite film, PLA/PCL film, and polyethylene (PE) film on the microbial and physicochemical quality of hot pepper ( Capsicum frutescens L.) stored at 4 ± 1 °C for 28 days was studied. The measured properties of hot peppers included weight loss, color, firmness, headspace atmosphere in package, vitamin C, total phenolic content, microbial, and sensory quality. The results indicated that the PLA/PCL/TH packaging can retard the harmful change of microbial, weight loss, anaerobic respiration, firmness, vitamin C, total phenolic content, and sensory quality. The color of hot peppers did not show significant ( p < 0.05) changes during the whole storage time. The results suggested that the PLA/PCL/TH composite film could maintain the quality of fresh hot peppers and extend its postharvest life. [ABSTRACT FROM AUTHOR]

In this study, the Fenton oxidized lignin was prepared to investigate the effect of Fenton oxidation modification on the activity of lignin immobilized β-glucosidase (β-GL). The results demonstrated that Fenton oxidation could significantly improve the activity and stability of immobilized β-GL. This is because the Fenton oxidation increased the electrostatic, hydrogen bonding, and hydrophobic forces between lignin and β-GL, resulting in increased lignin adsorption onto β-GL. The Fenton oxidation also changed the chemical structure of lignin, altering the lignin-β-GL binding site and reducing the negative effect of lignin on the β-GL catalytic domain. This research will improve understanding of the effect of Fenton lignin oxidation on immobilized β-GL activity and expand the use of lignin in enzyme immobilization. [Display omitted] • Fenton oxidized lignin was a promising support for immobilization of β-GL. • Activity and stability of immobilized β-GL was improved by Fenton oxidated lignin. • Fenton oxidized lignin had strong interactions with β-GL. • Negative effect of lignin on β-GL catalytic domain was reduced by Fenton oxidation. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the effect of poly(lactic acid) (PLA) based biodegradable film packaging combining 0.5% nisin antimicrobial polypeptide on the physicochemical and microbial quality of Boletus edulis wild edible mushrooms stored at 4 ± 1 °C. The experiment was set up by packaging mushrooms with extruded PLA films containing 0, 7.5, and 15 wt.% triethyl citrate plasticizer. The low-density polyethylene (LDPE) film was used as the control. Mushrooms stored in PLA films containing 7.5 and 15 wt.% plasticizer provided better retention of quality characteristics and received higher sensory ratings compared to mushrooms stored in pure PLA film and LDPE film. Samples with these two treatments underwent minimal changes in texture, PPO activity, total bacteria count, and sensory attributes. Results suggest that nisin in combination with plasticized PLA film has the potential to maintain B. edulis wild edible mushroom quality and extend its postharvest life to 18 days. Industrial relevance B. edulis is one of the most commercialized mushrooms worldwide. However, as with all fresh mushrooms, there are severe preservation problems. Extruded PLA films containing triethyl citrate plasticizer plus antimicrobial agent nisin proved to be a suitable technology for mushroom conservation. This material exhibits an environmental-friendliness potential and a high versatility in food packaging. [ABSTRACT FROM AUTHOR]

Poly(lactic acid)/poly(trimethylene carbonate) (PLA/PTMC) films incorporated with cinnamaldehyde (0, 3, 6, 9, and 12 wt%) were prepared by solvent casting and characterized by physical, mechanical, and antimicrobial properties. SEM analysis revealed that the surface of film became rougher with certain porosity when cinnamaldehyde was incorporated into the PLA/PTMC blends. Cinnamaldehyde acted as plasticizers which reduce the intermolecular forces of polymer chains, thus improving the flexibility and extensibility of the films. Differential scanning calorimetry showed that the crystallinity of PLA phase decreased by the presence of cinnamaldehyde in the composite films. Water vapor permeability of films increased with the increase of cinnamaldehyde loading. However, the active PLA/PTMC/cinnamaldehyde composite films showed adequate barrier properties for food packaging application. Incorporation of cinnamaldehyde to the PLA/PTMC polymer matrix improved the antimicrobial activity of active packaging films. These results indicated that the best compromise between mechanical, barrier, thermal, and antimicrobial properties could be achieved by the addition of 9 wt% cinnamaldehyde into PLA/PTMC blends. [ABSTRACT FROM AUTHOR]

The effect of biobased poly(lactic acid) (PLA)/poly(ɛ-caprolactone) (PCL) blend films with different cinnamaldehyde contents (0, 3, and 9 wt%) on the physicochemical and microbial quality of button mushrooms ( Agaricus bisporus ) stored at 4 ± 1 °C for 16 days was investigated. The low-density polyethylene (LDPE) film was used as the control. The microbial levels and physicochemical properties such as weight loss, firmness, total soluble solids, O 2 and CO 2 concentrations, microbiological quality, color, and sensory quality of mushrooms were measured. Although the highest weight loss (3.08%) was observed in the PLA/PCL/C9 treatment at the end of storage, it was still lower than 5%. Mushrooms packaged in the PLA/PCL/cinnamaldehyde blend films were significantly ( p < 0.05) firmer than those packaged in the control and PLA/PCL film. The CO 2 level inside the PLA/PCL film with cinnamaldehyde was lower than those inside the control and PLA/PCL film, but the O 2 level was similar in all packages. The PLA/PCL/C9 film was more effective in reducing microbial counts and preserving the color of mushrooms than the other three films. The overall acceptability of mushrooms packaged in the PLA/PCL/C9 film still remained good and within limit of marketability after 12 d of storage. The results suggested that the PLA/PCL/C9 film with higher water vapor permeability could be used to maintain the quality of fresh button mushroom and extend its postharvest life. [ABSTRACT FROM AUTHOR]

A blend of poly( l -lactide) (PLLA) with star-shaped poly(ɛ-caprolactone-co- l -lactide) (s-PCLA) at different contents (PLLA/s-PCLA = 100/0, 90/10, 80/20, and 70/30, w/w) were prepared by torque rheometer. Thermal and functional properties of the blends were investigated by FTIR, SEM, DSC, TGA, DMA, tensile, optical, and water vapor permeability tests. FTIR results showed that intermolecular hydrogen bonds existed between two components in the blends. SEM indicated that PLLA and s-PCLA showed limited miscibility. DSC showed that T g occurred at lower temperatures in the PLLA/s-PCLA blends than in neat PLLA, and the crystallinity of PLLA phase increased by the presence of s-PCLA in the PLLA/s-PCLA blends. TGA indicated that s-PCLA improved the thermal stability of the PLLA/s-PCLA blends. DMA results revealed that the storage modulus of the composites decreased with respect to the pure polymer. The result of tensile tests suggested that the PLLA/s-PCLA blends showed better elongation at break than neat PLLA. The effect of s-PCLA on the color and opacity of films could be considered as negligible. The WVP of PLLA/s-PCLA blend films increased with the increase in s-PCLA, and they were still lower than that of commercial LDPE films. [ABSTRACT FROM AUTHOR]

With the increasing environmental pollution caused by disposable masks, it is crucial to develop new degradable filtration materials for medical masks. ZnO-PLLA/PLLA (L-lactide) copolymers prepared from nano ZnO and L-lactide were used to prepare fiber films for air filtration by electrospinning technology. Structural characterization of ZnO-PLLA by H-NMR, XPS, and XRD demonstrated that ZnO was successfully grafted onto PLLA. An L9(43) standard orthogonal array was employed to evaluate the effects of the ZnO-PLLA concentration, ZnO-PLLA/PLLA content, DCM(dichloromethane) to DMF(N,N-dimethylformamide) ratio, and spinning time on the air filtration capacity of ZnO-PLLA/PLLA nanofiber films. It is noteworthy that the introduction of ZnO is important for the enhancement of the quality factor (QF). The optimal group obtained was sample No. 7, where the QF was 0.1403 Pa−1, the particle filtration efficiency (PFE) was 98.3%, the bacteria filtration efficiency (BFE) was 98.42%, and the airflow resistance (Δp) was 29.2 Pa. Therefore, the as-prepared ZnO-PLLA/PLLA film has potential for the development of degradable masks. [ABSTRACT FROM AUTHOR]

Abstract: Films of poly(l-lactide) (PLA) plasticized with varying levels of N-octyl lactate (NOL) were prepared by extrusion. The thermal and functional properties of the blends were investigated by SEM, DSC, TGA, tensile, opacity, water vapor permeability, and water contact angle tests. The compatibility of the plasticizer with PLA was confirmed by DSC and SEM analysis. A higher plasticizing effect on the thermal properties of PLA was generally observed with the increase in NOL content. Additionally, the mechanical properties were improved with the increase in NOL content. The mechanical resistance of the films could be related to their glass transition temperature. The effect of the concentration of plasticizer on the opacity of the films was negligible. The water vapor permeability of the PLA/NOL composite films increased with the increase in the concentration of NOL; however, the values observed were still lower than the water vapor permeability of commercial LDPE films. In conclusion, the extruded PLA-based films with NOL plasticizers could be used as food-packaging materials. [Copyright &y& Elsevier]

Highlights: [•] Indocalamus tesselatus is one of the most popular packing materials in China. [•] Heavy metals in Chinese I. tesselatus have received great interest. [•] A method for the determination of heavy metals by ICP-oa-TOF-MS is proposed. [•] Results show that I. tesselatus can be used as food packing material. [Copyright &y& Elsevier]

Highlights: [•] XRD and DSC indicated that the crystallinity of PLLA-PTMC/Talc composites increased. [•] FTIR suggested that there were strong interactions between PLLA-PTMC and talc filler. [•] SEM image of composite films revealed certain homogeneity between PLLA-PTMC and Talc. [•] PLLA-PTMC/Talc composites performed well in mechanical and barrier properties. [•] PLLA-PTMC/Talc composites can be used for development of food packaging materials. [Copyright &y& Elsevier]

Summary: This study aimed to develop a novel pH‐sensitive intelligent film for monitoring minced beef freshness based on chitosan/sodium alginate (CS–SA) and coffee peel anthocyanin (CPA). The different CPA content effects on the internal structure, physical properties and pH sensitivity of the CS–SA films were investigated. The results showed low contents of CPA (≤2%) could be evenly distributed within the CS–SA matrix with good compatibility. The addition of CPA significantly improved the physical properties and pH sensitivity of the CS–SA films. The CS–SA film containing 2% CPA (CS–SA–CPA2) showed the best tensile strength, water vapour barrier performance and most noticeable colour change. Moreover, this film exhibited good colour stability after 120 days. The CS–SA–CPA2 film changed colour from light yellow to brown to dark brown during minced beef storage, successfully indicating freshness. Therefore, the CS–SA–CPA2 film has the potential to be a pH‐sensitive material for monitoring minced beef freshness. [ABSTRACT FROM AUTHOR]

Summary: This work prepared a controlled release food packaging film by solvent volatilization using polylactic acid (PLA) and mesoporous silica nanoparticles (MSNs) loaded with clove essential oil (CEO). White button mushrooms were packaged with PLA and CEO‐loaded MSN PLA composite films to investigate postharvest qualities. The result indicated that PMC‐3 film improves the postharvest qualities of Agaricus bisporus, as reflected by lower weight loss (7.03%), higher total phenolics (2.29 g/kg), and ascorbic acid (27.1 mg/kg) compared with A. bisporus packaged with PLA film. In addition, PMC‐1, PMC‐2, and PMC‐3 treatment significantly improved the antioxidant system of A. bisporus, which inhibited the activity of polyphenol oxidase and peroxidase, as well as control the release of clove essential oil during the storage period. These findings suggest that PMC film is a promising method in postharvest preservation of A. bisporus. [ABSTRACT FROM AUTHOR]

Summary: A high‐glycaemic index diet can lead to elevated blood glucose levels and chronic diseases. In this study, Dictyophora indusiata powder, oats powder and Polygonatum kingianum powder were substituted for some wheat flour to make pizza crust. The aim was to investigate the effects of the three powders on the chemical composition, physical quality, antioxidant properties, in vitro digestibility of starch and sensory characteristics of pizza crust. The addition of the three powders enhanced the nutritional value of the pizza crust, especially the dried Dictyophora indusiata flour and oats powder were rich in dietary fibre and protein, the three powders also increased the total phenolic content (214%) and antioxidant activity (ABTS+185%, DPPH30.5%) of the pizza crust and improved the shelf‐life of the pizza crust. In addition, the three powders increased the slowly digestible starch (25.9%) and decreased the reducing sugar levels and hydrogenation index, and expected glycaemic index of the pizza crust compared to the control group. The results suggest that the three powders could be used as functional ingredients to enhance the nutritional value and lower the glycaemic index of pizza crusts. This study provides new ideas for the development of nutritious and hypoglycaemic functional bakery products. [ABSTRACT FROM AUTHOR]

An intelligent pH indicator film was prepared by mixing cassava starch, polyvinyl alcohol (PVA), and natural anthocyanin extracted from grape skin (GSE) and mangosteen rind (MRE). The effects of GSE and MRE on the physical, structural, and pH‐sensing performance of composite films were studied. Scanning electron microscope results showed that the microstructure of film had little difference when the anthocyanin extracts were incorporated into the polymer matrix. A significant (p <.05) effect of GSE and MRE on the tensile strength, moisture content, and elongation at the break of the films were observed. The two indicator films could respond to different pH values and showed good color stability. During the storage of pork, the cassava starch/PVA/GSE film showed a visible color variation from pink, blue, purple to yellow, while the cassava starch/PVA/MRE film showed color variation from light yellow, bright yellow, green to dark green. The result indicated that the two films could be used to monitor pork freshness for intelligent pH indicator packaging. Novelty impact statement: Using fruit waste to extract anthocyanin.Indicator film has good color stability, and the color change was obvious at different pH values.The color of the indicator film changed obviously in the process of indicating the freshness of pork. [ABSTRACT FROM AUTHOR]

A pH indicator film was prepared by mixing natural polymeric chitosan (CH) with natural dye from butterfly pudding extract (BP). The films were determined by color changes at different pH value, absorbance, thickness, moisture content, swelling property, water contact angle, mechanical property, barrier property, and microstructure of films. The structural change of film was analyzed by Fourier transform infrared spectra. The application to monitor fish freshness was also studied. The prepared film was sensitive to the changes in pH value and showed distinct color changes from pink purple to yellow, with pH value ranging from 1 to 14. The films showed visible color changes from purple-blue to dark green during fish preservation. The total volatile basic nitrogen (TVB-N) content and pH value changes of tilapia were closely related to the visual color changes in film. The result indicated that the fabricated film was a highly pH-sensitive film for monitoring fish freshness. [ABSTRACT FROM AUTHOR]

The aim of this study was to prepare a novel pH-sensitive smart film based on the addition of purple garlic peel extract (PGE) and TiO2 nanoparticles in a sodium alginate (SA)/polyvinyl alcohol (PVA) matrix to monitor the freshness of beef. FT-IR spectroscopy revealed the formation of stronger interaction forces between PVA/SA, PGE, and TiO2 nanoparticles, which showed good compatibility. In addition, the addition of PGE improved the tensile strength and elongation at break of the composite film, especially in different pH environments, and the color response was obvious. The addition of 1% TiO2 nanoparticles significantly improved the mechanical properties of the film, as well as the light barrier properties of the film. PGE could effectively be uniformly dispersed into the composite film, but it also had a certain slow-release effect on the release of PGE. PGE had high sensitivity under different pH conditions with rich color changes, and the color showed a clear color change from red to yellow-green when the pH increased from 1 to 14. The same change was observed when it was added to the film. In particular, by applying this film to the process of beef preservation, we judged the freshness of beef by monitoring the changes in the TVB-N value and pH value during the storage process of beef and found that the film showed obvious color changes during the storage process of beef, from blue (indicating freshness) to red (indicating non-freshness), and finally to yellow-green (indicating deterioration), which indicated that the color change of the film and the freshness of the beef maintained a highly consistent. [ABSTRACT FROM AUTHOR]

Nisin was loaded in mesoporous silica nanoparticles (MSN) (0, 1, 2 and 3 wt%) and incorporated into poly (lactic acid) (PLA) matrix by casting method. The mechanical property, water vapor permeability, thermal property, and antimicrobial property of PLA nanocomposite films were measured. And the internal structure of the composite film was observed through the Scanning electron microscope. Meanwhile, the kinetic of nisin releasing from food simulated solution was investigated and the migration model was established. The result showed that mesoporous silica had an effect on the mechanical and thermal property of the composite films. Both water vapor transmission rate (WVP) and oxygen permeation rate (OTR) decreased, especially for 3MSN/NI/PLA, where WVP decreased by about 9.64% and OTR decreased by 35.19%, which was beneficial to improve the preservation effect. With the addition of MSN, the amount of loaded nisin increased, and at 3MSN/NI, the nisin loading reached 88.75%, and the mesoporous silica could effectively control the release of nisin, thus prolonging the preservation effect. The release kinetic of nisin was described by Fick's law and Weibull's model. In short, the PLA nanocomposite film has the potential to be used as an antimicrobial active film by adding nisin as an antimicrobial agent. Highlights: A biodegradable antimicrobial food grade film was prepared.Nisin was added to the films as an antimicrobial agent.The ordered mesoporous structure of MSN was used as a carrier of antimicrobial agent.The film effectively inhibits E. coli and S. aureus by controlling the release of nisin.Fick's law and Weibull's model were used to describe the release kinetics of Nisin. [ABSTRACT FROM AUTHOR]

Summary: This study aimed to investigate the physical, nutritional, antioxidant and sensory properties, as well as the starch digestibility of wheat bread containing Dictyophora Indusiata powder (DIP) as a functional addition. Results showed that though the specific volume of wheat breads decreased with the addition of DIP, the chewiness showed an increasing trend. The wheat bread containing DIP showed significantly higher (P < 0.05) content of protein and dietary fibre compared to the control bread. On the other hand, with the addition of DIP, the total phenolic content and antioxidant properties of wheat bread significantly (P < 0.05) increased. The moisture and texture of bread during storage improved significantly (P < 0.05), and the enthalpy of bread decreased significantly (P < 0.05) in staling period. In conclusion, the wheat bread added with DIP could be a feasible baking product with improved nutritional, antioxidant properties and bread staling. [ABSTRACT FROM AUTHOR]

Drying is a crucial process in the production of tea. The effects of sun drying (SD), hot air drying (HAD), microwave drying (MD), vacuum drying (VD) and freeze drying (FD) on the color, taste, bioactive, and aroma of coffee pulp tea (CPT) were evaluated systematically. The results showed that FD could better retain the original color, total phenolics (4.75 mg/mL), trigonelline (0.31 mg/mL), chlorogenic acid (0.067 mg/mL), protocatechuic acid (0.81 mg/mL), and total soluble sugars (24.33 mg/mL) of CPT, but its drying time was longer (32.56 h), and the taste and flavor were the worst. HAD and SD displayed the highest loss rates of most bioactive components, exceeding 40%. In contrast, MD can better improve the quality of CPT, giving it a better color, superior retention of bioactive components, and the most attractive taste and aroma, and decrease the drying time by 66.1% and 96.5%, respectively. Overall, MD is a promising production method for obtaining high-value-added CPT products. [Display omitted] • FD can keep coffee pulp tea's color and phytochemical profiles considerably. • The volatile components of coffee pulp tea were modeled using OPLS-DA. • MD-dried coffee pulp tea had a better attractive aroma under shorter drying times than other drying. • MD was more suitable to produce dried coffee pulp tea on an industrial scale. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is one of the most promising biodegradable materials, which can reduce the environmental pollution caused by food and material industry. The effect of the addition proportion of nano‐silver and different food simulant on the migration and the performance changes of film during migration were evaluated, revealing the association between the performance changes and nano‐silver migration. The results showed that nano‐silver had the largest migration amount and the fastest migration rate in 4% (v/v) acetic acid solution, followed by 50% (v/v) ethanol solution, and the lowest in isooctane solution. Performance changes were affected by the compatibility of silver nanoparticles and PLA, and the strength of the interaction between the film and acetic acid. Performances of composite film deteriorated during high proportions of nano‐silver addition and long soaking. Adding a small amount of nano‐silver to the composite was the effective method considering the balance between good performances and migration. [ABSTRACT FROM AUTHOR]

Natural pigments are widely used in the food industry because of their unique sensory properties and nutritional value. However, natural pigments are susceptible to color change and loss of bioactivity due to their high temperature decomposition, which hinders the ideal application of traditional thermal technology in natural pigment retention related fields. Therefore, the food industry is gradually adopting non-thermal physical technologies (NPT) including ultrasonic technology (US), ultrahigh-pressure technology (UHP), supercritical fluid extraction technology (SFE), irradiation technology (IR), pulsed electric field technology (PEF) and cold plasma technology (CP), in order to achieve better results. Although several researches have been conducted, the underlying mechanism behind the effect of NPT on the structural of natural pigments remains elusive. In this review, the principle of NPT in extraction of different types of natural pigments is described. Moreover, the application of NPT in the extraction of natural pigments and the possible impact and connection of these technologies on the extraction yield, structure and bioactivities of natural pigments are examined. The aim of this review is to broaden the application of NPT in extracting natural pigments from food and agricultural by-products. • The NPT can improve the extraction yield of natural pigments. • The NPT enhance bioactivity of natural pigments because their structure may be changed. • The NPT will be the future of natural pigments extraction after overcoming its defects. [ABSTRACT FROM AUTHOR]

BACKGROUND: Our living environment is being increasingly polluted by petroleum‐based plastics and there is an increasing demand for biodegradable food packaging. In this study, the effect of various ultrahigh‐pressure (UHP) treatments (0, 200 and 400 MPa) on the microstructure and thermal, barrier and mechanical properties of poly(lactic acid) (PLA)/ZnO nanocomposite films was studied. RESULTS: The film‐forming solution was processed using UHP technology. The crystallinity, strength and stiffness of the composite film after UHP treatment increased. In addition, barrier property analysis showed that the UHP treatment significantly (P < 0.05) reduced the oxygen permeability and water vapor permeability (WVP) coefficient of the PLA/ZnO nanocomposite film. Furthermore, the WVP value of the film treated at 400 MPa (50 g kg−1 nano‐ZnO content) was the lowest and reduced by 47.3% compared with that of pure PLA film. The improvement in these properties might be due to the interaction between nano‐ZnO and PLA matrix promoted by UHP treatment. CONCLUSIONS: Therefore, the application of UHP technology on the film‐forming solution could improve the crystallinity and functional properties of the nanocomposite film, and has great potential in the production of food packaging films with ideal functions. © 2021 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Summary: This work aimed to prepare a controlled‐release antibacterial food packaging film by solvent volatilisation using chitosan (CS) and acidified modified montmorillonite (MMt) loaded with CIN (acid‐MMt‐CIN). MMt was successfully acidified and CIN was successfully loaded into acid‐MMt, which had been confirmed by X‐ray diffraction. The coordination of acid‐MMt‐CIN significantly increased the barrier properties of CS film to water vapour, as well as the rigidity and ductility of the film. Furthermore, the CS/acid‐MMt‐CIN film could significantly improve their UV resistance. It was found that the CIN release time of CS/acid‐MMt‐CIN film in isooctane (simulated fatty food) could reach 168 h, which was 72 h longer than that of CS/CIN film. The addition of acid‐MMt‐CIN had a significant inhibitory effect on Staphylococcus aureus and Escherichia coli. In short, CS/acid‐MMt‐CIN film could potentially be used as an antibacterial active food packaging film. [ABSTRACT FROM AUTHOR]

The migration study of nano‐Ag migration from polylactic acid (PLA) films was studied. Samples treated by high‐pressure food processing (0, 100, 200, 300, and 400 MPa pressure) were soaked in acetic acid solution and incubated at 20 °C for 90 days. At the end of storage, nano‐Ag particles (AgNPs) migration from the PLA/AgNPs composite film treated under 200 MPa high pressure was the lowest. However, AgNPs migration was accelerated under 400 MPa high pressure. High‐pressure processing (200 MPa) could cause denser structure and higher crystallinity degree in films than other treatments. Lower amount of AgNPs induced a decline in the intensity of specific characteristic peaks. The diffraction peak intensity of α‐crystal for the film sample treated with 400 MPa was the lowest on day 60. The crystallization index of the PLA matrix changed with different high‐pressure processing. The result indicated that appropriate high‐pressure food processing could effectively suppress AgNPs migration from PLA‐based film while contacting with acidic acid food simulant. Practical Application: The release of nanoparticles from food packaging material is a very important matter when the migration is concerned with regulatory and toxicity issues. The study described the migration kinetic of AgNPs from PLA nanocomposite film into acidic food simulant after different high‐pressure food processing. The results indicated that the PLA/AgNPs nanocomposite film was safe for acidic food after high‐pressure treatment. [ABSTRACT FROM AUTHOR]

The use of biodegradable packaging films for post-harvest preservation of wild edible mushrooms is an eco-friendly method. In this study, the nanocomposite films were prepared based on poly (lactic acid) and mesoporous silica (2, 4 and 6 wt% based on polylactide) loaded with citral. The effects of nanocomposite film on the postharvest quality and specific spoilage bacteria of Russula virescens wild mushroom were evaluated. The results showed that firmness, weight loss, color, electrolyte leakage for Russula virescens treated with mesoporous silica loaded with citral based on poly (lactic acid) films were maintained compared to the control group. In particular, the 4% mesoporous silica loaded with citral group prolonged the freshness of mushroom by 6 days. Acinetobacter , Lactococcus, Weissella, Serratia, unclassified Enterobacteriaceae , and unclassified Gammaproteobacteria were identified as the main dominant bacteria. After 12 d of storage, the relative abundance of these bacterial for mushrooms packed by 4 wt% mesoporous silica loaded with citral based on poly (lactic acid) film was reduced, except Lactococcus. This revealed that the poly (lactic acid) film prepared by 4 wt% mesoporous silica loaded with citral could be used to extend the shelf life of Russula virescens. • The MSN/CIT/PLA film inhibited POD and PPO enzyme activities. • The MSN/CIT/PLA film retarded the browning of R. virescens wild mushroom. • The relative abundance of bacteria for MSN/CIT/PLA group was reduced. • The MSN/CIT/PLA film could extend the shelf life of R. virescens. • 4MSN/CIT/PLA film was the most effective in preserving freshness of R. virescens. [ABSTRACT FROM AUTHOR]

Boletus, a widely-consumed wild mushroom, is susceptible to rapid deterioration due to shifts in symbiotic microorganisms and flavor alterations during preservation. This study investigated the effects of prolonged refrigerated storage on Boletus , focusing on softening and energy deterioration mechanisms, changes in volatile chemicals, microbial community composition, and their interconnections. Findings revealed that the fresh Boletus microbial community transitions towards spoilage microorganisms after 8 days of refrigeration. Spearman analysis established a correlation between porcini softening and energy deterioration mechanisms, as well as a robust link between microorganisms and spoilage volatile. The mushroom's freshness diminishes as volatile spoilage flavors increase. Collectively, the results highlighted significant changes in Boletus mushroom quality, microbial composition, and volatile compounds during storage. • Boletus chilling affects quality, volatiles, and microorganisms. • Extended storage reduces antioxidants, raises harmful ROS, potentially damaging cells. • Storage causes volatile shifts: 1-Octen-3-one freshness drops, acetic and adipic acids increase. • Initial microbes shift to Pseudomonas, and Vanrija during storage. • Study reveals microbial, flavor dynamics in cold-stored Boletus. [ABSTRACT FROM AUTHOR]

The poly(lactic acid) (PLA)/nano-TiO 2 composite films with different nano-TiO 2 loading (0 wt%, 1 wt%, 5 wt%, 10 wt%, 15 wt%, and 20 wt%) were prepared and contacted with 50% (v/v) ethanol solution as food simulant to study the behavior of nano-TiO 2 migration. The structural changes and intermolecular interactions were determined by scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The migration amount increased with the increase of initial nano-TiO 2 content. SEM images demonstrated that the microstructure of PLA nanocomposite films became rougher as exposure to ethanol solution in a few days. XRD spectra indicated that a decrease in the intensity of specific diffraction peak occurred as the decrease in nano-TiO 2 content of PLA nanocomposite films during exposure to ethanol simulant. DSC analysis confirmed that the higher crystallinity percentage obtained during the different degradation times. The reasonable food packaging application of the nano-TiO 2 composite films with restrained nano-TiO 2 migration could be accomplished by controlling the nano-TiO 2 loading. • PLA/nano-TiO 2 films were contacted with 50% (v/v) ethanol solution as food simulant. • The migration amount increased with the increase of initial nano-TiO 2 content. • PLA nanocomposite films became rougher as exposure to ethanol solution in a few days. • A decrease in the peak intensity occurred during exposure to ethanol simulant. • Restrained nano-TiO 2 migration could be accomplished by controlling nano-TiO 2 loading. [ABSTRACT FROM AUTHOR]

Wild morel mushroom is one of the most popular mushrooms, but fresh morels have a short shelf life and are highly susceptible to microbial influences that can lead to spoilage and changes in volatile organic compounds. Therefore, the microbial communities (bacteria and fungi) were studied by high-throughput sequencing technology on wild morel mushrooms in a post-harvest environment at 4 ℃. The volatile organic compounds (VOCs) of wild morel mushrooms were evaluated by headspace solid-phase microextraction (HS-SPME) in combination with gas chromatography-mass spectrometry (GC-MS) during storage. The results showed that there were 41 given genera of bacteria and 48 given genera of fungi with abundance > 0.01% during the whole storage period. Among them, bacteria: Pseudomonas , Pedobacter and Flavobacterium ; fungi: Cystofilobasidium , Aspergillus and Mucor had a greater impact on wild morel mushrooms during storage, especially Pseudomonas , whose abundance was consistently elevated and accounted for the largest share (47.51–73.73%). The main VOCs of wild morel mushrooms consist of aldehydes, alcohols, alkanes, ketones, phenols, esters and acids. Among them, 3-Octanone is predominant, but its content has been decreasing. The analysis showed a strong correlation between microorganisms and VOCs (P < 0.05, |r| > 0.9). Among them, Pseudomonas was correlated with 4 VOCs; Cystofilobasidium with 8 VOCs; Aspergillus with 7 VOCs; and Mucor with 7 VOCs. This suggests that microbes are crucial to the degradation and VOCs of morels during spoilage. The findings of the research provide information database for post-harvest preservation of morel mushrooms and efficient control of their spoilage. ● Analyzed changes in the microbial community of wild morel mushrooms during storage. ● Analysis of the composition and changes of odor substances in wild morel during storage. ● Aldehydes and alcohols were the most important VOCS during storage of wild morel. ● The link between microbial and VOCs on the surface of wild morel was established. ● The microbiota of wild morel mushrooms has a potential impact on VOCs. [ABSTRACT FROM AUTHOR]

In this work, we prepared chitosan/eugenol-loaded IRMOF-3 nanoparticles (CS/IRMOF-3-EU) composite films using (0, 2, 4, and 6 wt%) isoreticular metal-organic framework (IRMOF-3) nanoparticles loaded with eugenol (IRMOF-3-EU), co-blended with chitosan to develop environmentally friendly food packaging materials with sustained antimicrobial activity. The microstructure and physicochemical properties of the composite films were investigated. The addition of IRMOF-3-EU to the CS matrix significantly enhanced the UV-blocking property and elongation at the break of the composite films; the CS/IRMOF-3-EU composite films inherited the antioxidant and antibacterial properties of eugenol (EU), and the DPPH radical scavenging ability was increased to 53.8% with the addition of 6% IRMOF-3-EU, while it showed excellent antibacterial ability; in addition, the CS/IRMOF-3-EU composite films achieved the sustainable release of eugenol to achieve the long-lasting antibacterial effect. Experiments on strawberry preservation applications showed that the CS/IRMOF-3-EU films slowed down the deterioration of strawberry quality, delayed the decline of hardness, effectively suppressed weight loss, H 2 O 2 content, and malondialdehyde content, and delayed the decline of catalase activity and peroxidase activity. It showed that the CS/IRMOF-3-EU composite films could be used to maintain the postharvest quality and prolong the shelf life of strawberries. • Composite films were prepared from chitosan and eugenol-loaded IRMOF-3 nanoparticles. • IRMOF-3-EU improves the physical property of CS/IRMOF-3-EU composite films. • The CS/IRMOF-3-EU composite films exhibits excellent antioxidant properties. • Composite films has the ability to continuously release antimicrobial substances. • The CS/IRMOF-3-EU composite films has good effect on strawberry storage. [ABSTRACT FROM AUTHOR]

The effects of nano-Ag content, high pressure treatment, and migration time on nano-Ag migration and properties of polylactide (PLA)/nano-Ag composite films were investigated. The PLA films incorporated with 1 wt%, 5 wt%, 10 wt%, 15 wt%, and 20 wt% nano-Ag were treated by 100, 200, 300, and 400 MPa high pressure for 10, 20, and 30 min, respectively, and then soaked in isooctane food simulant at 40 °C for 49 days. The migration of nano-Ag in the PLA nanocomposite films increased by the addition of nano-Ag, the pressure of high pressure treatment, and migration time. Thermal and mechanical properties showed that high pressure and migration time would make the films rougher and increase the crystallization temperature of the PLA nanocomposite films. Moreover, the addition of nano-Ag could improve the barrier properties of the PLA nanocomposite films. However, the longer the migration time, the worse the barrier property. The results indicated that the migration amount of nano-Ag and performance of the PLA/nano-Ag composite films were greatly affected by the migration time. • This paper applied high pressure technology to the preparation of composite film materials. • The addition of nano-Ag could increase the crystallinity of the composite films. • The migration of the nano-Ag/PLA composite films in the oily food simulating liquid was safe. • As the migration time increased, the barrier and mechanical properties of the composite films deteriorated. • The results indicated that the migration of nano-Ag in the composite films increased as the initial addition quantity of nano-Ag. [ABSTRACT FROM AUTHOR]

Highlights • A film was prepared by adding TiO 2 and Ag nanoparticles into PLA matrix. • Weight loss in PLA nanocomposite group was lower than that for PLA and PLA/BEO group. • The PLA nanocomposite films provided better retention in firmness, color, and Vit C. • The PLA nanocomposite films had an obvious inhibition on the microorganism growth. • Mango sample packed by the PLA nanocomposite films achieved a shelf-life of 15 days. Abstract The effects of polylactic acid (PLA) film, PLA/bergamot essential oils (BEO) film, and PLA nanocomposite film (PLA/BEO/nano-TiO 2 film and PLA/BEO/nano-TiO 2 +nano-Ag film) on the physicochemical and microbial quality of mangoes stored at room temperature for 15 days was evaluated. The measured properties of mangoes included weight loss, fruit firmness, color, total soluble solids content, total acidity, vitamin C, microbial property, and sensory quality. The weight loss of mangoes packed by PLA nanocomposite films was significantly (p < 0.05) lower than that for PLA and PLA/BEO groups from day 9 to day 12. The PLA nanocomposite films could effectively delay the loss of mango firmness during the entire storage period. The PLA nanocomposite films could also retard the harmful changes in color, total acidity, vitamin C, and microbial property when compared with PLA and PLA/BEO films. The overall acceptability of mangoes packed by the PLA nanocomposite films was still higher than 5 scores and within limit of marketability at the end of storage period. The result indicated that the PLA nanocomposite films could be used to maintain the quality of fresh mango and extend its postharvest life to 15 days. [ABSTRACT FROM AUTHOR]

Summary: The chemical compositions, nonvolatile taste components and nutritional compounds of three wild edible Chanterelle mushrooms (C. cibarius Fr (CcF), C. cinnabarinus schwein (CcS) and C. tubaeformis Fr (CtF)) were evaluated. Results showed Chanterelle mushrooms were good sources of proteins and carbohydrates with low energy. CcS was rich in trehalose in free sugars and glucose in soluble sugars. Monosodium glutamate‐like free amino acids and flavour 5′‐nucleotides indicated Chanterelle mushrooms had good taste. Based on their amino acids compositions and nutrition evaluations, CcF, CcS and CtF were significant sources of amino acids and protein. CtF showed better protein quality than CcF and CcS. Stearic and oleic acids showed high contents in three mushrooms, and higher unsaturated fatty acids were found in CcF. Three mushrooms had high contents of K, Ca and Mg, and low content of Na. Organic acid and phenolic acids of three mushrooms were identified, and antioxidant activities were evaluated. [ABSTRACT FROM AUTHOR]

A novel antimicrobial packaging system was prepared by incorporating TiO2 or Ag nanoparticles into poly(lactic acid) (PLA) matrix. The effect of PLA, PLA/TiO2, and PLA/TiO2 + Ag film on the physicochemical and microbiological properties of Yunnan cottage cheese stored at 5 ± 1 °C for 25 days was investigated. The low density polyethylene (LDPE) film was used as the control. The weight loss, pH value, lactic acid bacteria count (LAB), texture, sensory quality, and antimicrobial activity were determined. Cheeses packed by PLA/TiO2 and PLA/TiO2+Ag film provided better retention in pH value, LAB, sensory quality, and antimicrobial activity compared with those packed by PLA and LDPE film. Migration of Ti and Ag nanoparticles was lower than the limit of 10 mg/kg as defined by EFSA for food contact materials. The results indicated that the incorporation of TiO2 or Ag nanoparticles into PLA matrix could maintain cheese quality and prolong its shelf life to 25 days. Practical applications Yunnan cottage cheese is one of the most popular cheeses in China. However, the shelf life of unpacked Yunnan cottage cheese is only 5-7 days under refrigerated condition. PLA film incorporated with antimicrobial TiO2 or Ag nanoparticles has great potential to prolong cheese shelf life. The novel packaging material may be an effective alternative for cheese preservation. [ABSTRACT FROM AUTHOR]

A high glycaemic index diet would cause a rapid increase in blood sugar levels and lead to chronic metabolic disorders. In this study, wheat bread enriched with mushroom (Pleurotus eryngii and Cantharellus cibarius) powder at different content (0, 5, 10, and 15 g/100 g replacement based on total weight) was prepared. The effect on the physical, chemical, sensorial, and in vitro digestibility of bread was determined. With the addition of mushroom powder, the total phenolic content of wheat bread significantly (p < 0.05) increased. The reducing sugar, hydrogenated index, and expected glycemic index gradually decreased with mushroom powder. The results suggested that mushroom powder could be used as a high-value ingredient to improve the nutritional profile and reduce bread's glycaemic index. Mushroom powder could be used as a natural food ingredient and showed new potential in improving the functional properties of bread products. • Wheat bread (WB) containing mushrooms powder (MP) exhibited higher quality. • The antioxidant properties of wheat bread increased with the MP addition. • Adding MP alongside WB retains the ability to reduce carbohydrate digestion in vitro. •With the increase of MP addition, WB demonstrated lower expected glycemic index. • Addition of MP promotes health products. [ABSTRACT FROM AUTHOR]

Currently, the main problems in cellulose conversion to glucose are the low enzymatic hydrolysis efficiency and the high cellulase cost. In this study, cellulose I allomorph substrates were from p-toluenesulfonic acid (PT), dilute sulfuric acid (DA) and sulfite (SP) treated cellulose substrates, and cellulose II allomorph were prepared by mercerization. XRD, NMR, FTIR and molecular docking were used to investigate the effect of cellulose allomorphs on hydrolysis efficiency. The results showed that cellulose II allomorph had a lower cellulase adsorption capacity and higher hydrolysis efficiency. This was because cellulose II allomorph owned gt conformation, and less tg and gg conformations of C-6 hydroxymethyl, causing the reduction of interchain hydrogen bonds and the increase in hydrolysis efficiency (PT, DA and SP: from 62.04%, 65.62% and 63.21% to 83.23%, 89.24% and 87.65%, respectively). This study provided theoretical supports for further understanding the effect of cellulose allomorphs on enzymatic hydrolysis. [Display omitted] • Cellulose-II has higher enzymatic hydrolysis efficiency (EHE) and less adsorbed enzyme. • The binding free energy of cellulose-II decreases in molecular docking. • The content of interchain H-bonds of cellulose-II is lower than that of cellulose-I. • The content of gg conformation decreased and gt conformation appeared after mercerization. [ABSTRACT FROM AUTHOR]

Lignin is widely used as an alternative to fossil resources in industrial production. However, its applications are limited due to its wide molecular weight distribution and chemical heterogeneity. In this study, alkali treated lignin (KL) and dilute acid-alkali treated lignin (DAKL) were prepared and compared through analyzing the functional groups, antioxidant and antibacterial activity of lignin. The results showed that DAKL displayed a smaller weight-average molecular weight (756 g/mol) and higher purity (93.74%). Further results showed that high contents of phenolic, syringyl (S), and guaiacyl (G) in DAKL increased its antioxidant activity (IC 50 : 38.5 µg/mL). Furthermore, DAKL exhibited a more excellent antibacterial effect on Staphylococcus aureus (96.71%) and Escherichia coli (100%) due to (1) the presence of several phenolic substances in lignin that damaged and ruptured the bacterial cell membrane, causing leakage of cell contents and bacterial death and (2) small molecule weight of lignin that allow it to penetrate the bacterial cell membrane, changing the physiological conditions of bacterial cell fluid and leading to cell death. [Display omitted] • DAKL produced phenolic hydroxyl groups with antioxidant activity due to β-O-4 bond breaking. • The content of S+G was positively correlated with the antioxidant activity of lignin. • The lignin isolated from sugarcane bagasse had good antibacterial effect. • Smaller Mw and higher antioxidant activity enhanced the antibacterial effect of lignin. [ABSTRACT FROM AUTHOR]

This study aimed to reinforce the barrier performance (i.e., oxygen–gas and water–vapor permeability) of poly(lactic acid) (PLA)-based films. Acetyltributylcitrate and zinc oxide nanoparticle (nano-ZnO), serving as plasticizer and nanofiller, respectively, were blended into a PLA matrix through a solvent-volatilizing method. The structural, morphological, thermal, and mechanical performances were then studied. Scanning electron microscopic images showed a significant dispersion of nano-ZnO in PLA ternary systems with low nano-ZnO content. The interaction between PLA matrix and ZnO nanoparticles was further analyzed by Fourier-transform infrared spectroscopy. Wide-angle X-ray scattering spectroscopy demonstrated high compatibility between PLA matrix and ZnO nanoparticles. Mechanical property studies revealed good tensile strength and low flexibility. Differential scanning calorimetry curves proved that an amorphous structure mostly existed in PLA ternary systems. The improvements in barrier property and tensile strength indicated that the PLA/nano-ZnO composite films could be used for food packaging application. [ABSTRACT FROM AUTHOR]

To study the relationship between performance changes and nanoparticles migration of the composite film at different migration stages, the poly (lactic acid) (PLA)/nano-TiO2 composite film treated by high pressure was immersed in 50% (v/v) ethanol solution for 45 days at 40 °C, and the film characteristics and migration behavior were analyzed. The results showed that the migration of the composite film with the highest loading of nano-TiO2 (20 wt. %) in alcoholic food simulated solution was far less than 10 mg/kg during the 45-day migration process. Although with the increase of migration time, the micro-morphology of composite film became rougher, the crystallinity decreased and the gas permeability increased, but the internal crystal structure of the composite film remained basically unchanged. The PLA/nano-TiO2 composite films treated by high pressure treatment were relatively stable, and had good performance and migration behavior in alcoholic food simulated solution, the nanocomposite film after high pressure treatment could be used to reduce nano-TiO2 particle migration and subsequently reduce human exposure as the packaging film for the packaging of alcoholic food, which provide a theoretical basis for the applications of high pressure treatment of PLA/nano-TiO2 composite films in food packaging material and broaden its application prospects. [ABSTRACT FROM AUTHOR]

The microstructure, thermal properties, mechanical properties and oxygen and water vapor barrier properties of a poly(lactic acid) (PLA)/nano-TiO2 composite film before and after high pressure treatment were studied. Structural analysis showed that the functional group structure of the high pressure treated composite film did not change. It was found that the high pressure treatment did not form new chemical bonds between the nanoparticles and the PLA. The micro-section of the composite film after high pressure treatment became very rough, and the structure was depressed. Through the analysis of thermal and mechanical properties, high pressure treatment can not only increase the strength and stiffness of the composite film, but also increase the crystallinity of the composite film. Through the analysis of barrier properties, it is found that the barrier properties of composite films after high pressure treatment were been improved by the applied high pressure treatment. [ABSTRACT FROM AUTHOR]

Effects of high pressure treatment (0, 200 and 400 MPa) on water vapour barrier, microstructure, thermal, and mechanical properties of poly (lactic acid) (PLA)/Ag nanocomposite films were investigated. The migration behavior of nano-Ag from the nanocomposite films in the presence of 50% (v/v) ethanol as a food simulant was also studied. The water vapour barrier properties increased as pressure was applied to film-forming solutions. High pressure treatment enhanced the mutual effect between PLA and nanoparticles, leading to a more compact network structure in PLA/Ag nanocomposite films. Furthermore, PLA/Ag nanocomposite films treated by high pressure were significantly affected by microstructure, thermal, and mechanical properties when, compared with untreated samples. High pressure treatment at 200 to 400 MPa significantly (p < 0.05) reduced the migration of nano-Ag from the films. Overall, high pressure treatment on film-forming solutions showed potential in improving the functional properties of nanocomposite films, especially in relation to water vapour barrier properties. [ABSTRACT FROM AUTHOR]

Different percentages (0%, 1%, 5%, and 10%) of nano-Ag particles were added to polylactic acid (PLA) to make an active nanocomposite packaging film. Strawberries were packaged by the nanocomposite films and stored at 4 ± 1 °C for 10 days. The freshness of strawberries was assessed by regularly measuring the physicochemical properties of the strawberries in each packaging film. The difference in the freshness of strawberries was evaluated by determining the following parameter changes: weight loss, hardness, soluble solids, titratable acid, color, vitamin C, total phenol, free radical scavenging activity, peroxidase activity, and sensory evaluation. The results revealed that the active nanocomposite packaging film has better preservation effect when compared with pure PLA film. Its preservation effect is mainly reflected in the more effective reduction of vitamin C loss, delaying the decline of total phenols and 1-Diphenyl-2-picrylhydrazyl (DPPH) in strawberries. It also showed better physical properties. The results showed that the PLA nanocomposite packaging film could effectively preserve freshness of strawberries. [ABSTRACT FROM AUTHOR]