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An intelligent indicator film was prepared with chitosan (CS) and sodium alginate (SA) as film-forming material with added black apple peel anthocyanin (BAA). The effects of different concentrations of BAA on the microstructure, thickness, color, mechanical properties, moisture content, and ultraviolet (UV) transmittance of the composite film were analyzed and compared. In addition, the feasibility of applying the composite film for monitoring shrimp freshness was studied. The results showed that addition of BAA made the components of the composite film interact with each other. BAA was well dispersed in the composite film, which significantly improved the mechanical properties of the composite film, and reduced its water content and UV transmittance. Furthermore, the color of BAA changed from red to yellow in the pH range of 1–14, which showed an obvious respond to pH. The composite film containing 15% BAA was sensitive to pH and thus could be used for monitoring shrimp freshness. On the 5th day of storage at 4 ℃, the total volatile basic nitrogen (TVB-N) content and pH of shrimp exceeded the spoilage threshold, indicating shrimp spoilage, and the color of the film changed from red to dark gray. Therefore, CS-SA composite films can be used as a good carrier for BAA to prepare an intelligent indicator film for shrimp freshness monitoring.

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]

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]

Smart film is widely used in the field of food packaging. The smart film was prepared by adding anthocyanin-rich Robusta coffee peel (RCP) extract into a chitosan (CS)–glycerol (GL) matrix by a solution-casting method. By changing the content of RCP (0, 10%, 15% and 20%) in the CS–GL film, the related performance indicators of CS–GL–RCP films were studied. The results showed that the CS–GL–RCP films had excellent mechanical properties, and CS–GL–RCP15 film maintained the tensile strength (TS) of 16.69 MPa and an elongation-at-break (EAB) of 18.68% with RCP extract. CS–GL–RCP films had the best UV-vis light barrier property at 200–350 nm and the UV transmittance was close to 0. The microstructure observation results showed that CS–GL–RCP films had a dense and uniform cross section, which proved that the RCP extract had good compatibility with the polymer. In addition, the CS–GL–RCP15 film was pH-sensitive and could exhibit different color changes with different pH solutions. So, the CS–GL–RCP15 film was used to detect the fermentation process of pickles at 20 ± 1 °C for 15 days. The pickles were stored in a round pickle container after the boiling water had cooled. The color of the CS–GL–RCP15 film changed significantly, which was consistent with the change of pickles from fresh to mature. The color of the smart film changed significantly with the maturity of pickles, and the difference of ΔE of film increased to 8.89 (15 Days), which can be seen by the naked eye. Therefore, CS–GL–RCP films prepared in this study provided a new strategy for the development of smart packaging materials. [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]

Herbal tea has numerous biological activities and exhibits broad benefits for human health. In China, the flower buds of Lyonia ovalifolia are traditionally processed as herbal tea, namely White Que Zui tea (WQT). This study was aimed to evaluate the effect of ultra-high hydrostatic pressure (UHHP) pretreatment on the chemical constituents and biological activities of free, esterified, and insoluble-bound phenolic fractions from WQT. A total of 327 chemical constituents were identified by a quasi-targeted metabolomics analysis. UHHP pretreatment extremely inhibited reactive oxygen species (ROS) production and cell apoptosis in H2O2-induced HepG2 cells, and it increased the activities of intracellular antioxidant enzymes (SOD and CAT) and GSH content in different phenolic fractions from WQT. In addition, after UHHP pretreatment, the anti-inflammatory effects of different phenolic fractions from WQT were improved by inhibiting the production of nitric oxide (NO) and pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) in LPS-induced RAW264.7 cells. Thus, the UHHP method might be a potential pretreatment strategy for improving the bioavailability of phytochemicals from natural plants. [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]

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]

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]

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]

The plant Sophora tonkinensis, possessed a range of active compounds, was traditionally used in the medicine of Chinese minorities. Endophytic fungi were isolated from this plant, of which the fungus Diaporthe sp. GDG-118 was fermented and extracted with methanol. The extract was screened by antifungal and antibacterial assays leading to the discovery of two new 21-acetoxycytochalasins (1–2) and five known cytochalasins (3–7). These two new compounds were elucidated by spectroscopic analyses, and further their absolute configurations were determined by the X-ray of compound 3 and comparing their experimental CD spectra. The antibacterial and antifungal effects of these compounds were evaluated. Compound 2 showed significant inhibitory activity against Bacillus anthraci and Escherichia coli with MIC value of 12.5 μg/mL, and 7 showed strong antifungal activity against Alternaria oleracea, Pestalotiopsis theae and Colletotrichum capsici with MIC values of 3.125, 1.56 and 1.56 μg/mL, respectively. [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]

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 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]

Two new phthalide derivatives, (-)-3-carboxypropyl-7-hydroxyphthalide (1) and (-)-3-carboxypropyl-7-hydroxyphthalide methyl ester (2), were isolated from the endophytic fungus Penicillium vulpinum isolated from the Chinese medicinal plant Sophora tonkinensis. Their structures were elucidated using spectroscopic methods, mainly on 1D and 2D NMR. Compound 1 exhibited medium antibacterial activities against Bacillus subtilis, Shigella dysenteriae and Enterobacter areogenes with MIC values of 12.5-25 μg/mL, and 2 showed a medium inhibition to E. areogenes with MIC value of 12.5 μg/mL. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) is the most suitable for biodegradable packaging film because of its excellent integrated property, but the poor gas barrier property is its weakness. In this study, a nanocomposite film based on PLA incorporated with 0‐, 1‐, 3‐, 5‐, 10‐, or 15‐wt% nano‐Ag was developed. Effect of multiscale structure on the barrier properties of PLA/nano‐Ag films was studied. The PLA nanocomposite film with 5‐wt% nano‐Ag had the lowest water vapor permeability (WVP) value. Oxygen transmission rate (OTR) value for PLA nanocomposites with 3‐wt% nano‐Ag was found to be the lowest among all the samples. Multiscale structure was demonstrated by the scanning electron microscopy, Fourier transform‐infrared spectroscopy, X‐ray diffraction measurement, and differential scanning calorimetry results. The crystallinity of the PLA phase increased with the content of nano‐Ag in the PLA composites. The evolution of the PLA phase crystallinity could improve the barrier properties of PLA/nano‐Ag composite films for food packaging applications. From the view of multiscale structure, it is better to achieve a balance among short‐range conformation in the amorphous region, long‐range‐ordered structure, and ordered aggregated structure to improve the barrier properties of PLA/nano‐Ag composite films. [ABSTRACT FROM AUTHOR]

A new eremophilane sesquiterpene, xylareremophil (1), together with five known eremophilanes, 1α,10α-epoxy-3α-hydroxyeremophil-7(11)-en-12,8β-olide (2), 1,10α,13-trihydroxyeremophil-7(11)-en-12,8-olide (3), 1α,10α-epoxy-13-hydroxyeremophil-7(11)-en-12,8β-olide (4), mairetolides B (5) and G (6) were isolated from the endophytic fungus Xylaria sp. GDG-102 cultured from Sophora tonkinensis. Their structures were elucidated on the basis of spectroscopic data analysis. The absolute configurations of 1 was determined by comparing computed electronic circular dichroism (ECD) and optical rotation (OR) with experimental results. Compounds 1, 5 and 6 showed antibacterial activities against Proteus vulgaris, Micrococcus luteus, Micrococcus lysodeikticus and Bacillus subtilis with MIC values of 25–100 μg/mL. [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]

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]

The effects of laponite (0, 1, 2, and 3 wt%) on poly(lactic-acid)/poly(trimethylene-carbonate) (PLA/PTMC) composite film properties were studied, and the effects of the use of such composite films on the postharvest quality of mushrooms (Agaricus bisporus) were determined. An increase in the laponite contents enhanced the toughness and water vapor permeability (WVP) of the PLA/PTMC/laponite composite films. The differential scanning calorimetry (DSC) results indicated that the crystallinity of the PLA phase increased by the presence of laponite filler. The PLA/PTMC/laponite composite films reduced the softening of mushrooms, but were not effective at reducing weight loss. The CO2 level inside of the PLA/PTMC/laponite composite films was significantly (p<0.05) lower than those inside of the LDPE film, but the O2 level was similar in all packages. The overall acceptability of mushrooms packed in the PLA/PTMC/L2 and PLA/PTMC/L3 films remained good and within the limits of marketability after 12 d of storage. These results support the applicability of laponite filler in PLA/PTMC blend films and the use of these composite films in the packaging of mushrooms. [ABSTRACT FROM AUTHOR]