Polyacrylic Acid-Reinforced gelatin hydrogels with enhanced mechanical properties, temperature-responsiveness and antimicrobial activity for smart encryption and salmon freshness monitoring.

Hydrogels hold great potential for use in intelligent packaging, yet they often suffer from limited functionality and inadequate mechanical strength when applied to anticounterfeiting and freshness monitoring. In this study, we present a straightforward method to create a multifunctional hydrogel by in-situ polymerizing acrylic acid (PAA) within a gelatin-Al system. The resulting hydrogels exhibited an elongation at break of over 1200 %, a tensile stress of 1.

Examination of primary aromatic amines content in polylactic acid straws and migration into food simulants using SERS with LC-MS.

Polylactic acid (PLA) straws hold eco-friendly potential; however, residual diisocyanates used to enhance the mechanical strength can generate carcinogenic primary aromatic amines (PAAs), posing health risks. Herein, we present a rapid, comprehensive strategy to detecting PAAs in 18 brands of food-grade PLA straws and assessing their migration into diverse food simulants. Surface-enhanced Raman spectroscopy was conducted to rapidly screen straws for PAAs.

Ammonia-responsive chitosan/polymethacrylamide double network hydrogels with high-stretchability, fatigue resistance and anti-freezing for real-time chicken breast spoilage monitoring.

Hydrogels are a promising option for detecting food spoilage in humid conditions, but current indicators are prone to mechanical flaws, posing a concern for packaging systems that require strong mechanical properties. Herein, a double network hydrogel was prepared by polymerizing methacrylamide in a chitosan system with aluminum chloride and glycerol. The resulting hydrogel demonstrated high stretchability (strain >1500 %), notch insensitivity, excellent fatigue resistance, and exceptional anti-freezing capabilities even at -21 °C.

Extrusion-blown oxidized starch/poly(butylene adipate-co-terephthalate) biodegradable active films with adequate material properties and antimicrobial activities for chilled pork preservation.

Food safety concerns from spoilage and non-degradable packaging risk human health. Progress made in biodegradable plastic films, but limited study on biomass composite films with favorable morphological, mechanical, and inherent antibacterial properties for fresh meat preservation. Herein, we present a versatile packaging film created through the extrusion blowing process, combining oxidized starch (OST) with poly(butylene adipate-co-terephthalate) (PBAT).

Sugarcane Pulp Take-Out Containers Produce More Microparticles in Acidic Foods.

In the current study, the production of microparticles released from fifteen commercial sugarcane pulp (SCP) take-out containers into different food simulants under different conditions was investigated, where deionized water (DI water), 4% acetic acid (4% HAc), and 95% ethanol (95% EtOH) were used to simulate aqueous, acidic, and fatty foods, respectively. Results showed that compared with DI water and 95% EtOH, 4% HAc caused the degradation of sugarcane fibers, thereby releasing the highest number of microparticles. The overall migration values of the sugarcane pulp take-out containers in 4% HAc were above the prescribed limit of 10 mg/dm.

Effect of neutralization treatment on properties of chitosan/bamboo leaf flavonoids/nano-metal oxide composite films and application of films in antioxidation of rapeseed oil.

Neutralization treatment improved the slow-release antioxidant food packaging function of chitosan (CS)/bamboo leaf flavone (BLF)/nano-metal oxides composite films. The film cast from the CS composite solution neutralized by KOH solution had good thermal stability. The elongation at break of the neutralized CS/BLF film was increased by about 5 times, which provided the possibility for its packaging application.

Progress in research on the safety of silicone rubber products in food processing.

Silicone rubber (SR) is widely used in the food processing industry due to its excellent physical and chemical properties. However, due to the differences in SR product production formulas and processes, the quality of commercially available SR products varies greatly, with chemical and biological hazard potentials. Residual chemicals in SR, such as siloxane oligomers and 2,4-dichlorobenzoic acid, are non-intentionally added substances, which may migrate into food during processing so the safe use of SR must be guaranteed.

Chemical contaminants from food contact materials and articles made from or containing wood and bamboo - a review.

Due to recently introduced 'so-called' bio- and plant-based friendly food contact materials and articles (FCM/FCA), some neglected safety issues need to be raised. In this review, potential chemical contaminants from FCM/FCA made from or containing wood and bamboo are presented. Sources, migration, and analytical issues in determining contaminants including intentionally and non-intentionally added substances (IAS and NIAS, respectively) are reviewed.

Method of Setting Environmental Administrative Fine Amounts.

In China, there are currently different degrees of arbitrariness in setting environmental administrative fines, and in many areas the faults are not equal to the penalties. To construct a more reasonable and feasible environmental punishment strategy where violators are fined in accordance with the severity of their actions, we use mathematical models to determine the specific range of environmental administrative fines based on the idea of realizing the appropriate balance between the interest of the violators and those of the public, meanwhile, law enforcement officers are allowed to use their discretion within a certain range. We use an example to prove that the punishment scheme provided by our models can be used to more effectively supervise violators' illegal behaviors than the penalty clause prescribed by law, and through sensitivity analysis and comparison, we prove that the described models are stable and feasible, and provide advantages over the existing methods.

Influence of cooking conditions on the migration of silicone oligomers from silicone rubber baking molds to food simulants.

The stability, surface micromorphology, and volatile organic compounds (VOCs) of silicone rubber baking molds (SRBMs) were tested while using the molds under severe conditions: baking at 175 °C, microwaving at 800 W, and freezing at -18 °C. Moreover, migration tests of SRBMs to food simulants (isooctane, 95% ethanol, and Tenax®) at 70 °C for 2 h (accelerated conditions) were performed. The initial total VOCs concentration was 2.

Molecular dynamics simulation of three plastic additives' diffusion in polyethylene terephthalate.

Accurate diffusion coefficient data of additives in a polymer are of paramount importance for estimating the migration of the additives over time. This paper shows how this diffusion coefficient can be estimated for three plastic additives [2-(2'-hydroxy-5'-methylphenyl) (UV-P), 2,6-di-tert-butyl-4-methylphenol (BHT) and di-(2-ethylhexyl) phthalate (DEHP)] in polyethylene terephthalate (PET) using the molecular dynamics (MD) simulation method. MD simulations were performed at temperatures of 293-433 K.

Migration of copper from nanocopper/LDPE composite films.

Three nanocopper/low-density polyethylene (LDPE) composite films were tested in food simulants (3% acetic acid and 10% ethanol) and real food matrices (rice vinegar, bottled water and Chinese liquor) to explore the behaviours of copper migration using ICP-OES and GFAAS. The effects of exposure time, temperature, nanocopper concentration and contact media on the release of copper from nanocopper/LDPE composite films were studied. It was shown that the migration of copper into 10% ethanol was much less than that into 3% acetic acid at the same conditions.

Influence of factors on release of antimicrobials from antimicrobial packaging materials.

Antimicrobial packaging materials (films or coatings) (APMs) have aroused great interest among the scientists or the experts specialized in material science, food science, packaging engineering, biology and chemistry. APMs have been used to package the food, such as dairy products, poultry, meat (e.g.

Study of the Migration of Stabilizer and Plasticizer from Polyethylene Terephthalate into Food Simulants.

This study investigates the determination and migration of stabilizers and plasticizers from polyethylene terephthalate (PET). Two methods [ultrasonic extraction with dichloromethane or methanol and total dissolution with phenol/tetrachloroethane (m:m/1:1)] for pre-concentration of additives in PET material were performed. The diffusion of these additives from PET was evaluated by immersing in deionized water, acetic acid 3% (w/v), ethanol 20% (v/v), ethanol 50% (v/v) and isooctane at 20, 40, 55 and 70°C, respectively.

Determination of Polymer Additives-Antioxidants, Ultraviolet Stabilizers, Plasticizers and Photoinitiators in Plastic Food Package by Accelerated Solvent Extraction Coupled with High-Performance Liquid Chromatography.

An analytical method for the quantitative determination of 4 antioxidants, 9 ultraviolet (UV) stabilizers, 12 phthalate plasticizers and 2 photoinitiators in plastic food package using accelerated solvent extraction (ASE) coupled with high-performance liquid chromatography-photodiode array detector (HPLC-PDA) has been developed. Parameters affecting the efficiency in the process such as extraction and chromatographic conditions were studied in order to determine operating conditions. The analytical method of ASE-HPLC showed good linearity with good correlation coefficients (R ≥ 0.

Triterpenoid saponins from the rhizome of Polygonatum sibiricum.

Three new triterpenoid saponins, polygonoides C (1), D (2), and E (3), were obtained from the ethanolic extract of the rhizome of Polygonatum sibiricum Redoute. On the basis of NMR and ESI-MS spectra, and chemical evidence, the structures of the three new compounds were elucidated as 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-3β,7β,22β-trihydroxy-oleanolic acid (1), 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-3β,7β,22β-trihydroxy-oleanolic acid methyl ester (2), and 3-O-β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)-[α-L-rhamno-pyranosyl-(1→2)]-β-D-glucopyranosyl-3β,21β-dihydroxy-oleanolic acid 28-O-β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→3)-β-D-glucopyranoside (3).

[Protective effect of extractive of Dioscorea zingiberensis against ischemia/reperfusion injury in cultured neonatal rat cardiomyocytes].

Objective: To define the structure of a water-soluble compound (SY-A) extracted from Dioscorea zingiberensis and investigate its protective effect against the neonatal rat cardiomyocytes ischemia/reperfusion (I/R) injured.

Methods: The SY-A was isolated from Dioscorea zingiberensis by utilizing column chromatograph and its structure was identified by 1H-NMR, 13C-NMR, 135DEPT. Neonatal rat cardiomyocytes were cultured and divided into 5 groups randomly.

[Isolation and structure determination of steroidal saponin from Dioscorea zingiberensis].

To study the chemical constituents of Dioscorea zingiberensis Wright, the EtOH extract of fresh rhizomes of D. zingiberensis was concentrated and partitioned further to produce petroleum ether-, ethylacetate-, n-butanol- and water-soluble fractions. The water-soluble fraction was subjected to column chromatography on macro resin AB-8, and the final products were obtained by repeated reversed-phase ODS and MCI gel CHP 20P column chromatography.

Two new steroidal saponins from the rhizome of Polygonatum sibiricum.

Two new furostanol saponins, polygonoides A (1) and B (2), along with three known compounds, were obtained from the ethanolic extract of the rhizome of Polygonatum sibiricum Redoute. On the basis of acid hydrolysis and comprehensive spectroscopic analyses, the structures of polygonoides A and B were elucidated as (25R)-26-O-beta-D-glucopyranosyl-furost-5,22(23)-dien-3beta,26-diol-3-O-alpha-L-rhamnopyranosyl-(1 --> 3)-beta-D-glucopyranosyl-(1 --> 4)-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (1) and 22 alpha-(propionyloxy)-furost-5-en-3beta,20 alpha-diol-3-O-beta-D-glucopyranosyl-(1 --> 4)-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (2).

[Isolation and structure determination of steroidal saponin from Dioscorea zingiberensis].

To study the chemical constituents of Dioscorea zingiberensis Wright, the EtOH extract of fresh rhizomes of D. zingiberensis was concentrated and partitioned further to produce petroleum ether-, ethylacetate-, n-butanol- and water-soluble fractions. The water-soluble fraction was subjected to column chromatography on macro resin AB-8, and the final products were obtained by repeated reversed-phase ODS and MCI gel CHP 20P column chromatography.