Optimization of antimicrobial nanocomposite films based on carboxymethyl cellulose incorporating chitosan nanofibers and Guggul gum polysaccharide.

The present study utilized response surface methodology (RSM) to investigate the impact of varying concentrations of carboxymethyl cellulose (CMC: 0.75-1.75 wt%), Commiphora mukul polysaccharide (CMP: 0-1 wt%), and Chitosan Nanofiber (CHNF: 0-1 wt%) on the physical and antimicrobial characteristics of nanocomposite films based on CMC. The optimization process aimed to enhance ultimate tensile strength (UTS), strain at break (SAB), and antibacterial activity, while minimizing water vapor permeability (WVP), solubility, swelling, moisture content, opacity, and total color difference (ΔE). The results revealed that both CMP and CHNF had a positive influence on reducing moisture content, WVP, and increasing UTS. However, higher concentrations of CMP and CHNF had a divergent effect on SAB, ΔE, and swelling. The incorporation of CMP led to increased opacity and solubility, while the inclusion of CHNF resulted in decreased opacity and solubility. Notably, only CHNF addition significantly improved the antibacterial properties of the films. By applying the optimization procedure utilizing RSM, the formulation containing CMC (1.5 wt%), CMP (0.25 wt%), and CHNF (0.75 wt%) demonstrated superior physical, mechanical, and antibacterial properties in the biodegradable film matrix. These findings highlight the potential of utilizing these components to enhance the performance of CMC-based nanocomposite films.

Optimization of Antibacterial, Physical and Mechanical Properties of Novel Chitosan/Olibanum Gum Film for Food Packaging Application.

Chitosan-based films are promising active biodegradable materials with the ability to be enhanced by different materials, including gums. This study aims to optimize the physical (transmittance, water vapor permeability and water solubility), mechanical (tensile strength and elongation at break) and antibacterial (against Staphylococcus aureus and Salmonella Typhimurium) properties of newly fabricated chitosan/olibanum gum (CH/OG) films as a function of different levels of CH (0.5, 0.75, 1, 1.25 and 1.5% w/v) and OG (0.125, 0.25, 0.375, 0.5 and 0.625% w/v), using response surface methodology (RSM). Moreover, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and differential scanning calorimetry (DSC) were used to better characterize the fabricated films. RSM analysis results showed the significant fitting of all dependent variable responses to the quadratic polynomial model. To attain the desirable physical, mechanical and antibacterial responses, the optimal concentrations were 1.31% (w/v) CH and 0.3% (w/v) OG. The encouraging antibacterial, physical and mechanical properties of the developed composites support the application of chitosan/gum blends in active food packaging, particularly for perishable foodstuffs, such as meat and horticultural products.

Development of Antibacterial Biocomposites Based on Poly(lactic acid) with Spice Essential Oil (Pimpinella anisum) for Food Applications.

Among the main biodegradable food packaging materials, poly-lactic acid (PLA) is a commercially successful polymer used notably in the food packaging industry. In this study, active PLA films containing different percentage of anise essential oil (AE) (0, 0.5, 1 and 1.5% v/v) were developed, and characterized by physical, mechanical and antibacterial analysis. Based on physical examinations, thermal stability of PLA/AE films was greater than the neat PLA film, and the minimum water vapor permeability (WVP) was recorded for PLA/0.5AE film (1.29 × 10 11 g/m s), while maximum WVP was observed for PLA/1.5AE (2.09 × 1011 g/m s). Moreover, the lightness and yellowness of the composites were decreased by the addition of AE. For the PLA composites with 1.5% AE, the tensile strength decreased by 35% and the elongation break increased by 28.09%, comparing to the pure PLA. According to the antibacterial analysis, the minimum inhibitory concentrations of PLA/AE film were 5 to 100 mg/mL and the active composite could create visible inhibition zones of 14.2 to 19.2 mm. Furthermore, the films containing AE inhibited L. monocytogenes and V. parahaemolyticus in a concentration-dependent manner. The confirmation of the success of the incorporation of EOs into the PLA films was further evaluated using principal component analysis, where positive results were obtained. In this context, our findings suggest the significant potency of AE to be used as an antibacterial agent in active food packaging.

Incorporation of nanoencapsulated garlic essential oil into edible films: A novel approach for extending shelf life of vacuum-packed sausages.

The efficacy of chitosan (CH) and whey protein (WP) films impregnated with garlic essential oil (GEO, 2% v/v) or nanoencapsulated GEO (NGEO, 2% v/v) to extend the shelf life of refrigerated vacuum-packed sausages were assessed and compared during 50 days. The primary evaluation of GEO and NGEO showed that GEO had a considerable amount of active compounds diallyl sulfide derivatives (~67%) and the mean size and zeta potential of NGEO were 101 nm and -7.27 mV, respectively. Based on the microbiological and lipid stability analysis of the sausages, all active films retarded lipid oxidation and the growth of main spoilage bacterial groups compared to the control, and CH film containing NGEO exhibited the best result with the peroxide value, thiobarbituric acid reactive substances and aerobic plate count of 0.37 (meq/kg lipid), 0.47 (mg malondialdehyde/kg) and 3.69 (log CFU/g), respectively, on day 50. The nanoencapsulation of GEO made no significant differences in the sensory properties comparing to free-GEO samples (P < .05).

Compliance with OIE animal welfare standards in slaughterhouses in Tehran Province, Iran: An introductory survey.

World Organization for Animal Health (OIE) recommends member countries to comply with global standards of animal welfare. The present study was conducted to reveal the compliance of animal welfare standards in slaughterhouses in Tehran province (Iran). The following three major parameters were evaluated through direct observation, study of plant records, and interviewing slaughterhouse staff across all 14 operative animal slaughterhouses in Tehran province: (1) employing trained and committed workers; (2) appropriate environment and proper design parameter; and (3) proper construction, equipment, and tools. Only 30% of modern slaughterhouses employed trained personnel for handling livestock in an appropriate way, which reaches zero for traditional slaughterhouses. Regarding electrical stunning application for sheep, animal welfare quality was significantly greater in modern slaughterhouses than in the traditional ones (P < 0.05). Out of nine slaughterhouses with unloading platforms and animal lairage, 55% and 35.7% were found to comply with standards, respectively. Concerning lairage parameters and entrance hall, modern plants stood higher compared to traditional slaughterhouses (P > 0.05). It is recommended training courses for involved veterinarians and slaughterhouse staff along with upgrading slaughterhouse construction.

Gas barrier enhancement of uncharged apolar polymeric films by self-assembling stratified nano-composite films.

The gas (O2 and CO2) permeability of an innovative stratified PE-organoclay (LLDPE/OMMT) nano-enabled composite films was studied for the first time and related to the self-assembly process driven by hydrophobic interactions. An 84.4% and a 70% reduction (i.e. a barrier improvement factor of about 6, sufficient for food packaging applications) were observed respectively in the oxygen and carbon dioxide permeability of the 5 bilayers coated film compared to the substrate, while only incorporating 2.4 v/v% of organoclay in the composite and increasing the thickness by 17.7%. Such drastic effect with so low amount of organoclays cannot be achieved by conventional melt blending/exfoliation of the clays into the polymer matrix and is due to a geometrical blocking effect of a brick-wall and compact layer structure of the impermeable clay tactoids. Mathematical prediction of oxygen barrier performance of PE/OMMT films has revealed that 12 bilayers would be necessary to further achieve a barrier improvement factor of 10.

Antimicrobial evaluation of novel poly-lactic acid based nanocomposites incorporated with bioactive compounds in-vitro and in refrigerated vacuum-packed cooked sausages.

Biodegradability and antimicrobial activity of food packaging materials are among the most attractive parameters in modern food industries. In order to develop biodegradable poly-lactic acid (PLA) film to antibacterial nanocomposites, different concentration of Zataria multiflora Bioss. essential oil (ZME), propolis ethanolic extract (PEE) and cellulose nanofiber (CNF) were incorporated to the polymer by solvent casting method. The resulting films were characterized by mechanical and physical tests and their antimicrobial application was evaluated in-vitro against four common foodborne pathogens and in vacuum-packed cooked sausages during refrigerated storage. Mechanical examination revealed that addition of ZME and PEE made films more flexible and incorporation of CNF improved almost all mechanical parameters tested. Moreover, according to physical analysis, incorporation of 0.5% v/v ZME to the composite primary solutions improved water vapor permeability of the resulting films. Almost all of the active films were effective against the tested bacteria except for PLA/PEE films, and maximum antibacterial effects recorded for the films containing both ZME and PEE. Based on the microbiological and sensory evaluation of the sausages, all of the PLA/1%ZME/PEE composites increased the shelf life to >40days. The results indicate that incorporation of natural antimicrobial substances such as ZME and PEE to packaging material could be an interesting approach in development of active packaging material without significant negative effect on polymer technical properties.