Mechanical and water vapor barrier properties of tapioca starch/decolorized hsian-tsao leaf gum films in the presence of plasticizer

Insights into recent innovations in barrier resistance of edible films for food packaging applications

The utilization of biopolymer-based food packaging holds significant promise in aligning with sustainability goals and enhancing food safety by offering a renewable, biodegradable, and safer alternative to traditional synthetic polymers. However, these biopolymer-derived films often exhibit poor barrier and mechanical properties, potentially limiting their commercial viability. Desirable barrier properties, such as moisture and oxygen resistance, are critical for preserving and maintaining the quality of packaged food products. This review comprehensively explores different traditional and advance methodologies employed to access the barrier properties of edible films. Additionally, this review thoroughly examines various approaches aimed at enhancing the barrier properties of edible films, such as the fabrication of multilayer films, the selection of biopolymers for composite films, as well as the integration of plasticizers, crosslinkers, hydrophobic agents, and nanocomposites. Moreover, the influence of process conditions, such as preparation techniques, homogenization, drying conditions, and rheological behavior, on the barrier properties of edible films has been discussed. The review provides valuable insights and knowledge for researchers and industry professionals to advance the use of biopolymer-based packaging materials and contribute to a more sustainable and food-safe future.

Characteristics and comparative analysis of Mesona chinensis Benth chloroplast genome reveals DNA barcode regions for species identification

Mesona chinensis Benth (MCB) is an important medicinal and edible plant in Southern China and Southeast Asian countries. Chloroplast (cp) genome is usually used for plant phylogeny, species identification, and chloroplast genetic engineering. To characterize the cp genome and determine the evolutionary position and perform the genetic diversity analysis of MCB, we sequence and characterize the MCB cp genome. The results show that the cp genome of MCB is a single circular molecule with a length of 152,635 bp. It is a typical quadripartite structure, comprising a large single-copy region (LSC, 83,514 bp) and a small single-copy region (SSC, 17,751 bp) separated by two inverted repeat regions (IRs, 51,370 bp). It encodes 129 unique genes, including 84 protein-coding genes (PCGs), 37 transfer RNAs (tRNAs), and 8 ribosomal RNAs (rRNAs). Altogether 127 simple sequence repeats (SSRs) are identified in the MCB cp genome with 86.61% of mononucleotide repeats. Phylogenetic analysis reveals that MCB is most closely related to Ocimum basilicum based on the whole cp genomes. Several highly divergent regions are found, such as trnH_psbA, rps16_trnQ, trnS_trnG, trnE_trnT, psaA_ycf3, rpl32_trnL, ccsA_ndhD, ndhG_ndhI, and rps15_ycf1, which can be proposed for use as DNA barcode regions. Genetic diversity analysis unveils a relatively narrow genetic basis of MCB germplasm resources. Therefore, the innovative breeding of MCB is very urgent and necessary in future research.

Specific Removal of Nitrite from Lake Urmia Sediments by Biohydrogel Based on Isolated Soy Protein/Tragacanth/Mesoporous Silica Nanoparticles/Lycopene

In this study, a biodegradable biohydrogel based on isolated soy protein/tragacanth containing mesoporous silica nanoparticles and lycopene pigment (ISP/TG/MPS/Lyc) is prepared. The physicochemical characteristics and structure of the biohydrogel are investigated by scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction, and thermal gravimetry analysis (TGA) techniques. Mechanical properties (tensile strength and elongation at break point), antioxidant activity, water solubility, water absorption capacity (WAC), and the humidity content of the biohydrogels are studied. Five optimal biohydrogels including pure ISP, ISP/TG, ISP/MPS, ISP/Lyc, and ISP/TG/MPS/Lyc are used for chemical treatment of Lake Urmia sediments. For this purpose, biochemical oxygen demand (BOD), chemical oxygen demand (COD), nitrate, and nitrite of sediments are examined before and after treatment with biohydrogels. According to the FTIR results, there is only physical interaction between lycopene and isolated soy protein. According to the TGA results, adding silica mesoporous to biohydrogel increases its thermal stability. Tragacanth gum and lycopene pigment reduce water solubility and increase the WAC of biohydrogel. The biohydrogel significantly reduces the BOD and COD of the sediments. The biohydrogel reduces nitrite content up to 90%, while reducing nitrate content by almost 30%. The results show that the biohydrogel containing lycopene selectively purifies nitrite from the sediment solution of Lake Urmia.

Application of different carbohydrates to produce squash puree based edible sheet

The production possibility of squash puree-containing edible sheet and its improvement by different hydrocolloids were studied. In this study, two hydrocolloids [carboxymethyl cellulose (CMC) and tragacanth gum] and also one plasticizer (glycerol) were used to produce squash puree-based edible sheets and optimization was performed to produce an edible sheet sample with the optimum properties. The results revealed that the CMC increased the tensile strength, elongation, and water vapor transition (WVT) of the edible sheets, whilst decreased their moisture content. The tragacanth increased the edible sheets elongation, oxygen transition (OT) and opacity. The glycerol also increased the elongation, density, OT, WVT, opacity and water solubility of the edible sheets; whereas the water activity, tensile strength, elastic modulus, and swelling capacity were decreased. The optimum quality of edible sheets was obtained from a combination of 0.14 g of CMC, 0.25 g of tragacanth and 1.88 g of glycerol.

Antimicrobial activity of carboxymethyl cellulose-gelatin film containing Dianthus barbatus essential oil against aflatoxin-producing molds

Edible films, as novel degradable materials in food packaging, play an important role in removing consumers' concerns about environmental pollution and food contaminations. Carboxymethyl cellulose (CMC)-gelatin (G) edible films with the ratio 4 to 1 was selected as the optimal film based on physical, mechanical, and physicochemical findings. Then, the effects of 0, 300, 450, and 600 ppm Dianthus barbatus essential oil (DbE) on water vapor permeability, tensile strength, elongation at break, water solubility, glass transition temperature, color, oxygen permeability, and antimicrobial activities on the optimal film were investigated. CMC: G (4:1) containing 600 ppm DbE as the antibacterial-antioxidant film was the best formulae (p < .05) for preventing three types of aflatoxin-producing mold including A. flavus (PTCC-5004), A. parasiticus (PTCC-5286), and A. parasiticus (PTCC-5018) on pistachios for 6 months.

Antimicrobial activity of carboxymethyl cellulose-gelatin film containing Dianthus barbatus essential oil against aflatoxin-producing molds

Edible films, as novel degradable materials in food packaging, play an important role in removing consumers' concerns about environmental pollution and food contaminations. Carboxymethyl cellulose (CMC)-gelatin (G) edible films with the ratio 4 to 1 was selected as the optimal film based on physical, mechanical, and physicochemical findings. Then, the effects of 0, 300, 450, and 600 ppm Dianthus barbatus essential oil (DbE) on water vapor permeability, tensile strength, elongation at break, water solubility, glass transition temperature, color, oxygen permeability, and antimicrobial activities on the optimal film were investigated. CMC: G (4:1) containing 600 ppm DbE as the antibacterial-antioxidant film was the best formulae (p < .05) for preventing three types of aflatoxin-producing mold including A. flavus (PTCC-5004), A. parasiticus (PTCC-5286), and A. parasiticus (PTCC-5018) on pistachios for 6 months.

Improving Functional Properties of Cassava Starch-Based Films by Incorporating Xanthan, Gellan, or Pullulan Gums

The effect of the partial substitution of cassava starch in edible films for 10 and 20 wt% of gellan, xanthan, or pullulan gums was analysed in films obtained by casting. The tensile properties, barrier capacity to water vapour, and oxygen and water sorption isotherms of the samples were analysed. The blend of starch with gellan gum was effective to reduce the moisture sorption capacity of starch films while reducing water vapour permeability, enhancing the film strength and resistance to break and preserving films against starch retrogradation throughout the storage time. Xanthan gum improved the tensile behaviour of the starch films, but did not reduce their water sorption capacity and water vapour permeability. Pullulan did not notably improve the functional properties of the starch films. Gellan gum at 10 and 20 wt% in the blend could be used to obtain starch films with more adequate properties for food packaging purposes.

Effect of extrusion process on the functional properties of high amylose corn starch edible films and its application in mango (Mangifera indica L.) cv. Tommy Atkins

Starch is an attractive raw material as ingredient for edible film manufacture because of its low cost, abundant availability, renewability, and biodegradability. Nevertheless, starch based films exhibit several disadvantages such as brittleness and poor mechanical and barrier properties, which restrict its application for food packaging. The use of the extrusion technology as a pretreatment of the casting technique to change the starch structure in order to obtain edible films, may constitute an alternative to generate coatings with good functional properties and maintain longer the postharvest quality and shelf life of fruits. For this reason, the objective of this study was to optimize the conditions of an extrusion process to obtain a formulation of modified starch to elaborate edible films with good functional properties using the casting technique and assess the effect during the storage when applied on a model fruit. The best conditions of the extrusion process and concentration of plasticizers were obtained using response surface methodology. From optimization study, it was found that appropriate conditions to obtain starch edible films with the best mechanical and barrier properties were an extrusion temperature of 100 °C and a screw speed of 120 rpm, while the glycerol content was 16.73%. Also, once applied in fruit, the loss of quality attributes was diminished.

Physical and mechanical properties of a new edible film made of pea starch and guar gum as affected by glycols, sugars and polyols

The influence of different plasticizers (glycols, sugars and polyols) on the moisture sorption, mechanical, physical, optical, and microstructure characteristics of pea starch-guar gum (PSGG) film was studied. All plasticizers formed homogeneous, transparent, and smooth films, while PEG-400 did not produce film with suitable characteristics. Fourier transform infrared (FTIR) spectroscopy results indicated some interaction between plasticizers and the polymers. Scanning electron microscopy (SEM) observations of the films presented surfaces without cracks, breaks, or openings which were indicator of the miscibility and compatibility of employed plasticizers with PSGG films. The results showed that the films containing plasticizers with higher functional groups had lower equilibrium moisture content at aw <0.4. In general, a reduction in tensile strength and Young's modulus and an increase in elongation at break were detected when molecular weight of plasticizers and relative humidity increased in all film formulations. Films plasticized with monosaccharide showed similar mechanical properties to those with sorbitol, but lower solubility and water vapour permeability (WVP), higher transparency and moisture content than the sorbitol-plasticized films. The most noticeable plasticization effect was exerted by following order: glycerol > EG > PG > xylitol > fructose > sorbitol > mannitol > galactose > glucose > sucrose > maltitol.

Effect of replacement of corn starch by whey protein isolate in biodegradable film blends obtained by extrusion

The aim of this study was to evaluate the effect of replacing corn starch by whey protein isolated (WPI) in biodegradable polymer blends developed by extrusion. X-ray diffraction showed the presence of a Vh-type crystalline arrangement. The films were homogeneous, indicating strong interfacial adhesion between the protein and the thermoplastic starch matrix (TPS) as observed in scanning electron microscopy. The addition of WPI on TPS matrix promoted an increase in the thermal stability of the materials. It was observed 58.5% decrease in the water vapor permeability. The effect of corn starch substitution by WPI on mechanical properties resulted in a more resistant and less flexible film when compared the TPS film. The addition of WPI caused greenish yellow color and less transparent films. The substitution of corn starch by WPI made it possible to obtain polymer blends with improved properties and represents an innovation for application as a packaging material.

Synthesis of biodegradable films with antioxidant properties based on cassava starch containing bixin nanocapsules

Biodegradable and active packaging based on cassava starch incorporated bixin nanocapsules with different concentrations were developed. The physical, mechanical, barrier properties and antioxidant activity of the active packaging were studieds. The films incorporated with bixin nanocapsules were found to be homogeneous and thermally stable. Films with higher concentrations of bixin nanocapsules exhibited a significant decrease in tensile strength, water solubility and increase in elongation at break and water vapour permeability, well as, significant improvement in protection against UV and visible light. The films were used to pack sunflower oil under accelerated oxidation conditions (65 % RH/35 °C). Sunflower oil packaged in films with bixin exhibited lower oxidation rates, thus maintaining its freshness according to Codex Alimentarius guidelines (<10 mEq kg^-1). Films containing bixin nanocapsules are very promising materials for use as packaging with antioxidant properties for maintaining food safety and extending the shelf life.

Creep behavior of starch-based nanocomposite films with cellulose nanofibrils

Nanocomposite films were successfully prepared by incorporating cellulose nanofibrils (CNFs) from sugar beet pulp into plasticized starch (PS) at CNFs concentration of 5-20%. The storage (G') and loss (G″) moduli, creep and creep-recovery behavior of these films were studied. The creep behavior of these films at long time frame was studied using time-temperature superposition (TTS). The CNFs were uniformly distributed within these films up to 15% of CNFs. The PS-only and the PS/CNFs nanocomposite films exhibited dominant elastic behavior. The incorporation of CNFs increased both the G' and G″. The CNFs improved the creep resistance and reduced the creep recovery rate of the PS/CNFs nanocomposite films. TTS method was successfully used to predict the creep behavior of these films at longer time frame. Power law and Burgers model were capable (R(2)>0.98) of fitting experimental G' versus angular frequency and creep strain versus time data, respectively.

Use of allyl isothiocyanate and carbon nanotubes in an antimicrobial film to package shredded, cooked chicken meat

We developed antimicrobial packaging incorporated with allyl isothiocyanate (AIT) and carbon nanotube (CNT), and this packaging was used for shredded cooked chicken meat inoculated with Salmonella Choleraesuis. The following parameters were analysed during the 40 days of storage: microbial counts, colour characteristics and changes in the oxidation of the meat as well as changes in the mechanical properties of the film, the structure of the antimicrobial film and the diffusion of the antimicrobial agent into the food. The incorporation of AIT into the films increased the elongation at the break (E) value of the films and decreased the tensile strength (TS) value of the films. The CNT was important to retain the AIT which is a volatile substance in the film. The diffusion of the AIT from the film into the chicken reduced the microbial contamination, controlled oxidation and reduced the colour changes. Thus, these packages were effective for the 40 days of storage.

Design, characterization, and in vitro evaluation of antifungal polymeric films

The objective of the present paper was the development and the full characterization of antifungal films. Econazole nitrate (ECN) was loaded in a polymeric matrix formed by chitosan (CH) and carbopol 971NF (CB). Polyethylene glycol 400 and sorbitol were used as plasticizing agents. The mechanical properties of films were poorer when the drug was loaded, probably because crystals of ENC produces network outages and therefore reduces the polymeric interactions between the polymers. Polymers-ECN and CH-CB interactions were analyzed by Fourier-transform infrared spectroscopy (FTIR), thermal gravimetry analysis, and differential thermal analysis (DTA-TGA). ECN did not show structure alterations when loaded into the films. In scanning electron microphotographs and atomic force microscopy analysis, films prepared with CB showed an evident wrinkle pattern probably due to the strong interactions between the polymers, which were observed by FTIR and DTA-TGA. The in vitro activity of the formulations against Candida krusei and Candida parapsilosis was twice as greater as the commercial cream, probably as a result of the antifungal combination of the drug with the CH activity. All these results suggest that these polymeric films containing ECN are potential candidates in view of alternatives dosages forms for the treatment of the yeast assayed.

Characterization of starch films containing starch nanoparticles. Part 2: viscoelasticity and creep properties

Starch films were successfully produced by incorporating spray dried and vacuum-freeze dried starch nanoparticles. The frequency sweep, creep-recovery behavior and time-temperature superposition (TTS) on these films were studied. All these films exhibited dominant elastic behavior (than viscous behavior) over the entire frequency range (0.1-100 rad/s). The incorporation of both types of starch nanoparticles increased the storage and loss modulus, tanδ, creep strain, creep compliance and creep rate at long time frame and reduced the recovery rate of films while the effect of different kinds of starch nanoparticles on these parameters was similar both in magnitude and trend. TTS method was successfully used to predict long time (over 20 days) creep behavior through the master curves. The addition of these nanoparticles could increase the activation energy parameter used in TTS master curves. Power law and Burger's models were capable of fitting storage and loss modulus (R(2)>0.79) and creep data (R(2)>0.96), respectively.