Starch-based environment friendly, edible and antimicrobial films reinforced with medicinal plants.

Edible films and coatings have received considerable attention in recent years because of their advantages including use as edible packaging materials over synthetic films. This could contribute to the reduction of environmental pollution. Edible films of hydroxy propyl methyl cellulose (HPMC) containing mixtures of glycerol(Gly) and polyethylene glycol (PEG) as plasticizers were prepared by water solution caste technique and evaluated mechanical (tensile strength, elongation at break. burst strength, impact strength and Young's modulus) and barrier properties (water vapor transmission rate and oxygen transmission rate), color and haze properties were measured. Intermolecular interactions between HPMC-glycerol and HPMC-PEG were measured using FT-IR technique. Thermal properties were investigated by differential scanning calorimetry analysis. All these properties were found to be improved with variation of plasticizers concentrations. Practical Applications This work is on food packaging. Polymer films are edible films. These films are eco-friendly and bio-plastics and have good mechanical, barrier and optical properties.

The amyloid fibril-stabilized Pickering emulsion significantly enhances the mechanical and barrier properties of Konjac Glucomannan active films for cherry preservation.

Clove oil as a potent antimicrobial agent was added to enhance the properties of edible films. Clove oil was converted to single and double emulsion emulsions for homogenous dispersion in a starch based edible film suspension. Double emulsion was made with two steps emulsification with CaCl2 as inner water phase and guar gum as outer water phase. Single emulsion was prepared similarly without inner water phase. The physico-chemical characteristics and the antimicrobial activity of the of starch-based edible film added with the emulsion were observed. MBC/MFC of clove oil was determined against E. coli, S. aureus, R. stolonifer, and A. niger which gives value of 1.95, 1.46, 0.52, and 0.35 mg/ml respectively. Incorporation of different emulsions on starch-based edible films affect the properties of resulting edible films by increasing thickness, opacity, elongation at break, water vapor transmission rate, and swelling index. Both emulsions showed comparable physicochemical characteristics such as thickness, WVTR, and swelling index value. However, double emulsion produced more superior edible films in terms of tensile strength and antimicrobial activity. 15% addition of double emulsion were able to show strong antimicrobial activity with inhibition zone of more than 8.0 mm for E. coli and 24.0 mm for R. stolonifer.Keywords: clove oil; edible film; single and double emulsion

Preparation of N-vanillyl chitosan and 4-hydroxybenzyl chitosan and their physico-mechanical, optical, barrier, and antimicrobial properties

Cellulose nanofibrils/nanoclay hybrid composite as a paper coating: Effects of spray time, nanoclay content and corona discharge on barrier and mechanical properties of the coated papers

Effects of plant essential oils and oil compounds on mechanical, barrier and antimicrobial properties of alginate–apple puree edible films

Structural, mechanical, antioxidant and antibacterial properties of soy protein isolate (SPI)-based edible food packaging films as influenced by nanocellulose (NC) and green extracted phenolic compounds from date palm leaves

Rachmawati AK, Anandito RBK, Manuhara GJ. 2010. Extraction and characterization of pectin on green cincau (Premna oblongifolia) in edible film production. Biofarmasi 8: 1-10. The use of green cincau pectin was presumed to influence the result of edible film characteristics, i.e. thickness, solvability, elongation, tensile strength, and water vapour transmission (WVTR). The aims in this research were: (i) to find out the chemical characteristics of green cincau pectin on the physical (thickness and solvability) and mechanical properties (elongation and tensile strength), (ii) to determine the edible film inhibition of green cincau pectin against the water vapour transmission rate, and (iii) to find out the edible film capability in inhibiting the weight loss on green grape by wrapping and coating method. The five major steps in this research were material preparation (making green cincau powder and pectin extraction), the characterization of extraction result pectin, making edible film, edible film characterization, and edible film application. This research used a completely randomized design with twice replications in edible film making for each treatment concentration and twice replication for edible film characteristic testing in each edible film making replication. Variance analysis was used to analyze data, if there was a significant difference, it will be continued with a Duncan Multiple Range Test at a significance level of 0.05. The yield of green cincau powder and pectin were 27.5% and 15.2%, respectively. The extraction result pectin consisted of 5.09% water, 11.06% protein, 0.35% fat, 28.5% ash, 55.00% carbohydrate (by different), and 12.15% crude fiber. The increasing of pectin concentration tends to increase the thickness and tensile strength, but reduced the water vapour transmission rate. The lowest water vapour transmission rate occurred at the edible film with 30% pectin concentration. Its water vapour transmission rate was 0.317 g.mm/m2.hour. The green grape weight loss with a wrapping method was 0.0212 g/hour, and the green grape weight loss with a coating method was 0.0634 g/hour.

Essential oils (EOs) derived from plants are rich sources of volatile terpenoids and phenolic compounds. Such compounds have the potential to inactivate pathogenic bacteria on contact and in the vapor phase. Edible films made from fruits or vegetables containing EOs can be used commercially to protect food against contamination by pathogenic bacteria. EOs from cinnamon, allspice, and clove bud plants are compatible with the sensory characteristics of apple-based edible films. These films could extend product shelf life and reduce risk of pathogen growth on food surfaces. This study evaluated physical properties (water vapor permeability, color, tensile properties) and antimicrobial activities against Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes of allspice, cinnamon, and clove bud oils in apple puree film-forming solutions formulated into edible films at 0.5% to 3% (w/w) concentrations. Antimicrobial activities were determined by 2 independent methods: overlay of the film on top of the bacteria and vapor phase diffusion of the antimicrobial from the film to the bacteria. The antimicrobial activities against the 3 pathogens were in the following order: cinnamon oil > clove bud oil > allspice oil. The antimicrobial films were more effective against L. monocytogenes than against the S. enterica. The oils reduced the viscosity of the apple solutions and increased elongation and darkened the colors of the films. They did not affect water vapor permeability. The results show that apple-based films with allspice, cinnamon, or clove bud oils were active against 3 foodborne pathogens by both direct contact with the bacteria and indirectly by vapors emanating from the films.

The aim of the work was to produce and assess properties of biodegradable antimicrobial films based on potato starch, glycerin and lactic acid as functional additives for food packaging. Films were produced by the casting method from the solution: 2 % (w/v) starch dispersion was gelatinized (70 ± 1 °C, 30 min), glycerin (0.4 %) and lactic acid (1.0 %) were added, the mixture was degased, poured and dried (60 °C, 24 h), and then conditioned (48 h, 23 ± 2 °C). Thickness, mechanical and barrier properties as well as the antimicrobial activity were measured. The antimicrobial activity was determined by the disc diffusion method on the LB nutrient medium with Escherichia coli and Bacillus subtilis as test cultures, 30 µg tetracycline as a positive control and sterile filter paper disc as a negative control (comparison with free lactic acid). The films obtained were optically homogeneous, without macro defects, and had a thickness of 0.09–0.11 mm. Films demonstrated high tensile strength of 74.8 ± 7.4 MPa and elongation of 23.7 ± 4.6 % ( n = 10). Water vapor transmission rate was 1290.7 ± 60.8 g · m –2 · day, vapor permeability coefficient was 2.05 ´ 10 –4 g · m · m –2 · day –1 · Pa –1 (90 % relative humidity of air). With that, in dry conditions (relative humidity of about 0 %), quite low gas permeability in terms of O 2 /CO 2 was recorded (lower than the threshold of the calculation of the stationary permeability). Analysis of the antimicrobial activity by the disc diffusion method showed that the films formed inhibition zones ( E. coli : 10.67 ± 1.53 mm; B. subtilis : 10.67 ± 0.58 mm) that were comparable with free lactic acid (9.67 ± 0.58 and 12.00 ± 1.00 mm, respectively). The combined results confirm that starch films with lactic acid have high barrier properties (in the dry phase) and antimicrobial activity (upon contact with the moist surface), which make them promising for using as active packaging for chilled meat and dairy products and as a functional layer in multi-layer films.

This study focused on the development of high‐performance bio‐based films from chitosan and rice husk nanocellulose, reinforced with either nano‐magnesium oxide (MgO) or neem oil. The films were evaluated for strength, crystallinity, thermal stability, swelling degree, solubility, water vapor transmission rate, moisture retention, apparent density, and antimicrobial and antioxidant activities. Adding nano‐MgO significantly enhanced film crystallinity by 84.9%, increased tensile strength and Young's modulus, and improved thermal stability up to 265°C while reducing swelling and biodegradability (33.07% compared to 35.71% for chitosan‐nanocellulose). The addition of MgO increased surface roughness, which influenced water uptake and barrier properties. However, neem oil improved flexibility, elongation at break (15.29%), antimicrobial activity against E. coli , antioxidant capacity (70.16% DPPH scavenging), and moisture management, but decreased crystallinity and thermal stability. Solubility and swelling behaviors were moderated by the interactions among chitosan, nanocellulose, and the fillers. Apparent density analysis indicated that MgO increased density by filling polymeric spaces, whereas neem oil slightly reduced stiffness without significantly affecting density. The functional properties of chitosan‐nanocellulose films could be tailored through selective incorporation of MgO or neem oil, achieving an optimized balance of mechanical, thermal, barrier, and bioactive performance, making them promising candidates for sustainable and effective food packaging applications.

This paper discusses a new method for development of transparent high barrier biaxially oriented polyethylene terephthalate film via offline coating method. In the present research, a more efficient coating method was employed which reduces the cost of the developed film by 30–35% and minimizes the energy consumption and saves the processing time of the film. Biaxially oriented polyethylene terephthalate film was corona treated or chemically coated during processing thus eliminating one process step. Further, biaxially oriented polyethylene terephthalate film was offline coated by polyvinylidene chloride dispersion for high barrier properties and then laminated with polyethylene. Processing parameters, polyvinylidene chloride coating formulations, and primer type were optimized based on the coating feasibility, laminate bond strength, barrier properties, and ink adhesion properties. Primer coating on biaxially oriented polyethylene terephthalate film substrate offers high laminate bond strength and improved ink adhesion. Polyvinylidene chloride coated biaxially oriented polyethylene terephthalate film has improved barrier properties compared to that of untreated biaxially oriented polyethylene terephthalate film. In polyvinylidene chloride coated biaxially oriented polyethylene terephthalate film, oxygen transmission rate value was observed as 6–7 cc/m2/day and water vapor transmission rate was observed as 3–4 g/m2/day.

Non-degradable packaging materials are doing much damage to the environment. So the interest has been developed in biodegradable films and coatings these days. Use of edible films and coatings is eco-friendly technology used for enhancing the shelf life of the fruits and vegetables. The use of antimicrobial compounds in edible coatings of proteins, starch, cellulose derivatives, chitosan, alginate, fruit puree, and egg albumin has been successfully added to the edible films and coatings. This chapter focuses on the development of edible films and coatings with antimicrobial activity, effect of these coatings on the target microorganisms, the influence of these antimicrobial agents on mechanical & barrier properties and application of antimicrobial edible coatings on the quality of fresh fruits and vegetables.

Synergistic effects of bilayer edible coatings: Protein-based and cocoa butter/linseed oil formulation for enhanced food preservation.

Wheat starch‐based films were formulated by dispersing 4 g starch in distilled water, and plasticized with Gly and PEG in different levels (Gly = 2 and 3 mL/100 mL and PEG = 0.0, 0.2, 0.3 and 0.4 mL/100 mL). The emulsion films were evaluated for mechanical properties, water vapor transmission rate (WVTR). Pistachio kernels packed in wheat starch‐based films, as well as unpacked ones, were placed in the experimental apparatus. Unpacked pistachio kernels were maintained as controls. Peroxide value (PV) and moisture uptake of control (unpacked) and packed pistachio kernels were evaluated for 56 days during storage in ambient temperature (25C). Increasing Gly content of films led to slight increase in Elongation (EL). Increasing the PEG ratio further resulted in an increase in EL for all films. No significant difference in WVTR was observed between films made from mixtures of various proportions of Gly with increasing PEG (addition) at all levels of plasticizer. Maximum moisture uptake was found (6.83 ± 0.08%) in unpacked (control) pistachio kernels, but packaging pistachios in wheat starch films led to minimize moisture uptake. Wheat starch bags reduced the rate of oxidation in pistachio kernels. Incorporation of Gly and PEG in wheat starch films had no significant effect on the PV of packed pistachios. These results suggest that wheat starch‐based films are a viable alternative packaging process for pistachio kernels and improvement of shelf life. PRACTICAL APPLICATIONSThe main advantages of using edible films are extending food shelf life, improving food quality, preventing lipid oxidation in nuts and reducing synthetic packaging materials. There has been a renewed interest in edible and biodegradable films application in food packaging. These films have the potential to replace conventional packaging in some applications. Edible films and coatings derived from polysaccharides have been under intense investigation in recent years.