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The aim of this work was the activation of biopolymer material based on wild flax cake (Camelina Sativa) with eucalyptus and rosemary essential oils added in different concentrations (0.5%, 1% and 2%). The wild flax cake, left over after the cold pressing of the oil, was used to obtain biopolymer films. To obtain active packaging, essential oils were added to this biopolymer material and the influence of the addition of essential oils on the physico-chemical, mechanical, barrier and biological properties of biopolymer films based on wild flax cake was examined. The obtained results showed the most significant influence on water vapor permeability. The control sample had a water vapor permeability value of 5.43 g/m 2 h, while in the sample with 2% added eucalyptus essential oil, this value was 3.14 g/m 2 h. Antioxidant activity was also confirmed in the control sample without added essential oils (60.10%), but with the addition of 2% eucalyptus essential oil, this value increased to 78.54%. Eucalyptus essential oil proved to be more effective than rosemary oil on the investigated properties of the films. The addition of essential oils to biopolymer films broadens the spectrum of functional properties, including the improvement of mechanical, barrier and biological properties.

In this paper, zein-based films with the addition of shellac were synthesized by lamination on the existing dry zein film (L samples) and by adding shellac alcohol solution during the synthesis of zein film in a ratio of 50-50 by casting process (M samples). Zein films without the addition of shellac were designated as control samples. Physico-chemical (thickness, moisture content and solubility), mechanical (tensile strength and elongation at break) and barrier characteristics (water vapor permeability) were examined for all samples. The resulting films were transparent, glossy, light yellow (control) to ocher (samples with shellac), flexible, and non-sticky. The results showed significantly higher values of elongation at the break of the samples with shellac (11.49% for M and 18.99% for L) compared to the control (7.14%). Significantly lower water vapor permeability values were found, 10.04 g/(m²ꞏh) for L, and 18.41 g/(m²ꞏ h) for M, compared to the control pure zein film (40.33 g/(m² ꞏh)).

This study aimed at investigating the synthesis of biopolymer films based on the Camelina sativa cake, an agricultural waste which remains after cold pressing of the oil from seed. During the film synthesis, three different granulations of the camelina cake were used: the whole cake, fractions with a size of 180-250 µm and fractions smaller than 180 µm. Half of the samples were pre-treated with an ultrasonic bath in order to examine the influence of the native mucilage from the cake on the properties of the obtained films. The biopolymer film samples were tested for mechanical, barrier, physicochemical and structural properties. The obtained films were dark, firm and flexible. Application of mucilage removal pre-treatment contributed to lower tensile strength and higher elongation at break. Significantly lower water vapour permeability was recorded in the samples not pre-treated regarding mucilage removal. A foil with optimal physicochemical characteristics was produced using oilcake with a particle size less than 180 µm, regardless of the pre-treatment application. There were no structural differences or differences in thermal behaviour among the tested samples. Statistical analysis (Z-Score analysis) showed the sample CSoC˂180,wo was optimal due to good mechanical, barrier and physicochemical properties.

The main aim of this research was to apply biopolymer coatings on osmotically dehydrated mushrooms and monitor their quality during storage. Mushrooms were osmotically dehydrated in sugar beet molasses (80% dry matter) under optimized conditions (45 °C for 5 hours), as previously reported elsewhere. Two different biopolymers were chosen: chitosan, a polysaccharide polymer, and zein, a protein polymer. A non-treated mushroom sample was chosen as a control sample. The mushroom samples were analysed for sugar and protein content, as well as water loss and microbiological profile. An increase in sugar content was the most noticeable in the osmotically dehydrated mushrooms compared to the control sample due to the use of molasses as a hypertonic solution. The contribution of used biopolymer coatings to the sugar and protein content of the coated and osmotically treated mushrooms was negligible. Chitosan coating contributed to better storage stability of treated mushrooms by lowering the moisture loss and microbial count. For this reason, chitosan treated sample was chosen for further examination related to the evaluation of its baking potential as a filling in a traditional stuffed pie-like layered bakery product - burek. Burek was stuffed with fresh mushrooms, osmotically treated mushrooms or osmotically treated mushrooms coated with chitosan. The sensorial assessment proved that control burek and burek samples with osmotically dehydrated mushrooms coated with chitosan were the most preferred groups based on odour and overall impression.

Among many important requirements for packaging materials, environmental friendliness is a property that has become necessary for any material that needs to be competitive in the market. Life Cycle Analysis (LCA) is an analytical instrument that provides a framework for analyzing the impact of products and services on the environment, i.e. provides an understanding and the possibility of comparing different products. LCA studies the use of resources and the consequent emissions of pollutants on the environment during the entire life of a product from raw materials exploitation, through production, use and treatment at the end of the life cycle - recycling and final disposal. This paper will provide an overview of the LCA results of various commercial polymer packaging materials, as well as the results of LCAs of biopolymer materials. Although LCA faces the problem of data heterogeneity, since some studies focused on individual segments of the analysis, while some related to all aspects of the process, as well with the problem of interpreting heterogeneous results, because the output parameters were arbitrarily selected by the researcher, still it could be concluded that the available LCA studies and environmental assessments support further development of biobased polymers. When comparing biopolymer materials with commercial synthetic polymers, they have advantages - lower consumption of fossil fuels and lower emission rate of greenhouse gases from the whole life cycle.

Summary: Plum protein isolate obtained from plum cake after oil extraction had protein content over 90% and amino acid composition of 36% which about 13% were essential amino acids. Evaluation of functional properties of conjugates obtained by interaction between plum protein isolate and caffeic acid, in three different concentrations, was carried out in this study. The conjugation of proteins with phenols forms complexes of higher molecular weights as a result of cross‐linking. The solubility of obtained conjugates was increased with the increase a concentration of caffeic acid at alkaline pH (8–10) for about 50%. Moreover, emulsion properties also were improved by conjugation with caffeic acid. In vitro digestion is considered to characterise and understand 'fate' of food components after passing gastrointestinal conditions. The obtained conjugates were digestible and have a good bioavailability of bioactive compounds. [ABSTRACT FROM AUTHOR]

There are many biodegradable and recyclable packaging materials available, alternatives for plastics: paper and cardboard; biodegradable polyethene (degradable due to additives incorporated during production, whose role is to lead to the polyethylene breakdown into CO2, H2O, biomass and minerals when in landfill) and biodegradable plastic (made from renewable biomass-biopolymers in a relatively energy-efficient process). The decomposition routes of degradable materials are reflected in the degradation for which realization a physico-chemical stimulus is required and biodegradation for which microorganisms are responsible. The global biodegradable plastic market was valued at $1.6 billion in 2019 and it is expected to reach $4.2 billion by 2027. The largest segment by application of biodegradable materials is in packaging with a market share of more than 60%. Some examples of degradable packaging existing on the market will be presented in the paper.

Lipid oxidation is a major cause of off-flavors and the loss of nutrients in fat-containing foods and oils. The prevention or retardation of those deteriorative reactions of oil during processing and storage is required. Commercially available synthetic packaging materials are causing serious environmental problems due to their non-degradability. To reduce environmental impacts associated with synthetic plastics, biopolymer materials have a great potential to be used instead. Further, biopolymers play an important role in food preservation because of their antioxidant and antimicrobial activities. The packing system is comprised of natural active materials that can improve the shelf life of oil-packed, minimize oxidation and improve mechanical, barrier and biological properties of biopolymer films. This paper aims to review currently available literature in the field of biopolymer materials application for packaging different types of edible oils.

Biopolymer-based materials present good alternatives for synthetic materials. However, their high water sensitivity may limit their usage for food products packaging. Addition of hydrophobic components into the material formulation could improve this property. In this work 3, 4 and 5 % (v/v) of Satureja montana or Ocimum basilicum essential oil was incorporated into biopolymer films based on pumpkin oil cake. The obtained materials were analyzed regarding mechanical, physicochemical, barrier and structural properties. Incorporation of the essential oils increased the thickness of the pumpkin oil cake film. Significant reductions in moisture sensitivity, related to physicochemical properties and water vapor transmission rate (almost for 30 %), were observed (p < 0.05). Improvement of light barrier properties was also observed so that the visible light transmission was decreased for around 50 % while the UV light transmission was lower than 1 %. The obtained FTIR spectra confirmed the presence of added essential oils in pumpkin oil cake films, as well as their influence on the reduction in the film surface hydrophilicity. However, mechanical properties, tensile strength and elongation at break, decreased significantly (p < 0.05). These results suggest that incorporation of Satureja montana or Ocimum basilicum essential oil improved barrier properties of pumpkin oil cake-based films and reduced the film affinity toward water.

In this work, pumpkin seed oil cake that remains after process of cold pressed oil extraction, was used for the production of composite biopolymer based packaging films. During the production of films, four degrees of filtration were applied. The obtained composite biopolymer films were analyzed for antioxidant activity using three different antioxidant activity assays: the ability to capture free radicals, including •DPPH radical and hydroxyl radical, •OH, as well as reduction power assay of the analyzed films. By comparing the antioxidant activity of the films obtained with different degrees of filtration, it can be concluded that the films obtained by finer filtration (smaller diameter of the filter pore) exhibit greater ability to capture •DPPH radicals, as well as higher reducing power, while the ability to capture hydroxyl radicals showed different trend. Films obtained from the coarser filtered fractions (higher diameter of the filtrate medium) showed greater •OH scavenging ability.

Biopolymer films can be used as packaging materials in the food industry, when they contribute to a better mechanical integrity of packaged foods and act as barrier to various environmental agents. The greatest disadvantage regarding biopolymer films application are poor barrier characteristic, which is a consequence of their high hydrophilicity; their mechanical and physico-chemical properties are considered to be a moderate disadvantage. This paper presents the effects of chemical modifications, such as the addition of hydrophobic components (essential oils), to the properties of biopolymer films. Except that the addition of essential oils significantly affects the mechanical, barrier and physico-chemical properties of biopolymer films, in this way, biopolymer films become active and exhibit antimicrobial and antioxidant action. Changes in the mechanical and barrier properties of various biopolymer films have been observed in particular, with and without the addition of oil in different concentrations.

Active films based on pumpkin oil cake, with 1 % and 2 % of winter savory and basil essential oil, were synthesized in the paper, and the antioxidant activity of the films obtained was subsequently examined. A biopolymer film based on pumpkin oil cake without the addition of essential oils was used as a control. The following methods were used for determining the antioxidant activity of the films: the DPPH radical scavenging activity, the hydroxyl radical scavenging activity and the reducing power assay. The control film showed some antioxidant activity (DPPH radical scavenging activity = 61 %, hydroxyl radical scavenging activity = 33 %, reducing power = 0.534). However, the addition of essential oils increased the antioxidant activity of the films, especially their reducing power, where as the film with 2 % of winter savory essential oil exhibited the highest activity. A slight increase in the DPPH radical and the hydroxyl radical scavenging activities was also observed with the incorporation of essential oils into the experimental films.

Packaging is inseparable retainer of almost all food products. However, most of produced packaging ends as packaging waste after consumption of the product. Increasing amounts of packaging waste that should be managed represents serious challenge of every modern society. There are many different approaches to address this subject, amongst which biodegradable, natural biopolymer-based or even edible packaging holds considerable potential. In this paper, a by-product of edible oil industry, left after completed extraction by cold pressing of oil from hulls of pumpkin seeds, was used to produce biopolymer packaging films. Pumpkin oil cake was used to produce composite bio-based films. Different filtration of film forming suspension was applied in order to test composite film production using different filtration fractions, leading to higher process yield and minimizing waste. In addition, films were casted on surface, about ten times larger comparing to the cast surface typically reported for these types of films in the literature, in order to test the possibility for commercial production and scale up process. Also, casted mass of film forming suspension was varied in order to define minimal casting mass per unit area. Presented results showed that biopolymer films based on the pumpkin oil cake can be successfully produced in sheets (50x35 cm), compared to films earlier produced in the form of discs with diameter 12 cm. Different filtration fractions from initial film forming suspension can be used for film formation, leading to increased production yield. Different filtration fractions lead to different film properties that should be adjusted according to selected application. Casted mass of film forming suspension was successfully decreased (comparing to earlier literature data) without compromising film functional properties and minimal casting mass was defined as 26 g/m2.

In this paper, the application of a biopolymer coating based on chitosan was tested. The optimized coating was formed as a two-layer coating, wherein the first layer (which is in contact with the product) was formed of chitosan with emulsified caraway essential oil as an active component, whereas the second layer was formed of chitosan with the addition of beeswax to optimize the moisture barrier of the coating. As a substrate, the traditional dry fermented sausage Petrovská klobása was selected. The coating was applied to the sausage after drying. During two months of storage under controlled conditions, the influence of the coating on the loss of moisture, the oxidative stability and the sensory characteristic of aroma of the control sausage (without the coating) and sausage with the coating was monitored. The results obtained indicate a significant contribution of the applied dual layer chitosan-based coating to the preservation of the sausage quality parameters analyzed.

The purpose of this paper is the synthesis and characterization of biodegradable composite films based on whole sunflower oil cake, as well as the effect of process parameters (pH and temperature)on the film properties obtained. Films were synthesized at different temperatures (room temperature, 60 °C and 90 °C) and pH values (10 and 12). The film samples obtained were characterized by the mechanical, barrier and physicochemical properties determination. The experimental results showed that the tensile strength values increased with temperature and pH value increments, whereas the sample with the highest elongation at break value was 60 °C/pH12. The water vapour permeability values were uniform (8.62 g/m2h - 11.63 g/m2h), and lower values were recorded in samples synthesized at higher temperatures. The results obtained relative to light transmission were uniform, and the maximum transmission value was reached at 800 nm (24.1- 35.7 %). The values obtained for swelling and solubility parameters are characteristic of the nature of biopolymer films.

Fatty acid composition of Ricotta cheese filled bakery product was examined using a GC-MS method immediately after production and packaging in the case of a control sample, and after production, packaging under air atmosphere in a seven-layer packaging material consisting of PE/Ad/PA/Ad/PE/Ad/PET, and storing during a four weeks period at room temperature, in the case of the experimental samples. The statistical significance of the fatty acid profile change was examined using ANOVA method. The results of this research showed that there are no significant changes of fatty acids composition and content after defined storing period, with the exception of diunsaturated cis,cis-9,12-octadecadienoic (linoleic) acid, whose average content was reduced by 83.705%. However, a small amount of linoleic acid was converted to cis,trans-9,11-octadecadienoic (conjugated linoleic) acid. Therefore, it could be considered as appropriate to pack and storage Ricotta-filled pastry for the period of four weeks, considering the insignificant changes of fatty acid composition and content.

In this work, the possibility of obtaining biopolymer films from Camelina sativa oilseed cake (CSoC) at different parameters of the synthesis process was investigated. The pH (values 8, 10, and 12), the temperature (60, 80, and 100 °C), and the concentration of the cake in the film-forming suspension (3, 4, and 5%) were varied. The films obtained were characterized by studying the mechanical, barrier, physico-chemical, structural, and biological properties (antioxidant and antimicrobial). The results showed moderate mechanical properties, indicating the application of these biopolymer materials as coatings. Low values of water vapor permeability (5.1–12.26 g/m2h) and very low transmission in the UV range (less than 2%) indicate good barrier properties. FTIR analysis confirmed the films' composite structures: peaks related to proteins, polysaccharides, lipids, and cellulose were detected. The biological activity of the obtained CSoC films was pronounced so that they could be used for active packaging. All films have high antioxidant activity, which is more pronounced in samples synthesized at pH 8. The films possess antibacterial properties against S. aureus, while some had an inhibitory effect on S. typhimurium. Standard score analysis showed that the film sample synthetized at pH = 10, temperature = 100 °C, and concentration = 5% had optimal investigated properties. [ABSTRACT FROM AUTHOR]

In this study, three biopolymer films were synthesized: zein (protein), gelatin (protein), and starch (polysaccharide) films and characterized by determining mechanical and physico-chemical properties. Gelatin films proved to be the strongest (tensile strength 84 N/15 mm), while the zein were most flexible (elongation at break 41.6 %). Moisture content was higher in starch films, which is a result of the hydrophilic nature of the polysaccharide films. Swelling degree was 22.5 % for zein, 90.9 % for gelatin, while the highest average value was recorded in starch film samples (840.6 %). Starch films had highest value of solubility degree (36.5 %), while zein film had 27.9 % and gelatin film had 11.85 %.Obtained characterization results are consequences of the different structure of the raw materials and synthesis routes. All undesirable characteristics could be improved by optimizing the composition of the film, as well as synthesis of composite/laminated films.

In this paper, influence of increasing concentrations of beeswax on the antimicrobial activity of chitosan-caraway essential oil biofilm was investigated. Selected microorganisms for the test were Salmonella Typhimurium and Listeria monocytogenes. Reduction of S. Typhimurium and L. monocythogenes viable counts in bacterial suspension in the presence of chitosan films with or without added beeswax amounted over 80 % after 24 h contact time, and over 95 % after 3 h of contact time, respectively and influence of added beeswax on growth reduction was not detected. However, when number of S. Typhimurium viable cells was analyzed (log CFU/ml), it was shown that addition of beeswax led to increased activity of films, especially for the films with 36 kg/m3 and 54 kg/m3of beeswax. When films were transferred, after 24 h in bacterial suspension, onto Petri dishes with nutrient agar and incubated for 24 h on 37°C, results also showed beeswax contribution to growth inhibition of S. Typhimurium.

The purpose of this paper is to improve the properties of biopolymer protein monofilms and produce a novel bilayer biopolymer film on the basis of the monofilms analyzed. Biopolymer monolayer films, based on pumpkin oil cake (PuOC) and zein, and a bilayer film, based on PuOC and zein (PuOC/Zein), were produced as a result of the study. The visual, mechanical, physicochemical and structural properties of the films were evaluated. The results obtained showed that the PuOC film exhibited the highest elongation at break, followed by the bilayer film, whereas the zein film showed the lowest elongation at break. However, the zein film showed the highest tensile strength, followed by the PuOC film. The tensile strength of the bilayer PuOC/Zein film was almost 3 times lower than that of the PuOC film, and almost 4 times lower than that of the zein film. The physicochemical properties recorded indicate that the hydrophobic zein film is the least sensitive to moisture, affecting the moisture sensitivity of PuOC film by reducing the moisture content, swelling and total soluble mater of the bilayer PuOC/Zein film. Based on the FTIR spectra, it could be concluded that there are no significant differences between the two sides of the bilayer PuOC/Zein film. Both sides of the bilayer film examined indicated characteristic peaks for protein biopolymer films in the FTIR spectrum.

Bilayer biodegradable films based on pumpkin oil cake (PuOC) and zein, as well as pouches made from these materials, were prepared, and the changes of their mechanical, physicochemical and barrier properties were analyzed during four weeks of storage. Heat seal quality of formed pouches and composition of the gas atmosphere in the pouches were also monitored. The results showed that the bilayer film had a thickness of 300 ± 10 (μm), and no its changes were observed during the storage time. The tensile strength of the tested film increased slightly in the third week, but the elongation at break showed a decreasing trend during the whole storage period. The decreases in the moisture content, total soluble matter and swelling of the obtained film, were also observed. After one month of storage, the O2 transmission rate of tested films, increased from 27 to 64 (ml/m2 24h 1 bar), and the CO2 gas transmission rate from 147 to 188 (ml/m2 24h 1 bar). The heat seal strength of the PuOC/Zein pouches decreased during the whole storage period. The percentage of O2 in PuOC/Zein pouches increased up to 7 times during the storage period; however, the percentage of CO2 decreased up to 18 times already after one week, and then remained stable in the rest of the storage period. These results are, to a smaller extent, due to the gas transmission rate through the material, especially for CO2 , and to a greater extent, due to the low heat seal strength, which decreased through the storage period, and probably influenced the content of the gases in the pouches.[Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 46010]

The objective of this study was to examine influence of glycerol and guar-xanthan in different concentrations on bi-layer film based on pumpkin oil cake (PuOC) and corn zein, and to find optimal concentrations of these additives which result in film with optimal mechanical and barrier characteristics. Different concentrations of glycerol (30%, 40%, and 50%) as plasticizer and guar-xanthan (0.1%, 0.3%, and 0.5%) as a stabilizer were added in PuOC layer, while zein layer stayed unchanged in all film compositions. Obtained results showed that the optimal mechanical properties had film with the lowest concentration of glycerol (30%) and the highest concentration of guar-xanthan (0.5%). Films showed poor barrier for water vapour, typical for biopolymer-based films. However, all tested films were very good barrier to O2 (transmission rate lower than 50 ml/m2/day at 1 bar). On the other hand, with increase of concentration of added substances, transmission rate of CO2 increased.

Growing consumer demand for the food without chemical preservatives focused significant extent of research in the direction of finding natural compounds that can be used in food preservation. In this context, natural substances with strong antimicrobial and antioxidant properties, like essential oils, as well as natural biopolymers, particularly draw attention. Natural biopolymers can serve as carriers of the active components, such as essential oils in order of their sustained release to the food during storage, and may themselves exhibit activity in protecting foods from oxidation and/or microbial spoilage. Chitosan has been extensively studied as semi-natural polymer with expressed bioactive properties. While antimicrobial activity of chitosan solution in different acids has been confirmed towards different bacteria, yeasts and moulds, reports concerning intensity, underlying machanism and different factors afecting antioxidant activity of chitosan vary through the available literature. This paper presents a review in the field of antioxidative activity of chitosan with different properties, as well as chitosan based biopolymer films in order to clarify this aspect of chitosan bioactivity and confront different reports found in the literature.

This study investigated properties of starch-based edible films with oregano and black cumin essential oil addition. Essential oils addition positively affected film swelling (decreased due to essential oil addition), mechanical properties (tensile strength decreased while elongation at break increased), and water vapor barrier properties (decreased along with essential oils addition). Control film did not have any biological activity, which proves the need for essential oils addition in order to obtain active packaging. Oregano oil was more effective in terms of biological activity. Endothermal peak, above 200°C, represents total thermal degradation of edible films. Diffraction pattern of control film showed significant destruction of A-type crystal structure. Addition of essential oils resulted in peak shape change: diffraction peaks became narrower. Principal Component Analysis has been used to assess the effect of essential oils addition on final starch-based edible films characteristics with the aim to reveal directions for the film characteristics improvement, since the next phase will be optimal film application for food packaging.

The aim of this work was to evaluate the simultaneous effect of glycerol (30%, 40%, 50%) and guar-xanthan gum addition (0.1%, 0.3%, 0.5%) effect on starch based edible film mechanical and barrier properties. According to Response Surface Methodology, the most influential parameter in the second order polynomial models calculation was the percentage of glycerol, while the linear term of guar-xanthan content was important only for second order polynomial model calculation for tensile strength and water vapor permeability. According to Principal Component Analysis, samples grouping along the first component are primarily due to the content of glycerol, which is also confirmed by ANOVA analysis. According Cluster Analysis, two separate clusters are observed on the dendrogram, which includes the right (with the increased value of tensile strength) and the left cluster (with the increased value of elongation break and water vapor permeability). The observed distance the two clusters is considerable (approx. 80). [Projekat Ministarstva nauke Republike Srbije, br. TR-31055: Osmotic dehydration of food - energy and environmental aspects of sustainable production]

The aim of this study was to investigate starch and starch based edible films with and without oregano essential oil addition in terms of crystallinity by using X-ray diffractometry. Starch crystallinity is related to amylopectin linear chains which may give different X-ray diffraction patterns, described as A, B and C chains. Diffraction pattern of starch based edible film without essential oil addition showed broad diffraction peak in 15-20° 2θ region, indicating destruction of A-type crystal structure due to experimental conditions of casting procedure used in this work. Diffraction peaks of samples with 0.5 %, 1 % and 2 % oregano essential oil, whose shapes are to some extent retained after oregano oil addition, were centered at 20.8°, 20.1° and 21.6° 2θ respectively, while pattern of sample with 2% oregano essential oil showed additional diffraction peaks at 31.1°, 35.1°, 38.3°, 44.5° and 64.9° 2θ. X-ray diffraction patterns showed polymorphous nature of investigated starch samples with essential oils addition.

The application of biopolymer films and coating to food products represents a new approach to reduce r migration of moisture, oxygen, carbon dioxide, aromas, and oil in or out of food. Also, biopolymer films, as packaging materials, need to enhance appearance of food and to improve mechanical integrity. In order to facilitate handling and application films must be strong, but flexible enough. Addition of plasticizer could modify the flexibility of biopolymer films. It is known that guar-xanthan can improve the flexibility of polysaccharides films. Therefore, the objective of this study was to examine the influence of guar-xanthan on characteristics of pumpkin oil cake (PuOC) films, with emphasis on the flexibility of the film. Two approaches of guar-xanthan addition in the pumpkin oil cake were applied - stirring with laboratory stirrer and using of ultra turrax homogenizer. The results showed that guar-xanthan improved physical and mechanical properties of PuOC films, but only if film-forming solution was homogenized by ultra turrax. The films with guar-xanthan slightly improved mechanical properties - tensile strength and elongation at break, water content, solubility and swelling properties, but were much easier for handling.

The aim of this study was to evaluate bioactivity of chitosan film with incorporated caraway essential oil by measuring antioxidant and antimicrobial activity. A Fourier transform infrared spectroscopy was used to determine the potential interaction of functional groups of chitosan film and incorporated caraway essential oil. New detected peaks and main shifts in the peaks of chitosan spectra are attributed mainly to presence of s-(+)-carvone and limonene, the main components of caraway essential oil. The antioxidant activity of chitosan film was analyzed by DPPH method. Chitosan film without incorporated caraway essential oil showed the lowest scavenging ability (29.95%, after 24 h). The addition of different concentrations of caraway essential oil into chitosan film significantly enhanced antioxidant activity of pure chitosan film, reaching the maximum of 95%. ASTM E 2149 - 01 method was performed to evaluate the antimicrobial activity of chitosan films. The reduction of bacteria cell number in contact with examined films was tested on Gram-positive bacteria Staphylococcus aureus and Listeria monocytogenes and Gram-negative bacteria Escherichia coli and Salmonella Typhimurium. The most sensitive bacteria was Staphylococcus aureus and the most resistant bacteria was Salmonella Typhimurium for all tested films. These results suggested that incorporation of caraway essential oil into chitosan film significantly improved its antioxidant and antimicrobial activity. The film showed a great potential to be used as an active packaging material.

In order to extend product shelf life while preserving the quality scientific attention focused to biopolymers research that are base for edible films and coatings production. Another major advantage of this kind of food packaging is their eco-friendly status because biopolymers do not cause environmental problems as packaging materials derived from non-renewable energy sources do. Objective of this work was to review recently studied edible films and coatings - their sources, properties and possible application. As sources for edible biopolymers were highlighted polysaccharides, proteins and lipids. The most characteristic subgroups from each large group of compounds were selected and described regarding possible physical and mechanical protection; migration, permeation, and barrier functions. The most important biopolymers characteristic is possibility to act as active substance carriers and to provide controlled release. In order to achieve active packaging functions emulsifiers, antioxidants and antimicrobial agents can also be incorporated into film-forming solutions in order to protect food products from oxidation and microbial spoilage, resulting in quality improvement and enhanced safety. The specific application where edible films and coatings have potential to replace some traditional polymer packaging are explained. It can be concluded that edible films and coatings must be chosen for food packaging purpose according to specific applications, the types of food products, and the major mechanisms of quality deterioration.

The main goal in this work was to investigate the structure of starch based edible films with essential oil addition. Films were obtained from water solution containing starch, polyol, guar-xantan gum modified mixture and essential oil by casting it on a Petri dish. Black cumin essential oil was added in three different concentrations. Starch based edible film without essential oil was used as a control. Physical, mechanical and structural properties are determined: thickness, tensile strength, elongation at break and film structure. FTIR results pointed to quantitative law dependency between amount of essential oil and spectra absorption values. Based on dependency coefficient of correlation was calculated (R2=0.99483).

In this paper, beeswax and caraway essential oil were added as hydrophobic compounds to chitosan film after synthesizing, to improve its water vapor resistance. Influence of these two hydrophobic compounds on visual properties, structure and water content of chitosan film was investigated. Results showed that addition of 1 % of caraway oil, as well as beeswax affected visual properties of the chitosan film, which became yellowish, opaque and turbid. Addition of caraway essential oil did not alter original structure of chitosan film (FTIR ATR technique), while addition of beeswax affected chitosan film structure. Water content in the films decreased with the addition of beeswax. This is a very important change that could be used in chitosan film functionality improvement for packaging application.

In this work, caraway or oregano essential oils were added to the cast chitosan film in an attempt to design a natural, biodegradable, bioactive (antioxidant and antimicrobial) packaging film. When the structure of the tested films was analyzed with Fourier transform infrared spectroscopy, no significant differences were found between the chitosan film with and without essential oils of caraway or oregano. The lowest antioxidant activity, based on the scavenging of the stable DPPH• free radical, was detected for the chitosan film without oil addition, going from 11.64%, after 2.5 h to 28.96%, after 24 h. When the caraway essential oil was added to the chitosan film, the antioxidant activity was increased (p

Present study investigated effects of plasticizer contribution on structural, barrier and mechanical properties of corn starch based edible films. Films were obtained from solutions (containing gelatinized starch, polyol, guar-xantan gum modified mixture and water) by casting it on a Petri dish. Sorbitol acted as a plasticizer and guar-xantan modified mixture had role to enable better film folding and handling. Sorbitol was used in concentrations: 100, 130 and 160% (dry starch basis). The film proved to be strong, moderately flexible with good barrier properties to oxygen and water vapor. It was estimated that oxygen and water vapor permeability increases as plasticizer content in the film increases. Mechanical strength of films decreases due to plasticizer addition.

Chitosan, the second most abundant polysaccharide in nature, after cellulose, has been tested for numerous applications, among which for edible film and coating. Chitosan-based coating showed positive results for shelf life prolongation of meet products. In this paper, dry fermented sausage (Petrovská klobása) was coated with chitosan-caraway film. The effect of coating on the moisture content, color and lipid oxidation was investigated during a fivemonth period of storage. The moisture content decreased rapidly during the storage and the coating did not slow down the loss of moisture. The Lightness (L*) of the sausage surface increased by the coating application, while the redness (a*) and yellowness (b*) did not change. The coated sausages showed a better color stability of the sausage core through the storage time. Also, coated sausage showed a better oxidative stability till the 60th day of storage, while this difference was not detected at the end of the storage period. Apart from slowing down sausage drying during the storage, chitosan-caraway coating was effective in preserving the sausage quality. [Projekat Ministarstva nauke Republike Srbije, br. TR31032]