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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 CSoC180,wo was optimal due to good mechanical, barrier and physicochemical properties. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]