Biotechnological potential of red yeast isolated from birch forests in Poland.

OBJECTIVES: This study aimed to isolate red yeast from sap, bark and slime exudates collected from Polish birch forests and then assessment of their biotechnological potential. RESULTS: 24 strains of red yeast were isolated from the bark, sap and spring slime fluxes of birch (Betula pendula). Strains belonging to Rhodotorula mucilaginosa (6), Rhodosporidiobolus colostri (4), Cystrofilobasidium capitaum (3), Phaffia rhodozyma (3) and Cystobasidium psychroaquaticum (3) were dominant. The highest efficiency of carotenoid biosynthesis (5.04 mg L-1) was obtained by R. mucilaginosa CMIFS 004, while lipids were most efficiently produced by two strains of P. rhodozyma (5.40 and 5.33 g L-1). The highest amount of exopolysaccharides (3.75 g L-1) was produced by the R. glutinis CMIFS 103. Eleven strains showed lipolytic activity, nine amylolytic activity, and only two proteolytic activity. The presence of biosurfactants was not found. The growth of most species of pathogenic moulds was best inhibited by Rhodotorula yeasts. CONCLUSION: Silver birch is a good natural source for the isolation of new strains of red yeast with wide biotechnological potential.

Comparison of the Chemical Composition and Antioxidant Properties of Propolis from Urban Apiaries.

Bee products from urban apiaries are increasingly used. They are mainly used to promote local apiaries and cities in which they are located. The aim of the study was to compare the chemical composition and antioxidant activity of propolis from 6 Polish apiaries located in cities (Legionowo, Torun, Cracow, Warsaw, Katowice, Lodz). The chemical composition was analyzed using liquid chromatography (HPLC-DAD) and the analysis of antioxidant activity by scavenging free radicals (ABTS and DPPH) and FRAP. The obtained results showed the presence of 24 phenolic compounds in propolis extracts. The tested samples showed differentiation in terms of the content of individual chemical components, however, cinnamic acid and its derivatives were dominant. High antioxidant activity of the tested extracts was demonstrated (ABTS was in the range of 16.80-51.53 mg Te/mL, DPPH was in the range of 7.54-22.13 mg Te/mL, while FRAP reduction was in the range of 10.93-29.55 mg Te/mL). The obtained results compared with literature data on propolis from agricultural areas allow to conclude that propolis samples from both Poland types of areas are similar and can be classified as poplar propolis.

Magnesium Binding by Cyberlindnera jadinii Yeast in Media from Potato Wastewater and Glycerol.

The aim of this study was to determine the magnesium-binding capacity of Cyberlindnera jadinii yeast in media prepared from potato wastewater and glycerol (after biodiesel production), supplemented with magnesium salt. The research was carried out in two stages. In the first, the ability to binding magnesium by yeast in media supplemented with various doses of this element was tested. In the second stage, after selecting the appropriate dose of magnesium, the culture was carried out in a bioreactor. The composition of the yeast biomass was also analysed in terms of lipids and protein content and amino acid composition. Studies have shown that this type of medium can be used as a culture medium for the growth of C. jadinii yeast. In the first stage of the study, the most magnesium (8.97 mg/gd.m.) was bound by yeast cells after 48 h of cultivation in a medium supplemented with the addition of magnesium at a dose of 2 g/L. In the second stage of the research, the highest magnesium content in the biomass (7.9 mg/gd.m.) was noted after 24 h of cultivation in the same medium. The lipid and protein contents in the biomass obtained after 24 h of cultivation in the bioreactor were 6.35 and 43.73%, respectively. The main fatty acids present in the yeast lipids were oleic acid (59.4%) and linoleic acid (8.6%). Analysis of the amino acid profile of the proteins showed the highest proportions were glutamic acid (13.7%) and aspartic acid (11%).

Diversity of Red Yeasts in Various Regions and Environments of Poland and Biotechnological Potential of the Isolated Strains.

Due to the growing demand for natural carotenoids, researchers have been searching for strains that are capable of efficient synthesis of these compounds. This study tested 114 red yeast strains collected from various natural environments and food specimens in Poland. The strains were isolated by their ability to produce red or yellow pigments in rich nutrient media. According to potential industrial significance of the carotenoids, both their total production and share of individual carotenoids (ß-carotene, γ-carotene, torulene, and torularhodin) were analyzed. The total content of carotenoid pigments in the yeast dry matter ranged from 13.88 to 406.50 µg/g, and the percentages of individual carotenoids highly varied among the strains. Most of the yeast isolates synthesized torulene at the highest amount. Among the studied strains, isolates with a total carotenoid content in biomass greater than 200 µg/g and those containing more than 60% torularhodin were selected for identification (48 strains). The identified strains belonged to six genera: Rhodotorula, Sporidiobolus, Sporobolomyces, Buckleyzyma, Cystofilobasidium, and Erythrobasidium. The largest number of isolates belonged to Rhodotorula babjevae (18), Rhodotorula mucilaginosa (7), Sporidiobolus pararoseus (4), and Rhodotorula glutinis (4).

Developments in Plant Proteins Production for Meat and Fish Analogues.

In recent years, there have been significant developments in plant proteins production for meat and fish analogues. Some of the key developments include the use of new plant protein sources such as soy, legumes, grains, potatoes, and seaweed, as well as insect proteins, leaf proteins, mushrooms, and microbial proteins. Furthermore, to improve the technological and functional properties of plant proteins, they can be subjected to traditional and unconventional treatments such as chemical (glycosylation, deamidation, phosphorylation, and acylation), physical (pulsed electric fields, ultrasound, high hydrostatic pressure, dynamic high-pressure treatment, and cold plasma), and biological (fermentation and enzymatic modification). To obtain the high quality and the desired texture of the food product, other ingredients besides proteins, such as water, fat, flavors, binders, dyes, vitamins, minerals, and antioxidants, also have to be used. The final product can be significantly influenced by the matrix composition, variety of ingredients, and water content, with the type of ingredients playing a role in either enhancing or constraining the desired texture of the food. There are several types of technologies used for meat and fish analogues production, including extrusion, shear cell technology, spinning, 3D printing, and others. Overall, the technologies used for meat and fish analogues production are constantly evolving as new innovations are developed and existing methods are improved. These developments have led to the creation of plant-based products that have a similar texture, taste, and nutritional profile to meat and fish, making them more appealing to consumers seeking alternatives to animal-based products.

The Influence of Lactic Acid Fermentation on Selected Properties of Pickled Red, Yellow, and Green Bell Peppers.

Red, yellow, and green peppers are vegetables rich in natural pigments. However, they belong to seasonal vegetables and need to be treated to prolong their shelf life. One new approach to processing vegetables is to pickle them using lactic acid bacteria. The use of such a process creates a new product with high health value, thanks to the active ingredients and lactic acid bacteria. Therefore, this study aimed to evaluate the effect of the applied strain of lactic acid bacteria (LAB) on the chemical properties, including the content of active compounds (pigments) and the physical properties of the peppers. Levilactobacillus brevis, Limosilactobacillus fermentum, and Lactoplantibacillus plantarum were used for fermentation and spontaneous fermentation. The pigments, polyphenols content, and antioxidant properties were determined in the pickled peppers, as well as sugar content, color, dry matter, texture properties, and the count of lactic acid bacteria. In all samples, similar growth of LAB was observed. Significant degradation of chlorophylls into pheophytins was observed after the fermentation process. No significant differences were observed in the parameters tested, depending on the addition of dedicated LAB strains. After the fermentation process, the vitamin C and total polyphenols content is what influenced the antioxidant activity of the samples. It can be stated that the fermentation process changed the red bell pepper samples in the smallest way and the green ones in the highest way.

Antimicrobial and prebiotic activity of mannoproteins isolated from conventional and nonconventional yeast species-the study on selected microorganisms.

Yeast mannoproteins are proposed as a paraprobiotics with antimicrobial and prebiotic properties. They can be used as biopreservatives in food and in diseases therapies. The knowledge about the specificity and/or capability of their influence on the growth of different microorganism is limited. The study determined the effect of mannoprotein preparations of Saccharomyces cerevisiae (S. cerevisiae) ATCC 7090 and nonconventional yeast origin [Metschnikowia reukaufii (M. reukaufii) WLP 4650 and Wickerhamomyces anomalus (W. anomalus) CCY 38-1-13] on the growth of selected bacteria of the genera: Lactobacilllus, Limosilatobacillus, Limosilatobacillus, Bifidobacterium, Staphylococcus, Enterococcus, Pseudomonas, Escherichia, Proteus and Salmonella. The degree of stimulation or growth inhibition of tested bacteria depended on the type and dose of the mannoprotein and the bacterial strain. The addition of the tested preparations in the entire range of applied concentrations had a positive effect especially on the growth of Lactobacillus arabinosus ATCC 8014 and Bifidobacterium animalis subsp. lactis B12. Mannoproteins isolated from S. cerevisiae limited the growth of the Escherichia coli (E. coli) ATCC 25922, Pseudomonas aureoginosa (P. aureoginosa) ATCC 27853, Proteus mirabilis ATCC 35659 and Salmonella Enteritidis ATCC 13076 to the greatest extent, while preparations of M. reukaufii and W. anomalus origin most effectively limited the growth of Staphylococcus aureus strains, E. coli and P. aureoginosa. The growth of Enterococcus faecalis was stimulated by the presence of all studied preparations in most of the concentrations used. Further research will determine how the purification process of studied mannoproteins or oligosaccharide fractions, its structure and composition influence on the growth of selected bacteria and what is the mechanism of its activity.

Characterization and Antifungal Activity of Pullulan Edible Films Enriched with Propolis Extract for Active Packaging.

Active pullulan films with the addition of 3, 5 or 10% propolis extract produced by the casting method were tested in the study. Propolis extracts from Bochnia County, Siedlce County and Elk County (Poland) were used. The appearance of the films was characterized, as well as physical parameters (thickness, moisture content, water solubility), tensile strength (TS), elongation at break (EB), optical characteristics (light transparency, UV barrier, color) and antifungal properties. The antifungal activity of the films was tested by the disc diffusion method against yeast (Candida albicans, C. krusei, Saccharomyces cerevisiae, Rhodotorula mucilaginosa) and mold (Alternaria solani, Fusarium solani, Rhizopus stolonifer, Colletotrichum gloeosporioides, C. cladosporioides, Aspergillus niger, A. ochraceus, Mucor mucedo, Penicillium expansum, P. chrysogenum). The origin of propolis influenced the color and water solubility of the films. The addition of increasing concentrations of propolis extract increased the film thickness and the intensity of the yellow color, extended the water dissolution time of the film and reduced the values of TS and EB. The addition of propolis extract in the pullulan film improved UV radiation protection but decreased light transparency. The antifungal activity increased significantly with the increasing concentration of propolis extract in the film, regardless of the origin of propolis. Molds showed greater sensitivity to pullulan films containing propolis extract than yeasts. In general, films made of pullulan with the addition of propolis extract can be considered as natural active packaging to protect against the growth of fungi in food.

Influence of Fermentation Beetroot Juice Process on the Physico-Chemical Properties of Spray Dried Powder.

Picking vegetables is, along with salting and drying, one of the oldest ways to preserve food in the world. This is the process of decomposition of simple sugars into lactic acid with the participation of lactic bacteria. The aim of the study was to obtain powders from fermented red beet juice with the highest possible amount of lactic acid bacteria (LAB) and active ingredients. For the analysis, juices were squeezed from the vegetables and two types of fermentation were used: a spontaneous fermentation and a dedicated one. After inoculation, samples were taken for analysis on a daily basis. Extract, pH, total acidity, pigments, and color were measured. In addition, microbiological tests were also carried out. The juices from the fifth day of fermentation was also spray dried, to obtain fermented beetroot powder. Juices from 3-5th day were characterized by a high content of LAB and betanin, had also a low pH, which proves that the lactic fermentation is working properly. The exception was the juice from spontaneous fermentation. According to the observations, the fermentation process did not run properly, and further analysis is needed. The powders were stable; however, results obtained from the pigment content and the LAB content are not satisfactory and require further analysis.

Characteristics of the Proteolytic Enzymes Produced by Lactic Acid Bacteria.

Over the past several decades, we have observed a very rapid development in the biotechnological use of lactic acid bacteria (LAB) in various branches of the food industry. All such areas of activity of these bacteria are very important and promise enormous economic and industrial successes. LAB are a numerous group of microorganisms that have the ability to ferment sugars into lactic acid and to produce proteolytic enzymes. LAB proteolytic enzymes play an important role in supplying cells with the nitrogen compounds necessary for their growth. Their nutritional requirements in this regard are very high. Lactic acid bacteria require many free amino acids to grow. The available amount of such compounds in the natural environment is usually small, hence the main function of these enzymes is the hydrolysis of proteins to components absorbed by bacterial cells. Enzymes are synthesized inside bacterial cells and are mostly secreted outside the cell. This type of proteinase remains linked to the cell wall structure by covalent bonds. Thanks to advances in enzymology, it is possible to obtain and design new enzymes and their preparations that can be widely used in various biotechnological processes. This article characterizes the proteolytic activity, describes LAB nitrogen metabolism and details the characteristics of the peptide transport system. Potential applications of proteolytic enzymes in many industries are also presented, including the food industry.

Propionic acid production from apple pomace in bioreactor using Propionibacterium freudenreichii: an economic analysis of the process.

Propionic acid and its salts are widely used as food and feed preservative. Currently, these compounds are chemically produced, which is more profitable compared to biotechnological production using bacteria of the Propionibacterium genus. Appropriate steps can enable reducing the production costs; for example, cheap industrial byproducts can be used as culture media. One such cost-effective raw material is apple pomace, a low-value byproduct from the food industry. It contains sugars such as glucose and fructose which can serve as potential carbon sources for microorganisms. This paper discusses the possibility of using apple pomace in the production of propionic acid and presents an economic analysis of the production process. The tested strain produced 8.01 g/L of propionic acid (yield 0.40 g/g) and 2.29 g/L of acetic acid (yield 0.11 g/g) from apple pomace extract. The economic analysis showed that the production of 1 kg of propionic acid (considering only waste) from 1000 kg of apple pomace would cost approximately 1.25 USD. The manufacturing cost (consumables, including feedstock, labor, and utilities) would be approximately 2.35 USD/kg, and the total cost including taxes would be approximately 3.05 USD/kg. From the economic point of view, it is necessary to improve the production of propionic acid from apple pomace, to increase the yield of fermentation and thus decrease the total production costs. This can be achieved, for example, using industrial byproducts as nitrogen and vitamin sources, instead of high-cost substrates such as yeast extract or peptone. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-020-02582-x.

The Influence of Two-Component Mixtures from Spanish Origanum Oil with Spanish Marjoram Oil or Coriander Oil on Antilisterial Activity and Sensory Quality of a Fresh Cut Vegetable Mixture.

The aim of this study was to evaluate two-component mixtures of essential oils (EOs) in sub-inhibitory concentrations for antilisterial protection of minimally processed vegetables. Spanish origanum oil (SOO), Spanish marjoram oil (SMO) and coriander oil (CO) and a mixture of fresh leafy vegetables with red beet were used. The chemical compositions of selected EOs were analyzed by gas chromatography. Carvacrol was the major component of SOO. The dominant active component of SMO was 1,8-cineole, while the major constituent in CO was linalool. The study shows that essential oils in combination, namely SOO + SMO and SOO + CO in a » MIC + » MIC (Minimal Inhibitory Concentration), have a synergistic effect against L. monocytogenes. The reduction of L. monocytogenes in vegetable mixtures treated by EOs in these selected combinations after 24 h of storage was approximately equal to the limit of detection. Furthermore, it was found that the vegetable mixture treated with SOO + SMO had the highest-rated sensorial quality and could therefore meet consumer expectations.

The Importance of Teachers' Need for Cognition in Their Use of Technology in Mathematics Instruction.

Modern technology offers an increasing number of tools for teaching mathematics, but technology adoption in schools encounters many barriers. The Technology Acceptance Model explains that technology usage is dependent on intentions, which rest on perceived ease of use and perceived usefulness. Less is known about the relationship between intentions and actual behavior. In the current study we show that the level of cognitive investment on the part of the teachers, captured by the construct of Need for Cognition (NC), is crucial in the use of technology in mathematical instruction, while controlling for a variety of background factors. Furthermore NC moderates the relationship between intentions and technology use, such that high NC weakens the relationship between the perceived usefulness of technology in pedagogy and its actual use.

The aspects of microbial biomass use in the utilization of selected waste from the agro-food industry.

Cellular biomass of microorganisms can be effectively used in the treatment of waste from various branches of the agro-food industry. Urbanization processes and economic development, which have been intensifying in recent decades, lead to the degradation of the natural environment. In the first half of the 20th century, problems related to waste management were not as serious and challenging as they are today. The present situation forces the use of modern technologies and the creation of innovative solutions for environmental protection. Waste of industrial origin are difficult to recycle and require a high financial outlay, while the organic waste of animal and plant origins, such as potato wastewater, whey, lignin, and cellulose, is dominant. In this article, we describe the possibilities of using microorganisms for the utilization of various waste products. A solution to reduce the costs of waste disposal is the use of yeast biomass. Management of waste products using yeast biomass has made it possible to generate new metabolites, such as ß-glucans, vitamins, carotenoids, and enzymes, which have a wide range of industrial applications. Exploration and discovery of new areas of applications of yeast, fungal, and bacteria cells can lead to an increase in their effective use in many fields of biotechnology.

Comparison of the antimicrobial activity of propolis extracts obtained by means of various extraction methods.

The objective of the study was to compare the antimicrobial activities of ethanolic propolis extracts obtained using different extraction methods. Extraction of propolis was carried out using 70% ethanol, propolis to ethanol ratios of 1:10 and 1:5, extraction times of 1 or 7 days, and shaking extraction (SE), ultrasound-assisted extraction (UAE), and ultrasound-assisted shaking extraction (SUAE) methods. A total of 12 propolis extract lyophilizates were obtained. Samples were tested for extraction yield and for total phenol content by the Folin-Ciocalteau colourimetric method, and total flavonoid content using a spectrophotometric method. GLC/MS was used for the identification of chemical compounds in selected extract lyophilizates. Antimicrobial activity against selected bacterial and fungal species was assessed using the disk diffusion method. Propolis extracts obtained as the result of 1-day and 7-day shaking extraction followed by 20 min of ultrasound-assisted extraction (SUAE) had better antimicrobial properties as compared to those obtained by SE or UAE alone. SE and UAE gave lower extraction yields as well as lower phenol and flavonoid contents compared to SUAE. No differences were observed with regard to the qualitative composition of extracts obtained by any of the methods. It is best to obtain the extract using the combined method of 1-day extraction and 20-min sonication.

Effect of exogenous stress factors on the biosynthesis of carotenoids and lipids by Rhodotorula yeast strains in media containing agro-industrial waste.

In this study, we aimed to determine the effect of exogenous stress factors (sodium chloride as osmotic stressor, hydrogen peroxide as an inducer of oxidative stress, white light irradiation, and low temperature) on the biosynthesis of carotenoids and lipids by red yeast (Rhodotorula glutinis, R. mucilaginosa, and R. gracilis) during cultivation in media containing potato wastewater and glycerol. According to our results, the yeast were able to grow and biosynthesize lipids and carotenoids in the presence of the applied stress factors. Low temperature caused an increase in the biosynthesis of intracellular lipids and carotenoids. R. gracilis synthesized lipids (21.1 g/100 gd.w.) and carotenoids (360.4 µg/gd.w.) in greater quantities than that of other strains. Under these conditions, there was also an increase in the content of unsaturated fatty acids, especially linoleic and linolenic acids. The highest percentage of polyunsaturated fatty acid (PUFA) (30.4%) was synthesized by the R. gracilis yeast after cultivation at 20°C. Their quantity was 2.5-fold greater than that of the biomass grown in control conditions. The contribution of individual carotenoid fractions depended both on the yeast strain and the culture conditions. Induction of osmotic stress and low temperature intensified the biosynthesis of ß-carotene (up to 73.9% of the total carotenoid content). In oxidative stress conditions, yeast synthesized torulene (up to 82.2%) more efficiently than under other conditions, whereas white light irradiation increased the production of torularhodin (up to 20.0%).

Growth Biocontrol of Foodborne Pathogens and Spoilage Microorganisms of Food by Polish Propolis Extracts.

Propolis is a natural mixture produced by bees from plant resin substances. This study focuses on the general characteristics of five samples of Polish extract propolis originating from agricultural areas. Chemical composition with high performance liquid chromatography‒diode array detector method, total content of flavonoids and polyphenols, and antioxidative activity were determined in the ethanol extracts of propolis (EEP) samples. Minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration (MBC/MFC) and time-kill curves were studied for foodborne pathogens and food spoilage microorganisms. In EEPs the predominant flavonoid compounds were pinocembrin, chrysin, pinobanksin, apigenin, and kaempferol and the predominant phenolic acids were p-coumaric acid, ferulic acid, and caffeic acid. A strong antioxidative action of propolis in vitro was observed (IC50 for DPPH radical was at the level of 0.9-2.1 µg/mL). EEPs had MIC values for bacteria in the range of 1-16 mg/mL, whereas MIC for fungi ranged from 2 to 32 mg/mL. Extract of propolis originating from southern Poland was distinguished by higher content of bioactive components, and stronger antioxidative and antimicrobial activity than EPPs from the remaining areas of Poland. The results indicate the possibility of applying ethanol extracts from Polish propolis to protect food against microbiological spoilage.

The scale-up cultivation of Candida utilis in waste potato juice water with glycerol affects biomass and ß(1,3)/(1,6)-glucan characteristic and yield.

New ideas on production of yeast origin ß-glucan preparations for industrial application are attracting interest considering market development of that high-value functional polysaccharide. Sellecting an efficient yeast producer and designing culture conditions are a prerequisite for obtaining high yield of ß-glucan. The aim of this study was to describe at the first time the influence of the mode of cultivation (shake-flasks and batch fermentation) and time of culture on characteristic and yield of biomass and ß(1,3)/(1,6)-glucan preparations of Candida utilis ATCC 9950 after cultivation in medium based on waste potato juice water supplemented with 10% of glycerol. After shake-flask culture, the biomass was characterized by higher protein content (app. 26.5%) compared to 19% after batch fermentation while the cultivation on a biofermentor scale promoted polysaccharides biosynthesis. The highest output of purified ß(1,3)/(1,6)-glucan preparation (5.3 gd.w./L), containing app. 85% of that polysaccharide, was found after 48 h cultivation in biofermentor. Batch fermentation promoted biosynthesis of alkali-insoluble ß(1,3)/(1,6)-glucan fraction, decreasing the content of ß(1,6)-glucan. The yield of ß(1,3)/(1,6)-glucan synthesis was 0.063 (g/g glycerol), while the productivity of that polysaccharide reached 0.094 (g/L/h). Longer batch fermentation (72 h) resulted in reduction of production efficiency of ß-glucan preparation under studied conditions. The results of the study provide a new efficient biotechnological solution to produce high-value ß-glucan preparations of C. utilis origin based on valorization of agro-waste potato juice water with glycerol.

Modification of the cell wall structure of Saccharomyces cerevisiae strains during cultivation on waste potato juice water and glycerol towards biosynthesis of functional polysaccharides.

Changes in cell wall structure of four strains of Sacccharomyces cerevisiae species (brewer's, baker's and probiotic yeast) after culturing on deproteinated potato juice water (DPJW) with diverse addition of glycerol and different pH were investigated. It allowed to select conditions intensifying biosynthesis of ß(1,3)/(1,6)-glucan and mannoproteins of cell walls of tested strains. Yeast cell wall structural polysaccharides show biological activity and technological usability in food industry but also decide about therapeutic properties of yeast biomass. The highest increase in the thickness of walls (by about 100%) and ß-glucan layer (by about 120%) was stated after cultivation of S. cerevisiae R9 brewer's yeast in DPJW supplemented with 5 and 10% (w/v) of glycerol and pH 7.0 while S. cerevisiae var. boulardi PAN yeast synthesized by ab. 70% thicker ß-glucan layer when the pH of growth medium was equal to 5.0. The cells of brewer's yeast (S. cerevisiae R9), probiotic (S. cerevisiae CNCM 1-745) and baker's (S. cerevisiae 102) intensified the ratio of mannoproteins in the structure of cell walls cultivated in mediums supplemented with above 15% of glycerol what point out the protective action of glycoprotein's under osmotic stress conditions. The study confirms at the first time the possibility of using agro-industrial waste in biosynthesis of functional polysaccharides of S. cerevisiae cell wall. It could be an new advantage in production of yeast biomass with therapeutic properties or ß-glucan preparation as a novel food ingredient.

Effect of Pullulan Coating on Postharvest Quality and Shelf-Life of Highbush Blueberry (Vaccinium corymbosum L.).

Fruits form an important part of a healthy human diet as they contain many ingredients with proven pro-health effects such as vitamins, phenolic compounds, organic acids, fiber, and minerals. The purpose of this work was to evaluate the effect of pullulan coating on the quality and shelf life of highbush blueberry during storage. General appearance, weight loss, dry matter, soluble solid content, reducing sugars, content of L-ascorbic acid, phenolic compounds (total phenolics, phenolics acids and anthocyanins) were determined in uncoated and coated blueberries fruits. The microbiological efficiency of pullulan coating was also evaluated. All parameters were monitored during storage at 4 °C and 16 °C by 28 and 14 days, respectively. The study showed that pullulan coating protects perishable food products especially susceptible to mechanical injury including fruits such as blueberries. Pullulan acts as a barrier that minimizes respiration rate, delaying deterioration and controlling microbial growth.