Probiotic Edible Films and Coatings: Concerns, Applications and Future Prospects

A comprehensive review on the utilization of biopolymer hydrogels to encapsulate and protect probiotics in foods

Probiotics must survive in foods and passage through the human mouth, stomach, and small intestine to reach the colon in a viable state and exhibit their beneficial health effects. Probiotic viability can be improved by encapsulating them inside hydrogel-based delivery systems. These systems typically comprise a 3D network of cross-linked polymers that retain large amounts of water within their pores. This study discussed the stability of probiotics and morphology of hydrogel beads after encapsulation, encapsulation efficiency, utilization of natural polymers, and encapsulation mechanisms. Examples of the application of these hydrogel-based delivery systems are then given. These studies show that encapsulation of probiotics in hydrogels can improve their viability, provide favorable conditions in the food matrix, and control their release for efficient colonization in the large intestine. Finally, we highlight areas where future research is required, such as the large-scale production of encapsulated probiotics and the in vivo testing of their efficacy using animal and human studies.

Recent advances in probiotic breads; a market trend in the functional bakery products

Although bread is the main consumed staple food worldwide containing essential micro- and macronutrients, incorporation of probiotics (PRO) into this nondairy product has been less documented. Due to the mechanical and thermal stresses during bread-making process, production of PRO bread (PRO-BR) is dependent on development of emerging strategies like edible coating, encapsulation, three-dimensional printing, and application of thermophilic PRO strains. In the present study, novel technological and formulation aspects of PRO-BR, as well as critical conditions for obtaining products with guaranteed PRO potential have been reviewed. The biological functionality of these products, their scale up, marketing and commercial success factors are also highlighted. Production of functional PRO-BR containing bioactive compounds, phytochemicals and prebiotic components as an emerging field also affects dough rheology and textural features, sensory attributes and shelf-life of the final product. Recent data has revealed the effect of PRO on acrylamide content and staling rate of the produced bread. Furthermore, there are clinical evidences confirming the effects of PRO and synbiotic breads on reduction of triacylglycerol, low-density lipoprotein, insulin level and malondialdehyde, along with the increase of nitric oxide in the patients with type II diabetes.

Edible Packaging as a Functional Carrier of Prebiotics, Probiotics, and Postbiotics to Boost Food Safety, Quality, and Shelf Life

The safety limitations of chemical preservatives led to an increasing trend among industries and customers toward preservative-free foods; hence, the necessity has arisen for developing innovative, safe antimicrobial elements to prolong the shelf life. Beneficial microorganisms that are described as probiotics and also their metabolites are increasingly being considered as bioprotective agents. These microorganisms could be beneficial for extending food shelf-life and boosting human health. During distribution and storage (25 °C or 4 °C), they could contribute to suppressing unwanted microbes and then improving food safety and quality. Also, by tolerating the harsh conditions of gastrointestinal tract (low pH (~3), presence of bile salts, digestive enzymes, competition with other microbes, etc.), probiotics could exert several biological effects at the host. Besides inclusion in foods and supplements, probiotics and their functional metabolites could be delivered via edible packaging (EP). Recent studies have demonstrated the strong potential of pre/pro/post-biotic EP in food biopreservation. These packaging systems may show different potency of food biopreservation. Among others, postbiotics, as metabolic by-products of probiotics, have gained tremendous attention among researchers due to their unique properties like presenting a variety of antimicrobial activities, convenience in use in different industrial stages and commercialization, extended shelf life, and stability in a wide range of pH and temperature. In addition to antimicrobial activities, various bio-EP could differently influence physical or sensorial attributes of food commodities, impacting their acceptance by consumers. Hence, this study is aimed at presenting a comprehensive review of the application of bio-EP, not only by providing a protective barrier against physical damage but also by creating a controlled atmosphere to improve the health and shelf life of food.

Effect of the molecular structure and mechanical properties of plant-based hydrogels in food systems to deliver probiotics: an updated review

Probiotic products' economic value and market popularity have grown over time as more people discover their health advantages and adopt healthier lifestyles. There is a significant societal and cultural interest in these products known as foods or medicines. Products containing probiotics that claim to provide health advantages must maintain a "minimum therapeutic" level (107-106 CFU/g) of bacteria during their entire shelf lives. Since probiotic bacteria are susceptible to degradation and reduction by physical and chemical conditions (including acidity, natural antimicrobial agents, nutrient contents, redox potential, temperature, water activity, the existence of other bacteria, and sensitivity to metabolites), the most challenging problem for a food manufacturer is ensuring probiotic cells' survival and stability enhancement throughout the manufacturing stage. Currently, the use of plant-based hydrogels for improved and targeted probiotic delivery has gained substantial attention as a potential approach to overcoming the mentioned restrictions. To achieve the best possible results from hydrogels, whether used as a coating for encapsulated probiotics (with the goal of stomach protection) or as carriers for direct encapsulation of live microorganisms should be applied kind of procedures that ensure high bacterial survival during hydrogels application. This paper summarizes polysaccharides, proteins, and lipid-based hydrogels as carriers of encapsulated probiotics in delivery systems, reviews their structures, analyzes their advantages and disadvantages, studies their mechanical characteristics, and draws comparisons between them. The discussion then turns to how the criterion affects encapsulation, applications, and future possibilities.

Application of innovative packaging technologies to manage fungi and mycotoxin contamination in agricultural products: Current status, challenges, and perspectives

The consumer demand for safe, "healthy," and premium foods, preferably with an extended shelf-life; demand for easy packaging; and choice for more sustainable food packaging have contributed to the development of novel packaging technologies. The application of adequate packaging materials has recently become a major post-harvest challenge concerning the control of fungi and mycotoxin. This review will describe the current antifungal packaging technology involved to prevent the contamination of fungi and mycotoxin, along with the characteristics and mechanism of action in food products. Antifungal packaging has incredible potential in the food packaging sector. The most suitable approach for the safe storage of agricultural produce for farmers is the hermetic packaging technology, which maintains quality while providing a good barrier against fungi and mycotoxin. Furthermore, active antifungal packaging is a viable method for incorporating antifungal agents against pathogenic fungi. Essential oils and organic acid have received more scientific attention due to their increased efficacy against mold growth. Polypeptides, chitosan, and natamycin incorporated in active packaging significantly reduced fungi. Even though nanotechnological advancements in antifungal packaging are promising, safety and regulation issues remain significant concerns.

Current Advances on the Development and Application of Probiotic-Loaded Edible Films and Coatings for the Bioprotection of Fresh and Minimally Processed Fruit and Vegetables

The application of probiotics has emerged as an innovative bioprotection technology to preserve fresh and minimally processed fruit and vegetables. This review discusses the most recent advances on the development and application of probiotic-loaded edible films/coatings as a strategy to preserve fresh or minimally processed fruit and vegetables. Available studies have shown a variety of materials, including hydrocolloids (polysaccharides and proteins) and lipids, used alone or in combination to formulate edible films/coatings loaded with probiotics. Plasticizers and surfactants are usually required to formulate these edible films/coatings. The reported antimicrobial effects of probiotic-loaded edible films/coating and quality parameters of coated fruit and vegetables could vary according to the characteristics of the materials used in their formulation, loaded probiotic strain and its dose. The antimicrobial effects of these films/coatings could be linked to the action of various metabolites produced by embedded probiotic cells with inhibitory effects on microorganisms contaminating fruit and vegetable surfaces. The implication of the use of probiotic-loaded edible films/coatings should be their antimicrobial effects against pathogenic and spoilage microorganisms and efficacy to control the ripening of fruit and vegetables, helping the coated products to maintain their safety, quality, nutritional and functional characteristics for a more prolonged storage period.

Development and characterization of probiotic mucilage based edible films for the preservation of fruits and vegetables

There is growing interest among the public and scientific community toward the use of probiotics to potentially restore the composition of the gut microbiome. With the aim of preparing eco-friendly probiotic edible films, we explored the addition of probiotics to the seed mucilage films of quince, flax, and basil. These mucilages are natural and compatible blends of different polysaccharides that have demonstrated medical benefits. All three seed mucilage films exhibited high moisture retention regardless of the presence of probiotics, which is needed to help preserve the moisture/freshness of food. Films from flax and quince mucilage were found to be more thermally stable and mechanically robust with higher elastic moduli and elongation at break than basil mucilage films. These films effectively protected fruits against UV light, maintaining the probiotics viability and inactivation rate during storage. Coated fruits and vegetables retained their freshness longer than uncoated produce, while quince-based probiotic films showed the best mechanical, physical, morphological and bacterial viability. This is the first report of the development, characterization and production of 100% natural mucilage-based probiotic edible coatings with enhanced barrier properties for food preservation applications containing probiotics.

Characterization and Cell Viability of Probiotic/Prebiotics Film Based on Duck Feet Gelatin: A Novel Poultry Gelatin as a Suitable Matrix for Probiotics

The probiotic viability, physicochemical, mechanical, barrier, and microstructure properties of synbiotic edible films (SEFs) based on duck feet gelatin (DFG) were evaluated. Four synbiotic systems were obtained by mixing four types of prebiotics, namely, dextrin, polydextrose, gum Arabic, and sago starch, with DFG to immobilize of probiotic (Lactobacillus casei ATCC). The ability of DFG to create a suitable matrix to increase probiotic viability was compared with those of other commercial gelatins in a preliminary evaluation. The DFG showed proper probiotic viability compared with other gelatins. The addition of prebiotics reduced the transparency of SEFs and increased color differentiation, uniformity, and complete coverage of probiotic cells. The estimated shelf-life of surviving bacteria in the SEFs stored at 4 and 25 °C showed that gum arabic showed the best performance and enhanced the viability of L. casei by 42% and 45%, respectively. Dextrin, polydextrose, and sago starch enhanced the viability of L. casei at 4 and 25 °C by 26% and 35%, 26% and 5%, and 20% and 5%, respectively. The prebiotics improved the physicochemical, mechanical, and barrier properties of all SEFs, except polydextrose film. The viability of L. casei can be increased with the proper selection of gelatin and prebiotics.

Edible films and coatings: properties for the selection of the components, evolution through composites and nanomaterials, and safety issues

Edible films and coatings, despite their practical applications, have only entered the food industry in the last decade. Their main functions are to protect the food products from mechanical damage and from physical, chemical and microbiological deteriorative changes. The ingredients used for their formation are polysaccharides, proteins and lipids, in individual or combined formulations. The edible films and coatings have already been applied on various food products, such as fruits, vegetables, meat products, seafood products, cheese, baked products and deep fat fried products. The techniques for their application on foods are of particular interest. Nowadays, composite edible films and coatings are also being studied, based on combinations of the properties of individual components. In addition to conventional materials, new ones, such as nanomaterials, are being investigated, aiming to enhance the resulting properties. However, before the incorporation of new materials to films and coatings, they must be thoroughly checked according to the legislation, to assure their lawful use. This review covers the recent developments on the edible films and coatings area in terms of the contribution of novel constituting materials to the improvement of their properties.

Edible packaging: Sustainable solutions and novel trends in food packaging

Novel food packaging techniques are an important area of research to promote food quality and safety. There is a trend towards environmentally sustainable and edible forms of packaging. Edible packaging typically uses sustainable, biodegradable material that is applied as a consumable wrapping or coating around the food, which generates no waste. Numerous studies have recently investigated the importance of edible materials as an added value to packaged foods. Nanotechnology has emerged as a promising method to provide use of bioactives, antimicrobials, vitamins, antioxidants and nutrients to potentially increase the functionality of edible packaging. It can act as edible dispensers of food ingredients as encapsulants, nanofibers, nanoparticles and nanoemulsions. In this way, edible packaging serves as an active form of packaging. It plays an important role in packaged foods by desirably interacting with the food and providing technological functions such as releasing scavenging compounds (antimicrobials and antioxidants), and removing harmful gasses such as oxygen and water vapour which all can decrease products quality and shelf life. Active packaging can also contribute to maintaining the nutritive profile of packaged foods. In this review, authors present the latest information on new technological advances in edible food packaging, their novel applications and provide examples of recent studies where edible packaging possesses also an active role.