Use of microencapsulation to improve the stability of probiotics

Use of microencapsulation to improve the stability of probiotics
Mahsa Heidari,¹ Mina Morovati,^2,*
Introduction: Probiotics are living microorganisms that have many health benefits to the host after being consumed [1]. Many studies have emphasized the vital importance of probiotics to health, including increasing metabolism, relieve chronic intestinal inflammation, reducing infections, reducing allergies, reducing lactose intolerance, reducing serum cholesterol levels and having anti-carcinogenic, anti-mutagenic, anti-hypertensive activity and detoxifying several toxins such as aflatoxins in products [2-5]. Lactobacillus sp. and Bifidobacterium sp. are two kinds of probiotics mainly used in functional foods like dairy products [6]. Since these probiotics are very sensitive to processing and storage conditions as well as passing through the gastrointestinal tract, various methods have been proposed to maintain the survival, activity, and stability of probiotics and subsequently maintains their numerous properties. One of these methods is microencapsulation [7-9]. Microencapsulation (ME) involves the separation of active, sensitive, and unstable compounds such as antioxidants, unsaturated fats, vitamins, drugs, flavorings, amino acids, enzymes, living cells such as probiotics from the environment and protected them by a coating layer [10-14]. Benefits of microencapsulation of probiotics The viability of probiotics is affected by various factors such as pH changes like acidification in fermented products, mechanical stress, oxygen toxicity during production, packaging, transporting conditions, and digestive enzymes in the stomach [15-18]. Stabilization and encapsulation of bacteria can protect cells during fermentation and drying, protect against bacteriophage attack, and enhance cell survival in heating and freezing processes [18]. Coating materials One of the most common biopolymers used for microencapsulation of probiotics is alginate, which increases the survival of bacteria during the food production process and protects them from adverse environmental conditions [19]. In addition to alginates, other compounds used to encapsulate probiotics are carbohydrates (such as Gum Arabic, pectin, maltodextrin, modified starch, alginate, agarose, chitosan, pectin, cellulose, carrageenan), proteins, gelatin, and waxes [20-23]. Microencapsulation methods There are not many choices for microencapsulating living cells because bacteria and living cells are not heat resistant [18]. Extrusion, Coextrusion, spray-drying, freeze-drying, and vacuum drying methods are mostly used for microencapsulation of probiotics [24-26]. Other methods of microencapsulation of probiotics are spray-coating, emulsion, and spray-cooling/chilling [27]. Due to the importance of maintaining the function, non-interference in bacterial metabolism, and maintenance of functional ligands, more gentle methods such as extrusion that maintain function and even enhance bacterial function are recommended [20].
Methods: In this study, reviewing various articles on the methods of microencapsulation of probiotics, coating materials, and the benefits of microencapsulation of probiotics in food products, the most important and up-to-date information was collected and presented as a review article.
Results: The results suggest that microencapsulation can enhance the survival, maintenance, activity of probiotics in food products like dairy, fermentation products, etc.
Conclusion: Consumption of probiotics in foods, especially dairy products, is beneficial for human health. Because probiotics are very sensitive to adverse environmental conditions during food processing and storage, as well as after consumption in the internal conditions of the gastrointestinal tract, so many methods have been proposed to stabilize and maintain them. One of these methods is microencapsulation. Microencapsulation of probiotics is performed using various compounds as coating materials. Alginates, agarose, chitosan, pectin, cellulose gelatin, gums, fats, carrageenan are examples of compounds used as coating materials. Also, extrusion, Coextrusion, Spray-drying, freeze-drying, Spray-coating, emulsion, and Spray-cooling/chilling is some of the methods used to microencapsulate these living cells.
Keywords: Probiotics, Microencapsulation, Dairy products, Microencapsulation methods, Coating materials