АннотацияThe present research features a natural polymer that can be used for immobilisation of bifidobacteria as well as a method of immobilisation. We described a modified method of microencapsulation of probiotics using sodi- um alginate. The experiment studied the effect of encapsulation on probiotic stability and involved an in vitro model of human digestive tract. The test sample of microencapsulated Bifi obacterium bifi um 791 showed a decrease in the activity from 3.0×107 to 2.2×105 CFU/ml in a mouse model with pH 1.2. By contrast, the control sample, unprotected by biodegradable polymer microcapsules, demonstrated a higher death rate of bifidobacteria: from 2.6×108 CFU/ml to 5.0×103 CFU/ml. The control sample demonstrated the same downward trend in in vitro gastrointestinal models with pH values of 4.5, 6.8, 7.2, and 5.8. Because the total plate count fell down to 4.0l g CFU/ml in acidity gradients, the titres of the initial microencapsulated biomass had to be increased up to > 109 CFU/ml. According to the results of scanning electron microscopy, the new type of microcapsules obtained by using a resistant starch had a closed sur- face. Prebiotics increased the resistance of bacteria to low pH and bile salts. Bifidobacteria encapsulated with natural biodegradable polymers proved to be well-tolerated and harmless for mice. The experiment revealed that biodegrad- able polymer microcapsules did not cause any chronic or acute toxicity when administered orally at 2×107 CFU per 1 gram of animal mass. The microcapsules demonstrated neither dermonecrotic properties nor any irritant effect on the ocular mucosa and, thus, can be used for food enforcement.
Ключевые словаMicroencapsulation , bifidobacteria , food products , yogurt , sheep milk
The functional food market keeps holding the leading positions around the world as consumers tend to choose products that taste better and provide additional health benefits. Most consumers would like to prevent some diseases and cure the ones they already have. Therefore, they buy products with bioactive supplements that are able to support their health physiologically. It has been scientifically proven that non-microbial and microbial functional products have a therapeutic effect and can be used in preventive medicine. However, these biologically active ingredients are prone to rapid degradation during food processing, storage, and gastrointestinal transit. One of the best ways to prevent the degradation of these non-microbial and microbial bioactive components is to encapsulate them.
Recently, the popularity of functional foodstuffs on the global food market has increased significantly. The turnover of the global functional food market will reach several hundred billion dollars in the nearest future. In addition to the positive effect they exert on human health, functional foods correspond to and satisfy all basic nutritional needs. Functional food products with probiotics and prebiotics have gained significant market share worldwide, especially in Europe, Asia (Japan), Australia, and, more recently, in the United States.
Despite all their fundamental differences, probiotic and prebiotic approaches to functional foods are equally beneficial for gastrointestinal tract (GIT). As a result, a symbiotic approach, i.e. a combination of probiotic and prebiotic approaches, is becoming more and more popular. Therefore, a number of symbiotic products are currently being developed for functional food markets.
Low survival rate of potential probiotics during storage and intestinal passage may limit the positive qualities of food products. Microencapsulation helps reduce the adverse effects on the viability of probiotics in GIT, as well as during food or nutraceutical processing, storage, and consumption. Microencapsulation separates and protects probiotic cells from the environment before their release.
There are various methods of gel microencapsulation that involve polymers: extrusion method, emulsification method, spray drying technology, etc. The main advantage of microencapsulation is in the controlled release of bacteria.
Microencapsulation is the process of enclosing substances in microcapsules, i.e. a material or a mixture of materials covered, or encapsulated, by another material or system. The coated material is called active, or base, material. It can be solid, liquid, or gaseous. The coating material is called shell, wall material, carrier, or encapsulating agent. Microparticles have a multicomponent structure with a diameter of 1–1,000 micrometers . As a rule, microspheres are described as a matrix system where the active ingredient is dispersed/dissolved in a carrier matrix. Microcapsules have, at least, one discrete domain of the active agent, sometimes more (reservoir system) . As a result, every microcapsule consists of a layer of an encapsulating agent that isolates and protects the active substance from any negative impact. Microcapsules can have a regular (spherical, tubular, or oval) or irregular shape .
An analysis of scientific resources resulted in the following list of substances used for microencapsulation of probiotics in food industry: sodium alginate, pectin, chitosan, carrageenan, gelatin, xanthan-gelatin mixture, and cellulose acetyl phthalate. All these substances help mitigate the process of immobilisation, thus, preserving the biological properties of substances and cell integrity. The most common encapsulating material is sodium alginate: it is simple, biocompatible, non-toxic, and cost effective. Alginate is a polysaccharide extracted from algae. It consists of β-d-mannuronic and α-l-guluronic acids. Different amounts and sequential distribution of β-d-mannuronic and α-l-guluronic acids in the chain can affect the functional properties of alginate as an auxiliary material .
If a polymer base is chosen as a shell, it results in the formation of microcapsules of various sizes, as well as in a good packing degree, molecular weight, structure, and shape, which guarantees targeted delivery of viable probiotics into the GIT as a part of food matrix.
When microencapsulating probiotics, one should take into account the chemical nature of coating materials. The use of microencapsulation techniques increases the viability of probiotics, both within food products and during their passage through the GIT. However, coating materials behave differently, and, therefore, their ability to protect living microorganisms and deliver biologically active substances also varies. In addition, the effectiveness of material depends not only on its encapsulating properties and strength, but also on its low cost, availability, and biocompatibility .
Microcapsules are currently applied in food , textile, pharmaceutical [5, 6], cosmetic, and agrochemical  industries. This method allows the producers to improve and/or modify the characteristics and properties of the active material, as well as its protection, stabilisation and slow release.
Microencapsulation can modify the colour, shape, volume, pressure sensitivity, heat sensitivity, and photosensitivity of the encapsulated substance . In addition, microencapsulation:
– protects the base material from ultraviolet rays, moisture, and oxygen;
– increases the shelf life of the volatile compound;
– reduces the rate of evaporation or transfer of active material from the core to the medium;
– prevents chemical reaction; reduces the problems of fine powders’agglomeration;
– improves the processing properties of sticky materials;
– controls the release of substances; and
– reduces toxicity.
Thus, a research in the following spheres seems very promising: immobilizing methods of bifidobacterial cells and their use in the development of enforced dairy products from goat or sheep milk. Microencapsulation of bifidobacteria is important since it allows one to preserve the useful properties of bifidobacteria in foodstuffs. In addition, it helps to protect the viable cells from gastric juice, bile, and other external conditions.
The research objective was to provide a scientific basis for choosing a natural polymer as a method of immobilisation of bifidobacteria; to evaluate their physical and chemical characteristics; to study the process of microencapsulation of probiotics with prebiotics; to study the morphological features of microparticles, formed by natural biodegradable polymer (sodium alginate), using optical and electron microscopy.
- Lam K.H., Cheng S.Y., Lam P.L., et al. Microencapsulation: past, present and future. Minerva Biotecnologica, 2010, vol. 22, no. 1, pp. 23–28.
- Patravale V.B. and Mandawgade S.D. Novel cosmetic delivery systems: an application update. International Journal of Cosmetic Science, 2008, vol. 30, no. 1, pp. 19–33. DOI: https://doi.org/10.1111/j.1468-2494.2008.00416.x.
- Huang H.-J., Chen X.D., and Yuan W.-K. Microencapsulation based on emulsification for producing pharmaceutical products: a literature review. Developments in Chemical Engineering and Mineral Processing, 2006, vol. 14, no. 3–4, pp. 515–544.
- Onwulata C.I. Microencapsulation and functional bioactive food. Journal of Food Processing and Preservation, 2012, vol. 37, pp. 511–532. DOI: https://doi.org/10.1111/j.1745-4549.2012.00680.x.
- Scalia S., Coppi G., and Iannuccelli V. Microencapsulation of a cyclodextrin complex of the UV filter, butyl methoxy- dibenzoylmethane: In vivo skin penetration studies. Journal of Pharmaceutical and Biomedical Analysis, 2011, vol. 54, no. 2, pp. 345–350. DOI: https://doi.org/10.1016/j.jpba.2010.09.018.
- Lam P.-L., Lee K.K.-H., Wong R.S.-M., et al. Development of hydrocortisone succinic acid/and 5-fluorouracil/chi- tosan microcapsules for oral and topical drug deliveries. Bioorganic & Medicinal Chemistry Letters, 2012, vol. 22, no. 9, pp. 3213–3218. DOI: https://doi.org/10.1016/j.bmcl.2012.03.031.
- Alonso M.L., Laza J.M., Alonso R.M., et al. Pesticides microencapsulation. A safe and sustainable industrial process. Journal of Chemical Technology & Biotechnology, 2014, vol. 89, no. 7, pp. 1077–1085. DOI: https://doi.org/10.1002/ jctb.4204.
- Lamprecht A. and Bodmeier R. Microencapsulation. Weinheim: Wiley-VCH Publ., 2012, vol. 23, pp. 157–171.DOI: https://doi.org/10.1002/14356007.a16_575.pub2
- Singh M.N., Hemant K.S.Y., Ram M., and Shivakumar H.G. Microencapsulation: A promising technique for con- trolled drug delivery. Journal Research in pharmaceutical sciences, 2010, vol. 5, no. 2, pp. 65–77.
- Gamez-Garcia M. Fragrance delivery system for surface cleaners and conditioners. Patent, no. WO 2005/041918 A1, 2005.
- Weber H. and Raehse W. Cleaning agent contains fragrance microparticles. HAPPI, 2009, vol. 46, pp. 1–5.
- Xiao Z., Liu W., Zhu G., Zhou R., and Niu Y. A review of the preparation and application of flavour and essential oils microcapsules based on complex coacervation technology. Journal of the Science of Food and Agriculture, 2014, vol. 94, no. 8, pp. 1482–1494. DOI: https://doi.org/10.1002/jsfa.6491.
- Lam P.L. and Gambari R.J. Advanced progress of microencapsulation technologies: In vivo and in vitro models for studying oral and transdermal drug deliveries. Journal of Controlled Release, 2014, vol. 178, no. 1, pp. 25–45. DOI: https://doi.org/10.1016/j.jconrel.2013.12.028.
- Gharsallaoui A., Roudaut G., Chambin O., Voilley A., and Saurel R. Applications of spray-drying in microencapsula- tion of food ingredients: An overview. Food Research International, 2007, vol. 40, no. 9, pp. 1107–1121. DOI: https:// doi.org/10.1016/j.foodres.2007.07.004.
- Bansode S.S., Banarjee S.K., Gaikwad D.D., Jadhav S.L., and Thorat R.M. Microencapsulation: A review. Interna- tional Journal of Pharmaceutical Sciences Review and Research, 2010, vol. 1, no. 2, pp. 38–43.
- McClements D.J., Decker E.A., Park Y., and Weiss J. Structural Design Principles for Delivery of Bioactive Com- ponents in Nutraceuticals and Functional Foods. Critical reviews in food science and nutrition, 2009, vol. 49, no. 6, pp. 577–606. DOI: https://doi.org/10.1080/10408390902841529.
- Sadovoy V.V., Selimov M.A., Slichedrina T.V., and Nagdalian A.A. Usage of biological active supplements in tech- nology of prophilactic meat products. Research Journal of Pharmaceutical, Biological and Chemical Sciences, 2016, vol. 7, no. 5, pp. 1861–1865.
- Barybina L.I., Voblikova T.V., Beloysova E.V., et al. Usage of Vegetable Stuff in Dry Sausage Production. Research Journal of Pharmaceutical, Biological and Chemical Sciences, 2018, vol. 9, no. 4, pp. 1536–1540.
- Krasaekoopt W. and Watcharapoka S. Effect of addition of inulin and galactooligosaccharide on the survival of mi- croencapsulated probiotics in alginate beads coated with chitosan in simulated digestive system, yogurt and fruit juice. LWT – Food Science and Technology, 2014, vol. 57, no. 2, pp. 761–766. DOI: https://doi.org/10.1016/j. lwt.2014.01.037.
- Hassan A., Nawaz M., and Rasco B. Microencapsulation, survival and adherence studies of indigenous probi- otics. African Journal of Microbiology Research, 2014, vol. 8, no. 8, pp. 766–775. DOI: https://doi.org/10.5897/ AJMR2013.6182.
- Burgain J., Gaiani C., Linder M., and Scher J. Encapsulation of probiotic living cells: From laboratory scale to in- dustrial application. Journal of Food Engineering, 2011, vol. 104, no. 4, pp. 467–483. DOI: https://doi.org/10.1016/j. jfoodeng.2010.12.031.
- Mikhaylov P. Meditsinskaya kosmetika. Rukovodstvo [Medical cosmetics. Guide]. Moscow: Meditsina Publ., 1985. 208 p. (In Bul.).