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Microencapsulation in food science and biotechnology
Filomena Nazzaro1, Pierangelo Orlando2, Florinda Fratianni1 and
Raffaele Coppola1
Microencapsulation can represent an excellent example of
microtechnologies applied to food science and biotechnology.
Microencapsulation can be successfully applied to entrap
natural compounds, like essential oils or vegetal extracts
containing polyphenols with well known antimicrobial
properties to be used in food packaging. Microencapsulation
preserves lactic acid bacteria, both starters and probiotics, in
food and during the passage through the gastrointestinal tract,
and may contribute to the development of new functional
foods.
Addresses
1
Istituto di Scienze dell’Alimentazione, ISA-CNR, Via Roma 64, 83100,
Avellino, Italy
2
Istituto di Biochimica delle Proteine, IBP-CNR, Via P. Castellino, 121,
80134, Napoli, Italy
Corresponding author: Nazzaro, Filomena ([email protected])
Current Opinion in Biotechnology 2012, 23:182–186
This review comes from a themed issue on
Food biotechnology
Edited by Gabriella Gazzani and Michael Grusak
Available online 22nd October 2011
0958-1669/$ – see front matter
# 2011 Elsevier Ltd. All rights reserved.
DOI 10.1016/j.copbio.2011.10.001
Microencapsulation: principles and use with
natural ingredients
Microencapsulation (ME) is the envelopment of small
solid particles, liquid droplets or gases in a coating
(1–1000 mm). In general, one can differentiate between
mononuclear capsules, which have one core enveloped by
a shell, and aggregates, which have many cores embedded
in a matrix, usually polymers (Figure 1). The development of a successful encapsulation system for a target
application is based on the need of a good knowledge
about the stability of the chosen component, biomolecules or cells, to be encapsulated (core), the properties of
the materials used for encapsulation (encapsulant matrix)
and the suitability of the delivery system (microcapsule)
for its ultimate application [1]. The most available technologies for microencapsulation use a liquid (complex
coacervation, interfacial and in situ polymerization or
solvent evaporation from emulsions) or a gas as suspending medium (spray-drying or spray-cooling, fluidized-bed
coating or co-extrusion) [2]. ME has an evident impact on
the food industry. In food science and biotechnology, it
Current Opinion in Biotechnology 2012, 23:182–186
involves the incorporation of natural ingredients, polyphenols, volatile additives, enzymes, bacteria (i.e. lactic
acid bacteria acting as starters or probiotics) in small
capsules, giving them the chance to be stable, protected
and preserved against nutritional and health loss and to
eventually act as antimicrobial agents. The matrices in
contact with food are generally natural components, but
mainly they must be Generally Recognised As Safe
(GRAS) for human health.
Microencapsulation of bioactive components is performed through use of different materials, for example
water and oil. A usual water-oil-water emulsion is formed
with small water droplets, dispersed in large oil droplets,
themselves dispersed in an outer aqueous phase. The
functional component can be encapsulated within the
inner phase, the oil phase or the outer water phase after
drying; thus, a single delivery system can contain multiple
functional components.
Micro-emulsions, with droplets sizes less than 500 nm
diameter, are produced by micro-fluidization or micelle
formation techniques. ME can be successfully applied to
entrap natural compounds, like essential oils (EOs) or
vegetal extracts containing polyphenols with well known
antimicrobial properties. This aspect represents an
important starting point for industries, which can try
out new natural and safe materials or systems of packaging capable to prolong the shelf life of foods, such as
highly perishable fresh foods (vegetables, fruits, meat,
etc.), without lessening their characteristics in terms of
quality and hygiene. ME can be considered as a real
resource for food packaging also to mask unpleasant
flavors and odors, or to supply barriers between the
sensitive bioactive materials and the environment
(represented by food or oxygen). Many of the EOs have
antimicrobial properties against several foodborne pathogens and can be potentially used in different food
matrices, including meat products [3,4]. However, limits
to their use are linked to the aroma that can be unpleasant
for consumers, or having poor water solubility and
volatility.
Encapsulation makes it possible to increase the effectiveness of EOs and to decrease their sensory impact on
foods. Microencapsulation of EOs is generally achieved in
two steps. Firstly, an emulsion of the volatile compound is
made in an aqueous dispersion of a wall material which
also functions as the emulsifier. Then, the microencapsulated emulsion must be dried under controlled conditions so as to diminish the loss of the encapsulated
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Microencapsulation in food science Nazzaro et al. 183
Figure 1
Figure 2
Rosemary extract
entrappedin PVA
Polyphenols
Negative
control
re
co
Ou
te
rm
at
Pure
Rosemary
extract
rix
Current Opinion in Biotechnology
Current Opinion in Biotechnology
Example of a multilayer matrix used to entrap polyphenols.
material by volatilization [5]. Encapsulation of rosemary
EO has proven to have a more effective antimicrobial
activity than rosemary EO alone against L. monocytogenes
in pork liver sausage [6]. Eugenol and carvacrol encapsulated in micelles of non-ionic surfactant are highly effective against L. monocytogenes and E. coli O157: H7, thanks
to the greater amount of antimicrobial compound exposed
to the surface of the bacteria when presented in this form
[7,8]. Microencapsulated EOs also have been successfully assessed against E. coli O157:H7 inoculated in
refrigerated, chopped beef packed under nitrogen [9].
Polyphenols play a well known essential role in food
quality and safety, as well as for human health. In food
science, their stabilization could be improved using
encapsulation and spray drying, which could protect them
against oxygen, water or any condition that could affect
their stability [10]. Different encapsulating agents are
used for spray drying: polysaccharides (starch, maltodextrins, corn syrups and gum arabic), lipids (stearic acid,
mono and diglycerides), and proteins (gelatin, casein,
milk serum, soy and wheat) [11]. Maltodextrins, the
most common used materials for ME, are obtained by
an acidic hydrolysis of several starches (corn, potato or
others). In general, maltodextrins have high solubility in
water, low viscosity, bland flavor and colorless solutions
[11]. An interesting possible encapsulation agent is inulin, which owing to its nutritive and prebiotic properties
[12,13] would also render ME as helpful in the ideation
and development of functional foods.
The limited range of suitable encapsulant materials
allowed for food use is still the main challenge in material
selection, especially when more complex properties are
required by food manufacturers and consumers. New
generations of encapsulating systems are continuously
emerging for food applications. Polyvinyl alcohol (PVA)
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Antimicrobial activity exhibited by rosemary extract at different
percentage entrapped in PVA, against the toxinogenic strain E. coli DSM
8579. No activity was observed using only PVA matrix (negative control)
or only the pure form of rosemary extract at the same amount (from A.
Ottombrino, F. Fratianni and F. Nazzaro, Biomicroworld 2011).
might be one of the most promising materials. PVA, a
highly polar, nontoxic, water-soluble synthetic polymer
prepared by the hydrolysis of polyvinyl acetate, is used in
polymer blends with natural polymeric materials.
Furthermore it is utilized for a variety of biomedical
applications [14], because of its inherent non-toxicity,
non-carcinogenicity, good biocompatibility and desirable
physical properties, in addition to excellent film forming
properties. PVA has been recently used to entrap a hydroalcoholic extract obtained from rosemary that is used as an
antimicrobial agent against different foodborne pathogens like E. coli [14,15] (Figure 2). The excellent results
suggest its suitability of use in food packaging, to prolong
the shelf life of highly perishable fresh foods, thereby
enhancing their quality and safety (Nazzaro et al., unpublished data).
Microencapsulation of bacteria
In food biotechnology, ME can be also used to entrap or
enclose microorganisms by segregating them from the
external environment with a coating of hydrocolloids,
such that the cells are released in the appropriate gut
compartment at the right time. The technology protects
lactic acid bacteria (LAB) in food and during the passage
through the gastrointestinal tract [16,17,18,19,20]; other
advantages include prevention of interfacial inactivation,
stimulation of production and excretion of secondary
metabolites, and continuous utilization. Additionally,
ME may enhance microbial survival and operating efficiency during fermentation [21]. Generally, LAB present
two sets of problems: their size, which immediately
excludes nanotechnologies, and the fact that they must
be kept alive [22]. Viability of encapsulated cells is
Current Opinion in Biotechnology 2012, 23:182–186
184 Food biotechnology
affected by the physico-chemical properties of the capsules: type and concentration of the coating material,
particle size, initial cell numbers and bacterial strains
are some of the parameters to be considered [23].
The main purpose of probiotic encapsulation is to protect
cells against an unfavourable environment, and to allow
their release in a viable and metabolically active state in
the intestine [24]. Microparticles should be water-insoluble to maintain their structural integrity in the food
matrix and in the upper part of the GI tract; above all,
particle properties should allow progressive liberation of
the cells during the intestinal phase [24,25]. For ME of
microorganisms, the most used polymers (all natural,
inexpensive, biocompatible and GRAS) are chitosan
(obtained from arthropods), alginate (a polymer
extracted from seaweed), carrageenan, whey proteins,
pectin, poly-l-lysine, and starch. Different types of starch
and modified starches have been tested as entrapping
agents of probiotics [26]; unfortunately, in some cases,
the low pH and the presence of proteases, two of the
conditions commonly experienced by probiotic organisms during their passage through the stomach, diminish
their adhesion to starch [27]. Resistant starch is not
degraded by the pancreatic amylase and arrives at the
intestine in an indigestible form. This provides a good
release of bacterial cells in the large intestine and offers
them prebiotic functionality [28]. The materials are
used alone (monolayer) or in combination: in this last
case, coating the microcapsules with an additional film
can avoid their exposure to oxygen during storage and can
enhance their stability at low pH. For example, one of the
most common double (or triple) layer strategy is
represented by an inner layer of alginate, containing
the entrapped microorganisms, then covered by a monolayer of chitosan that might be eventually contained in a
further outer layer of alginate, chitosan or other polymer
[29–31]. Chitosan-coated alginate beads give better protection in simulated gastric conditions than other outer
coating films [27,32].
Different techniques are used in microencapsulation of
probiotics: coacervation, emulsion, extrusion, spray-drying, and gel-particle technologies (including spray-chilling). Coacervation is a fluid–fluid phase separation of an
aqueous polymeric solution, where a change in pH
enables the formation of the shell by the polymer complex. Microcapsules are then dried by spray-drying or
freeze-drying [33,34]. When using the emulsion technique [35], the encapsulating material is added to the
bacterial cells; then, the mixture is suspended in an oil
bath containing Tween 80 (acting as emulsifier). The
emulsion is then broken by adding CaCl2 and microcapsules are collected by centrifugation. For extrusion, probiotics are added to a hydrocolloid solution, then the
solution is dripped through a syringe needle or nozzle
[27], which influences the size of microcapsules.
Current Opinion in Biotechnology 2012, 23:182–186
Spray drying involves atomization of a suspension of
probiotics and carrier material into a drying gas, giving
rise to a rapid evaporation of water. Spray-drying preconditions the cells so that they can be better stressadapted to subsequent environmentally adverse conditions, such as high temperatures, acidic environment,
or presence of bile salts. However, despite these advantages, the high temperatures needed to facilitate water
evaporation also lower the viability of the probiotics and
reduce their activity in the final product.
Spray chilling involves the dispersion of the core material
into a warm coating material and the subsequent spraying
through a heated nozzle into a controlled environment,
where the encapsulant solidifies to form the microcapsule
particles [27]. The process is performed in equipment
similar to that used in spray drying except that the process
air is not heated.
Sometimes, microcapsules have a certain number of
particles located at their surface. This type of microencapsulation is known as matrix encapsulation, and often
provides more protection during spray drying and storage
of probiotics, as well as during their passage through the
stomach [27].
The size of the microcapsules is an important parameter
that affects the sensory properties of foods. The size of
alginate beads ranges from 20 mm to 4 mm. However, a
bead size of 150 mm can be obtained with the new
extrusion technologies, thereby allowing the achievement of more uniformly shaped microcapsules than those
reached through the emulsion technique. Spray drying
produces capsule sizes ranging between 5 and 80 mm.
Bead size also affects the adhesion property of probiotics,
and is optimal with granules of starch that are 50 mm in
diameter [27,28,29,36–37].
Co-encapsulation of microorganisms and other important
components like prebiotics protects probiotics in food
systems and in the gastrointestinal tract much better,
owing to synbiosis [38–40]. To date, dairy-based products
have emerged as the main carriers for the delivery of
probiotics to humans [18]. However, increasing demand
by consumers has opened a trend in using nondairy-based
products as potential carriers of probiotics. Most of the
foods containing probiotic microorganisms are found in
the refrigerated section of supermarkets; this being owing
to the fact that the bacteria are sensitive and can be
destroyed by heat.
Research is ongoing to develop new envelopes, especially
formed by double or triple layers of alginate-chitosan, that
allow a better resistance of bacteria to heat (e.g. to
pasteurization). Ding and Shah [25] demonstrated, in
fact, that the heat tolerance of microencapsulated probiotic bacteria incubated at 65 8C for up to 1 h survived at
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Microencapsulation in food science Nazzaro et al. 185
Figure 3
1 mm
Current Opinion in Biotechnology
Lactobacillus acidophilus microencapsulated in
alginate + inulin + xanthan and grown in berry + grape juice (F. Nazzaro,
figure not published).
frontiers in the use of ME in food industry. Fratianni et al.
[46] used the microencapsulated L. acidophilus to ferment a fruit juice (berry + grape). The strain not only was
capable to grow in fruit juice and ferment it, creating a
new functional product but, after fermentation, microcapsules exhibited a noticeable microbial viability and an
amount of anthocyanins similar to that present in a litre of
red wine (Figure 3). One of the increasing interests in the
future will concern mainly the use of new probiotic/
prebiotic combinations. Special attention is needed to
design future carrier matrices and technology, to keep
pace with the increasing consumer interest in health
issues, food safety and environmental consciousness.
References and recommended reading
Papers of particular interest, published within the period of review,
have been highlighted as:
of special interest
of outstanding interest
30 min with good protection. Use of probiotics is continuously expanding in the food industry. From that point
of view, ME can achieve a wide variety of functionalities
according to the development of the technology, and
nowadays encapsulated probiotic cells can be incorporated into many types of food products.
Different foods containing encapsulated probiotic cells
are present on the market. Belgium group Barry Callebaut
produces chocolate containing encapsulated probiotic
cells that do not negatively affect the taste, texture or
mouth feel of the final functional product, and which, at
doses of 13. 5 g per day, might be sufficient to positively
affect the gut microbiome. In some cases, inulin or other
prebiotics have been added to probiotics in the manufacturing of the bar called ‘Attune’ (www.attunefoods.com), into yogurt-covered raisins, nutrient bars, chocolate
bars, or tablets (www.balchem.com). The ice cream
industry is viewing the probiotic market with much interest. Unilever, Hansen, and company Dos Pinos, have
developed a probiotic ice cream having multiple health
benefits (www.chr-hansen.com). Many products containing encapsulated probiotic cells are available in a tablet/
capsule form or in a powder form [22], ensuring the
probiotic cells to be preserved against the acidic juices
of the stomach and able to reach the intestine, and with a
shelf life over 24 months if stored at refrigerated temperature (www.cerbios.ch).
Today, new foods such as cereal-based products, soybased products, fruits, vegetables and meat products are
considered as potential carriers of probiotics. However,
growth in non-dairy products such as sausage and fruit
juices is diminished by the presence of inhibitory substances such as nisin, organic acids and curing salts.
Appropriate selection of cultures to be microencapsulated
can improve their viability without affecting the sensory
property of the final products [41–44,45], opening new
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Augustin MA, Sanguansri L: Encapsulation of bioactives. In
Food Materials Science Principles and Practice, vol 3. Edited by
Aguilera sec, Lillford Peter JtrJ. Springer; 2008:577-601.
It is a very interesting review on the argument for encapsulation of
bioactives.
1.
2.
Schrooyen PMM, van der Meer R, De Kruif CG:
Microencapsulation: its application in nutrition. In Symposium
on ‘Nutritional effects of new processing technologies’
Proceedings of the Nutrition Society, vol 60. Cambridge University
Press; 2001:475-479.
3.
De Martino L, De Feo V, Nazzaro F: Chemical composition and in
vitro antimicrobial and mutagenic activities of seven
Lamiaceae essential oils. Molecules 2009, 14:4213-4230.
4.
De Martino L, De Feo V, Fratianni F, Nazzaro F: Chemistry,
antioxidant, antibacterial and antifungal activities of volatile
oils and their components. Nat Prod Commun 2009,
4:1741-1750.
5.
Kim Y, Morr C, Schenz T: Microencapsulation properties of gum
arabic and several food proteins: liquid orange oil emulsion
particles. J Agric Food Chem 1996, 44:1308-1313.
6.
Pandit VA, Shelef LA: Sensitivity of Listeria monocytogenes to
rosemary (Rosmarinus officinalis L.). Food Microbiol 1994,
11:57-63.
7.
Gaysinsky S, Davidson PM, McClements DJ, Weiss J:
Formulation and characterization of phytophenol-carrying
antimicrobial microemulsions. Food Biophys 2008, 3:54-65.
This is an example of how microencapsulation can be used to develop an
antimicrobial formulation.
8.
Perez-Conesa D, McLandsborough L, Weiss J: Inhibition and
Inactivation of Listeria monocytogenes and Escherichia coli
O157:H7 colony biofilms by micellar-encapsulated eugenol
and carvacrol. J Food Prot 2006, 69:2947-2954.
9.
Chacon PA, Buffo RA, Holley RA: Inhibitory effects of
microencapsulated allyl isothiocyanate (AIT) against
Escherichia coli O157:H7 in refrigerated, nitrogen packed,
finely chopped beef. Int J Food Microbiol 2006, 107:231-237.
10. Desai KGH, Park HJ: Recent development in
microencapsulation of foods ingredients. Drying Technol 2005,
23:1361-1394.
11. Gibbs S, Alli KI, Mulligan CN: Encapsulation in the food industry:
a review. Int J Food Sci Nutr 1999, 50:213-224.
A good review about the application of encapsulation in food science.
12. Stevens C, Meriggi A, Booten K: Chemical modification of inulin,
a valuable renewable resource, and its industrial applications.
Biomacromolecules 2001, 2:1-16.
Current Opinion in Biotechnology 2012, 23:182–186
186 Food biotechnology
13. Saénz C, Tapia S, Chávez J, Paz R: Microencapsulation by
spray drying of bioactive compounds from cactus pear
(Opuntia ficus-indica). Food Chem 2009, 114:616-622.
14. Xu XJ, Huang SM, Zhang LH: Biodegradability, antibacterial
properties, and ultraviolet protection of polyvinyl alcoholnatural polyphenol blends. Polym Compos 2009, 30:1611-1617.
The first article related to use of PVA as entrapping agent for polyphenols.
from UHT- and conventionally treated milk during storage.
LWT - Food Sci Technol 2006, 39:177-183.
30. Chávarri M, Marañón I, Ares R, Ibáñez FC, Marzo R, Villarán M:
Microencapsulation of a probiotic and prebiotic in alginatechitosan capsules improves survival in simulated gastrointestinal conditions. Int J Food Microbiol 2010, 142:185-189.
15. Ottombrino A, Fratianni F, Nazzaro F: Antibacterial properties of
polyvinyl alcohol-rosemary polyphenol blends. International
Conference BIOMICROWORLD; Torremolinos, Spain: 2011.
31. Li XY, Chen XG, Sun ZW, Park HJ, Cha DS: Preparation of
alginate/chitosan/carboxymethyl chitosan complex
microcapsules and application in Lactobacillus casei ATCC
393. Carbohydr Polym 2011, 83:1479-1485.
16. Mohammadi R, Mortazavian AM, Khosrokhavar R, Gomes da
Cruz A: Probiotic ice cream: viability of probiotic bacteria and
sensory properties. Ann Microbiol 2011. published online 6
January 2011.
32. Zhou Y, Martins E, Groboillot A, Champagne CP, Neufeld RJ:
Spectrophotometric quantification of lactic bacteria in
alginate and control of cell release with chitosan coating.
J Appl Microbiol 1998, 84:342-348.
17. Favaro-Trindade CS, Grosso CRF: Microencapsulation of L.
acidophilus (La-05) and B. lactis (Bb-12) and evaluation of
their survival at the pH values of the stomach and in bile.
J Microencapsul 2002, 19:485-494.
33. Champagne CP, Gaudy C, Poncelet D, Neufeld RJ: Lactococcus
lactis release from calcium alginate beads. Appl Environ
Microbiol 1992, 58:1429-1434.
18. Champagne CP, Lacroix C, Sodini-Gallot I: Immobilized
cell technologies for the dairy industry. Crit Rev Biot 1994,
14:109-134.
One of the most important reviews about use of microencapsulation in the
dairy industry.
19. Chandramouli V, Kailasapathy K, Peiris P, Jones M: An improved
method of microencapsulation and its evaluation to protect
Lactobacillus spp. in simulated gastric conditions. J Microbiol
Methods 2004, 56:27-35.
20. De Giulio B, Orlando P, Barba G, Coppola R, De Rosa M, Sada A,
De Prisco PP, Nazzaro F: Use of alginate and cryo-protective
sugars to improve the viability of lactic acid bacteria after
freezing and freeze-drying. World J Microbiol Biotechnol 2005,
21:739-746.
21. Nazzaro F, Fratianni F, Coppola R, Sada A, Orlando P:
Fermentative ability of alginate-prebiotic encapsulated
Lactobacillus acidophilus and survival under simulated
gastrointestinal conditions. J Funct Foods 2009, 1:319-323.
22. Burgain J, Gaiani C, Linder M, Scher J: Encapsulation of
probiotic living cells: from laboratory scale to industrial
applications. J Food Eng 2011, 104:467-483.
34. Oliveira AC, Moretti TS, Boschini C, Baliero JCC, Freitas O,
Favaro-Trindade CS: Microencapsulation of B. lactis (BI 01) and
L. acidophilus (LAC 4) by complex coacervation followed by
spouted-bed drying. J Microencapsul 2007, 24:673-681.
35. Gouin S: Microencapsulation: industrial appraisal of existing
technologies and trends. Trends Food Sci Technol 2004,
15:330-347.
36. Sheu TY, Marshall RT: Microentrapment of lactobacilli in
calcium alginate gels. J Food Sci 1993, 58:557-561.
37. Muthukumarasamy P, Holley RA: Survival of Escherichia
coli O157: H7 in dry fermented sausages containing
micro-encapsulated probiotic lactic acid bacteria.
Food Microbiol 2007, 24:82-88.
38. Dinakar P, Mistry VV: Growth and viability of Bifidobacterium
bifidum in cheddar cheese. J Dairy Sci 1994, 77:2854-2864.
39. Reid AA, Vuillemard JC, Britten M, Arcand Y, Farnworth E,
Champagne CP: Microentrapment of probiotic bacteria in a
Ca2+-induced whey protein gel and effects on their viability in a
dynamic gastro-intestinal model. J Microencapsul 2005,
22:603-619.
23. Chen MJ, Chen KN: Encapsulation of probiotics in alginate
systems. Drug Deliv Technol 2005:6–9, online:
wwww.controlledrelease.org.
40. Lee KY, Heo TR: Survival of Bifidobacterium longum
immobilized in calcium alginate beads in simulated gastric
juices and bile salt solution. Appl Environ Microbiol 2000,
66:869-873.
24. Picot A, Lacroix C: Encapsulation of Bifidobacteria in whey
protein-based microcapsules and survival in stimulated
gastrointestinal conditions and in yoghurt. Int Dairy J 2004,
14:505-515.
41. Nazzaro F, Fratianni F, Sada A, Orlando P: Synbiotic potential of
carrot juice supplemented with Lactobacillus spp. and inulin
or fructooligosaccharides. J Sci Food Agric 2008, 88:2271-2276.
25. Ding WK, Shah NP: Acid, bile, and heat tolerance of free and
microencapsulated probiotic bacteria. J Food Sci 2007,
72:M446-M450.
A good example of development of encapsulating matrix to protect
probiotics also against heat.
26. Crittenden R, Laitila A, Forssell P, Matto J, Saarela M, MattilaSandholm T, Myllärinen P: Adhesion of bifidobacteria to
granular starch and its implications in probiotic technologies.
Appl Environ Microbiol 2001, 67:3469-3475.
27. Rokka S, Rantamäki P: Protecting probiotic bacteria by
microencapsulation: challenges for industrial applications.
Eur Food Res Technol 2010, 231:1-12.
28. Mortazavian A, Razavi SH, Ehsani MR, Sohrabvandi S: Principles
and methods of microencapsulation of probiotic
microorganisms. Iran J Biotechnol 2010, 5:2007-2020.
The authors wrote an excellent review on the topic of probiotic microencapsulation.
29. Krasaekoopt W, Bhandari B, Deeth HC: Survival of probiotics
encapsulated in chitosan-coated alginate beads in yoghurt
Current Opinion in Biotechnology 2012, 23:182–186
42. Mattila-Sandholm T, Myllärinen P, Crittenden R, Mogensen G,
Fonden R, Saarela M: Technological challenges for future
probiotic foods. Int Dairy J 2002, 12:173-182.
43. Krasaekoopt W, Bhandari B, Deeth H: Evaluation of
encapsulation techniques of probiotics for yoghurt. Int Dairy J
2003, 13:3-13.
44. Yeo SK, Ewe JA, Sau-Chan Tham C, Liong MT: Carriers of
probiotic microorganisms. Probiotics Microbiol Monogr 2011,
21:191-220.
45. Muthukumarasamy P, Holley RA: Microbiological and sensory
quality of dry fermented sausages containing alginatemicroencapsulated Lactobacillus reuteri. Int J Food Microbiol
2006, 111:164-169.
A really interesting application of microencapsulation in the manufacturing of sausages.
46. Fratianni F, Coppola R, Sada A, Mendiola J, Ibanez E, Nazzaro F: A
novel functional probiotic product containing phenolics and
anthocyanins. Int J Probiotics Prebiotics 2010, 5:85-90.
A good example of a new functional formulation.
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