SEMINAR ONMICROENCAPSULATION TECHNIQUES, METHODS AND APPLICATION IN FOOD INDUSTRY Student P. Adiyaman II Ph.D (FSN)
ADVISORY COMMITTEECHAIRMAN Dr. S. KANCHANA, Ph.D., Professor, Dept. of Food Science and Nutrition, Home Science College & Res. Instt., Madurai-625 104.MEMBERS Dr. G. HEMALATHA, Ph.D., Professor, Dept. of Food Science and Nutrition, Home Science College & Res. Instt., Madurai-625 104. Dr. S. BALAKRISHNAN, Ph.D., Professor, Dept. of Horticulture, Agricultural College & Res. Instt., Madurai – 625 104. Dr. M. R. DURAISAMY, Ph.D., Professor (Maths), Dept. of Family Resource Management, Home Science College & Res. Instt., Madurai-625 104.
Content Introduction Microencapsulation Architecture of microencapsulation Microencapsulation methods employed in industry Application in food industry Recent development in microencapsulation of food ingredients Controlled release mechanisms of food ingredients
Introduction Microencapsulation is process of enclosing micron sized particles in a polymeric shell (Desai & Park, 2005). Microencapsulation means “encapsulation around microscopic particles” (Mike, 2004). Size - ranges -1 to 1000µm. Firstly microencapsulation procedure - discovered - Dutch chemist H.G. Bungenberg de Jong, in 1932 - deal with the preparation of gelatine spheres - coacervation process (Nupoor & Rathore, 2012).
Cont., Commercial product - microencapsulated dye by NCR of American in 1953 (Complex coacervation). Microencapsulation of cholesteric liquid crystal by complex coacervation of gelatin and acacia (thermosensitive ) – 1960 (Rama Dubey et al., 2009). Not a new technology for food processing industry
Microencapsulation Microencapsulation is a technique by which liquid droplets (or) solids particles are coated with thin film of protective materials. The droplets (or) particles are called “core materials”. The thin film coating is called “wall material”. The film (or) wall material protects the “:core material” against deterioration, evaporation of volatile core (flavors) and also facilitates the release of core under predetermined conditions Natural example : eggs shells, plant seeds and sea shells
Core and wall material Core material It is substance to be encased. For example : solids, liquids (or) mixture of these such as dispersion of solids in liquids, solutions and complex emulsion have been used. Wall material To protect the corer material The primer function - protect the core material against deterioration and evaporation (losses) of the volatile.
Characteristics of the coating material Good rheological properties at high concentration and easy work. Ability to disperse or emulsify the active material and stabilize. Non-reactivity. Ability to seal and hold the active material. Ability to completely release the solvent or other materials. Provide maximum protection. Solubility in solvents. Chemical non-reactivity. Inexpensive, food-grade status
Commonly used coating materials Kuang et al, 2010 (Kuang et al., 2010)
cont., Category Coating materials Widely used methods References Starch,maltodextrins, Spray- and chitosan, freeze-drying, Carbohydrate Reineccius (1991) corn syrup solids, extrusion, dextran, modified Coacervation and starch, cyclodextrins inclusion complexation Carboxymethylcellulose, methyl cellulose, Coacervation and Cellulose Reineccius (1991) ethylcellulose, spray-drying celluloseacetate-phthalate, celluloseacetatebutylate- phthalate Gum acacia, agar, sodium Dziezak (1991) Gum alginate, carrageenan Spray-drying Wax, paraffin, beeswax, diacylglyerols, oils, fats Inclusion complexation Lipids Kim and Baianu1(1991) Gluten, casein, gelatin, Inclusion complexation Protein albumin, peptides and spray-drying Dziezak (1991)
Cont., Gibbs et al. (1999) - Gum Arabic (GA) - increase the retention of volatiles and shelf-life of microcapsules - excellent solubility and surface active properties. McNamee et al. (2001) - GA + MD - better emulsification characteristics and oxidative stability. Gibbs et al. (1999) - MD - poorer emulsification properties (lower viscosity & lack of lipophilic groups). Zhu et al. (1998) - Gelatin - good emulsification properties, film formation, water-solubility and biodegradation.
Cont., Francoise et al. (2012) - Vegetable proteins (PPI, SPI, wheat gliadins, corn zein and barley protein. ) - Widely used. Expected product objectives and requirements Nature of the core material Process of encapsulation Economics It should be approved by FDA (Kuang et al., 2010).
Reasons for microencapsulation (Rathor and Mudaliar, 2012 ) Enhances the overall quality of food products. Reduces the evaporation or transfer of the core material to the outside environment. Superior handling of the active agent. Effectively retains volatile components particularly flavours. Provides - incorporating vitamins, minerals and oxygen- sensitive oils - palatable and shelf-stable food products. Improved stability in final product and during processing. Control release of the active components. Masks the aroma, flavour, and colour of some ingredients.
Architecture of microencapsulationMorphology of microcapsules.Classified - mononuclear, polynuclear, and matrix types. Wall wall Core Core
Cont., Technology Morphology Particle size (μm) Spray-drying Matrix 10–400 Spray-chilling/ cooling Matrix 20–200 Co - crystallization Matrix Fluid bed coating Reservoir 5 - 500 Coacervation Reservoir 10–800 Inclusion complexation Molecular inclusion 0.001– 0.01 RESS Matrix 10–400 Freeze- or vacuum Matrix 20–5,000 drying Centrifugal suspension Reservoir 30µm to 2mm extrusion Centrifugal extrusion Reservoir 250μm to few mm (Nicolaas and Shimoni, 2010)
SPRAY-DRYING One of the oldest processes Spray-drying of active agent is commonly achieved by dissolving, emulsifying, or dispersing the active in an aqueous solution of carrier material, followed by atomization and spraying of the mixture into a hot (Gharsallaoui et al., 2007). Economical process Readily available equipments and uses flexibly Produce good quality particles & particles size ranges between 10 -400μm
Schematic diagram of spray drying process Core material Wall material Homogenise Inlet temperature -150 -200oC Outlet temperature- 115 to 130oC150 - Atomizer speed – 30,000rpm Feed rate – 20 to 45ml/min
Cont., Commonly used shell materials include gum acacia, maltodextrin and hydrophobically modified starches. Rice and wheat starch - applied with small amount (0.1 to 1.0% ) bounding agent (Protein or hydrophilic polysaccharides )(Zhao & Whistler, 1994). Other polymers including alginate, carboxymethylcellulose (CMC), guar gum (GG) and proteins – (expensive, low solubilities, much larger evaporation and presence of core material on the surface of microcapsules ) (Desai et al., 2005).
2011 Aim : The analysis and stability of microencapsulated folic acid during the processing and preparation of instant Asian noodles. Method : Prepared of microencapsulated folic acid by spray drying with combination of alginate and pectin as a wall material. Result : Microencapsulation of folic acid with combinations of alginate and pectin as the binding agents, proved to be effective in maintaining folic acid stability after spray drying. Study recommended - Microencapsulated folic acid (7mg) was successfully incorporated in Asian noodles (300 g of flour) and Virtually no FA lost during boiling in moderate periods. Readily measurable losses (only extended periods of heating).
Cont., 20µm FA encapsulated with Alginate & Pectin
SPRAY-CHILLING OR SPRAY-COOLING Core and wall mixtures are atomized into the cooled or chilled air-causes- wall to solidify around the core. To produce lipid-coated active agent. Does not involve evaporation of water. Spray-cooling - vegetable oil or its derivatives Others fat and stearin - melting points of 45–122oC - hard mono- and diacylglycerols - melting points of 45–65oC.
Cont., Spray – chilling - fractionated or hydrogenated vegetable oil with a melting point of 32–42oC. Microcapsules - insoluble in water due to the lipid coating. These techniques - utilized for encapsulating water- soluble core materials such as minerals, water- soluble vitamins, enzymes and some flavors. Particle size – 20 to 200µm
FLUIDISED-BED COATING (Hammad et al., 2011) Otherwise called air suspension coating. Originally developed - pharmaceutical technique - now increasingly - applied in the food industry (Gouin, 2004). Encapsulating solid or porous particles with optimal heat exchange.Principle The liquid coating is sprayed onto the particles and the rapid evaporation helps in the formation of an outer layer on the particles.
Cont., Great variety of coating materials - Cellulose derivatives, dextrins, lipids, protein derivatives, and starch derivatives. Yield relatively defect-free coatings. Particles size – 5 to 500µm. Three types (Top spray, Bottom spray, and Tangential spray).
Top- spray fluidized - bed coating Coating material is sprayed downwards onto the fluid-bed. Coating solution Increased encapsulation efficiency and prevention of cluster formation. Produce higher yields. Inlet air flow
Bottom- spray fluidized - bed coating Its also known as “Wurster’s coater (Prof. D.E. Wurster). Wurster chamber Coating chamber - cylindrical nozzle and a perforated bottom plate. Spraying the coating material and particles move upward Nozzle direction. Desired thickness and weight is Perforated bottom plate obtained. Time consuming process - multilayer coating - reducing particle defects.
Tangential- spray fluidized - bed coating Consists of a rotating disc at the bottom of the coating chamber. Disc is raised to create a gap. Coating solution Particles move through Rotating the gap into the spraying disc zone and are encapsulated.
Aim: To investigate microencapsulation of probiotic by Air – suspension Fluidized – Bed Coating method using Trehalose and MD as a wall material. Methods : Trehalose + MD + DW – heated at 93oC – cooled addition dry probiotic culture – spray coating in the sir suspension process. Results: Trehalose and maltodextrin provided enhanced protection of the probiotic cells during the air-suspension drying process and further enhanced the stability of the coated particles during storage (28days). Particels size - 20µm.
COACERVATION Latin ›acervus‹, meaning “heap”. Made Via - liquid-liquid phase separation mechanism. Simple coacervation and complex coacervation . Frequently used shell material – GA and Gelatin. Particle size - 10–800µm
Schematic representation of complex coacervation Isopropanol & H 2o to 5 - 10oC Dried by SD &FD (Nicolaas and Shimoni , 2010)
Aim: To investigate microencapsulation of olive oil by complex coacervation method using gelatin A with sodium alginate as a wall material. Methods : Gelatin + olive oil - mechanical stirring + addition Na alginate - temperature lowered - Cross linking - washing (Hexane & H2O) - FD. Results: Maximum coacervation occurred at 3.5:1 gelatin to sodium alginate ratio and at pH of 3.75. The encapsulation efficiency was found to increase - increase in the concentration of olive oil, glutaraldehyde and polymer. SEM - the size of the microcapsules were increased as the amount of olive oil and polymer concentration increased. Particels size - 0.5µm.
CENTRIFUGAL SUSPENSION SEPARATION More recent microencapsulation process. Continuous and high-speed method – Highly suitable for foods. Taken a few seconds. Widely used coating materials - fats, polyethylene glycol (PEG) and diglycerides. Particels size – 30 µm to 2mm. (Swapan Kumar, 2006)
CENTRIFUGAL EXTRUSION (Raouf Ghaderi, 2000) Wall materials - gelatin, sodium alginate, carrageenan, starches, cellulose derivatives, gum acacia, fats / fatty Core acids, waxes, and polyethylene glycol. Wall Produced larger size, from 250 microns up to a few millimeters in diameter.
POLYMER ENCAPSULATION BY RESS Whats SCF ? Widely used SCF - Co2. Highly suitable for processing heat-sensitive materials. Non-toxic, non-flammable, inexpensive and reasonably high dissolving power. Other SCF (Ethylene. Ethane, Propane, Ammonia, Isopropanol, Cyclohexane and Benzene). Pesticides, pigments, pharmaceutical ingredients, vitamins, flavors, and dyes. Paraffin wax, acrylates, polyethylene glycol, proteins and polysaccharides
Schematic Representation of RESS (Raouf Ghaderi, 2000)
FREEZE-DRYING AND VACUUM DRYING Lyophilization –dehydration of heat sensitive materials and aromas. Water-soluble essences and natural aromas as well as drugs (Except for the long dehydration period). Sample frozen (-90 to -40oC) - Dried by direct sublimation- Grinding, if necessary. Disadvantages – Particle Size – 20µm to 5mm. Vacuum-drying - very similar to freeze-drying, but operates at a temperature above the freezing point of the solvent (>0 C in case of water) - faster and cheaper. (Shami and Bhasker, 2009)
Aim : Passion fruit juice was encapsulated in Capsul® and stored at different temperatures and analysed stability of vitamin C. Method : Passion fruit juice was filtered - mixed with 20% Capsul® and freeze-dried. The encapsulated passion fruit power was stored at 7, 25, and 37 C, in the dark, for 12 weeks and analysed Vitamin C stability. Results : Very stable microcapsules (homogeneous white powder with strong and pleasant smell of passion fruit). 91.4, 81.1, and 36.2% vitamin C retained after 12 weeks, samples stored at 7, 25, and 37 C. Particle size - an average 205.7 0.09 μm.
Cont.,Cont., (1µm) 205.7 0.09 μm Microencapsulated Passion fruit juice (Capsul®)
INCLUSION COMPLEXATION Achieving encapsulation - molecular level. Encapsulating medium - β-cyclodextrin. Guest molecules - entrapped(dimensionally) by hydrophobic interaction. Internal cavity - 0.65nm diameter. Suitable for essential oils and flavour compounds. Particle size - 0.001– 0.01µm
Chemical structure and geometry of β-cyclodextrin (Kashappa Goud, 2005)
Cont., Three methods to produce the flavor or oil - β-cyclodextrin complex. β-cyclodextrin - dissolved in H2O - added flavour - Crystallin form- dried. β-cyclodextrin - dissolved in a lesser amount of H2O. β-cyclodextrin - dissolved in a much lower H2O- Kneading. Use of β-cyclodextrin in food application- very limited, possibly due to regulatory requirements in a number of countries. (Barreto et al., 2011)
Aim : The aim of the present study was to prepare the inclusion complexes of the Cinnamomum verum essential oil with β- cyclodextrin in various ratios (5:95, 10:90, 15:85 and 20:80 (w/w). Result : The retention of essential oil volatiles and maximum inclusion efficiency (94.18%) of β-cyclodextrin was achieved at the ratio of 15:85, in which the complex powder contained 117.2 mg of oil/g of β-cyclodextrin - commercially acceptable .
CO-CRYSTALLIZATION New encapsulation process . Widely used core material – Sucrose. Flow-chart of co-crystallization process Sucrose syrup Addition of (supersaturated state ) core material Crystallize Nucleation Vigorous Mechanical agitationAgitation is continued Agglomerates are discharged Dried (Sanjoy Kumar Das et al., 2011)
APPLICATION IN FOOD INDUSTRY Current trend - healthier way of living. Improve nutritional value by adding ingredients. Overcome all these challenges by microencapsulation. Incorporate minerals, vitamins, flavours and essential oils. Simplify food manufacturing process, decreasing production costs , extend shelf-life, help fragile and sensitive.
Aim : To study the microencapsulation of Garcinia cowa fruit rinds extract by spray drying technique using whey protein isolate as a wall material. The effects of different outlet temperatures (90 & 105oC) of the spray dryer and wall-to- core ratios (1:1 & 1.5:1) and HCA retention were also studied. Result : Microencapsulation efficiency (HCA recovery 94.49 %) and antioxidant Properties (flavonoids and xanthones) were higher at 90 C outlet temperature of the spray dryer using 1.5:1 wall-to-core ratio. Incorporation of this powder in pasta had higher antioxidant activity as well as better cooking and sensory characteristics.
Aim : To evaluate the influence of the wall materials based on maltodextrin and whey protein isolate on the efficiency of the microencapsulating process via spray-drying and retention of ginger oil in microcapsule. Method : Ginger oil (steam distillation) + Wall solutions (mixture of WPI and 18DE MD) = spraydried (inlet and outlet air temperature of 120 3 C and 60 3 C ) Result : High MEE (99.36% )and ginger oil (93.30% 0.1%) at optimum conditions 1:1 ratio of WPI to MD, 1:4 ratio of core to wall material, and total solid content of 25%.
• Aim : To explore the possibility of delivering omega-3 PUFA-rich oils using different types of microemulsion and investigated the conversion of ALA to long chain omega-3 PUFA when given to rat as microemulsion.• Method : LSO/SNO was encapsulated in microemulsions using gum acacia, whey protein and lipoid - feed (Male Wistar rats) 1 mL of LSO (46 mg of LA) or SNO (41 mg of ALA) for 30 days – Blood (cardiac puncture), serum (centrifugation) and liver (removed) – analyzed.• Result : ALA absorption (LSO) enhanced, ALA converted to EPA & DHA (microemulsion in lipoid) in rat. LSO microemulsion (lipoid) - (41 and 34 µg/ml)EPA &DHA found in serum. LSO microemulsion (lipoid) – enhanced uptake of ALA - conversion to long chain omega-3 fatty acids in liver lipids
CONTROLLED RELEASE MECHANISMS OF ENCAPSULATED INGREDIENTS
Controlled, Sustained or Targeted release of core material. Release of the core material - involve one or a combination of stimuli. Number of factors affect release – (nature of the coating and the core material, , capsule size, capsule storage, application as well as capsule structure).Diffusion membrane controlledPressure activated Tearing peelingpH sensitive Temperature sensitiveOsmotically controlled
Cont., Diffusion – diffusion controlled by solubility of compound in the matrix & permeability of the matrix to the compound. Core diffusion rate - Chemical structure, thickness, pores size and surface integrity . Pressure activated release - Pressure applied on the walls of the microcapsules. pH sensitive release - microcapsule coating or matrix contains chemical bonds - cleaved -pH value . Temperature sensitive release - Melting of the capsule wall (lipids or waxes) to release the active material. Osmotically controlled release- Utilising osmotic pressure. (Eg. If encapsulated core material has a high affinity for water – larger internal pressure – core material released (Gibbs et al., 1999).
References• Rodney Hau. (2011). The analysis and stability of microencapsulated folic acid during the processing and preparation of instant Asian noodles. Thesis of Doctor of Philosophy, School of Applied Sciences Science, Engineering and Technology Portfolio RMIT University.• Sanjoy Kumar Das, Sheba Rani Nekka David and Rajan Rajabalaya. ( 2011). Microencapsualtion Techniques and Its Practice. Int J of Pharam Sci Tech, Vol (6): 1- 23.• Kashappa Goud H. Desai and Hyun Jin Park. (2005). Recent Developments in Microencapsulation of Food Ingredients. Drying Technology, 23: 1361–1394.• Sharma Nupoor and Rathore KS. (2012). A Review on Microencapsulation: A New Multiutility Advanced Technology. International Journal of Advanced Research in Pharmaceutical and Bio-Sciences, Vol.1 (4):477-489.• Goran M. Petrovic, Gordana S. Stojanovic and Niko S. Radulovic. (2010). Encapsulation of cinnamon oil in β-cyclodextrin. Journal of Medicinal Plants Research Vol. 4(14), pp. 1382-1390.
Cont.,• Daniela Borrmann, Selma Gomes Ferreira Leite, and Maria Helena Miguez da Rocha Leao . (2011). Microencapsulation of Passion Fruit (Passiflora) Juice in Capsul®. International Journal of Fruit Science, 11:376–385.• D. Sugasini • B. R. Lokesh. (2012). Uptake of a-Linolenic Acid and Its Conversion to Long Chain Omega-3 Fatty Acids in Rats Fed Microemulsions of Linseed Oil. Springer, AOCS.• Dipin S. Pillai, P. Prabhasankar, B.S. Jena, and C. Anandharamakrishnan. (2012). Microencapsulation of garcinia cowa fruit extract and effect of its use on pasta process and quality. International Journal of Food Properties, 15:590–604.• Alhassane Touré, Hong Bo Lu, Xiaoming Zhang and Xu Xueming. (2011). Microencapsulation of Ginger Oil in 18DE Maltodextrin/Whey Protein Isolate. Journal of Herbs, Spices & Medicinal Plants, 17:183– 195.