ENCAPSULATION ORMICROCAPSULATION TECHNIQUES IN FOOD INDUSTRY
Santanu Nath1, Susmita Majumder2, Bedika bora1
- Division of Livestock Products Technology, ICAR- IVRI, Izatnagar, pin- 243122
- Division of Physiology and Climatology, ICAR- IVRI, Izatnagar, pin- 243122
INTRODUCTION:
The food industry using microencapsulation techniques to increase the shelf-life of some perishable food products, as well as also for adding some nutraceuticals compounds, vitamins, minerals, and antioxidants to the food products at the time of processing, which will be beneficial for human health(COMAN et al., 2012; SILVA et al.,2014 and 2015). Nowadays food safety is the major issue to meet consumer satisfaction.
Microencapsulation is the physical process where thin polymer coats or films are applied to surround the small solid particles or droplets of liquid substance or gasses(Gharsallaoui et al. 2007).This process can preserve the core materials and release on demands. Core materials is also known as actives, internal phase, fill or payload and the coating materials is also called as membrane, wall materials, capsules, carrier, or shell.
Microcapsule usually ranges from 0.2 to 5000 µm in diameter but the final particles size is dependent of some factors like nature of the encapsulating materials and processing techniques (A.G. Gaonkar et. al, 2014). There are many applications of microencapsulation’s techniques in food industry such as to protect, isolates and control release of active substance which increase the interest for using microencapsulation’s techniques during processing of many food products. These methods are most frequently used by the food industry to add flavouring, antioxidants, and antimicrobials to food items. So, microencapsulation technology will be a useful technique for protect the sensitive food ingredients from degradation by lessening its hygroscopicity, reactivity, evaporation or transfer rate, and exposure to the environment (e.g. heat, moisture, air, light) (Mourtzinos et al. 2008).
Due to the superior health benefits of natural food ingredients than the synthetic chemicals consumers are now aware about the uses of natural ingredients in foods (R. Domínguez, et, al. 2020). These natural ingredients are obtained from plant, animal, or microbial origin and its comparatively safer for human health. These natural bioactive ingredients are good source for antioxidant, antimicrobials, nutritional, colouring, flavouring and therapeutic properties which is widely used in food industry for preservation of food ingredients (J.M Lorenzo, et, al. 2018). But problem rises at the time of processing and storage of these natural bioactive compounds due the degradation. Microencapsulation is the best solution to encounter this degradation problem of bioactive compounds at the time of processing and storage (R. Domínguez, et, al. 2021).
MICROENCAPSULATING MATERIALS OR WALL MATERIALS:
Encapsulating materials for uses in food industry should be GRAS recognize (Rahman, & Van Vuong, 2019). There are several encapsulating materials uses by the food industry (Table- 1) among them most frequently used encapsulating materials are chitosan (Sabaghi et, al. 2015), maltodextrins (Vladi´c et al., 2016), alginate (Teixeira, et, al. 2015), β-cyclodextrin and derivatives (Kfoury et al., 2016), whey proteins (Hernandez- ´ Marín, et, al. 2016) starch (Santander-Ortega et al., 2010) and sucrose or a combination of different materials. The ideal wall material should possess the following characteristics: not being receptive to the centre; ability to seal and maintain the centre inside the case; ability to provide the greatest amount of protection against hostile conditions; lack of unfavourable preference for the instance of sustenance appropriateness and financial viability (Nazzaro et al., 2012).
Table No:1According to origin encapsulating agents used for encapsulation:
| Encapsulating agent | example |
| Natural | Gelatin, gum arabic, carrageenan, sodium alginate, wax, chitosan, caseinate, dextran, agar, and sucrose |
| Synthetic | Polymers of acrylic acid and copolymers. |
| Semisynthetic | Sodium carboxymethylcellulose, hydroxypropylcellulose, methylcellulose, monoglycerol, monostearate, myristyl alcohol, diacylglycerol or dipalmitate, cellulose nitrate, ethylcellulose, cellulose acetate, glycerol distearate and tristearate, |
Source: (Laurenti and Garcia, 2013)
MECHANISAM INVOLVES FOR RELEASING OF CORE MATERIALS:
As encapsulation process able to isolates the core materials from external environment and release under control condition that is, up to the moment at which it is intended to be released. Mechanisms involve for releasingof corematerialsor active agent like diffusion, degradation activation, activation by temperature, activation by pH control, activation by pressure and solvent activation.
MICROENCAPSULATION TECHNIQUES:
In general, microencapsulation process comprises four steps- 1) Formation of core, 2) Formation of encapsulant, 3) Incorporation and 4) Solidification (B. Gómez, et, al. 2018). There are several techniques used for microencapsulation process, broadly it can be classified in: physicochemical, physical, or chemical methods (Table 2) for different food ingredients (SOHAIL et al., 2011).
As micro capsulation techniques have various functionality in food industry, so the biggest challenge is to choose most efficient and appropriate techniques at the time of encapsulation process (ANAL and SINGH, 2007). Based on usefulness, advantage and disadvantage and process of some common microencapsulation techniques are discuss on (Table no 3)(Calderón-Oliver, M., & Ponce-Alquicira, E. 2022).
Table No: 2 Micro capsulation techniques classification:
| METHODS | TECHNIQUES |
| Chemical methods | Polymerization and Molecular inclusion |
| Physico-chemical methods | Solvent evaporation, Simple or complex coacervation, Emulsions, Process with nanostructured lipid matrices, Liposomes, Micelles, and Internal ionic gelation. |
| Physical methods | Spray drying, Freeze drying, Spray coating, Extrusion, External ionic gelation, Fluidized bed and Supercritical fluids. |
Table No: 3 Advantage and disadvantage of encapsulations techniques:
| Microencapsulation Technique | Process | Advantages | Disadvantages |
| Freeze drying | Freezing, sublimation (lyophilization) and desorption. | Temperaturesensitive compounds will preferable. | Styrofoam texture,Slow process, and Product cost. |
| Spray drying | Particles are drying by using hot air. Then emulsion, solution or suspension is atomized in the equipment. | Operation cost will be less, able to process in short time, reproducibility, efficiency and production rate is higher, Easy to handle products powders, It is used in a wide variety of compounds, with diverse polarities and compositions. | Nonuniform particles Can form aggregates, Not recommended for thermolabile compounds. |
| Spray chilling | Microcapsule mainly made by lipids and other appropriate compounds, then automized in cold chamber and leaving a solid particle. | It is suitable for heat sensitive compounds and operation cost is low. | Active compounds are release rapidly especially hydrophobic compounds, Nonuniform particles Variable encapsulation efficiency. |
| Complex coacervation | Combination of 2 polymers, such as protein and carbohydrate at specific pH value and proportion | Heat-resistant Different core compounds can be used Stable products | Expensive, Different forms depending on materials, Use of organic solvents, Variable encapsulation efficiency |
| Extrusion | Physical–mechanical process that involves the extrusion of the material through a nozzle | Cost-effective method No need for high temperatures, nor the use organic solvents or any specific pH condition | Difficulties with viscous solutions, Different sized and shaped products |
| Encapsulation in cyclodextrins | Inclusion molecular complex in a cyclic oligosaccharide | Controlled release of actives, Reduce loss and volatility of compounds, Solubility, and stability of hydrophobic actives | Expensive material Restricted to low-molecular-weight compounds Can form aggregates |
SOURCE: (Calderón-Oliver, M., & Ponce-Alquicira, E. 2022)
APPLICATION OF MICROENCAPSULATION TECHNIQUES IN FOOD INDUSTRY:
Food industry mainly uses microencapsulation techniques to enhance flavour, reduce shading and increase surface property as well as to improve the shelf life of food stream.Utilizing the bioactive compounds in actual food systems is the only way to access the overall effectiveness of microencapsulation in terms of bioactivity or functional impacts of the bioactive compounds.Many bioactive chemicals that are employed in the creation of food items have key properties such as antioxidant capacity, antibacterial activity, taste improvement, and food stability.Dairy goods, meat products, and pastry items are just a few of the food businesses whose products might potentially include microencapsulated substances(Table no -4)(N. Mehta, et, al. 2022).
One of the most crucial sensory qualities of any food product is taste. As previously mentioned, it is quickly disrupted by a variety of processing and storage circumstances. Consequently, the food sector faces significant hurdles in the microencapsulation of taste chemicals and their use in actual food systems.On the other hand, using microencapsulated nutrients is a fantastic choice for creating food items that are nutrient-rich.
Table No: 4Application of microencapsulated bioactive compounds in different food matrix:
| INDUSTRY | BIOACTIVE COMPOUNDS | BIOACTIVITY/NUTRIENTS | FOOD MATRIX |
|
MEAT INDUSTRY |
Thyme essential oil | Antioxidant and antimicrobial activities | Hamburgers |
| Allium sativum essential oil | Antimicrobial activity | Minced meat | |
| Pitaya peel extract | Colorant and antioxidant activity | Pork patties | |
| Prickly Pear Extract | Antioxidant and antimicrobial activities | Beef burger | |
| Fish oil | Fortification omega-3 | Chicken nugget,Beef burger, Cooked and cured sausages, Frankfurter-type sausages | |
| Flaxseed oil and Vitamin E | Fortification omega-3 and vitamin E | Chicken sausages | |
|
Dairy |
Folic acid, Vitamin B12, Vitamins A, E and CoQ10 | Fortification vitamins, Fortification CoQ10 | Cheese |
| Flaxseed oil | Fortification omega-3 | Milk | |
| Thymol | Antimicrobial activity | Milk | |
| Pomegranate peel phenolics | Antioxidant and α-glucosidase inhibitory activities | Ice cream | |
| β-Carotene and α-tocopherol | Colorant/carotene fortified/antioxidant activity | Yogurt | |
| Chia oil | Fortification omega-3 | Butter | |
| Opuntia stricta fruit juice | Colorant/betacyanin retention | Yogurt and soft drinks | |
|
Cereal and Bakery |
Garcinia fruit extract | Hydroxycitric acid | Bread |
| Chia oil | Fortification omega-3 | Cookies | |
| Flaxseed oil and garlic oil | Fortification omega-3 | Bread | |
| Green tea polyphenols | Antioxidant activity | Bread | |
| Hydrocitric acid | Antioxidant activity | Pasta |
SOURCE:(N. Mehta, et, al. 2022).
CONCLUSION:
Numerous products from other industries have been linked to microencapsulation, and studies have revealed that it has a significant potential to provide the centre with advantageous features and produce products of unparalleled quality that may be included into the food business.The microencapsulation technology provides flavouring components at the appropriate moment while also protecting the volatile component. Its release mechanism improves the product’s acceptance.. Recent investigations indicated that the encapsulation process might help in overcoming the limitations of plant bioactive compounds. Among different encapsulation techniques for natural plant antioxidants, spray-drying and extrusion are mainly explored for protecting added natural antioxidants to prevent their degradation. By using plant bioactive compounds encapsulation, promising results have been achieved in meat preservation.
