# Sustainability in Bio-Based Edible Films, Coatings, and Packaging for Small Fruits
## 5 Edible Film and Coating Functionalities Important for the Small Fruit Industry
### Encapsulation Techniques and Mechanisms of Shelf-Life Extension Through Encapsulation Techniques  
From a conventional point of view, edible film formation requires adding bioactive ingredient(s) to the film-forming solution, followed by the film's casting [182]. An alternative approach is encapsulating the active component before mixing it with the film-forming materials [183]. Encapsulation can be defined as keeping compounds of interest within a carrier/matrix to improve the delivery of these active substances into food products while aiming to improve their properties or enhance stability to external factors [184; 185]. The used carriers can comprise several substances, including carbohydrates, proteins, lipids, and other organic and inorganic materials [186]. Nonetheless, they must conform to some criteria to be suitable for encapsulation systems, some of those regarding structure (composition and phase state), functionality (solubility, viscosity, particle size, morphology of surface, total charge of particles), organoleptic characteristics (color, flavor, and aroma) physicochemical parameters (resistance to changes in pH, temperature, humidity, oxidizing agents and radiation), physiological behavior (release mechanism, conformational changes in gastrointestinal tract, release rate, and toxicity), economic feasibility (financial availability of materials and technologies), and finally cultural, religious, and food restrictions [187; 188]. Carriers can be classified according to their morphological structure, phase state, or material nature [189]. The techniques used to achieve encapsulation can also be classified into different categories according to their carrier material, delivery systems, or state of the core material [189; 190]. A standard classification includes three main classes: physical-mechanical, physical-chemical, and chemical methods [191]. All of them present several advantages and limitations. Even so, encapsulation is viewed by the food industry as a beneficial technology that provides numerous benefits, such as easy handling and protection of active compounds, controlled release, control of sensory properties, and specific marketing effects. In the food industry, encapsulation can be used aiming at multiple effects, from improvement of the core material characteristics, focused on its release conditions or rate [192] or protection of the core material from environmental factors, that will ultimately improve the shelf life the encapsulated material [193]. Encapsulation can be used to make edible films or coatings that can be applied to fruits and vegetables, aiming to extend their shelf-life [194]. To be used in encapsulation materials for the food industry, ingredients have to be \"generally recognized as safe\" (GRAS) [195]. Several approaches to the encapsulation exist, including electrospinning, electro-spraying, spray drying, microfluidics, extrusion, 3D printing, coaervation, lyophilization, incorporation into nanotubes, porous micro/nanospheres, nanocomposites, isoelectric precipitation, antisolvent coprecipitation, and ionic gelation, depending the physical state of core (solid, liquid or gas), summarized in Table 3. Spray drying is one of the most used and old techniques due to its flexibility, continuous operation, and economical value [196; 197; 198]. Other methods are extrusion methods, where droplets of an aqueous solution of polymer and the desired compound to be encapsulated are dropped into a gelling bath [199]. Another common technique is emulsions, which can be used in two main combinations,water/oil emulsions or oil/water emulsions, that can be further dried to produce a powder. Fluid bed coating can also be applied, where core particles are suspended in airflow and sprayed with an atomized coating material that might be an aqueous solution of cellulose or starch derivatives, proteins, and gums [200].