# Microencapsulation of Anthocyanins--Critical Review of Techniques and Wall Materials
## 2 Microencapsulation Techniques
### Physicochemical Methods
#### 2.3.2 Liposomes  
When considering aspects such as flavor preservation and release, improved stability, and shelf life of sensitive materials, the microencapsulation technique provides exciting possibilities for food technologists. A new microencapsulation concept involves the liposome microencapsulation of food ingredients that benefit from cheap, commonly accepted as safe substances. Liquid particles, solid particles, or gaseous materials are packed inside continuous shells that can, under desired conditions, release their components at controlled rates. A liposome (or lipid vesicle) is a structure that consists of several aqueous or liquid compartments that enclose lipid bilayers [87]. Over the past 20 years, liposomes have been researched extensively as model membranes and drug delivery systems. Techniques for liposome microencapsulation have been produced, even to the point that they can be used in many commercial implementations. Previously, there have been engaging experiments in anthocyanins microencapsulation to apply liposomes in the food processing industry. The majority of encapsulating methods are based on the first formation of particles of the active agent, enclosed by a membrane via the various processes [88]. It is possible to think of the liposome as a hollow sphere, whose size can vary from a few nanometers to a few microns. Phospholipid molecules, which are the same molecules that form the cell membrane, are usually made of liposomes. There are various studies involving the application of liposomes for the microencapsulation of anthocyanins. For preserving anthocyanins, liposomes are a strong and advanced encapsulation vehicle. Liposomes are nano/microsized phospholipid bilayer colloidal vesicles that can be used to encapsulate high-value hydrophilic and hydrophobic components. Liposomes can shield unstable and active compounds from environmental conditions while also increasing their absorption and bioavailability due to their biocompatibility, amphiphilicity, nontoxicity, and non-immunogenicity. An enhanced supercritical carbon dioxide (SC-CO\({}_{2}\)) method was used to create anthocyanin-loaded liposomes in a study. Anthocyanin and cholesterol concentrations were investigated. The study's results showed that anthocyanin-loaded liposomes have significant promise in functional food and nutraceutical implementations [87]. Protein-polysaccharide interrelationships open up possibilities for creating new functional foods for food and pharmaceutical applications. One study used a single-stage SC-CO\({}_{2}\) method to develop anthocyanin-loaded liposomes. A phospholipid/anthocyanin suspension equilibrated with CO\({}_{2}\) was depressurized at a constant pressure and rate in this study. This study investigated the effects of strain, depressurization rate, and temperature on the liposome characterization. According to the researchers, this approach allows for the use of dense phase CO\({}_{2}\) to process phospholipid aggregates into nano/microparticles and regulate their properties through the tuning of processing parameters [89]. The SC-CO\({}_{2}\) method had a promising demonstration in the versatile processing of liposomes containing various bioactive compounds for food applications. Anthocyanin encapsulated in liposomes can be shielded from hazardous environmental factors, potentially improving their potency and health advantages in food and nutraceutical compositions. Liposomes are increasingly attractive for use in food science as a method of encapsulating anthocyanins because they can protect and retain hydrophilic bioactive compounds. Additionally, what also attracts the research attention is the possibility of using liposomes as suitable substance carriers through intestinal absorption with the minor use of carrier agents [90]. However, it is worth paying attention to the fact that liposomes are systems of relatively low stability since the interfacial connections are delicate.