# The Yeast-Based Robotic Encapsulation Scenario: A Systematic Review and Meta-Analysis
## 3 Results and Discussion
### Study Inclusion
[39] used three ingredients, both individually and in combination (sodium alginate; sodium alginate/chitosan; sodium alginate/starch/vegetable oil). The encapsulation efficiency (EE) is a very important category of data in studying the encapsulation process of a probiotic. However, only few articles (n = 4) reported these data in their results. The EE varied between 35 and 98.1%. The highest EE wereobserved in studies using gum arabic (91.4-98.1%) and sodium alginate (90-94%) in their composition. The authors of [39] reported an EE ranging from 35% to 45%, indicating the lowest observed efficiency. A total of eight yeast genera/species were used as probiotics in the tests, with _Saccharomyces bouldaridii_ reported in seven studies, _Saccharomyces cerevisiae_ reported in five studies, and _Issacthenkia occidental_, _Kluyveromyces marxianus_, _Pichia barkeri_, _Yarrowia lipolytica_, _Wickerharomyces anomalus_, _Lactobacillus acidophilus_, and _Saccharomyces_ sp. reported only once. The yeast survival after the different treatments ranged from 1.7 to 100%. These values were obtained from 9 works that described these data in their results. Conclusively, in the chosen articles, yeast microencapsulation was efficient in maintaining survival after gastrointestinal tests, viability studies, and thermal resistance in distilled water and food. The determined survival percentage varied greatly among and within the articles themselves due to the high number of treatments and variables considered. The path taken by probiotic microorganisms from encapsulation to the colon presents many challenges. Temperature and storage time can present concerns, namely viability through the pH and temperature of the gastrointestinal tract, among other factors [40; 41]. In addition, there is the possibility that microorganisms do not establish themselves as part of the intestinal microbiota. All these factors influence the effectiveness of the delivery of probiotics by commercial formulations or through food. The more influential are humidity (RH), temperature, pH, osmotic stress, and the amount of oxygen available in the environment [42; 43; 44]. Therefore, it is necessary to develop technologies that allow for achieving greater probiotic stability [43; 44]. Microencapsulation emerges as a viable and efficient alternative to systems commonly used to encapsulate small molecules, such as vitamins, minerals, and some drugs, and systems that do not contain bacteria and yeasts [45; 46; 47]. The strategies employed in microencapsulation to improve the viability of probiotics are diverse and must be considered: the presence of a physical barrier blocking the adversities from the environment; joining the probiotics with nutrients or additives that will help in their survival and in maintaining the environmental conditions inside the capsule; and capturing compounds from the external environment that help the survival of probiotic microorganisms [48; 49; 50]. From the point of view of human health, it is worth discussing that the cell viability of the probiotic is not the only variable to be considered. The term posbiotic has been used to refer to inanimate microorganisms and/or their components that confer health benefits. Therefore, the beneficial effects of probiotics are not only due to the action of the living cell in the intestine, but also due to the immunomodulatory potential of the constituent molecules [51; 52; 53]. The study carried out differs from the method commonly used in keywords of statistical investigation, since the interest in it is the choice of the best results, meaning the indicators (categorical or continuous) that were able to generate a better response in keywords of efficiency. The tool chosen for analysis was the \"Response Optimizer\", which determines, based on the amount of data provided, which indicators should be used to produce the best response.