PThe consumption of probiotics are defined by the Food and Agriculture Organizhas been associated with a wide range of health benefits for consumers. Products containing probiotics need to have effective delivery of the microorganisms for their consumption to translate into benefits to the consumer. In the last few years, the microencapsulation of the United Nations (FAO) and the World Health Organization (WHO) as “livingprobiotic microorganisms has gained interest as a method to improve the delivery of probiotics in the host as well as extending the shelf life of probiotic-containing products. The microencapsulation of probiotics presents several aspects to be considered, such as the type of probiotic microorganisms which, when ingested in certain amounts, the methods of encapsulation, and the coating materials. The aim of this review is to present an updated overview of the most recent and common coating materials used for the microencapsulation of probiotics, as well as the involved techniques and the results of research studies, provide health benefits to the host”ing a useful knowledge basis to identify challenges, opportunities, and future trends around coating materials involved in the probiotic microencapsulation.
The consumption of probiotics has been associated with a wide range of health benefits for consumers. Products containing probiotics need to have effective delivery of the microorganisms for their consumption to translate into benefits to the consumer. In the last few years, the microencapsulation of probiotic microorganisms has gained interest as a method to improve the delivery of probiotics in the host as well as extending the shelf life of probiotic-containing products. The microencapsulation of probiotics presents several aspects to be considered, such as the type of probiotic microorganisms, the methods of encapsulation, and the coating materials.
Probiotics are defined by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) as “living microorganisms which, when ingested in certain amounts, provide health benefits to the host” [1]. The consumption of probiotics positively influences the growth of targeted microorganisms in the host gastrointestinal tract, eliminates harmful bacteria or fungi, and boosts the naturally occurring defence actions of the host’s immune system. Additionally, it also helps in the treatment for irritable bowel syndrome (IBS), gastrointestinal dysbiosis, as for other intestinal disorders [2][3][4]. Most of the known probiotics are Generally Recognized As Safe (GRAS), including
Lactobacillus
Bifidobacterium
Saccharomyces boulardii
S. cerevisiae
Lipomyces starkeyi VIT-MN03 [3][4][5][6]. Several mechanisms are proposed on how these microorganisms are beneficial to the host wellbeing. Some examples are: by the production of antimicrobial or antifungal peptides; by stimulating changes in the intestinal environment which make it unfavourable for other microorganisms, including pathogens; as well as by competing for nutrients and for attachment to intestinal epithelial cells [7][8][9]. Probiotic microorganisms are also required to have certain features, such as: genetic stability; resistance to the gastric environment (acid and bile tolerance); adhesion capability to a mucosal surface; good in vitro/in vivo growth properties; maintaining high viability at processing; survival during storage, among others. These features ensure the survivor of a large number of these beneficial microorganisms for the successful colonization of the host’s colon. Strict safety criteria are also compulsory, such as origin, the lack of pathogenicity and infectivity, or presence of virulence factors (toxicity, metabolic activity, and intrinsic properties, i.e., antibiotic resistance) [10][11].
Microencapsulation with edible coatings is often used to carrying a wide variety of products, such as: probiotics, flavours, fragrances, enzymes, antioxidants, antimicrobials, lipids, minerals, edible pigments, nucleic acids, etc. [12][13]. During the last decades, the microencapsulation has arisen as a trendy method for enhancing the survival of probiotic microorganisms. Probiotic microcapsules, when ingested, should result in more efficient probiotic delivery to the host gastrointestinal tract [14][15]. The term “microencapsulation” is defined as a process in which tiny particles or droplets of liquid or solid material are surrounded by a coating, or embedded in a homogeneous or heterogeneous film of polymeric matrix, to give small capsules with many useful properties [16][17]. According to the size, the capsules can be classified as: macro- (>5000 μm), micro- (0.2 to 5000μm), and nano-capsules (<0.2 μm) [18].