# Advances in the Application of Microcapsules as Carriers of Functional Compounds for Food Products
## 6 Incorporation of Microcapsules in Food Matrices  
Quite a lot of studies have already been carried out on the microencapsulation of bioactive compounds and probiotics. However, there are few studies reported in the literature regarding how loaded microcapsules behave in terms of stability when incorporated in real food matrices [93]. An important factor regarding this incorporation is that food products should not be adversely affected, namely their sensory properties altered by the addition of microencapsulated bioactive ingredients [101]. Therefore, the incorporation of bioactive compounds into a food matrix presents a challenge for the food industry. Nevertheless, some good examples may be highlighted (Table 1).  
[PERSON] et al. [21] microencapsulated carotenoids from sea buckthorn extract by coacrevation using whey protein isolate and arabic gum as wall materials. The encapsulated powders obtained were incorporated into muffins in order to evaluate the influence of the food matrix on the stability of the bioactive compounds. The amount of total carotenoids, antioxidant activity, physicochemical characteristics, sensory analysis, and stability of the bioactive materials during storage of the food matrix were tested. The stability analysis of the encapsulated carotenoids incorporated into the muffins during storage at 25 \({}^{\circ}\)C for 21 days showed a loss of carotenoid content of approximately 55%. However, no significant changes in the color of the muffins were observed. The sensory analysis showed that the muffins containing microcapsules were preferred by the panellists, and neither aroma nor flavor of the sea buckthorn berries was detected.  
Carotenoid-rich gac oil was microencapsulated in a mixture of whey protein concentrate and arabic gum (7:3) by spray drying [34]. The microencapsulated gac oil obtained was incorporated into a viscous food (yogurt), a low viscosity liquid food (pasteurized milk), and a dry food (cake mix) with the purpose of fortifying the food matrix. The authors analyzed these fortified products for color, peroxide value, and the amount of carotenoids present during four weeks of storage for yogurt and pasteurized milk, and during four months for cake mixing. Overall, they concluded that encapsulated gac oil can be successfully incorporated into these food products, exhibiting a slight color change and high levels of carotenoids during storage. However, further research is needed to study the release and bioavailability of carotenoids reached in the bloodstream after ingestion.  
Green tea extract rich in polyphenols was microencapsulated in maltodextrin by spray-drying and freeze-drying and then added to bread [48]. This study evaluated the impact of microcapsules on bread quality and polyphenol content after baking. The amount of polyphenols present in the baked bread was 33% lower than in the dough before baking. In terms of bread quality, no significant differences were observed in the color or flavor of the breads or in the volume and crumb firmness between the samples incorporated with particles produced by spray-drying and freeze-drying. According to the authors, the fortification of bread with polyphenols of green tea maintains bread quality and most of the functionality of the bioactive compounds, suggesting that such fortification could be efficient to increase polyphenol intake.  
[PERSON] et al. [15] studied the effect of microencapsulated anthocyanins incorporated into fermented milk to act as a prebiotic for _L. casei_. Microencapsulation of anthocyanins from an extract of sour cherry skin was performed by coacrevation followed by freeze-drying using whey protein isolate and arabic gum as wall materials. The microencapsulated bioactive compounds exerted the prebiotic function and favoured the growth of the _L. casei_ probiotic during storage for 21 days. The number of viable cells in fortified samples remained in the 10\({}^{10}\) CFU/g range.