## 3 Results and Discussion  
### Cell Number and Encapsulation Efficiency of Microcapsules  
The cell number of microencapsulated _L. plantarum_ 299v samples varies from 7.66 to 11.34 Log CFU/g (Figure 2A). All samples showed numeration above 6 Log CFU/g, the minimal requirement of probiotics as a functional food [1]. Additionally, the cell number was approximately 10 Log CFU/g of most samples except DWP sample. These results are similar to the values published in the studies of Kluyveromyces maxianus VM004 [15] and Bifidobacteriumumin animals subsp. Lactis INL1 [32] when they microencapsulated microorganisms with whey protein and spray-drying technology. Additionally, the cell number of samples with core-to-wall ratio 1:1 is significantly higher than that of those samples with a core-to-wall ratio 1:1.5. This may be due to the lower ratio of wall materials leading to a higher amount of probiotic bacteria in a certain microcapsules complex, which can result in a higher cell number in truth. In addition, the cell number of the samples with WP and WP:DWP 3:1 is significantly higher than samples with WP:DWP 1:1, WP:DWP 1:3, and DWP; the samples with WP and WP:DWP 1:1 is significantly higher than samples with DWP; the samples with WP:DWP 1:1 and WP:DWP 3:1 is significantly higher than samples with DWP. The reason may be due to the stable membrane stabilization properties of whey proteins, which can avoid cell damage, and with a decrease core-to-wall ratio of whey protein in the microcapsules, more probiotic bacteria lost their viability during the lyophilization process. The encapsulation efficiency of microencapsulated _L. plantarum_ 299v samples varied between 76.25% and 105.39% (Figure 2B). This agrees with the result published in the study by [PERSON] [15] when they microencapsulated Kluyveromyces maxianus yeast cells using whey protein concentrate as the wall material. [PERSON] & [PERSON] in 2015 also reported that both whey protein isolate (WPI) and denatured WPI in combination with fructooligosaccharide (FOS) in 1:1 ratio exhibited higher encapsulation efficiency, lower  
Figure 2: Cell number (**A**) and encapsulation efficiency (**B**) of microencapsulated _L. plantarum_ 299v strain with different core-to-wall ratios and wall material ratios. WP: whey protein, DWP: denatured whey protein. Results are shown as the means and standard deviations. The superscript letters indicate significant differences (\(p\) < 0.05). residual moisture content, and a narrower range of particle size distribution than 1:1.5. In our case, the encapsulation efficiency of samples with ratio 1:1 is significantly higher than that of those samples with ratio 1:1.5. This may also be due to the lower ratio of wall materials will lead to a higher the number of probiotic bacteria in a certain microcapsules complex, which can result in a relatively higher cell number after lyophilization under the same formulation. In addition, the encapsulation efficiency of the samples with WP is significantly higher than samples coated by DWP in the circumstances with ratio 1:1 and 1:1.5. The probable reason may be due to the protecting ability of the cell membrane of WP, which is better than DWP, and results in a relatively higher encapsulation efficiency. Microencapsulation plays a huge impact in food developments. It can transform essential and conventional foods into fortified processed foods for better nutritional, functional, and controlled delivery. Encapsulation efficiency refers to the percentage of probiotics successfully embedded into the microcapsules, which is one of the most essential criteria for the use of probiotics [13]. Under the same effectiveness of probiotics per unit, based on the quality definition of the products of probiotics, the higher the encapsulation efficiency, the better the product. Due to the definition of encapsulation efficiency, there is some connection between cell number and encapsulation efficiency. In addition, the viable cell number is also a noteworthy indicator for checking the quality of probiotic products [12].