Abstract
In this study, Lacticaseibacillus casei and Lactobacillus acidophilus probiotic bacteria were encapsulated using oleaster flour, which is rich in phenolic compounds and has prebiotic properties as potential. The optimum conditions required for the encapsulation of L. casei and L. acidophilus bacteria with maximum efficiency using oleaster flour were determined by central composite design-response surface methodology. As a result of the optimization process, the encapsulation efficiency for L. casei and L. acidophilus capsules was 93.66 ± 2.58% and 74.97 ± 1.34%, respectively. The capsule sizes of L. casei and L. acidophilus encapsulated with oleaster flour were determined by scanning electron microscopy to be 104.8 ± 26.3 and 95.7 ± 12.1 μm, respectively. Fourier transform infrared spectroscopy analyses showed that there was no change in the structure of the encapsulation material, oleaster flour, after encapsulation. Also, the storage stability of free and encapsulated bacteria was investigated, and it was found that the viability losses of encapsulated probiotic bacteria were less than those of free probiotic bacteria. Finally, the effect of encapsulation on bacterial viability during in vitro gastrointestinal digestion was investigated, which is the main purpose of the study. While free probiotic bacteria cannot reach the intestinal environment alive after in vitro gastrointestinal digestion due to pH and enzyme effects, encapsulated L. casei and L. acidophilus bacteria largely preserved their viability, and their postdigestion viability was 39.59 ± 1.50% and 36.28 ± 0.01%, respectively. The results showed successful encapsulation of L. casei and L. acidophilus probiotic bacteria with oleaster flour.