P13: Enhancing Viability of Lactobacillus plantarum pi06 Microgranules Prepared by a Coating Pan at Low Temperature

High viability of Lactic acid bacteria (LAB) enhances their values during preparation such as the drying condition. Lactobacillus plantarum pi06 with the immune-enhancing ability was isolated from health infant feces and dried by a coating pan at low temperature to produce microgranules. Suspension cells or freeze dried powder of LAB was sprayed on the surface of sugar core with hydroxypropyl methylcellulose (HPMC) as the binder. Then, enteric soluble materials were coated onto the LAB layer to produce microgranules at 28~32°C for 4 hrs. Viable counts, acid resistance, enteric solubility, and stability were determined and compared among different kinds of microgranules. Results indicate that Shellac as the coating material exhibits a better preservative for cells survival. Over 1 x10¹¹ cfu/g of viable counts were obtained in most of coated samples which showed 0.4~0.6 of Aw and 4.6~6.1% of water content. In simulating gastrointestinal tract experiment, disintegration time of coated samples with shellac is around 8~9 min at pH 6.8 buffer solution. Significant improvement of viability of shellac-coated LAB was observed when treated in buffer solution with pH 1.5 or pH 3.5. Survival rates were still higher and more stable during storage at temperature of 4, 25, and 37°C. Besides, viable counts in microgranules prepared by directly using the LAB powder were higher than that by using liquid cell suspension. In conclusion, shellac-coated microgranules by a coating pan at low temperature results in higher viability and acid-resistance which are beneficial for further application in food industry.