کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6397750 | 1330677 | 2013 | 8 صفحه PDF | دانلود رایگان |
- Chitosan coated beads increased cell survival in simulated gastric solution.
- Coated beads increased cell survival in pomegranate juice during 6-week storage.
- The beads' hardness decreased in the juice due to the sequestering of calcium ions.
- No correlation existed between cell survival and the hardness of the beads.
The aim of this work was to compare alginate and pectin beads for improving the survival of Lactobacillus plantarum and Bifidobacterium longum during storage in pomegranate and cranberry juice, and to evaluate the influence of various coating materials, including chitosan, gelatin and glucomannan on cell survival and on the size and hardness of the beads. In pomegranate juice, free cells of L. plantarum died within 4Â weeks of storage and those of B. longum within 1Â week; in cranberry juice both types of cells died within one week. Encapsulation within either alginate or pectin beads improved cell survival considerably, but coating of the beads with chitosan or gelatin improved it even further; coating with glucomannan did not have any positive effect. The double gelatin coated pectin beads gave the highest protection among all types of beads, as a final concentration of approximately 108Â CFU/mL and 106Â CFU/mL for both L. plantarum and B. longum was obtained after 6Â weeks of storage in pomegranate and cranberry juice, respectively. The good protection could be attributed to the very strong interaction between the two polymers, as measured by turbidity experiments, leading to the formation of a polyelectrolyte complex. It was also shown that the coating was able to inhibit the penetration of gallic acid within the beads, which was used in this study as a model phenolic compound with antimicrobial activity; this is a likely mechanism through which the beads were able to protect the cells from the antimicrobial activity of phenolic compounds present in both types of juices. Despite their good protective effect, the pectin beads were considerably softer than the alginate beads, an issue that should be addressed in order to increase their mechanical stability.
Journal: Food Research International - Volume 53, Issue 1, August 2013, Pages 304-311