The Bifidobacterium bifidum susceptibility in gastrointestinal conditions and storage stability limit its use as potential probiotics. The current study was design to encapsulate B. bifidum using sodium alginate (SA, 1.4% w/v) and different concentration of zein as coating material, that is, Z1 (1% w/v), Z2 (3% w/v), Z3 (5% w/v), Z4 (7% w/v), Z5 (9% w/v). The resultant microbeads were further investigated for encapsulation efficiency, survival in gastrointestinal conditions, release profile in intestinal fluid, storage stability and morphological characteristics. The highest encapsulation efficiency (94.56%) and viable count (>107 log CFU/g) was observed in Z4 (7% w/v). Viable cell count of B. bifidum was >106 log CFU/g in all the zein-coated microbeads as compare to free cells (103 log CFU/g) and SA (105 log CFU/g) at 4 °C after 32 days of storage. Therefore, B. bifidum encapsulated in zein-coated alginate microbeads present improved survival during gastric transit and storage.
Keywords: Zein; coating; microencapsulation; survival.