<i>In vitro</i> survival of <i>Bifidobacterium bifidum</i> microencapsulated in zein-coated alginate hydrogel microbeads

Abstract

The <i>Bifidobacterium bifidum</i> susceptibility in gastrointestinal conditions and storage stability limit its use as potential probiotics. The current study was design to encapsulate <i>B. bifidum</i> using sodium alginate (SA, 1.4% w/v) and different concentration of zein as coating material, that is, <i>Z</i>₁ (1% w/v), <i>Z</i>₂ (3% w/v), <i>Z</i>₃ (5% w/v), <i>Z</i>₄ (7% w/v), <i>Z</i>₅ (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 <i>Z</i>₄ (7% w/v). Viable cell count of <i>B</i>. <i>bifidum</i> 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, <i>B. bifidum</i> encapsulated in zein-coated alginate microbeads present improved survival during gastric transit and storage.