Thermo-tolerant Saccharomyces cerevisiae var. boulardii coated cornflakes as a potential probiotic vehicle

Abstract

Functional probiotic breakfast products are being sought because of strong consumer demand. Cornflakes, a popular breakfast cereal is usually consumed with hot milk in Asian countries. Coating the probiotics on cornflakes would potentially be a way to deliver a probiotic; however, the survivability of the probiotics is a major concern. Thus, this study aimed to develop a heat-stable probiotic cornflakes using hydrocolloids as a coating agent. Hydrocolloids were blended with Saccharomyces boulardii, coated on the cornflakes, and then assayed for the viability of S. boulardii after exposure to pre-heated milk. Probiotic-coated cornflakes with acacia gum (6%) showed maximum protection of S. boulardii (7.3 ± 0.1 log CFU/g) over the control (2.3 ± 0.1 log CFU/g) when treated with pre-heated milk at 80±2 °C. The water absorption index, water absorption capacity, milk absorption capacity, and surface area were significantly reduced in the probiotic-coated cornflakes. Brunauer-Emmett-Teller modeling of the surface area using nitrogen, and scanning electron microscopy analysis showed the efficient binding of hydrocolloids to cornflakes. The simulated gastrointestinal model suggested a noticeable resistance of S. boulardii to acid, pepsin, and moderate resistance to pancreatic juice. Probiotic-coated cornflakes showed an 88.3% survival rate of S. boulardii when stored at 30±2 °C for 90 days. In conclusion, acacia gum might protect probiotic microorganisms in hot served food products.