In this study, a simplex-centroid mixture design using design of experiment (DOE) software was implemented to evaluate the effect of biopolymers as excipients, which are hydroxypropyl methylcellulose, and alginate, on the gastrointestinal tolerance of probiotic tablet containing Saccharomyces boulardii. Microbial viability and dissolution time were used to evaluate the ideal formulation made using 39.01% carboxymethylcellulose and 60.99% alginate as excipients, which protected the probiotics from the acidic condition in the stomach with good dissolution time. The formulated probiotic tablet is more stable in terms of viability when stored at 4 °C compared to room temperature. However, the viability remains above 106 CFU/tablet after six months of storage at room temperature. This study shows that the simplex-centroid mixture design is valid and can be used to formulate probiotic tablets that possess gastrointestinal tolerance. This study can lead to the development of commercial production of probiotic yeast tablets with gastrointestinal tolerance.
The escalation of the global population has accelerated the demand for sustainable energy sources such as bioethanol. Traditionally, bioethanol was obtained by the fermentation of sugar from agricultural crops and grains. However, this technique creates serious threats on the global food supplies, thus hindering the commercial production of bioethanol. Therefore, there is a need to develop new technologies and low-cost raw materials in order to ensure that bioethanol is economically comparable to the first generation of bioethanol. Solid-state fermentation (SSF) has been in the limelight within the scientific community because of its efficiency, cost-effectiveness, and promising technology to produce bioethanol. SSF involves the cultivation of microorganisms on a solid substrate in the absence of free-flowing water, which eliminates the need for sugar extraction and reduces wastewater production. This systematic review provides an overview of the applications of SSF in bioethanol production while presenting recent studies and advancements of this technology for producing sustainable and cost-effective bioethanol.