Development of microencapsulated sodium metabisulfite (SMBS) for deoxynivalenol (DON) detoxification in animal feed

Deoxynivalenol (DON) contamination in animal feed may cause a reduction in growth performance and compromise the immune system of farm animal. Sodium metabisulfite (SMBS) is a promising chemical agent to detoxify DON in animal gastrointestinal tract. However, SMBS can quickly decay at acidic conditions such as in the stomach, which results in loss of its ability to detoxify DON. Therefore, protection of SMBS is critical to prevent its release before arriving at the small intestine. The objective of the current study was to develop encapsulated SMBS microgranules, which can stand the acidic condition of stomach and release the SMBS in the small intestine. Three encapsulation procedures were used which include hot melt granulation, hot melt granulation + secondary coating and two-step granulation methods. The efficiency of these methods were compared by the releasing profiles of SMBS in the simulated salivary fluid (SSF), gastric fluid (SGF) and intestinal fluid (SIF). The two-step granulation method was selected and further optimized to release less than 20% of SMBS in SSF and SGF, and completely release the encapsulated SMBS within 4 hours in SIF. The developed SMBS microgranules will be further evaluated in experimental animals.