Improvement in the quality of a fermented seaweed beverage using an antiyeast starter of Lactobacillus plantarum DW3 and partial sterilization

The quality of a fermented beverage (FSB) produced from seaweed (Gracilaria fisheri) was investigated after four different fermentation processes. 1, a normal fermentation as control (N-N); 2, batch with addition of an inoculum of an antiyeast starter culture, Lactobacillus plantarum DW3 (N-S); 3, a partial sterilization of the seaweed with 0.5% potassium metabisulfite (KMS) (P-N); and 4, a partial sterilization followed by an inoculum as for 2 (P-S). At the end of fermentation (60 days) and after storage for 3 months, all treatment sets passed the microbiological quality guidelines, as no bacterial indicators (total coliforms and Escherichia coli) or foodborne pathogens (Salmonella sp. Clostridium perfringens and Staphylococcus aureus) were detected. All treatments improved the availability of elements (Cu, Zn, and Fe) in the seaweed beverage and they were all below the recommended safety levels. Toxic compounds such as methanol, and the elements As and Pb were below either the detection or safety limits. The starter culture controlled yeast contamination and had inhibitory effects against foodborne pathogenic bacteria (Vibrio parahaemolyticus PSSCMI 0064 > Bacillus cereus ATCC 11778 > Salmonella typhi PSSCMI 0034 ∼ Staphylococcus aureus PSSCMI 0004 ∼ E. coli PSSCMI 0001). The inoculation set without pretreatment by KMS (N-S) was the treatment that produced the best FSB based on its antibacterial activity, reduction of contaminated yeasts, remaining probiotic LAB and organoleptic properties.