Analysis of Biological Activities and Functional Components in Fermented Gastrodia elata Blume by Lactobacillus

To improve the unpleasant flavor and taste of Gastrodia elata Blume, G. elata was fermented by Lactobacillus brevis (KCCM 41029) and then analyzed for functional components and biological activity changes. G. elata samples before (NFG, non-fermented Gastrodia) and after (FG, fermented Gastrodia) fermentation were compared with a liquid product from FG (FG-P, product from FG). Crude lipid and crude ash contents were elevated after fermentation. pH level decreased from 4.76 to 4.26, total soluble solids increased from 5.2°Bx to 6.1°Bx, and yellowness (b value) in terms of Hunter’s color value significantly increased. Transmittance (%) decreased after fermentation. Total sugar and reducing sugar contents significantly decreased, and total polyphenols increased from 16.6 mg GAE/g to 24.2 mg GAE/g. Three index compounds, gastrodin, gastrodigenin and p-hydroxybenzaldehyde, were isolated by HPLC concurrent with vanillyl alcohol and vanillin. Gastrodin level significantly increased from 146.63 ppm (NFG) to 166.26 ppm (FG) and 751.05 ppm (FG-P) upon fermentation. The level of gastrodigenin, which is an aglycone of gastrodin, decreased and was similar to that of p-hydroxybenzaldehyde. Reduction of these two compounds is thought to contribute to the gross increase in the main component, gastrodin. Vanillyl alcohol and vanillin contents increased upon fermentation. IC50 of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability to determine the antioxidant activity was 8.05 mg/mL (NFG) compared with 5.86 mg/mL (FG) and 8.19 mg/mL (FG-P). Antibiotic activities against five food poisoning microorganisms, Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella enteritidis, were determined by the paper disc method. The diameter of the clear zone was concentration-dependent and FG showed the highest activity.