The Determination of Microbial and Chemical Identity Quality of Fingerroot Soy Milk

Abstract

     The purpose of this study was to examine the quality of herbal products: fingerroot (Krachai Khao) soy milk. The study process is based on the experimental research by examination of microbial contamination of 3 groups of samples: fingerroot boiled water, soy milk, and fingerroot soy milk that were stored in the refrigerator at 4 °C on day 1, 7 and 14 of preparation day. The study found that all 3 samples were examined for contamination on the first day of preparation day compared to day 7 and day 14 of refrigerated storage. No contamination of fungi and yeast, Clostridium spp., Escherichia coli, Salmonella spp. and Staphylococcus aureus. However, further two days of keeping, only fingerroot boiled water was not contaminated, while soy milk and fingerroot soy milk were contaminated with fungi and yeasts, Escherichia coli and Salmonella spp. This indicated that the standard of storage and quality of fingerroot soy milk was not more than 14 days in the 4˚C refrigerator. In addition, the chemical identity was examined by the high-performance thin layer chromatography (HPTLC) technique of 3 samples at day 1 and 14. The separation of soy milk and fingerroot soy milk with similar R_f values was observed under 366 nm UV light, and fingerroot boiled water was detected under 254 nm UV light. Therefore, this research showed an opportunity to develop a quality determination standard for healthy drink products.