The conditions for extracting phenolic compounds from Jambolan seeds were studied Effects of the type of solvent (distilled water, and ethanol solution with the concentration of 50% and 95%), the extraction period (1 – 8 hours), and the extraction temperature (a room temperature, 45 and 80 degree Celsius and Soxhlet extractor) on the total phenolic and total flavonoid contents, yields, phenolic and flavonoid concentrations and the anti-pathogenic bacteria activities of the seed extracts were investigated. Escherichia coli (E. coli) ATCC 25922, salmonella Typhimurium (S. Typhimurium) ATCC 13311 and Staphylococcus aureus (S. aureus) ATCC 25923 were chosen as gram-negative bacteria and gram-positive bacteria for the tests, respectively. The seed extracts obtained from the 50% ethanol solution gave the highest amounts of total phenolic and flavonoid contents, yields and phenolic and flavonoid concentrations (p<0.05). However, the extraction period had an insignificant effect on the amount of total phenolic and flavonoid contents contained in the seed extracts. The seed extracts obtained from 1 hour extraction period using various kinds of solvents were tested for antibacterial activities against E. coli, S. Typhimurium and S. aureus. The results showed that the seed extracts that were extracted by 50% and 95% ethanol solution could inhibit the growth of bacteria better than those extracted from water. Therefore, the extraction using 50% ethanol solution with the extraction period of 1 hour was chosen to determine of the suitable extraction temperature. It was found that the Soxhlet extraction yielded the lowest total phenolic and flavonoid contents and yield in the seed extract, but gave the highest phenolic and flavonoid concentrations. The results also showed that the extraction temperature had a little effect on antibacterial activities of the seed extracts. Thus, the room temperature was chosen as washing agent to reduce bacterial contents on fresh sweet basil. By soaking sweet basil in the 4 MBC 25 mg/mL) seed extracts for 10 minutes, the total bacterial count (TBC) and E. coli was significantly decreased. Additionally, the remaining amounts of E. coli was within the acceptable range indicated in the safety requirements for agriculture commodity and food in Thailand. In order to maintain the antibacterial activities of the seed extracts, it was recommended that the seed extracts should be stored in a brown bottle tightly closed at a room temperature (27 2 degree Celsius) for the period of less than 3 months.
