Antimicrobial and antioxidative effects of defatted tea seed meal.

Antimicrobial and antioxidative effects of solvent extracts of defatted tea seed meal (DTSM) were investigated for possible utilization as food ingredients. Of the extracts from DTSM, the ethyl acetate-soluble fraction showed much stronger antibacterial activity against the Gram-positive bacteria, S. aureus, M. luteus and S. epidermidis, than did the control benzoic acid solution. It also exhibited stronger effects against the Gram-negative bacteria, E. coli, S. typhimurium and P. aeruginosa, than control. The ethyl acetate and butanol fractions displayed stronger antioxidant activity than BHA, BHT and α-tocopherol. The SC 50 of the butanol fraction was 16.2 µg/mL, which was higher than that of BHA. The solvent extract of DTSM could be a good source for antimicrobials and antioxidants.