Sensitivity of microorganisms distributed through Japanese tea manufacturing process by radiation

• Published in: FOOD IRRADIATION, JAPAN Vol. 37; no. 1-2; pp. 1 - 5
• Main Authors: "Ogura, M. (Osaka Univ. of Pharmaceutical Sciences, Takatsuki (Japan)), Kimura, S, Sugimoto, Y, Jo, N, Nosaka, K, Iwasaki, I, Nishimoto, S.
• Format: Journal Article
• Language: Japanese
• Published: JAPANESE RESEARCH ASSOCIATION FOR FOOD IRRADIATION 2002
• Subjects: CAMELLIA SINENSIS; IRRADIATION; MICROORGANISMS; PROCESSING; STERILIZING
• ISSN: 0387-1975; 1884-3611
• DOI: 10.5986/jrafi.37.1

"The number of bacteria adhering to Japanese tea is 10E7-10E8 cfu/g in picked fresh tea leaves (almost radiation irresistance), decreasing every heat-treatment in manufacturing process to 10E3-10E4 cfu/g in tea on the market (only radiation resistance). Still more, its decreasing one figures after half a year by effect of anti-bacterium component contained Japanese tea. The number of fungi adhering to almost samples is below 50cfu/g, but that adhering to some powdered tea is 10E2 cfu/g. At heat treatment (80degC, 15min), the number of bacteria decrease very little. The other side, by EB-irradiated treatment (2kGy), its below 10E2 cfu/g (D sub(10-)value; 1.4 ~ 3.8kGy). The needed dose to decrease 10E2 cfu/g is 0.9 ~ 2.5kGy."