hnolo

References

Chou, C.C., Lin, L.L., Chung, K.T., 1999. Antimicrobial activity of tea as affected by thedegree of fermentation and manufacturing season. Int. J. Food Microbiol. 48 (2),125–130.

Kawakami, M., Kobayashi, A., Yamanishi, T., Shoujaku, S., 1987. Flavour constituentsof the microbially fermented teas Zhuan-cha and Koku-cha. Nippon Nogeika-gaku Kaishi. J. Agric. Chem. Soc. Jpn. 61 (4), 457–465.

Mo, H.Z., Xu, X.Q., Yan, M.C., Zhu, Y., 2005. Microbiological analysis and antibacterialeffects of the indigenous fermented Puer tea. Agro Food Ind. Hi-Tech. 16 (6),16–18.

Mo, H., Zhu, Y., Chen, Z., 2008. Microbial fermented tea – a potential source of natural

S722 Abstracts / Journal of Biotec

The levels of triglycerides were also lower, due to uptake ofmushroom mycelia.

As a result of conducted studies it is possible to draw aconclusion that the additives of submerged mycelia of severalbasidiomycetes, to manage diabetes and leads to essential decreasein a risk of development of arteriosclerosis.

doi:10.1016/j.jbiotec.2008.07.1716

VIII1-P-004

Thermal stability of immobilized lipase from Candida antarcticain 1-alcohols and glycerol

Shuji Adachi ∗, Takashi Kobayashi

Division of Food Science and Biotechnology, Graduate School of Agri-culture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan

E-mail address: adachi@kais.kyoto-u.ac.jp (S. Adachi).

The immobilized lipase from Candida antarctica has been widelyused for the synthesis of esters through condensation or transester-ification. 1-Alcohols and glycerol themselves are one of substratesfor their condensation with a carbonic acid to produce theircorresponding esters. The condensation at a high temperatureaccelerates the reaction rate, but inactivation of the enzyme wouldbecome more significant. In this context, we examined the thermalstability of the immobilized lipase in 1-alcohols with 4–8 carbonsat 70 ◦C to 115 ◦C and in glycerols with various water contents at80 ◦C to 100 ◦C. The plots of the residual activity versus the incu-bation time on a semi-logarithmic scale did not give a straight linefor all the tested 1-alcohols and glycerol at any temperature, indi-cating that the inactivation did not obey the 1st-order kinetics.Assuming the heterogeneity in the susceptibility of the immobi-lized enzyme to the inactivation, the process was expressed by thefollowing equation (Kawamura et al., 1981):

Ce

Ce0= RT√

2��

∫ ∞

−∞exp

(−R2T2(ln kd− ln k̄d)

2

2�2

)exp(−kdt)d(ln kd)

(1)

where Ce is the active enzyme concentration, Ce0 is the initial Ce, Ris the gas constant, T is the absolute temperature, kd is the rate con-stant of thermal inactivation, k̄ is the k corresponding to the mean

d dvalue of the free energy of activation, �G‡, and � is the standarddeviation of �G‡. The inactivation processes of the immobilizedlipase from Candida antarctica in all the tested 1-alcohols and glyc-erols could be well expressed by Eq. (1). The results indicated thatalkyl or glyceryl esters could be synthesized using the enzyme atan abnormally high temperature.

Acknowledgement

This study was partially supported by Cooperative for InnovativeTechnology and Advanced Research in Evolutional Area (CITY AREA)program from the Ministry of Education, Culture, Sports, Scienceand Technology, Japan.

Reference

Kawamura, Y., Nakanishi, K., Matsuno, R., 1981. Stability of immobilized �-chymotrypsin. Biotechnol. Bioeng. 23, 1219–1236.

doi:10.1016/j.jbiotec.2008.07.1718

gy 136S (2008) S717–S742

VIII1-P-009

Antimicrobial activity of the indigenously microbial fermentedFuzhuan brick-tea

Haizhen Mo 1,∗, Hao Zhang 1, Yingqiu Li 2, Yang Zhu 3

1 School of Food Science, Henan Institute of Science and Technology,Xinxiang, 453003, China2 College of Food and Bioengineering, Shandong Institute of LightIndustry, Jinan 250353, China3 Food and Bioprocess Engineering Group, Wageningen University, P.O.Box 8129, 6700 EV Wageningen, Netherlands

E-mail address: hzmo@yahoo.com.cn (H. Mo).

Antimicrobial activity of extracts from an indigenously fermentedtea, Fuzhuan, was tested in addition to the microbiological analysis.Microbial counting and identification revealed that Aspergillus spp.,Penicillium spp. and Eurotium spp. were the main microorganismsisolated from the samples of fermentation and Eurotium spp. wasthe dominating fungus responsible for the fermentation. Antibac-terial tests of extracts of fermented tea showed inhibitory effecton several food borne bacteria, including spore forming bacteriaBacillus cereus, Bacillus subtilis, Clostridium perfringens and Clostrid-ium sporogenes. The antibacterial activity increased with the courseof the fermentation. This implied that certain metabolites of thefungi growing on tea leaves had the feature of inhibiting certainfood borne spoilage and pathogen microorganisms. These naturalantimicrobial substances have the potential as innovative and mildfood preservatives.

Keywords: Antimicrobial activity; Aspergillus spp.; Penicillium spp.;Erothium spp.; Fuzhuan brick-tea; Solid-state fermentation; Foodfermentation

food preservatives. Trends Food Sci. Technol. 19 (3), 124–130.Schillinger, U., Geisen, R., Holzapfel, W.H., 1996. Potential of antagonistic microor-

ganisms and bacteriocins for the biological preservation of foods. Trends FoodSci. Technol. 7 (5), 158–164.

Si, W.D., Gong, J., Tsao, R., Kalab, M., Yang, R., Yin, Y.L., 2006. Bioassay-guided purifica-tion and identification of antimicrobial components in Chinese green tea extract.J. Chromatogr. A 1125 (2), 204–210.

Xu, X.Q., Mo, H.Z., Yan, M.C., Zhu, Y., 2007. Analysis of characteristic aroma of fungalfermented Fuzhuan brick-tea by gas chromatography/mass spectrophotometry.J. Sci. Food Agric. 87 (8), 1502–1504.

doi:10.1016/j.jbiotec.2008.07.1719