Raman spectroscopy has been used to investigate the structure of coal tar pitch heat-treated up to 3000℃ by using 514.5 run Ar ion laser line. Four critical temperature ranges were found on pyrolyzing coal tar pitch, which correspond to four distinct processes from disordered carbons to the well-ordered graphite structure. The range of heat treat temperature (HTT) below 1000℃ corresponds to gas evolution during the pyrolysis of coal tar pitch. Above the HTT are correlated to rearrangements of enlarged molecules, growth of the molecules along the direction of plane, finally stacking in the normal direction of the plane, in the respective HTT ranges of 1000-2000, above 2000 and 2500-3000℃.

The effects of acetic acid (AA) on aerobic plate counts (APC), gram-negative bacterial counts (GNC), and generation time (GT) in chicken wings stored at 4℃ were assessed. Chicken wings were treated with 0.5-1.5% (v/v) AA at exposure times of 5 min. Treatments of AA for 5 min significantly (P$lt;0.05) reduced aerobic plate counts (APC) and gram-negative bacterial counts (GNC) on the surface of chicken wings for 8 days, respectively. After 4 days of storage, treatments of 1.0% AA and 1.5% AA for 5 min completely (P$lt;0.05) inhibited APC and GNC compared to initial controls. Based on these results, treatments of 1.0% AA and 1.5 % AA for 5 min prolonged the microbiological shelf-life for 8 days compared to those of 0.5% AA and the controls. All treatments of AA increased the lag phase and GT of aerobic microorganisms.