ESTIMATION OF THE CONCENTRATIONS OF CELLS, ASTAXANTHIN AND GLUCOSE INA CULTURE OF PHAFFIA-RHODOZYMA BY NEAR-INFRARED REFLECTANCE SPECTROSCOPY

Near infrared reflectance spectroscopy (NIR) was employed to estimate the concentrations of cells, astaxanthin and glucose in the culture br oth of Phaffia rhodozyma. The culture broth (119 samples) was directly subjected for NIR analysis without any pretreatment. When the data ob tained by NIR were compared with those obtained by conventional method s, high correlation coefficients were obtained: 0.98 for cells, 0.99 f or astaxanthin and 0.94 for glucose. These results suggest that NIR an alysis, which is very simple and requires only 3 to 5 min for a sample , is applicable to monitor P. rhodozyma cultures.