The SW-NIR transmittance spectra of the mangosteens
were measured in the range from about 640 to 980 nm at
1.29 nm intervals using a silicon photodiode array detector
with a fiber optic cable and a 100 m input slit. A high
speed shutter unit switched the optical path during measurement
into three modes: target, reference and dark reference.
Integration time could be varied from 1 to 3000 ms with a
detector count level of 20 bit A-to-D. The measurement data
were transmitted to a computer via real time transfer interface
boards. Each mangosteen was loaded for measuring on a
turntable instrument (Fruits analyzer, SAIKA TIF.) consisting
of three silicone sample holders and a reference holder
positioned symmetrically on the radius of the turntable. Four
100 W tungsten halogen light sources (SAIKA TIF.) could
each be controlled in 10 W increments and a single lamp up
to four lamps were used together.