2.5.2. Vitamin C
Vitamin C content of broccoli juice was determined by HPLC. The extraction
procedure was based on a method validated by OdriozolaSerrano
et al. (2007). Briefly, broccoli juice was mixed with 4.5%
metaphosphoric solution in a proportion 1:1. The mixture was homogenized
and centrifuged at 2401 g for 10 min at 4 °C (Centrifuge
AVANTI™ J-25, Beckman Instruments Inc., Fullerton, CA, USA). Then,
the vacuum-filtered sample was passed through a Millipore 0.45-μm
membrane to be injected in the HPLC system.