Concerning the HPHT treatment at 70 C (625 MPa, 5 min) a significant
degradation of chlorophyll a of about 27% in broccoli, 52%
in green pepper and 12% in spinach was found. Contrarily, chlorophyll
b content remained stable after the treatment and even a significant
rise (25%) was pointed out after HPHT treatment at 70 C
in broccoli, which was due to a concentration increase of this chlorophyll
after the preheating step at 48 C. As chlorophylls content
remained unaffected after the preheating step at 48 C, except for
chlorophyll b in broccoli, the observed chlorophyll a degradation
took part during the HPHT process at 70 C. The lower stability of
chlorophyll a to HPHT at 70 C could be supported by the fact that