Table 5

Table 5. Pressure stability of PPO derived from various sources

Origin of PPO	Medium	Treatment	Activation/Inactivation	Reference
Apple	crude extract (pH 4.5) crude extract (pH 5.4) crude extract (pH 7)	#300 Mpa/25^oC/1min >500 Mpa/25 ^oC/1 min #300 Mpa/25^oC/1min >700 Mpa/25 ^oC/1min #100 Mpa/25^oC/1min	activation inactivation activation inactivation inactivation	Anese et al. (1995)
Avocado	partially purified	800 Mpa/25 ^oC	inactivation	Weemaes et al. (1998)
Onion	purified enzyme in Tris buffer (pH 6.5, 0.01M)	> 700 Mpa/25 ^oC/10 min	activation, which is maximal at 500 MPa	Butz et al., (1994)
Pear	in slices partially purified	400 Mpa/25^oC/10 min 900 Mpa/25 ^oC	activation slight inactivation	Asaka and Hayashi (1991) Weemaes et al. (1998)
Plum	partially purified	900 Mpa/25 ^oC	no inactivation	Weemaes et al. (1998)
Potato	in cubes	400 Mpa/<50^oC/15 min	no inactivation	Knorr (1993)
White grapes	partially purified	700 Mpa/25 ^oC	inactivation	Weemaes et al. (1998)