Quality Parameters of Juice Obtained from Hydroponically Grown Tomato Processed with High Hydrostatic Pressure or Heat Pasteurization

Table 2

Effect of processing on colour parameters measured in untreated, HHP-treated, and pasteurized (LPT and HPT) tomato juice after 0, 7, and 14 days of storage.

Sample		Storage time (days)
	0	7	14
Untreated/reference		^Ab	^Aa
400 MPa/15 min	^Ba	^Bb	^Bc
600 MPa/15 min	^Ba	^Cc	^Cb
LPT (74°C/2 min)	^Cc	^Eb	^Da
HPT (90°C/1 min)	^Ca	^Db	^Dc
Untreated/reference	^Cc	^Ab	^Aa
400 MPa/15 min	^Ca	^Ea	^Ca
600 MPa/15 min	^Cb	^Da	^Cc
LPT (74°C/2 min)	^Ba	^Ca	^Bb
HPT (90°C/1 min)	^Aa	^Bb	^Bc
Untreated/reference	^Ab	^Aa	^Ba
400 MPa/15 min	^Bc	^Bb	^Ca
600 MPa/15 min	^Bc	^Ab	^Aa
LPT (74°C/2 min)	^Db	^Ca	^Da
HPT (90°C/1 min)	^Ca	^Db	^Eb
Untreated/reference	^Aa	^Db	^Db
400 MPa/15 min	^Bab	^Ba	^Bb
600 MPa/15 min	^Ba	^Cb	^Cc
LPT (74°C/2 min)	^Cb	^ABa	^Aa
HPT (90°C/1 min)	^Cc	^Aa	^Bb

The results are expressed as the , . Three independent measurements: (lightness), (redness), and (yellowness). is the colour difference between the control and processed tomato juices. Uppercase letters indicate differences between treatment types (in columns) on particular days of storage, whereas lowercase letters indicate differences between storage times for individual samples (in lines) ().