Table 1—Freezing rates, (Distance from surface to thermal center) / (Time
surface
(Ta = initial freezing point) - Time
center
(Ta = 10°C below the
initial freezing point)) • 106m/s temperature of the freezing medium (°C) and characteristic freezing times, t = Time (Ta = –15 °C) – Time (Ta
= Initial freezing point) (min), of the assayed freezing methods
FREEZING PROCESSES PEACH
N2
HPSF MANGO Air-blast N2 HPSF Air-blast
Freezing rate (•106 m/s) 5.9 ± 0.5 11.8 ± 0.2 11.7 ± 1.7 4.6 ± 0.5 10.6 ± 0.5 9.7 ± 0.8
Freezing medium temp. (°C) -40 -196 -21 / -25 -40 -196 -21 / -25
tc at the surface (min) 10.4 ± 0.8 2 ± 0.2 -- 12.3 ± 1.1 1.1 ± 0.1 --tc at the center
(min) 84.3 ± 3.9 30.2 ± 2.1 56.6 ± 5.5 91.7 ± 4.4 40.3 ± 2.8 79.6 ± 4.3
Data are mean values ± standard deviation