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. 2021 Aug 11;78:105714. doi: 10.1016/j.ultsonch.2021.105714

Table 1.

The relaxation time (T21, T22 and T23) and relative peak area (A21, A22 and A23) of strawberry samples pretreated before and after drying.

Mode T2 (ms)
Area of T2 (%)
T21 T22 T23 A21 A22 A23
Pretreatment Control 0.43 ± 0.05c 265.61 ± 5.01a 1072.27 ± 3.35b 2.19 ± 0.10a 39.26 ± 0.20d 58.55 ± 0.51a
SM-20 1.75 ± 0.09b 256.23 ± 4.20b 925.26 ± 5.02e 0.91 ± 0.07b 48.78 ± 0.21b 50.31 ± 0.32c
SM-40 10.11 ± 0.10a 231.01 ± 4.51c 936.60 ± 3.71d 0.72 ± 0.08c 58.90 ± 0.15a 40.38 ± 0.15e
SeDM 200.92 ± 4.24d 1232.85 ± 6.02a 57.79 ± 1.65a 42.21 ± 0.25d
SiDM 206.02 ± 3.62d 1065.07 ± 7.65c 46.71 ± 0.22c 53.29 ± 0.51b



Vacuum freeze drying Control 0.43 ± 0.05a 7.06 ± 0.13a 75.65 ± 0.15a 29.33 ± 0.15c 39.62 ± 0.14b 31.05 ± 0.50a
SM-20 0.22 ± 0.02bc 6.14 ± 0.15c 68.27 ± 0.21c 32.24 ± 1.07b 40.08 ± 0.45b 27.68 ± 0.33c
SM-40 0.38 ± 0.08a 6.77 ± 0.20b 70.83 ± 0.12b 30.70 ± 0.25bc 39.83 ± 0.18b 29.47 ± 0.18b
SeDM 0.14 ± 0.04c 4.64 ± 0.15d 49.77 ± 0.15e 42.33 ± 1.12a 38.55 ± 0.31c 19.12 ± 0.14d
SiDM 0.25 ± 0.05b 4.82 ± 0.21d 65.79 ± 0.12d 24.33 ± 0.70d 48.17 ± 0.20a 27.50 ± 0.29c

Note: Values are means ± SD, n ≥ 3. Different letters in the same column mean significant difference at p < 0.05. T23 refers to the the free water’s transverse relaxation time; T21 and T22 refer to the transverse relaxation time of the bound water and the immobilized water, respectively. A21 represents the corresponding water fraction to T21, A22 represents the corresponding water fraction to T22, and A23 represents the corresponding water fraction to T23. Control: no-ultrasound; SM-20: single-frequency mode of 20 kHz; SM-40: single-frequency mode of 40 kHz; SeDM: sequential dual-frequency mode of 20/40 kHz; SiDM: simultaneous dual-frequency mode of 20 and 40 kHz.