Table 4 The changes of aromatic, acidic, alkaline amino acid content in tobacco leaves under different curing time.

From: Regression prediction of tobacco chemical components during curing based on color quantification and machine learning

Location

Curing time (h)

Indicators (mg/g)

Aromatic amino acid content

Acidic amino acid content

Alkaline amino acid content

Phenylalanin

Tryptophan

Tryptophan

Aspartic

Glutamic

Histidine

Arginine

Upper leaves

0

0.25 ± 0.04f

0.26 ± 0.01f

0.17 ± 0.03a

0.50 ± 0.07a

0.28 ± 0.11a

0.09 ± 0.02e

0.05 ± 0.01abc

24

0.54 ± 0.02cde

0.55 ± 0cd

0.16 ± 0.05a

0.19 ± 0.11b

0.16 ± 0.05b

0.25 ± 0.01d

0.08 ± 0.03a

48

0.81 ± 0.17ab

0.74 ± 0.13ab

0.13 ± 0ab

0.16 ± 0.04b

0.13 ± 0.03b

0.42 ± 0.05ab

0.07 ± 0.01a

60

0.84 ± 0.11a

0.80 ± 0.08a

0.12 ± 0.01bc

0.20 ± 0.02b

0.16 ± 0.05b

0.49 ± 0.07a

0.07 ± 0.01ab

72

0.63 ± 0.09bc

0.69 ± 0.13abc

0.10 ± 0.02bcd

0.15 ± 0.02b

0.13 ± 0.02b

0.40 ± 0.08abc

0.05 ± 0.02abc

84

0.58 ± 0.15cd

0.64 ± 0.08bc

0.10 ± 0.02bcd

0.20 ± 0.06b

0.14 ± 0.02b

0.39 ± 0.05abc

0.05 ± 0.01abc

96

0.47 ± 0.08cdef

0.56 ± 0.05cd

0.09 ± 0.02bcd

0.16 ± 0.04b

0.13 ± 0.02b

0.35 ± 0.05bcd

0.04 ± 0.01bc

108

0.43 ± 0.12cdef

0.46 ± 0.09de

0.09 ± 0.02cd

0.18 ± 0.05b

0.17 ± 0.02b

0.30 ± 0.09cd

0.05 ± 0.02abc

120

0.40 ± 0.10def

0.44 ± 0.09de

0.09 ± 0.01bcd

0.16 ± 0.03b

0.19 ± 0.03b

0.26 ± 0.06d

0.04 ± 0.01c

132

0.33 ± 0.09ef

0.39 ± 0.03ef

0.07 ± 0.02d

0.18 ± 0.02b

0.18 ± 0.03b

0.27 ± 0.05d

0.05 ± 0.02abc

Middle leaves

0

0.19 ± 0.04c

0.22 ± 0.07e

0.10 ± 0.02a

0.32 ± 0.03a

0.21 ± 0.07a

0.26 ± 0e

0.03 ± 0ab

24

0.38 ± 0.03abc

0.58 ± 0.01ab

0.09 ± 0.02ab

0.10 ± 0.01b

0.13 ± 0.01b

0.22 ± 0.01cd

0.03 ± 0ab

48

0.37 ± 0.04abc

0.60 ± 0.05ab

0.09 ± 0.01ab

0.10 ± 0.02b

0.09 ± 0.02b

0.28 ± 0.02bcd

0.04 ± 0ab

60

0.46 ± 0.08ab

0.67 ± 0.07a

0.09 ± 0.01ab

0.13 ± 0.01b

0.11 ± 0.01b

0.33 ± 0.04ab

0.05 ± 0.01a

72

0.50 ± 0.12a

0.70 ± 0.08a

0.09 ± 0.02ab

0.14 ± 0.04b

0.12 ± 0.03b

0.38 ± 0.08a

0.05 ± 0.02ab

84

0.27 ± 0.02bc

0.52 ± 0.04bc

0.07 ± 0.02ab

0.12 ± 0.02b

0.10 ± 0.02b

0.29 ± 0.04abc

0.03 ± 0b

96

0.31 ± 0.11bc

0.48 ± 0.11bcd

0.07 ± 0.02ab

0.14 ± 0.03b

0.09 ± 0.01b

0.27 ± 0.09bcd

0.03 ± 0.01ab

108

0.28 ± 0.03bc

0.42 ± 0.04cd

0.07 ± 0.01ab

0.13 ± 0.02b

0.10 ± 0.03b

0.25 ± 0.04bcd

0.03 ± 0ab

120

0.27 ± 0.05bc

0.45 ± 0.03cd

0.08 ± 0.01ab

0.14 ± 0.02b

0.10 ± 0.03b

0.22 ± 0.03cd

0.03 ± 0ab

132

0.21 ± 0.14c

0.39 ± 0.11d

0.06 ± 0.03b

0.13 ± 0.06b

0.12 ± 0.04b

0.18 ± 0.07d

0.03 ± 0.01ab

  1. Note: Different letters indicate significant differences (P ≤ 0.05) at different curing times for the same part of the tobacco.