Skip to main content

Table 1 Change in phenolic compounds content in soybeans during the 30-day pickling process (μg g−1, dry basis, P < 0.05, n = 6)

From: Comparative study of phenolic compounds, vitamin E, and fatty acids compositional profiles in black seed-coated soybeans (Glycine Max (L.) Merrill) depending on pickling period in brewed vinegar

 

Untreated soybean (control)

Pickled soybean

LSD (0.05)

Day 1

Day 5

Day 10

Day 20

Day 30

Phenolic acid

 PR

12.1 ± 1.5d

11.7 ± 1.2d

14.6 ± 1.9c

15.3 ± 2.3c

19.4 ± 1.3a

17.6 ± 2.5b

1.6

 mC

1.9 ± 0.2a

1.5 ± 0.2c

1.7 ± 0.2b

1.5 ± 0.1c

1.4 ± 0.1cd

1.3 ± 0.2d

0.1

 tC

2.1 ± 0.3f

3.5 ± 0.5e

4.7 ± 0.6d

5.5 ± 0.5c

6.9 ± 0.9b

7.9 ± 0.9a

0.6

 VA

144.3 ± 6.4a

94.6 ± 9.7b

90.0 ± 6.0bc

86.4 ± 3.3c

73.2 ± 10.8d

72.3 ± 7.5d

6.5

Flavonoid

 CA

53.0 ± 1.7a

39.6 ± 3.5b

37.3 ± 18.7b

36.2 ± 5.1b

48.5 ± 14.0a

49.3 ± 3.7a

8.5

 NA

38.6 ± 2.4a

35.3 ± 2.2ab

32.5 ± 4.3bc

31.3 ± 2.5 cd

27.9 ± 4.2d

26.3 ± 5.2d

4.0

 QU

7.2 ± 1.6b

7.6 ± 1.4ab

7.4 ± 1.7b

7.3 ± 2.1b

8.9 ± 1.0a

8.0 ± 2.3ab

1.5

 NG

2.5 ± 0.5f

10.3 ± 0.9e

18.1 ± 1.3d

25.0 ± 2.3c

41.4 ± 2.6b

60.3 ± 5.8a

2.4

Total phenolics

 

261.7 ± 8.1a

204.1 ± 10.0d

206.2 ± 24.2d

208.4 ± 4.4d

227.5 ± 19.2c

242.8 ± 17.5b

13.3

 

Vinegar (control)

Pickling solution

 

Day 1

Day 5

Day 10

Day 20

Day 30

LSD (0.05)

Phenolic acid

 PR

ND

13.1 ± 1.6bc

15.3 ± 1.2ab

14.3 ± 2.4ab

17.3 ± 4.5a

11.8 ± 2.3c

1.7

 mC

ND

0.9 ± 0.0c

1.1 ± 0.2b

1.2 ± 0.3ab

1.3 ± 0.2a

1.3 ± 0.3a

0.1

 tC

ND

1.8 ± 0.1c

1.9 ± 0.2bc

2.0 ± 0.2b

2.3 ± 0.3a

2.3 ± 0.3a

0.1

 VA

ND

14.8 ± 3.6b

18.7 ± 4.2a

16.7 ± 2.1ab

17.6 ± 3.0a

14.5 ± 2.7b

2.0

Flavonoid

 CA

ND

62.4 ± 9.4 cd

66.3 ± 3.7c

60.1 ± 8.5d

82.5 ± 8.4b

93.4 ± 4.8a

4.7

 NA

ND

4.1 ± 0.4b

4.8 ± 1.1a

4.7 ± 0.6a

5.1 ± 0.5a

5.0 ± 0.4a

0.4

 QU

ND

TR

TR

4.3 ± 0.2

5.6 ± 0.7

5.9 ± 0.2

 NG

ND

1.8 ± 0.9c

1.8 ± 0.1c

2.0 ± 0.2c

3.0 ± 0.1b

3.6 ± 0.2a

0.3

Total phenolics

 

ND

102.2 ± 11.3c

110.6 ± 6.4b

108.9 ± 12.6bc

135.6 ± 5.0a

140.9 ± 9.2a

6.0

  1. ND not detected, TR trace level concentrations, PA phenolic acid, F flavonoid, PR protocatechuic acid, mC m-coumaric acid, tC t-cinnamic acid, CA catechin, NA naringin, QU quercetin, NG naringenin, VA vanillin
  2. a–f Values with different superscripts differ significantly according to pickling period (P< 0.05)