Table 1 Changes in the VOCs (%) of terpenes of MCR ensilage with Lactic acid over time

1

(+)-α-pinene

7785-70-8

0.19 ± 0.02A

0.13 ± 0.01AB

0.09 ± 0.05AB

0.09 ± 0.05AB

0.05 ± 0.05AB

ND

0.03 ± 0.03B

2

tricyclo[2.2.1.0(2,6)]heptane, 1,7,7-trimethyl-

508–32-7

0.17 ± 0a

0.09 ± 0.05abc

0.05 ± 0.05bc

0.04 ± 0.04bc

0.13 ± 0.01ab

0.1 ± 0.05abc

ND

3

Linalool

78–70-6

0.57 ± 0.01C

0.81 ± 0.08 BC

0.97 ± 0.11B

0.89 ± 0.04 BC

0.92 ± 0.05 BC

1.05 ± 0.04B

1.42 ± 0.15A

4

terpinen-4-ol

562–74-3

0.47 ± 0.11ab

0.65 ± 0.18a

0.5 ± 0.26ab

0.84 ± 0.18a

0.31 ± 0.31ab

ND

0.01 ± 0.01b

5

Copaene

3856-25-5

0.08 ± 0.04b

0.12 ± 0.06ab

0.1 ± 0.05ab

0.12 ± 0.06ab

0.17 ± 0ab

0.05 ± 0.05b

0.24 ± 0.01a

6

beta-elemene

515–13-9

0.18 ± 0.11a

0.21 ± 0.01a

0.15 ± 0.08a

0.11 ± 0.11a

0.12 ± 0.06a

0.11 ± 0.05a

0.08 ± 0.08a

7

(−)-alpha-gurjunene

489–40-7

0.79 ± 0.04AB

0.84 ± 0.07AB

0.8 ± 0.06AB

0.65 ± 0.04B

0.69 ± 0.1B

0.86 ± 0.08AB

1.13 ± 0.1A

8

Caryophyllene

87–44-5

14.67 ± 0.45A

15.7 ± 0.2A

14.19 ± 0.53A

15.24 ± 0.09A

15.21 ± 0.08A

14.62 ± 0.45A

9.85 ± 0.26B

9

cis-a-bergamotene

18,252–46-5

0.47 ± 0.02a

0.38 ± 0.19a

0.2 ± 0.17a

0.21 ± 0.21a

0.26 ± 0.15a

0.56 ± 0.28a

0.42 ± 0.22a

10

cis-β-farnesene

28,973–97-9

9.46 ± 0.18AB

13.46 ± 1.66A

14.03 ± 1.44A

11.54 ± 0.95AB

11.11 ± 0.96AB

14.04 ± 1.42A

7.97 ± 0.32B

11

2-epi-trans-β-caryophyllene

68,832–35-9

0.24 ± 0.03b

0.69 ± 0.11a

0.6 ± 0.22ab

0.45 ± 0.04ab

0.44 ± 0.04ab

0.53 ± 0.18ab

0.24 ± 0.12b

12

(1e,4e)-germacrene b

15,423–57-1

0.9 ± 0.03 BC

1.93 ± 0.12A

1.49 ± 0.13AB

1.48 ± 0.08AB

1.6 ± 0.15AB

0.93 ± 0.23 BC

0.26 ± 0.26C

13

(1 s,2e,6e,10r)-3,7,11,11-tetramethylbicyclo[8.1.0]undeca-2,6-diene

24,703–35-3

0.6 ± 0.06A

0.32 ± 0.07B

0.11 ± 0.02C

ND

ND

ND

ND

14

ß-longipinene

41,432–70-6

0.24 ± 0.09b

0.46 ± 0.06ab

0.39 ± 0.1ab

0.56 ± 0.19ab

0.6 ± 0.12a

0.25 ± 0.05ab

0.29 ± 0.06ab

15

2-carene

554–61-0

0.17 ± 0.02A

ND

ND

ND

ND

ND

ND

16

naphthalene, 1,2,3,5,6,7,8,8a-octahydro-1,8a-dimethyl-7-(1-methylethenyl)-, [1 s-(1a,7a,8aa)]-

10,219–75-7

0.09 ± 0.09b

0.33 ± 0.02a

0.18 ± 0.09ab

0.23 ± 0.04av

0.22 ± 0.06ab

0.19 ± 0.05ab

0.18 ± 0.05ab

17

(−)-germacrene-d

317,819–80-0

ND

1.95 ± 0.18A

0.97 ± 0.31ABC

1.43 ± 0.49AB

1.58 ± 0.36AB

0.35 ± 0.14 BC

0.8 ± 0.04ABC

18

(−)-spathulenol

77,171–55-2

ND

0.13 ± .0.01a

0.15 ± .0.02a

0.16 ± .0.01a

0.15 ± 0.02a

0.13 ± .0.03a

0.15 ± 0.02a

19

Junenol

472–07-1

ND

0.2 ± 0.03CD

0.21 ± 0.01CD

0.42 ± 0.03 BC

0.45 ± 0.01B

0.48 ± 0.01B

1.1 ± 0.13A

20

Carveol

99–48-9

ND

ND

ND

ND

0.37 ± 0.19ab

0.17 ± 0.17ab

0.07 ± 0.07b

21

Isothujol

7712-79-0

ND

ND

ND

ND

ND

0.05 ± 0.05B

0.34 ± 0.01A

23

(−)-α-thujone

33,766–30-2

ND

ND

ND

ND

ND

ND

0.07 ± 0.01A

24

(−)-.β.-bourbonene

5208-59-3

ND

ND

ND

ND

ND

ND

0.14 ± 0.01A

25

(s)-β-bisabolene

495–61-4

ND

ND

ND

ND

ND

ND

0.14 ± 0.02A

26

Nerolidol

7212-44-4

ND

ND

ND

ND

ND

ND

0.89 ± 0.11A

27

3,7,11,15-tetramethyl-2-hexadecen-1-ol

102,608–53-7

ND

ND

ND

ND

ND

ND

0.24 ± 0.07A

28

Isoneral

72,203–97-5

ND

ND

ND

ND

ND

0.15 ± 0.01B

0.27 ± 0.03A

29

(±)-trans-nerolidol

40,716–66-3

ND

ND

ND

ND

ND

ND

0.88 ± 0.07A

30

bicyclo[3.1.1] heptane, 6,6-dimethyl-2-methylene-, (1 s)-

18,172–67-3

3.01 ± 0.27A

0.96 ± 0.15 BC

1.18 ± 0.07 BC

1 ± 0.2 BC

1.24 ± 0.08 BC

1.21 ± 0.04 BC

0.56 ± 0.05 BC

31

terpinolene

586–62-9

8.24 ± 0.25A

7.72 ± 0.2AB

7.15 ± 0.18ABC

6.8 ± 0.15 BC

7.18 ± 0.59ABC

6.27 ± 0.05C

4.62 ± 0.15D

32

d-limonene

5989-27-5

5.56 ± 0.14A

3.55 ± 0.13B

3.49 ± 0.24 BC

3.32 ± 0.12 BC

3.44 ± 0.22 BC

3.3 ± 0.05 BC

2.57 ± 0.36C

33

ß-ocimene

13,877–91-3

4.92 ± 0.31A

4.2 ± 0.23A

4.07 ± 0.24A

3.98 ± 0.27A

4.43 ± 0.32A

4.21 ± 0.22A

2.38 ± 0.27B

34

Piperitone

89–81-6

12.17 ± 0.11a

9.93 ± 0.47b

10.08 ± 0.68b

10.76 ± 0.32ab

10.16 ± 0.31b

10.51 ± 0.24b

10.1 ± 0.7b

35

Sabinene

3387-41-5

0.31 ± 0.06A

ND

ND

ND

ND

ND

ND