Table 4 The concentrations of some flavonoids compounds in two varieties of Zingiber officinale, Fulbaria and Syedpuri grown under various CO₂ concentrations

Quercetin

0.961 ± 0.013^a

0.894 ± 0.039^a

1.22 ± 0.06^e

1.137 ± 0.023^e

1.19 ± 0.122^b,e

0.985 ± 0.032^a

1.33 ± 0.124^b

1.26 ± 0.01^b

Epicatechin

0.128 ± 0.028^b

0.085 ± 0.007^a,e

0.073 ± 0.009^a

0.049 ± 0.018^c

0.12 ± 0.004^b

0.103 ± 0.0034^d,e

0.096 ± 0.021^a,e

0.038 ± 0.009^c

Catechin

0.416 ± 0.024^c

0.492 ± 0.020^a,c

0.673 ± 0.044^b,e

0.637 ± 0.044^e

0.668 ± 0.079^b,e

0.533 ± 0.034^a

0.734 ± 0.014^b

0.684 ± 0.05^b,e

Kaempferol

0.041 ± 0.006^d

0.052 ± 0.003^c,d

0.117 ± 0.014^a

0.147 ± 0.023^e

0.051 ± 0.002d^d

0.067 ± 0.005^c

0.162 ± 0.011^b,e

0.184 ± 0.019^b

Fisetin

0.982 ± 0.022^d

0.633 ± 0.033^f

2.051 ± 0.27^a

2.88 ± 0.19^b

1.53 ± 0.121^c

1.32 ± 0.13^c

2.37 ± 0.397^e

3.12 ± 0.185^b

Morin

0.532 ± 0.057^d

0.464 ± 0.014^d

0.491 ± 0.052^d

0.876 ± 0.046^b

0.765 ± 0.024^e

0.607 ± 0.006^c

0.662 ± 0.029^a

0.517 ± 0.025^d