Chemical compound identification and antibacterial activity evaluation of cinnamon extracts obtained by subcritical n‐butane and ethanol extraction

Abstract

Four important <i>Cinnamomum</i> species in China including <i>C. cassia</i>, <i>C. loureiroi</i>, <i>C. wilsonii</i>, and <i>C. burmannii</i> were chosen to be extracted by subcritical n-butane and ethanol. The chemical compounds of extracts were identified by GC-MS and HPLC-MS, and the antibacterial activities were evaluated by agar-well diffusion assay and twofold microdilution broth method. There were 47 compounds identified in n-butane extracts and 11 compounds in ethanol extracts totally. The major compounds in n-butane extracts varied significantly among different <i>Cinnamomum</i> species, and (<i>E</i>)-cinnamaldehyde and coumarin were major compounds for <i>C. cassia</i> with area percentage of 74.32%; (<i>E</i>)-cinnamaldehyde and α-copaene for <i>C. loureiroi</i> with area percentage of 67.83%; linalool, (<i>E</i>)-cinnamaldehyde, and citral for <i>C. wilsonii</i> with area percentage of 58.74%; and eugenol, (<i>E</i>)-cinnamaldehyde, and coumarin for <i>C. burmannii</i> with area percentage of 76.43%. The maximum compounds in ethanol extracts were (<i>E</i>)-cinnamaldehyde and (<i>Z</i>)-cinnamaldehyde, and others varied among the <i>Cinnamomum</i> species. All cinnamon extracts showed antibacterial activities that n-butane extracts were much more sensitive than ethanol extracts. The inhibition zone for N-butane extracts against <i>Listeria monocytogenes</i>, <i>Staphylococcus aureus</i>, <i>Escherichia coli</i>, and <i>Salmonella anatum</i> was from 18.98 to 37.45 mm while for ethanol extracts from 7.11 to 10.11 mm. The minimum bactericidal concentrations for n-butane extracts were ranged from 0.31 to 2.50 mg/ml and for ethanol extracts ranged from 20.00 to 160.00 mg/ml. N-butane extracts of <i>C. cassia</i> and <i>C. loureiroi</i> processed much higher antibacterial activities than <i>C. wilsonii</i> and <i>C. burmannii.</i> N-butane extracts of <i>C. cassia</i> and <i>C. loureiroi</i> have the potential to be used as food biopreservative.