Embodiments of the invention relates to an antimicrobial composition comprising an alkyl pyrazine compound or mixture of compounds selected from the group consisting of 2-isobutyl-3-methylpyrazine, 2-isobutyl-3-methoxypyrazine, 2-isopropylpyrazine, 2-isobutylpyrazine and mixtures of methylpyrazines having one, two and three isopropyl or isobutyl substituents. Further embodiments of the invention relate to uses of alkyl pyrazine compounds, in particular for controlling microbial growth.