Sensory evaluation, chemical identification, and QCM-type e-nose analysis of odor compounds from a microalga Scenedesmus sp. (Chlorophyta) for development of odor sensing culture method

Abstract

Although several microalgae species have been used for industrial purposes, it is generally difficult to visually observe their growth conditions during cultivation. Our group has attempted to develop a way to control algae cultivation, using a method we refer to as “Odor Sensing Cultivation” (OSC). This is a new and simple observation method that is based on the odors produced by algae. In this study, as a representative microalgal species, Scenedesmus sp. was employed. Odors produced from its culture were investigated by olfactory evaluation, chemical identification, and “e-nose” analysis. As a result of olfactory evaluation, “green tea”, “sweet”, and “fishy” were the characteristic odors identified from this species. In the chemical analysis, the odors from this species were identified as 1-nonanal, α-ionone, β-ionone, and tentatively identified as 2-undecenal and acetic acid. Based on the QCM-type e-nose analysis, the odors from this alga and the control medium could be separated. These results suggest that the OSC is applicable as a practical technique for production of this species.