Aroma characterization of five microalgae species using solid-phase microextraction and gas chromatography-mass spectrometry/olfactometry

Abstract

In this study, aroma compounds produced by three marine microalgae species (Crypthecodinium cohnii, Schizochytrium limacinum and Tetraselmis chuii) and two fresh water microalgae (Chlorella vulgaris and Chlorella protothecoides) important for nutritional applications were identified by means of solid-phase microextraction followed by gas chromatography-mass spectrometry (GC-MS), GC-olfactometry (GCO) and a sensory panel. Principal components analysis (PCA) was applied to the instrumental and sensory analysis data to visualize differences between the samples in terms of descriptive attributes and volatile compounds. Accordingly, C. cohnii was characterised by a high level of sulfur compounds (dimethyl sulfide, ethanethiol), and ester and alcohol compounds associated with distinct 'sulfur-cabbage', 'fruity', 'rosy', and 'boiled potato' aroma notes. While S. limacinum was characterised more by aldehydes and alcohol compounds associated with 'mushroom', 'cucumber', and 'fatty-grassy' aroma characteristics, the other three samples showed relatively higher levels of ketone and terpene compounds with 'woody' and 'cereal-like' sensory characteristics.

Keywords: Aroma active compounds; Gas chromatography-olfactometry; Gas chromatography–mass spectrometry; Microalgae; Sensory evaluation.