Metabolite profiles of processed finger millet (Eleusine coracana) and edible crickets (Acheta domesticus) using gas chromatography-mass spectrometry

Variations occur in metabolite profiles after food processing, with gas chromatography-mass spectrometry (GC-MS) being one such technique used in profiling metabolites. In this study, finger millet (FM) (Eleusine coracana) grains were traditionally (malted and fermented) and also novelly processed (ultra-sonicated), while edible crickets (ECs) (Acheta domesticus) were fermented and ultra-sonicated. One hundred and nine (109) compounds using GC-MS in raw and processed FM and EC flour were observed and categorised into different metabolite groups: Acids, alcohols, amino acids, aromatic compounds, benzene, ethanol, fatty acids, organic acids, and sugars. Significant differences in metabolite profiles, average peak area levels, and the metabolite composition between the FM and EC samples before and after traditional and novel processing demonstrate the influence of the processing methods used. Principal component analysis (PCA) observed the relationship among the processing technique's distribution of metabolite profiles, while OPLS-DA highlighted the significant metabolite profiles observed within the different processing techniques. Differences were observed in the samples as a function of the processing technique used and the modifications, which are attributable to the pre-existing composition of the substrate and the impact of the different techniques, among others. The study's findings provide a crucial framework for tracking and controlling the metabolite composition of FM and EC flours during traditional and novel processing.