A score plot of principal-component analysis (PCA) showing the metabolite changes of MA samples incubated at 15°C, 20°C, 25°C, and 30°C during the entire fermentation period.

<p>Numbers beside the symbols represent the fermentation time (days) of MA samples. The score plot was constructed using the mean values of all ¹H-NMR peaks obtained from triplicate analyses. The curved arrows indicate the routes of the metabolite changes during the fermentation period in MA samples fermented at different temperatures.