Impact of frying methods on colours, morphological properties, and aroma compounds of arrowhead (Sagittaria latifolia) corm chips

Abstract

Arrowhead is a starchy vegetable with a unique taste and many health promoting effects. To diversify the usage and increase the consumption of arrowhead, the effects of different frying methods on the morphology and aroma compounds of arrowhead corm chips were studied. The analysis of aroma compounds by accelerated solvent extraction coupled with high-vacuum flavour extraction analysis (ASE-HVFEA), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O) of deep- and air-fried arrowhead corm chips was conducted. The aim was to understand the variability and abundance of aroma compounds between deep- and air-fried arrowhead chips. In addition, the colours and morphological characteristics of the corm chips were also studied. Twenty-three aroma compounds were identified in the differently fried chips. The predominant aroma compounds were the Strecker-aldehydes, in which 2-methylbutanal, (E)-2-heptenal, hexanal, and (E,E)-2,-4-decadienal were identified as the major aroma constituents of the fried chips. This was followed by the pyrazines. Results of the odour activity values (OAVs) revealed significant (p < 0.05) differences in the aroma profiles of the differently fried chips. Deep-fried chips produced more potency for the baked-like, 2-3-diethyl-5-methylpyrazine, potato-like, methional, deep-fried, (E,E)-2,4-decadienal, roasty, 2-ethyl-3,5-dimethylpyrazine, malty, and 2-methylbutanal. However, air-fried chips exhibited similar but lower potency for the same compounds. Whilst there was no significant (p ≥ 0.05) difference in the external appearance of the differently fried chips, deep-frying significantly (p < 0.05) altered the cell walls of the deep-fried chips more than the air-fried chips. These results would serve as a guidance for aroma flavour evaluation, improvement, and quality control during oil- and air-frying of chips.