Processing and fermentation effects on kelp flavour: sensory profiles and flavour-active compounds

Summary

The kelps Alaria esculenta and Saccharina latissima are promising food ingredients as sources of nutrients and flavours, particularly in the context of a shift towards more plant-based diets. This study investigated the effects of commercially relevant processing steps on the sensory profile of the kelps and the concentrations of flavour-active compounds, including free amino acids (FAAs), minerals, mannitol and volatile compounds. The tested processes included pre-treatments aiming to reduce iodine levels, i.e., pulsed electric field (PEF) and warm seawater (W-SW) exposure at low temperature (50°C), as well as fermentation (6 days, pH < 4.0 within 72 h) as a low-input stabilisation method. Sensory profiling by a trained panel of 7–8 assessors revealed relatively minor differences between treatment groups for each kelp species, primarily reflecting variations in saltiness and umami intensity. FAAs, minerals, mannitol and volatile compounds were measured to identify key flavour-contributing compounds, with a specific focus on umami, considered the main flavour of interest in kelps. Partial least squares regression revealed weak correlations between perceived umami and free glutamate levels, while other FAAs (alanine, tryptophan, arginine and glycine) were identified as potential umami contributors. Several volatile compounds, including 2,3-butanedione, 3,5-octadien-2-one, 1-penten-3-ol, 2-hexenal and 2,4-heptadienal, showed strong correlations and were identified as potential aroma components contributing to odour-induced umami enhancement. Among the tested combinations, W-SW-treated A. esculenta yielded the most umami-potent ingredient while maintaining safe iodine levels, making it a promising candidate for large-scale food applications.

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DOI : doi.org/10.1016/j.fufo.2026.10...
NVA : hdl.handle.net/11250/5581165