In the present comparative study, we investigated the relative reactivity of three aldopentoses (ribose, xylose, and arabinose) and two hexoses (glucose and fructose) in the Maillard reaction (55°C, pH 6.5) with a hydrolysate produced on an industrial scale from marine by-products. Results revealed the prevailing propensity of pentoses over hexoses to react in the Maillard reaction, with a distinguishable behavior for the ribose-hydrolysate system compared to the other aldopentoses. All the aldopentoses tested appeared to differ mainly in terms of reaction rate: molecular rearrangements studied using SEC‐FPLC exhibited similar chromatographic patterns after 6 h of incubation with ribose, compared to 17 and 24 h of incubation with xylose and arabinose, respectively. No cytotoxicity was observed when incubation was performed at neutral pH and mild temperature. To conclude, the glycation reaction conducted under controlled conditions can be considered as a promising way to upgrade marine hydrolysates without generating deleterious compounds.