Odor formation in reused potato processing water: potential causes, VOC markers and sensor needs

The potato industry has adopted sustainable practices such as water reuse during blanching. However, prolonged water reuse often releases unpleasant smells, the origin of which remains unknown. This odor issue not only affects sensory quality but may also influence food safety and sustainability efforts. This narrative literature review investigates the odor formation by focusing on three core aspects: identifying the underlying causes of odor, pinpointing the volatile organic compounds (VOCs) responsible, and evaluating sensor technologies for real-time monitoring. Experimental studies on blanching water composition, along with reviews addressing potato-derived VOCs under conditions comparable to blanching, such as boiling or steaming, and potato-associated microorganisms, were critically and comparatively analyzed. The findings reveal that blanching water is under-researched, despite emerging evidence suggesting microbial survival during reuse. The VOC analysis highlights overlap between compounds derived from thermal processing and those produced by microbial activity, complicating odor source identification. However, this review highlights potential VOC classes and outlines key requirements for targeted sensor development to enable real-time monitoring of blanching water quality and usage. Overall, this review provides a critical foundation for addressing odor-related challenges in the potato industry, with direct implications for enhancing sustainability, food quality, and safety.