Cold Sweetening in Stored Potatoes: Reducing Sugars, Fry Colour and Acrylamide

Expert perspective: Alexander Samsonov, Agricultural Storage Engineer. Read the original LinkedIn perspective.

Potatoes intended for chips and French fries are judged after frying as well as before storage. When reducing sugars rise, the Maillard reaction can produce darker colour, bitter notes and more acrylamide during high-temperature processing.

Alexander Samsonov has highlighted the need to manage storage as a quality process—not merely to keep tubers cold. The correct strategy combines variety, maturity, temperature, sprout control, sampling and processor feedback.

Processing potatoes in controlled long-term storage

What Cold Sweetening Means

At unsuitable low temperatures, some potato varieties convert more starch and sucrose into the reducing sugars glucose and fructose. The response is variety-dependent and also influenced by crop maturity, growing conditions, stress, time in storage and sprout-control programme.

Those sugars react with amino acids during frying. FDA guidance identifies reducing-sugar management, variety selection, growing and harvesting practice, maturity, handling and storage conditions as relevant to acrylamide reduction in potato products.

Why One Universal Temperature Is Unsafe

A lower storage temperature can suppress sprouting and disease development, yet it may increase cold sweetening in a susceptible processing variety. A warmer regime may protect fry colour but accelerate respiration, dehydration and sprouting. The operating point must balance these risks for the actual variety and processing specification.

Build a Quality-Control Loop

Set the buyer specification: define fry colour, glucose or reducing-sugar limits, dry matter and defect tolerances.
Sample at intake: establish the initial sugar and fry-colour baseline for every lot.
Control pull-down: avoid uncontrolled cold shocks and large temperature gradients.
Trend the crop: compare temperature history, ventilation, sprouting and laboratory or strip-test results.
Plan dispatch: match lots to processing dates before quality moves outside specification.

Reconditioning Is a Process, Not a Rescue Button

Some varieties can reduce accumulated sugars when held at a suitable warmer temperature before processing. The response and time required vary. Reconditioning should therefore be tested with representative samples and coordinated with sprouting, disease and dispatch risks.

Raising room temperature without uniform airflow can create condensation and inconsistent tuber response. The whole lot must move through a controlled temperature trajectory, and the processor should verify fry colour before release.

What Automation Can—and Cannot—Do

Automation can maintain set points, limit gradients, schedule ventilation and refrigeration, trend sensor data and alert the operator when the storage trajectory departs from plan. Predictive analytics may help identify risk earlier when it is trained on real crop and quality data.

It cannot measure sugar from temperature alone with laboratory certainty, guarantee zero acrylamide, or overcome an unsuitable variety and damaged intake. Product sampling remains part of responsible control.