In the industrial processing of potatoes into French fries, chips and other potato products, foam formation regularly occurs in process water due to the interaction of plant-based components, intensive water circulation and intentional air entrainment.

Potatoes have a dry matter content of approximately 20–25%. This dry matter consists mainly of starch, as well as proteins, dietary fiber, minerals and small amounts of sugars, organic acids and fats. Depending on potato quality—affected by variety, cultivation conditions, fertilization and storage—the proportion of these components can vary significantly.

In particular, soluble proteins, starch degradation products, oligosaccharides and other surface-active substances released from the potato reduce surface tension and promote the formation of stable foam structures. These effects are further intensified by mechanical stress, temperature and water recirculation.

The foam-related mechanisms follow the same physico-chemical principles across all process steps, regardless of the individual stage:

• Release of plant-derived components (e.g. during washing, peeling, cutting, slicing, shredding or blanching)
• Intensive contact between water and air (e.g. in conveying systems, washing units or circulation loops)
• Accumulation of foam-active substances due to process water circulation and reuse
• Temperature-dependent changes in solubility and surface tension

In addition, raw material quality and potato storage conditions influence foam formation. Differences between varieties, protein and starch contents, as well as partial conversion of starch into sugars, can significantly increase the foaming tendency of the process water.

Typical process areas with increased foam formation:

• Washing systems and drum washers
• Cutting and peeling processes
• Blanching systems
• Transport and conveying water systems
• Packaging lines with water recirculation
• CIP cleaning systems

The higher the concentration of foam-active components in the circulating water and the more intensive the water circulation, the more pronounced the foam formation—directly impacting process stability, hygiene, plant availability and operating costs.

Operational consequence: The targeted use of a high-performance, food-grade defoamer for potato processing is therefore a key factor in achieving:

• Stable production conditions
• Trouble-free conveying and washing processes
• Clean and reliable plant equipment
• Reproducible product quality for French fries and chips
• Economically efficient process operation

The defoamer KEBOSPUM PP from the KEBOSPUM product range significantly reduces foam formation and thus optimizes the entire production process.

Our best practice for potato processing: This case study documents how a manufacturer processing approx. 200,000 tons of raw potatoes per year sustainably improved its dosing strategy, reduced chemical consumption and increased process reliability through the targeted use of KEBOSPUM PP—even with varying potato varieties and fluctuating starch loads. A practical example demonstrating how effective foam control becomes a decisive efficiency factor.

Download Best Practice (PDF)