A new whey for CIP in dairies

Between one and 60 L of water is needed for cleaning and sanitation per kg of processed milk. This is equates to massive amounts of water and huge demands on waste systems.

Researchers at the University of Nebraska-Lincoln looked at this issue and investigated recycling and re-using the water from whey for clean-in-place systems. Their findings, reported in the Journal of Dairy Science, provide scientific evidence of the safety of re-use of reconditioned water in food processing plants, contributing to building a culture of water conservation and sustainable production throughout the food supply chain.

Current regulations indicate that only potable water may be used to clean food contact surfaces and equipment surfaces, but reconditioning and re-use of water is a promising alternative currently acceptable for initial cleaning of fruits and vegetables as well as scalding of meat and poultry. In their study Yulie Meneses and Rolando Flores tested wastewater from whey of Cheddar cheese by subjecting it to reverse osmosis and ultrafiltration, as well as an additional step of spray drying. The resulting reconditioned water was used to clean stainless steel surfaces that had a biofilm, with promising results from both bacterial counts and scanning electron microscopy analysis.

“Using the combined ultrafiltration and reverse osmosis system, 47% of water can be recovered from whey,” lead author Yulie Meneses said. “This demonstrates the viability of our method for wastewater, as the cleaning efficiency was comparable to potable water in clean-in-place systems,” added project leader Rolando Flores.

Further, by incorporating spray-drying and condensation into the process, recovery of additional water can be achieved; after suitable treatment, that water could also be used in cleaning applications or other activities with high water demand.

Because of its potential in terms of revenue and conserving natural resources, these wastewater reclamation techniques are highly interesting. More research is required, however, to further elucidate risks and broader environmental issues as they relate to the techniques in this study.