Milk powder: a global formula for food security

New Zealand is one of the world’s largest manufacturers and exporters of whole milk powder (WMP) and skimmed milk powder (SMP), producing an estimated 1.42 million metric tons of WMP in 2024/25 — approximately 32% of global output.

Oversupply challenges in global dairy production often force farmers to discard milk before it even reaches processors. In regions like Oceania, seasonal peaks further compound the issue, especially when cold storage capacity is limited.

Current industrial food production methods can place considerable strain on the environment. When production continues to exceed demand, perishable goods like milk are at risk of being wasted. Powdered dairy products such as WMP and SMP offer a practical solution by extending shelf life and helping reduce global food waste.

Global role model

Cost savings, versatility and sustainability are the driving force behind the growing popularity of milk powder. Aside from decreasing milk dumping, a longer shelf life means that less milk is wasted, helping to reduce food waste and conserve resources.

A key environmental benefit of milk powders is their compact size and reduced weight, which lowers transportation emissions and eliminates the need for cold storage. Utilising milk powders in place of fresh milk eradicates the requirement for cold storage and requires a significantly smaller amount of space in processing facilities and transportation vehicles.

In New Zealand, dairy processors are implementing innovative technologies to enhance sustainability. For instance, Fonterra’s Maungatūroto milk powder plant has developed a wetland recycling system that reuses water extracted during the milk powder condensation process. This initiative produces between 500,000 and 700,000 litres of reclaimed water daily, accounting for approximately a quarter of the plant’s total water usage. The reclaimed water undergoes treatment through the wetland and the site’s water treatment facilities, making it suitable for reuse in processing operations and even as drinking water.

HACCP standards for sustainability

One of the most sustainable methods of reducing waste is implementing inspection technology into milk powder production lines. Metal detection and checkweighing systems help processors reduce waste, optimise sourcing, and address sustainability targets by identifying inefficiencies and contamination risks early. This includes addressing upstream product giveaway, non-conforming food packs and packaging, and contamination issues.

Stringent regulations and growing consumer awareness regarding food safety mean that milk powder processors, like all dairy manufacturers, adopt advanced technologies like metal detectors to maintain product integrity and satisfy export requirements. While gravity metal detectors are commonly used to inspect free-flowing milk powder prior to packaging, airborne dust at these points can present combustible hazards and must be carefully managed.

For milk powder processors looking to inspect free-flowing product, inspection equipment must meet the defined hazardous location standards and be robust enough to withstand vibrations and temperature changes without compromising performance. Milk powder processors that don’t have free-falling inspection systems often use magnets and sieves to remove any large contaminants.

End-of-line big bag metal detectors and checkweighers are more frequently used to inspect milk powders in 25 kg formats or larger after the product is packaged and sealed. Functioning as a final defence, at this phase there is virtually zero possibility of a new contaminant being introduced. However, if rejected, the costs incurred through wasted food, labour and packaging can be exponentially higher.

Testing software to optimise safety

Given the sophistication of New Zealand’s milk powder production lines, many processors are adopting automatic testing systems. These simulate a contaminant signal passing through the centre of the metal detector aperture, ensuring food safety, and quality control standards are upheld without interrupting production. Test results are automatically logged and digitally stored, providing consistent data for GFSI audits, reducing manual testing risks and minimising human error in hazardous environments.

“It is virtually impossible to consistently and accurately replicate a metal contaminant passing through the exact centre of a product or metal detector aperture using manual testing,” said Tim Whyte, General Manager of Fortress Technology New Zealand.

Automatic testing enables operators to pre-program ferrous, non-ferrous and stainless steel test samples, each calibrated to replicate a contaminant travelling through the centre of the aperture. These tests can be activated remotely, locally or automatically on a timer.

Image credit: iStock.com/Smederevac