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Seven-Eleven uses microbial testing tech to extend katsudon shelf life

Japanese retail company Seven-Eleven has improved its factory’s microbial environment to keep comfort-food staple, katsudon, fresher for longer.

Convenience store brand Seven-Eleven has extended the shelf life of katsudon by a day, using new technology. Katsudon is a Japanese comfort-food staple featuring rice, pork and egg.

At a glance:

• Seven-Eleven extends product’s shelf life by using advanced microbial testing, not preservatives or recipe changes.
• MALDI-TOF mass spectrometry technology cut testing time from weeks to hours, improving hygiene and reducing costs.
• A longer shelf life can reduce food waste and improve supply chain efficiency.

Rather than adding preservatives or changing the product, Seven-Eleven extended the product’s shelf life by using advanced MALDI-TOF mass spectrometry microbial testing technology to identify microorganisms in the production space and how these can affect product quality.

Seven-Eleven collaborated with Kyushu Sangyo University and food manufacturer Warabeya Nichiyo Foods to explore how microorganisms affected katsudon production.

Researchers carried out around 5,000 swab tests across the manufacturing environment. Beyond investigating simply whether microorganisms were present, they used MALDI-TOF mass spectrometry to identify them, and trace their sources and movement. This gave Seven-Eleven a more comprehensive understanding of its factory’s microbial content and its impact.

Advanced technology reduced weeks of testing to hours

MALDI-TOF mass spectrometry identifies microorganisms by analysing their molecular profiles. Its core benefits, when applied to Seven-Eleven products, were speed, cost, and specificity.

Seven-Eleven and Kyushu Sangyo University found that conventional identification could take several weeks of testing per sample. Applying MALDI-TOF mass spectrometry reduced this to a few hours. They also found that testing costs fell from approximately ¥50,000–¥80,000 (€3,000 - €4,000) per sample to ¥2,000–¥3,000 (€11-€16).

Locating bacteria changed cleaning strategies

During the research phase, extensive swab testing helped the collaborators pinpoint locations and transmission routes for microorganisms. Seven-Eleven and Warabeya Nichiyo Foods could then strengthen hygiene controls and improve the factory environment at precise points in the production process, rather than relying on less targeted interventions.

The technology’s capabilities reflect Seven-Eleven’s broader approach, which considers taste and food safety to be closely connected, it said.

“For us, deliciousness and safety/security are always two sides of the same coin,” said Shunji Saito, general manager of the quality control department at Seven-Eleven Japan.

“Professor Nakayama's cutting-edge analytical technology was indispensable in achieving extended freshness while maintaining the home-style taste by eliminating excessive heating,” Saito added.

‘In retail, the challenge is not selling more, but losing less’

Guaranteeing an extra day of freshness creates more room for production, transportation and sales planning. It also reduces the number of products discarded simply because they have reached the end of their freshness window.

“From a financial perspective, extending shelf life goes beyond the product itself; it can affect the entire economics of the value chain,” Carlos Alfredo Hernandez Aguilar, senior accountant at Bomohsa, an agricultural equipment supply company, told Ingredients Network.

The longer a safe, high-quality product remains sellable, the greater the opportunity to extract value from inventory that might otherwise become waste. “Inventory is capital sitting on a shelf waiting to become cash,” said Aguilar.

Longer shelf life does not automatically create value, though. The financial question is whether the savings in waste, logistics, and working capital justify the investment required to achieve it.

“That may be one of the most useful lessons for manufacturers from Seven-Eleven’s approach: innovation creates real business value when operational improvement eventually translates into better economics,” added Aguilar.

From a retail perspective, the objective is not necessarily to hold more inventory, but to have better visibility over time, demand and availability.

“In convenience retail, the real challenge is not selling more, but losing less,” Daniel Aarón Reynoso Alvarado, sales strategy director at retail systems provider Sensormatic América Latina, told Ingredients Network.