Sonofai: How Ultrasound and AI Grade Tuna in 12 Seconds — No Knife Needed

Think grading tuna for fat content is all about slicing and looking at marbling? Think again. Fujitsu’s Sonofai machine replaces that age-old method with non-destructive scanning, combining ultrasound and AI to assess frozen tuna in just 12 seconds. It’s fast, clean, and hits every industry pain point—labor availability, food safety, waste, and consistency. Let’s explore why seafood processors are all ears for this tech.

The Age-Old Tuna Tail Cut

In Japan, tuna grading is still a respected craft. Until now, that meant grabbing a frozen bluefin tuna tail, slicing off a chunk, and inspecting the fat lines—known as shimi—by sight and feel. Masters in this field, tuna graders learn their trade over years, much like sommeliers. But it’s not flawless. You need skill, time, and frankly, a strong stomach. Each fish loses a bit of flesh. Each decision can vary with fatigue, lighting, or bias. For large-scale operations, this process is a bottleneck, and frankly—a messy, risky one.

Meet Sonofai: 12 Seconds of Science

Sonofai starts by placing a frozen tuna on a scanning platform. Without thawing or cutting, ultrasound transducers glide over the sides, sending sound waves through the muscle. Fatty tissues reflect sound back differently than lean muscle. Fujitsu’s AI combines thousands of pre-labeled scans with expert grader feedback, learning to correlate wave results with fat quality. In a single dozen seconds, it produces a fat distribution map and selects a grade. No blood, no thaw, and importantly—no subjectivity.

What It Means for Seafood Producers

Picture a processing plant scanning 400 fish per day. Manual grading means slicing, exposing the fish to warm air, handling waste, and relying on graders who need time and breaks. With Sonofai, no initial cut happens, and fish remain in cold storage longer. Output is consistent; the machine doesn’t tire. That’s measurable yield improvement—meaning more profit on every fish. Plus, traceability: every scan is timestamped, logged, and easy to trace back to batches, dates, operators, or even shipping conditions.

No Knife, Less Risk

Manual grading carries hidden costs: slip injuries, knives, blood, and water pooling on floors. By replacing knives with ultrasound, Sonofai drastically cuts safety hazards. You also avoid thawing downtime; the fish stays frozen, no additional cooling steps before grading. That’s a win for both food safety and productivity. Less thawing, less risk of pathogen growth, and fewer cleanups after grading—makes total sense.

Skill Level Moves from Knife to Screen

Not everyone can become a tuna grading expert. It takes time, mentorship, and natural talent. Sonofai, on the other hand, needs training—it can be learned in hours. Load fish, press scan, review results. That’s it. Suddenly, remote processing facilities in Southeast Asia, Europe, or North America gain access to consistent grading results without relying on a limited pool of certified Japanese graders. That democratizes quality control across the globe.

What About Non-Frozen Fish?

Right now, Sonofai only works in frozen environments. Don’t expect to walk in with thawed sashimi-grade fish and get a reading. Fair. But frozen bulk processing is huge—canned tuna, steaks, pet food, and more. Fujitsu is planning to adapt the tech to chilled or thawed fish, which would be a major leap. They’re testing adjustable probe pressure and AI models tuned to different temperatures. Could be part of the next-gen unit.

Industry Feedback + Pilot Results

Early users in 2024 said Sonofai’s grades matched expert assessments about 90% of the time. And in those rare cases of mismatch? It flags results for human check—never auto-reject. One plant noted less than 2% of fish were misgraded. Combined with a 30% reduction in fish weight loss, the economics are clear: better yield, faster ops, fewer safety incidents, and full audit trail.

From Tuna to Cheese: Beyond the Fish

The beauty of Sonofai is its modular foundation. Ultrasound physics isn’t limited to seafood. Fat content in pork, gel detection in cheese, bruise detection in fruit—the same underlying tech applies. Fujitsu is already testing fruit firmness, water content in cantaloupe, and marbling in beef. Tomorrow’s food factories could use a unified scanner for quality across categories.

Bridging Tradition and Tech

Some traditionalists might bristle at “machine grading,” but Sonofai isn’t killing tradition—it’s enhancing it. Tuna grading still counts fat, follows the same rules—just faster and more reliably. Sonofai isn’t asking for replacement; it’s offering a powerful upgrade. You keep your quality hierarchy and standards, while improving efficiency and traceability. You still decide on export grade or restaurant quality—but with fresh insight.