TOKYO (Bloomberg) - The meat-free movement is finding its way into strange and exotic dishes.

The latest example: imitation uni. Usually, the orange innards of sea urchins served in sushi restaurants are harvested from spiky creatures that live on seabeds. The delicacy requires much labour to collect and keep fresh. That makes it one of the most expensive items on menus; a 100g box of top-grade uni from Japan's northern island of Hokkaido can easily fetch 5,000 yen (S$65).

Although Beyond Meat Inc. and Impossible Foods Inc. are grabbing headlines these days, vegan seafood is considered the next frontier in plant-based foods due to sustainability concerns. Good Catch, based in Newton, Pennsylvania, sells crab-free crabcakes and fish-free tuna. San Francisco-based Wild Type is developing lab-grown salmon. At stake is a piece of a vegan market that is projected to exceed US$24 billion (S$33 billion) by 2026.

Japan already consumes 80 per cent of the world's uni supply, and demand will only climb thanks to sushi's growing global popularity. That's why Fuji Oil Holdings Inc., maker of processed foods such as chocolate and soy products, developed the world's first imitation uni, using flavored vegetable oils and soy-based ingredients.

Uni is an acquired taste. The small textured orange lumps are the gonads of male and female sea urchins that produce sperm and eggs. Connoisseurs seek out uni for its fresh-from-the-sea aroma; the best uni is firm until it is eaten, and dissolves into a creamy texture on the tongue. It is typically dolloped atop sushi rice, then wrapped with seaweed. Uni can also be mixed in with pasta, or spread over small pieces of toast, like caviar.

Fuji Oil's version of uni is treated more like an ingredient meant to be used in a variety of dishes. Even so, one Tokyo sushi restaurant expressed an interest in trying it out. "We'd have to taste it first, but yes, we'd consider it," said Yuki Haga, a sushi chef at Gonpachi.

Restaurants may eventually have little choice but to add plant-based seafood to their menus. Overfishing is becoming a serious concern, as a rising global population consumes fish faster than it can be pulled out of the sea. Even with farm-raised fish, which account for more than half of consumption, it is not enough.

Fuji Oil, which also makes vegan tuna flakes, got its start in the post-war years, becoming the first food company in Japan to extract palm oil. The Osaka-based company provides everything from the soy milk used in Starbucks lattes in Japan to meatless burgers for fast-food chains. The company's goal is to make "milk that's tastier than milk, butter that's tastier than butter," said Hiroshi Shimizu, Fuji Oil's chief executive officer.

Plant-based food is not just a business opportunity - US retail sales of plant-based foods climbed 20 per cent to US$3.3 billion last year - but an answer for an impending global food crisis, according to the United Nations. Earlier this month, the Intergovernmental Panel on Climate Change warned that rising temperatures are putting the world's food supply at risk.

Now one of Japan's biggest providers of compound fats and proteins for chocolate bars and puddings, Fuji Oil is projected to see its sales climb 42 per cent to 426 billion yen in the fiscal year to March. After more than doubling from 2014 through 2018, the stock is down 21 per cent this year as higher cocoa prices and costs from a recent merger erode margins. Fuji Oil has a valuation of about 246 billion yen.

"High-end restaurants could be the next target clientele for Fuji Oil, with their vegan uni," said Norikazu Shimizu, an analyst at IwaiCosmo Securities Co.