WalMart’s membership-based bulk food offshoot, Sam’s Club, has introduced restrictions on the amount of rice people can buy from some of its stores across the US. And its major rival Costco has reported some signs of customers bulk buying flour, rice and other commodities at higher rates than normal.

Sam’s Club said overnight that it’s limiting sales of Jasmine, Basmati and long grain white rice to four 20-pound (9kgs) bags per customer per visit “due to recent supply and demand trends.” The restrictions have been introduced in states where they are allowed by law, but Sam’s Club said it is not limiting sales of flour or cooking oil at this time.

Costco says some of its stores have introduced limits on sales of items such as rice and flour, but it was trying to “modify” those restrictions to meet customer demand.

It’s the most obvious sign yet of the impact and reach of the food crisis, especially the rice crunch.

The global price of rice has jumped 68% this year and more than doubled for premium types like jasmine from Thailand or basmati from India. Countries like India, China, Vietnam, Indonesia and Cambodia are banning exports or limiting shipments by raising the price. 

American bakers also are dealing with tight supplies. Rye flour stocks have been depleted and, according to the American Bakers Association, there will be no more American rye flour to purchase by June or July. Imports will have to be made from Europe.

The Association’s members have already been grappling with ultra high prices for prime bread making wheat which topped $US19 a bushell last month.

Food companies have been cutting back on the use of edible oils, such as soybean oil and using more water in whips, mayonnaise and other spreads. Some have gone to containers with straight sides and larger openings to allow consumers to scrape as much product from the container as possible.