New laws have just gone into effect that require distributors to reveal the country of origin on some food products, but many items are still exempt.
As far as what company manufactured a particular item, it is for the distributor to know and you aren't supposed to find out. It's like those ads you see: "We can't tell you the Brand Name on TV, but our prices are way below their suggested retail price!" A private label product is often made by a major brand, but the major brand doesn't want you to know that the cheaper item is the same as theirs.