The use of corn was mentioned earlier. This may be of interest. It was found here.   

Meanwhile, Prime Minister Peel came up with his own solution to the food problem. Without informing his own Conservative (Tory) government, he secretly purchased two shipments of inexpensive Indian corn (maize) directly from America to be distributed to the Irish. But problems arose as soon as the maize arrived in Ireland. It needed to be ground into digestible corn meal and there weren't enough mills available amid a nation of potato farmers. Mills that did process the maize discovered the pebble-like grain had to be ground twice.
To distribute the corn meal, a practical, business-like plan was developed in which the Relief Commission sold the meal at cost to local relief committees which in turn sold it at cost to the Irish at just one penny per pound. But peasants soon ran out of money and most landowners failed to contribute any money to maintain the relief effort.
The corn meal itself also caused problems. Normally, the Irish ate enormous meals of boiled potatoes three times a day. A working man might eat up to fourteen pounds each day. They found Indian corn to be an unsatisfying substitute. Peasants nicknamed the bright yellow substance 'Peel's brimstone.' It was difficult to cook, hard to digest and caused diarrhea. Most of all, it lacked the belly-filling bulk of the potato. It also lacked Vitamin C and resulted in scurvy, a condition previously unknown in Ireland due to the normal consumption of potatoes rich in Vitamin C.
Out of necessity, the Irish grew accustomed to the corn meal. But by June 1846 supplies were exhausted.