Costlier potatoes and pulses pushed food inflation higher to 17.56 per for the week ended January 23. This is the second week in a row that food inflation has increased, after easing for three successive weeks.Food inflation had stood at 17.4 per cent in the week ended January 16. Food inflation rose mainly because potatoes became dearer by 45 per cent and pulses by 44 per cent over the previous year.On a weekly basis, the index for food articles declined by 0.1 percent, mainly due to lower prices of tea, arhar and urad, fruits & vegetables, and eggs.