Food inflation inched up to 17.40 per cent for the week ended January 16 on account of high prices of potato and pulses. The wholesale price-based food inflation was 16.81 per cent in the previous week.Potato prices rose as much as 57.56 per cent over the last year, followed by prices of pulses which jumped by 46.87 per cent.The inflation for primary articles, which include food and non-food items, stood at 14.66 per cent .