See how many times a word appears throughout a workbook

Just like the title, making a workbook for work and it has a list of items per different stores(each store has its own sheet). I need a master list that can pull how many times a word appears in the entire workbook. For example how many times does a "red apple" appear in the workbook and how many stores are carrying it. Cant figure out the formula for it to pull the data, any help would be a great help!