text <- "PEANUTS (PEANUTS, PEANUT OIL AND/OR COTTONSEED OIL AND/OR CANOLA OIL AND/OR SOYBEAN OIL, SALT), GOLDEN RAISINS (RAISINS, SULFUR DIOXIDE), DRIED CRANBERRIES (CRANBERRIES, SUGAR, CITRIC ACID, SUNFLOWER OIL (PROCESSING AID), ELDERBERRY JUICE CONCENTRATE (COLOR)), ALMONDS (ALMONDS, PEANUT OIL AND/OR COTTONSEED OIL AND/OR CANOLA OIL AND/OR SOYBEAN OIL, SALT), MACADAMIAS (MACADAMIAS, MALTODEXTRIN, SALT)"
strsplit(text, "(\\((?:[^()]++|(?1))*\\))(*SKIP)(*F)|,", perl=TRUE)