We describe a food additive comprising a PS4 variant polypeptide, in which the PS4 variant polypeptide is derivable from a parent polypeptide having non-maltogenic exoamylase activity, in which the PS4 variant polypeptide comprises an amino acid mutation at one or more positions selected from the group consisting of: 146, 157, 158, 198, 229, 303, 306, 309, 316 and 353, with reference to the position numbering of a Pseudomonas saccharophilia exoamylase sequence shown as SEQ ID NO: 1. Preferably, the PS4 variant polypeptide comprises an amino acid mutation selected from the group consisting of: 146G, 146M, 157M, 158T, 158A, 158S, 198W, 198F, 229P, 303E, 303D, 306T, 306G, 309P, 316S, 316P, 316K, 316Q and 353T, preferably 146G, 157M, 158T, 198W, 229P, 303E, 303D, 306T, 306G, 309P, 316S, 316P or 353T. in highly preferred embodiments, the PS4 variant polypeptide has a sequence selected from SEQ ID NO: 15 to 28.