A modified endoinulinase is provided, comprising modified wild-type T. purpuregenus endoinulinase, or a functional fragment thereof, in which an amino acid residue at each one of one or more positions corresponding to 128, 316, 344, 350 or 504 of wild-type T. purpuregenus endoinulinase is substituted, wherein: (i) a tyrosine residue corresponding to Y128 is substituted with H, K or R; a glutamate residue corresponding to E344 is substituted with K, H or R; and a threonine residue corresponding to T504 is substituted with M, S or Y; and optionally an alanine residue corresponding to A316 is substituted with T, S, C or M; (ii) a tyrosine residue corresponding to Y128 is substituted with H, K or R; a glutamate residue corresponding to E344 is substituted with K, H or R; a threonine residue corresponding to T504 is substituted with M, S or Y; and a glutamine residue corresponding to Q350 is substituted with L, G, A, V or I; or (iii) a tyrosine residue corresponding to Y128 is substituted with H, K or R.