Antifreeze　proteins　belonging　to　structurally　diverse　families　of　genetically　coded　proteins　from　several　living　organisms　have　been　isolated　and　characterized　in　the　past.　This　paper　reports　that　collagen　peptides　of　a　certain　molecular　size　range　derived　from　Alcalase　hydrolysis　of　bovine　gelatin　are　able　to　inhibit　recrystallization　of　ice　in　frozen　ice　cream　mix　as　well　as　in　frozen　sucrose　solutions　in　a　manner　similar　to　natural　antifreeze　proteins.　The　optimum　conditions　for　producing　such　ice-structuring　peptides　(ISP)　were　hydrolysis　at　pH　9.0　for　30　min　at　45　°C　and　an　Alcalase-togelatin　ratio　of　0.176　unit　per　gram　of　gelatin.　The　collagen　peptides　were　fractionated　on　size　exclusion　(Sephadex　G-50)　and　ion　exchange　(sulfopropyl-Sephadex　C-25)　columns,　and　the　molecular　mass　distribution　of　the　ice-structuring　peptide　fractions　was　determined　by　matrixassisted　laser　desorption　ionization-time-of-flight　(MALDI-TOF)　mass　spectrometry.　The　collagen　peptide　fractions　in　the　molecular　mass　range　of　600-2700　Da　inhibited　ice　recrystallization　in　a　supercooled　ice　cream　mix　and　in　concentrated　sucrose　solutions.　The　cationic　collagen　peptides　within　this　fraction　with　molecular　mass　in　the　range　of　1600-2400　Da　were　more　effective　than　the　anionic　peptides　in　inhibiting　ice　crystal　growth.　©2009　American　Chemical　Society.