Low molecular weight peptide with a high affinity to calcium was recovered from pepsinolytic hydrolysates of Theragra chalcogramma backbone discarded from fish processing using a hydroxyapatite affinity chromatography. T chalcogramma backbone peptide (TBP), Val-Leu-SerGly-Gly-Thr-Thr-Met-Ala-Met-Tyr-Thr-Leu-VaI (Mw: 1442 Da), exhibited the highest affinity to calcium ion on the surface of hydroxyapaptite (HA) crystals. In vitro calcium-binding assay elucidated that TBP can solublize a similar content of calcium with casein phosphopeptide (CPP). In the present study, it is possible to provide utilization of fish backbones in a novel nutraccutical material with a high solubility for calcium to oriental people with lactose indigestion and intolerance. (c) 2006 Elsevier Ltd. All rights reserved.