en Fish processing Fish processing پژوهشي Orginal research papers The main objective of this study was to determine the optimum application level of acidic extracted grass carp (<em>Ctenopharyngodon idellus</em>) gelatin as a protein-based fat replacer in the development of low-fat milk cream. A cream mixture consisting of fish gelatin at different concentrations (0-8%), milk cream, and cow milk was used to find the best formula for developing a low-fat milk cream. The optimization of the formula was based on the physicochemical and sensory properties of the prototypes using a mixture design model. Results showed that the crude protein content of the prototypes was increased by increasing fish gelatin concentration. However, the fat content was significantly reduced from 30% in the control to 12.5% in the low-fat sample with 8% fish gelatin. The highest values of freeze-thaw stability and water holding capacity were seen in the low-fat samples with 4% and 8% fish gelatin. The microstructural characteristics revealed that fish gelatin could cause smaller particles of oil globules compared to the full-fat cream. The lightness value was decreased significantly in the prototypes by increasing fish gelatin concentration, while the highest yellowness index was observed in the prototype with 8% fish gelatin. This study revealed the successful application of fish gelatin in low-fat milk cream at the level of 8%. At this level, the sensory attributes and texture properties were improved. This study noted that it is possible to develop a low-fat milk cream enriched fish gelatin as a novel functional ingredient with high nutritional values and potential health benefits.<br> <gdiv></gdiv> Grass carp, Fish gelatin, Fat replacer, Low-fat milk cream, Acidic extraction 1277 1290 http://jifro.ir/browse.php?a_code=A-10-779-4&slc_lang=en&sid=1 S.P. Hosseini Shekarabi hosseini.pezhman@yahoo.com 100319475328460041301 100319475328460041301 No Department of Fisheries Science, Science and Research Branch, Islamic Azad University, Tehran, Iran N. Rostami NilofarRostami@yahoo.com 100319475328460041302 100319475328460041302 No Department of Fisheries Science, Science and Research Branch, Islamic Azad University, Tehran, Iran A.R. Shaviklo shaviklo@gmail.com 100319475328460041303 100319475328460041303 Yes Animal science reserach institute of Iran N. Mhd Sarbon norizah@umt.edu.my 100319475328460041304 100319475328460041304 No Department of Food Science, Faculty of Fisheries and Food Science, University Malaysia Terengganu, Malaysia