title: Assessment of changes in crystallization properties of pressurized milk fat.
abstract: The aim of the study was to demonstrate the use of fractal image analysis as a possible tool to monitor the effect of pressurization on the crystallization pattern of anhydrous milk fat. This approach can be useful when developing new products based on milk fat. The samples were subjected to different hydrostatic pressure (100, 200, 300, and 400 MPa) and temperature (10 and 40 °C) treatments. The crystallization microphotographs were taken with a scanning electron microscope. The image analysis of scanning electron microscope photographs was done to determine a fractal dimension. Milk-fat pressurization under the applied parameters resulted in slight, but statistically significant, changes in the course of crystallization curves, related to the triacylglycerol fraction crystallizing in the lowest temperature (I exothermic effect). These changes were dependent on the value of pressure but not dependent on the temperatures applied during the process of pressurization (at either 10 or 40 °C). In turn, significant differences were observed in crystallization images of milk-fat samples subjected to this process compared with the control sample. The results of additional fractal analysis additionally demonstrated the highest degree of irregularity of the surface of the crystalline form for the nonpressurized sample and the samples pressurized at 200 and 300 MPa at 10 °C. The lowest value of fractal dimension-indicative of the least irregularity-was achieved for the fat samples pressurized at 400 MPa, 10 °C and at 100 MPa, 40 °C. The possibilities of wider application of the fractal analysis for the evaluation of effects of parameters of various technological processes on crystallization properties of milk fat require further extensive investigations.
authors: Faculty of Food Sciences, University of Warmia and Mazury, Oczapowskiego 7, 10-719 Olsztyn, Poland. Electronic address: bostuwm@gmail.com.
authors: Bogusław
authors: B
authors: Staniewski
authors: Faculty of Food Sciences, University of Warmia and Mazury, Oczapowskiego 7, 10-719 Olsztyn, Poland.
authors: Michał
authors: M
authors: Smoczyński
authors: Faculty of Food Sciences, University of Warmia and Mazury, Oczapowskiego 7, 10-719 Olsztyn, Poland.
authors: Katarzyna
authors: K
authors: Staniewska
authors: Faculty of Food Sciences, University of Warmia and Mazury, Oczapowskiego 7, 10-719 Olsztyn, Poland.
authors: Maria
authors: M
authors: Baranowska
authors: Faculty of Food Sciences, University of Warmia and Mazury, Oczapowskiego 7, 10-719 Olsztyn, Poland.
authors: Katarzyna
authors: K
authors: Kiełczewska
authors: Faculty of Food Sciences, University of Warmia and Mazury, Oczapowskiego 7, 10-719 Olsztyn, Poland.
authors: Justyna
authors: J
authors: Zulewska
mesh_terms: D000818:Animals; D002152:Calorimetry, Differential Scanning; D003080:Cold Temperature; D003460:Crystallization; D005223:Fats / Q000737:chemistry*; D005511:Food Handling; D007091:Image Processing, Computer-Assisted; D008853:Microscopy; D008892:Milk / Q000737:chemistry*; D011312:Pressure; D014280:Triglycerides / Q000737:chemistry
chemical_list: D005223:Fats; D014280:Triglycerides
keywords: fractal analysis; milk fat; physical and crystallization properties; pressurization; triacylglycerol composition