Publications in year 2016

Vol. 23, Issue 4



Rheological properties, texture and color of ricotta available on the Polish market

International Agrophysics
Year : 2016
Volumen : 23
Issue : 4
Pages : 695 - 704
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Authors: Krzysztof Siemianowski1, Dorota Mickiewicz2, Anna Lis1, Elżbieta Tońska3

1Chair of Dairy Science and Quality Management, University of Warmia and Mazury ul. M. Oczapowskiego 7, 10-719 Olsztyn, Poland
2Department of Process Engineering and Equipment, University of Warmia and Mazury, M. Oczapowskiego 7 street, 10-957 Olsztyn, Poland
3Department of Commodity Science and Food Analysis, University of Warmia and Mazury, Cieszyński Square 1, 10-726 Olsztyn, Poland
Abstract :

The aim of this study was to analyze the rheological properties, texture and color of ricotta available on the Polish market. The experiment was performed on fresh (unripened) ricotta supplied by four manufacturers, purchased in retail in the city of Olsztyn, Poland. Ricotta samples were analyzed to determine their content of dry matter, total protein, fat, lactose and ash. Active acidity was also measured. The rheological properties of ricotta were determined with the use of a rotary rheometer. Measurements were carried out at increasing shear rates, from 0.2 to 50 s–1. Texture, including hardness, adhesiveness, cohesiveness, springiness and gumminess, was evaluated with a texture analyzer. Color parameters L*, a*, b* were measured with a spectrophotometer, and chroma (C*) was determined. The evaluated ricotta products were characterized by significant differences in chemical composition and active acidity. Their viscosity decreased with increasing shear rates. In ricotta from two manufacturers, shear stress increased at higher shear rates. A significant positive linear correlation was found between dry matter content and fat in dry matter content vs. shear stress and viscosity at the maximum shear rate. Significant differences in hardness, adhesiveness and gumminess were noted between the analyzed ricotta samples. The products characterized by higher adhesiveness had a higher protein to fat ratio. Significant differences were also observed between the analyzed products with regard to the values of color parameters L*, a*, b* and C*. A significant negative linear correlation was found between protein in dry matter content vs. color parameters a*, b* and C*, whereas a significant positive linear correlation was noted between fat in dry matter content and parameter a*.

Keywords : dairy product, chemical composition, rheology, texture, colour
Language : polish