HYBRID EVENT: You can participate in person at Rome, Italy or Virtually from your home or work.
Justyna Zulewska, Speaker at Nutrition Conference
University of Warmia and Mazury in Olsztyn, Poland


Lactose intolerance is a condition in which a person cannot digest or absorb lactose due to a genetically programmed decrease in intestinal galactosidase (lactase). People who follow a strict lactose-free diet often suffer from various nutritional deficiencies that can generate various health disadvantages. Increasing the amount of cheese in lactose intolerant people diet provides the right amount of energy (fat), fulfil calcium requirements and keep the lactose intake low. 

The aim of this study was to evaluate the properties of tvarog cheeses (traditional acid coagulated cheese produced in Poland and other Eastern European countries) produced with the addition of lactose hydrolysing enzyme – β-galactosidase.

Standard tvarog (traditional production protocol) and tvarog with normalized lactose content (lactose-free tvarog) were produced in semi-industrial scale. The lactose content in cheese were measured using Lactosens test (Chr. Hansen) involving a direct assay on a biochip. The cheeses were subjected to texture profile analysis and sensory analysis. Experimental cheeses were compared with commercial products on the same market segment. 

The study showed that the enzyme addition neither altered the acidity of milk nor the acidity of obtained curds. Dynamics of milk acidification and cheese yields were similar in case of lactose-free tvarog production process and standard tvarog production process. Lactose content in lactose-free tvarog was below 0.01%. Lactose-free cheeses contained slightly lower amount of protein and fat, however, slightly longer drainage time could possibly affect the composition of the final product. Texture profile analysis indicated that cheeses with reduced lactose content were characterized by increased cohesiveness. Sensory analysis conducted by the panelists showed that the overall rating was higher for lactose-free cheese compared to standard tvarog and commercial products. The study confirmed that the precise control of technological parameters enables the production of  high quality lactose-free cheeses with properties similar to traditionally made tvarog.

Audience take away

  • The trends in dairy products development will be presented.
  • The technological and regulatory issues related to development of functional food in Europe, especially in relation to dairy products will be discussed.
  • The consumer perception of novel food will be presented.


Dr. Justyna ?ulewska studied Food Technology and Nutrition at Olsztyn Academy of Agriculture and Technology, Poland. Her doctorate was received in 2004 from University of Warmia and Mazury in Olsztyn, Poland with her dissertation in the area of functional properties of whey proteins. She then has been employed at University of Warmia and Mazury in Olsztyn, Poland. She completed several fellowships at Universidade Catolica Portuguesa, Universidade de Aveiro, University of Hawaii at Manoa, and Cornell University.  She has published over 80 journal articles and presented over 90 communications/abstracts to national and international conferences. Her main research interests are: factors influencing quality and yield of cheese, production of cheese with altered ratio of casein fractions, whey management, factors affecting the efficiency of filtration processes, food product development, functional dairy ingredients.