The Effect of Phycocyanin on the Microbial, Antioxidant, and Nutritional Properties of Iranian Cheese

Abstract

The prevailing conditions for the production, storage, and sale of traditional cheese seem to increase the probability of microbial contamination. <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> are among the bacteria that may cause major complications such as diarrhea, hemolytic uremic syndrome (HUS), food poisoning, and gastrointestinal infections in cheese consumers. The use of food coloring to enhance the microbial load of food products, as an innovative and cost-effective biological control, is one of the most efficient methods in managing the production, storage, and quality of food. Extracted naturally from <i>Spirulina</i> sp., phycocyanin is widely used in various pharmaceutical, food, cosmetic and health industries. This is the first attempt to investigate the possible effect of adding phycocyanin pigment into traditional cheese, in order to improve-the nutritional value, quality and shelf life of traditional cheese. This study collected five different types of traditional cheese from different localities in Iran. The researcher immersed the samples in concentrations of 1%, 1.5% and 2% phycocyanin pigment. After identifying the existing bacteria, the possible effect of the pigment on the total number of bacteria, as well as the number of<i> E. coli</i> and <i>S. aureus</i>, were evaluated within 15 days. The study used Ferric ion reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and nitric oxide trapping with the sensory testing in order to determine the amount of protein, fat, ash, moisture, and antioxidant properties. Statistical analyses showed that, compared to the control group, the concentration of phycocyanin rose when the number of bacteria decreased and antioxidant activity increased in all types of cheese. The results revealed a significant increase in the amount of protein (93%), fat (80%), moisture (100%), and ash (67%). In addition, the highest consumer satisfaction was observed on day 1 and days 7 and 15; cheese with a concentrations of 1.5% and 2% pigments were preferred.