Effect of Type of Colorant on the Physicochemical Properties of Ras Cheese and its Whey

Author's: Najeeb Yahia Al-Surmi*1, Mohamed Nour-Eldin Farid Hamad2, Sama Mohamed El-Sayed3
Authors' Affiliations
1Genetic Resources Center, Agriculture Faculty, Sana'a University, Yemen.2Dairy Department, Agriculture Faculty, Damietta University, Egypt.3Food Science Department, Home Economic Faculty, Al-Azhar University, Egypt.*CorrespondenceNajeeb Yahia Al-SurmiEmail:najeeblutf@gmail.com
Article Type: Research Article     Published: Dec. 19, 2021 Pages: 108-124
DOI:        Views 450       Downloads 0


Ras cheese was manufactured utilizing different cheese colorants (annatto, Curcumin, beta carotene based, and cheese without color), and coagulants (recombinant bovine). This study was conducted to understand their effect on the chemical, microbiological and rheological properties of Ras cheese. The highest yield was observed in the cheese treated with curcumin compared to other treatments of Ras cheese. The highest fat content was detected in β-carotene cheese after 180 days of ripening. The highest value of Water-soluble nitrogen (WSN) was recorded in β-carotene cheese (0.46) while the lowest value in Curcumin cheese (0.39). Total bacteria count and proteolytic bacteria were gradually decreased reaching its minimum at the end of the ripening period (180) days. The count of mold and yeast at 180 days old cheese were 0.17×105, 0.11×105, 0.07×105, and 0.09×105 CFU/g for treatments of cheese without color added, Annatto cheese, Curcumin cheese, and β-carotene cheese, respectively. The addition of colorants improved slightly the composition and sensory properties of Ras Cheese.


Ras cheese,


beta carotene,

Water-soluble nitrogen.

Authors’ Contribution

NYA and MNFH conceived and designed the study; SME performed and analyzed the microbiology part; NYA did the chemical part. MNFH and NYA wrote, revised, and gave final approval for the publication of the paper.

How to cite

Al-Surmi, N.Y., Hamad, M.N.F., El-Sayed, S.M., 2021. Effect of Type of Colorant on the Physicochemical Properties of Ras Cheese and its Whey. PSM Microbiol., 6(4): 108-124.