Journal of Dairy Research



Effect of chymosin and salt reduction on the quality of ultrafiltrated white-salted cheese


Mutlag M Al-Otaibi a1 and R Andrew Wilbey a1c1
a1 School of Food Biosciences, The University of Reading, RG6 6AP, UK

Article author query
al-otaibi mm   [PubMed][Google Scholar] 
wilbey ra   [PubMed][Google Scholar] 

Abstract

This study demonstrated that both chymosin and salt-in-moisture (SM) were important factors for proteolysis in the manufacture of ultrafiltrated white-salted cheese, with significant effects on water-soluble nitrogen and nitrogen soluble in trichloroacetic acid. In contrast, the levels of free amino acids were not significantly affected by chymosin and salt treatments. The cheeses made using high levels of chymosin with low SM had lower levels of residual αs1- and β-casein at the end of ripening. On texture profile analysis, the hardness and fracturability of the cheeses significantly increased with SM and decreased during ripening. Increases in chymosin significantly contributed to the overall weakening of the structure throughout ripening. Bitter flavour was detected after 12 weeks in the cheese made with the higher chymosin level and lower SM, which could be the result of accumulation of γ-casein fractions. The sensory data indicated that the hedonic responses for low chymosin with low SM cheeses were good and acceptable in flavour, which may be due to the moderate levels of proteolysis products.

(Received July 14 2003)
(Accepted November 10 2004)


Key Words: Ultrafiltration; white cheese; proteolysis; salt reduction; chymosin reduction.

Correspondence:
c1 e-mail: r.a.wilbey@reading.ac.uk