Pro þ Rheometer (Malvern Ltd., Worcestershire, UK) with the four
blade vane as a tool. The milk samples oscillated at a frequency of
1 Hz (1% shear strain) until pH reached 4.6. Gelation time and pH
were measured at the point when gels had a storage modulus value
(G0) 1 Pa (Lucey, Teo, Munro, & Singh, 1997). When the coagulation
process was finished, gels were cooled to 5 C (1 C min1)
and held at that temperature for 30 min before being subjected to a
frequency sweep (0.01e10 Hz; 0.1% strain). Parameters G0 and loss
modulus (G00) were determined at 1 Hz as measures of gel properties
after cooling, and the slopes of logelog plots of moduli versus
frequency were calculated using Microsoft Office Excel program.
Subsequently, strain sweep sequence was performed (0.001e500%)
at 1 Hz frequency and the yield stress valuewas calculated from the
cross-over point (G0 ¼ G00) (Guggisberg, Cuthbert-Steven, Piccinali,
Bütikofer, & Eberhard, 2009). All measurements were performed in
triplicate