were separated and the supernatant was again centrifuged at
10,000g for 60 min to assure the total separation of tiny oil droplets
and protein aggregates. After second step of centrifugation, appropriate
dilutions of supernatants were made and protein concentrationwas
determined using the modified Lowry method reported by
Markwell, Haas, Bieber, and Tolbert (1978). Bovine serum albumin
was used as standard. Assays were carried out in triplicate.
2.7. Apparent viscosity
A controlled-shear rate rheometer (AR-G2, TA instruments;
Newcastle, USA) with a cone-and-plate geometry (gap ¼ 55 mm;
cone diameter, 40 mm; cone angle, 2) was used to determine the
apparent viscosity (happ) of SB. The apparent viscosity was registered
after increasing the shear rate from 0.1 to 30 s1 for 100 s.
Temperature was controlled at 21.0 C with a water bath (Julabo
ACW100, Julabo Labortechnik; Seelbach, Germany) associated to
rheometer. For all freeze-thawed, highly-destabilized soy beverages,
this assay was discarded to avoid sampling errors.
2.8. Statistical analysis
Two independent replicates were measured at least two times in
each experiment and the results were reported as the mean and
standard deviation. The statistical analysis was performed by analysis
of variance (ANOVA) and test of least significant difference (LSD)
using the statistical program Statgraphics Plus v5.1 (Statgraphics
Corporation; USA, 2000). Significance was considered at p < 0.05.