Processing suitability of a rice and pine nut (Pinus koraiensis) beverage

In order to investigate the processing suitability of a cereal beverage with pine nuts (Pinus koraiensis), a beverage was prepared at various homogenization pressures and pHs and stored for 5 days at three temperatures (4, 25, and 40 °C). At day 0 the samples adjusted to pH 6.5 showed little change after heat treatment, but those adjusted to pH 7.5 showed a large drop to about pH 7.0 after heat treatment for 20 min at 121 °C, regardless of the level of homogenization pressure. The n values in all samples exhibited the range 0.70–0.85, indicating their pseudoplastic behavior. The apparent viscosities of the samples homogenized at 19.6 MPa were nearly constant, regardless of the three adjusted pHs (5.5, 6.5, and 7.5), with the exception of the samples stored at 40 °C, but the viscosities of the samples prepared at 29.4 MPa or without homogenization prominently increased as the pH increased. The suspension stability indices of all samples were close to 1.00, indicating the beverage was stable. In the initial state at day 0, nitrogen solubility index (NSI) of the samples homogenized of 19.6 MPa was not affected by the pH level, and the soluble starch content of samples without homogenization sharply decreased compared to the samples with homogenization as the pH was increased from 5.5 to 7.5.