The amino acid composition and physicochemical and functional properties of hemp (Cannabis sativa L.) protein isolate (HPI) were evaluated and compared with those of soy protein isolate (SPI). Edestin, a kind of hexameric legumin, was the major protein component. HPI had similar or higher levels of essential amino acids (except lysine), in comparison to those amino acids of SPI. The essential amino acids in HPI (except lysine and sulfur-containing amino acids) are sufficient for the FAO/WHO suggested requirements for 2-5 year old children. The protein solubility (PS) of HPI was lower than that of SPI at pH less than 8.0 but similar at above pH 8.0. HPI contained much higher free sulfhydryl (SH) content than SPI. Differential scanning calorimetry analysis showed that HPI had only one endothermic peak with denaturation temperature (T(d)) of about 95.0 degrees C, attributed to the edestin component. The T(d) of the endotherm was nearly unaffected by 20-40 mM sodium dodecyl sulfate but significantly decreased by 20 mM dithiothreitol (P < 0.05). The emulsifying activity index, emulsion stability index, and water-holding capacity of HPI were much lower than those of SPI, and the fat adsorption capacity was similar. The data suggest that HPI can be used as a valuable source of nutrition for infants and children but has poor functional properties when compared with SPI. The poor functional properties of HPI have been largely attributed to the formation of covalent disulfide bonds between individual proteins and subsequent aggregation at neutral or acidic pH, due to its high free sulfhydryl content from sulfur-containing amino acids.

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A novel method to create a discontinuous gaseous interface with a minimumsurface feature by the soap film technique is developed for three-dimensional (3D) Richtmyer-Meshkov instability (RMI) studies. The interface formed is free of supporting mesh and the initial condition can be well controlled. Five air/SF 6 interfaces with different amplitude are realized in shock-tube experiments. Timeresolved schlieren and planar Mie-scattering photography are employed to capture the motion of the shocked interface. It is found that the instability at the linear stage in the symmetry plane grows much slower than the predictions of previous two-dimensional (2D) impulsive models, which is ascribed to the opposite principal curvatures of the minimum surface. The 2D impulsive model is extended to describe the general 3D RMI. A quantitative analysis reveals a good agreement between experiments and the extended linear model for all the configurations including both the 2D and 3D RMIs at their early stages. An empirical model that combines the early linear growth with the late-time nonlinear growth is also proposed for the whole evolution process of the present configuration.