Effect of High-Hydrostatic-Pressure Treatment on the Physicochemical Properties of Kafirin

The kafirin derived from Jin Nuo 3 sorghum underwent a high-hydrostatic-pressure (HHP) treatment of 100, 300, and 600 MPa for 10 min to investigate alterations in its physicochemical attributes. The findings exhibited a reduction in protein solubility, declining from 83% to 62%, consequent to the application of the HHP treatment. However, this treatment did not lead to subunit-specific aggregation. The absorption intensity of UV light diminished, and the peak fluorescence absorption wavelength exhibited a shift from 342 nm to 344 nm, indicating an increased polarity within the amino acid microenvironment. In an aqueous solution, the specific surface area expanded from 294.2 m2/kg to 304.5 m2/kg, while the average particle-size value in a 70% ethanol solution rose to 26.3 nm. Conversely, the zeta-potential value decreased from 3.4 mV to 1.3 mV, suggesting a propensity for aggregation in ethanol solutions. A notable rise in the intermolecular beta-sheet content to 21.06% was observed, along with a shift in the peak denaturation temperature from 76.33 degrees C to 86.33 degrees C. Additionally, the content of disulfide bonds increased to 14.5 mu mol/g. Collectively, the application of the HHP treatment not only enhanced the thermal stability but also induced a more ordered secondary structure within the kafirin.

Automated summary

The physicochemical attributes of kafirin derived from Jin Nuo 3 sorghum were altered after undergoing high-hydrostatic-pressure (HHP) treatment. The treatment led to a decrease in protein solubility and increased polarity within the amino acid microenvironment. The specific surface area and particle size also increased, while the zeta-potential value decreased. This treatment enhanced thermal stability and induced a more ordered secondary structure in kafirin.