Physicochemical Modifications of High-Pressure-Treated Soybean Protein Isolates

• Published in: Journal of agricultural and food chemistry Vol. 52; no. 6; pp. 1564 - 1571
• Main Authors: Puppo, Cecilia, Chapleau, Nicolas, Speroni, Francisco, de Lamballerie-Anton, Marie, Michel, F, Añón, Cristina, Anton, Marc
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 24.03.2004
• Subjects: Biological and medical sciences; Chemical Phenomena; Chemistry, Physical; Drug Stability; Food engineering; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Hot Temperature; Hydrogen-Ion Concentration; Life Sciences; Pressure; Protein Denaturation; Protein Structure, Secondary; Solubility; Soybean Proteins - chemistry; Soybean Proteins - isolation & purification; Sulfhydryl Compounds - analysis; Modification; Physical dressing; Denaturation; Protein isolate; Soybean; Glycine max; Protein; High pressure; Aggregation; Grain legume; Leguminosae; Dicotyledones; Angiospermae; Spermatophyta; Structure; STRUCTURE
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf034813t

Changes induced by high pressure (HP) treatment (200−600 MPa) on soybean protein isolates (SPI) at pH 3 (SPI3) and pH 8 (SPI8) were analyzed. Changes in protein solubility, surface hydrophobicity (Ho), and free sulfhydryl content (SHF) were determined. Protein aggregation and denaturation and changes in secondary structure were also studied. An increase in protein Ho and aggregation, a reduction of free SH, and a partial unfolding of 7S and 11S fractions were observed in HP-treated SPI8. Changes in secondary structure were also detected, which led to a more disordered structure. HP-treated SPI3 was partially denatured and presented insoluble aggregates. A major molecular unfolding, a decrease of thermal stability, and an increase of protein solubility and Ho were also detected. At 400 and 600 MPa, a decrease of the SHF and a total denaturation were observed. Keywords: Soybean proteins; high-pressure treatment; protein structure; protein denaturation; protein aggregation