Phosphoesterification of soybean and peanut proteins with sodium trimetaphosphate (STMP): Changes in structure to improve functionality for food applications
Academic Article in Scopus
Soybean and peanut protein isolates underwent phosphorylation using sodium trimetaphosphate (STMP). Changes in functional properties and the influence of STMP (1, 2 or 3% w/w), pH (11.5 or 12.5), temperature (35 or 55 °C) and time (3 or 5 h) were evaluated. The highest degree of phosphorylation was achieved at 2% of STMP and pH 12.5. The best specific conditions varied according to the raw material: in soybean, 25% phosphorylation was achieved at 55 °C and 5 h whereas in peanut, 30% was reached at 35 °C and 3 h. The modified proteins showed an improved emulsifying activity (27.3% for soybean and 6.6% for peanut), whereas NSI for soybean increased more than three times and for peanut decreased by half. In vitro digestibility improved in both isolates around 1.5%. These results showed that phosphorylation with STMP of peanut and soybean proteins yielded isolates with a wide array of potential applications in food systems.