Antidiabetic bio-peptides of soft and hard wheat glutens

Abstract

The effects of various purification techniques on kiwifruit enzyme characteristics (protease activity, kinetic parameters, and protein patterns) and production of wheat gluten bio-active peptides were investigated. The enzyme extract purified by ammonium sulfate precipitation method exhibited the highest protease activity (26), Km (0.04 ± 0.002 mM), Kcat/Km (40), and yield (96%). Using actinidin, the hard and soft wheat gluten subunit proteins produced antidiabetic inhibitory (α-glucosidase and α-amylase) peptides. The smallest Mw fraction of soft wheat gliadin peptide (<1 kDa) showed the highest inhibitory capacity against α-glucosidase (18.4 ± 0.7%) and α-amylase (53.3 ± 1.9%). The presence of high levels of amino acids with hydroxyl groups and proline in P3 sub-fraction had a critical role on α-glucosidase (47.2%) and α-amylase (71.2%) inhibitory activities. In conclusion, wheat gluten subunit peptides showed significant metabolic effects relevant to glucose and insulin control in vitro.

Keywords

• Gluten
• Kiwifruit
• Hydrolysates
• Antidiabetic
• Amino acid composition