Enhancement of umami taste of hydrolyzed protein from wheat gluten by β-cyclodextrin

Abstract

Background: Wheat gluten was hydrolyzed by Flavourzyme and Neutrase at pH 7.0 and 50 °C for 8 h with β-cyclodextrin (β-CD) employed in the reaction. The hydrolysates were enzyme deactivated, cooled and centrifuged at 1500 × g for 15 min.

Results: Sensory and chemical characterization of wheat gluten hydrolysates WGH-1 (reaction conducted without β-CD), WGH-2 (reaction conducted with β-CD) and WGH-3 (β-CD added to WGH-1) was performed. WGH-2 revealed enhanced umami taste and higher hydrolyzing degree, total free amino acid amount, protein yield and umami taste amino acid (Glu + Asp) amount. High-performance liquid chromatography showed that the proportion of molecular weight 180-500 Da in WGH-2 was 11.5% higher than that in WGH-1. Further research indicated that β-CD had multiple effects on the hydrolysis. It could not only increase the solubility of wheat gluten but also form inclusion complexes with resultants. This can both promote the hydrolysis and protect oligopeptides from degradation.

Conclusion: β-CD was found to have the ability to increase the umami taste of enzyme-hydrolyzed vegetable protein from wheat gluten. The reasons analyzed were that β-CD could take part in the hydrolysis process by improving the solubility of wheat gluten and form inclusion complexes with resultants. © 2016 Society of Chemical Industry.

Keywords: enzyme hydrolysis; sensory evaluation; umami enhancement; wheat gluten hydrolysate; β-cyclodextrin.