Enzyme activities in quinoa (Chenopodium quinoa)

Abstract

The amylase, protease, cellulase and hemicellulase activities were determined in the flour of untreated quinoa seeds, and again after mechanical abrasion and after water and heat treatment to remove saponins. Optimum pH for amylase activity was approximately 5.0 and for protease activity it was 4.2 In comparison with a non‐malted wheat flour, which generally would have a Braben‐der unit (BU) reading of over 2000 in the Amylograph, values for quinoa were very low, indicating a high α‐amylase activity. Mechanical abrasion, which removed about 18% of kernel weight, increased α‐amylase and protease activities of the seeds because of removal of layers low in activity. Only toasting of seeds at 170°C after saponin removal reduced activities of these enzymes substantially. Total amylase, cellulase and hemicellulase activities were highest in the unprocessed seeds. Activities decreased after mechanical abrasion of seeds. Heat treatment after saponin removal caused a further decrease in activity of these enzymes. Copyright © 1989, Wiley Blackwell. All rights reserved