Cornaggia C.,Megazyme International IDA Business Park Southern Cross Road Bray |
Ivory R.,Megazyme International IDA Business Park Southern Cross Road Bray |
Mangan D.,Megazyme International IDA Business Park Southern Cross Road Bray |
Mccleary B.V.,Megazyme International IDA Business Park Southern Cross Road Bray
Journal of the Science of Food and Agriculture | Year: 2015
The measurement of α-amylase (EC 18.104.22.168) in sprout-damaged grains is a crucial analysis yet a problematic one owing to the typically low α-amylase levels in ground wheat samples. A number of standardised methods such as the Falling Number method and the Ceralpha method exist which are routinely used for the assay of α-amylase. These methods, however, are either highly substrate-dependent or lack the required sensitivity to assess sprout damage. RESULTS: Novel colorimetric and fluorometric reagents have been prepared (Amylase HR, Amylase SD, BzCNPG7 reagent and BzMUG7 reagent) for the direct and specific assay of α-amylase activity in sprout-damaged wheat. Assays employing these reagents have been developed and optimised to include a decolourisation step using activated charcoal. When used in a convenient assay format, Amylase SD - containing EtNPG7 (II) as the colorimetric substrate and α-glucosidase as the ancillary enzyme - was found to be an excellent reagent for the assessment of sprout damage in wheat with incubation times as short as 5 min. CONCLUSION: The assay using Amylase SD is completely specific for α-amylase. The use of the Amylase SD assay represents a sensitive and valid alternative to the traditionally used Falling Number values for the assessment of sprout damage in wheat samples. © 2015 Society of Chemical Industry.