Carbohydrates and their degrading enzymes from native and malted finger millet (Ragi, Eleusine coracana, Indaf-15)

A recently released hybrid ragi, Indaf-15 was germinated up to 96 h at 25 d egrees C and the sprouts, drawn at 24 h intervals, were dried, devegetated, powdered and evaluated for malting loss, reducing sugar, free sugar profil e, starch content, dietary fibre and an array of carbohydrate-degrading enz ymes. Malting loss was maximum (32.5%) at 96 h. The total reducing sugar co ntent increased from 1.44 to 8.36%, whereas the total carbohydrate content decreased from 81 to 58% at 96 h of germination. Analysis of 70% alcohol-so luble sugars revealed glucose, fructose and sucrose in different proportion s with respect to germination time. Maltose and maltotriose were detected a fter 48 and 72 h, respectively. There was a linear decrease in starch conte nt (from 65 to 43%). Activities of amylase and pullulanase were maximum at 72 h whereas those of cc-D-glucosidase and 1,3-beta-D-glucanase, were maxim um at 48 h. Xylanase activity was maximum at 96 h with a concomitant decrea se in arabinose to xylose ratio from 1:1 to 1:0.38 in the dietary fibre. al pha-Galactosidase activity was negligible, which is in tune with a very sma ll amount of raffinose series oligosaccharides. The above results indicated that Indaf-15 is a potential variety for malting purposes as it develops h igh levels of amylases during germination, acid its malt form is a rich sou rce of reducing sugar. (C) 2000 Elsevier Science Ltd. All rights reserved.