Interaction of amyloglucosidase and α‐amylase supplements in breadmaking

Abstract

Amyloglucosidase (Novo 150 L. 5 mlilOO kg) used with optimum ct-amylase supplements [MSKB/100 g flour] of wheat malt, 7.5, fungal, 20. and bacterial, 0.4, increased the reducing sugars of sour doughs (pH 4.55. 3 h/30 "C) by 71.7 to 72.2, 94.0 to 103.1 and 71.7 to 77.0% as compared to 48.3 to 58.0, 61.1 to 71.3 and 7.3 to 12.0% of initial pH 5.8 doughs, respectively. Amyloglucosidase alone or with ct-amylase supplements had negligible effect on mixing properties of dough, falling number values and paste viscosities which were affected more by the wheat malt a-amylase. The combined enzymes had a beneficial effect on bread quality of the medium-protein flours without extraneous sugar in the formula.In the previous paper, HARINDER et al. [I] described the effect of cereal, fungal and bacterial a-amylase supplements on the rheological and breadmaking properties of mediumprotein flours. Accumulation of maltose in the bread crumb due to a-amylase action, was reported. Although, application of amyloglucosidase in fermentation industry and dextrose manufacturer is well established [2], its use in bread making has received scant attention [3] as compared to a-amylase supplements [l, 4, 51. The present investigation aimed at producing easily fermentable dextrose in the dough system using amyloglucosidase with and without cr-amylase supplements, and to evaluate the consequences of their interaction on the rheological and breadmaking properties of medium-protein flours. Experimental Amyloglucosidase (150 L )ICC method [7] after inactivation of the u-amylase in pH 4.2 solution at 60 'Cjl h. This was obtained from M/S Novo Industries, Denmark. Its activity (103 SKB/g) was determined by the u-amylase supplements Fungal ( A . oryzae) a-amylase (Fungamyl 180 S) with a designated activity of 4500 SKB/g was Novo brand. Bacterial (B. subtilis) a-amylase was supplied by M/S Schwarz/Mann, U.S.A., with a rated activity of 19900 SKB/g. Wheat malt with an activity of 100.9 SKB/g was prepared in the Laboratory. The a-amylase activities