Enzymes addition to gluten-free breads: effects on starch and protein fractions and bread quality

SCIARINI L; RIBOTTA PD; LEON AE; PEREZ GT

Congreso; 2nd International ISEKI_Food Conference “Bridging Training and Research for Industry and the Wider Community”; 2011

ISEKI_Food Network

The aim of the present work was to study the effect of glucose oxidase and α-amylase on gluten-free dough protein and starch properties, respectively, and on bread quality. Base formulation included: rice flour (45 g), cassava starch (45 g), full-fat active soy flour (10 g), shortening (2 g), salt (2 g), compressed yeast (3 g) and water (65 g). Two doses of each enzyme were used: 0.03 g and 0.003 g of glucose oxidase (GOX 1 and GOX 2, respectively), and 0.001 g and 0.0006 g of α-amylase (Am 1 and Am 2, respectively). Proteins were extracted from dough with TRIS/HCl 0.5 M, pH 8.8 and TRIS/HCl + SDS and then separated by means of SDS-PAGE. Dough calorimetric properties (starch gelatinization and retrogradation during 7 days of storage) were evaluated with a DSC. Bread quality parameters considered were specific bread volume (SBV), crumb hardness and staling rate. When comparing the obtained electrophoregrams, it was observed a new band of high molecular weight in proteins extracted from GOX dough, compared to control dough, and this could be associated to protein polymerisation due to GOX presence. No differences were found between Am and control proteins. Both doses of Am delayed gelatinization occurrence, while ΔH was not modified. Regarding amylopectin retrogradation, ΔH was not modified by Am or GOX presence. SBV was slightly increased by Am addition, and it was not affected by GOX. GOX crumb hardness was lower than control crumb and it was not modified in breads with Am. Staling rate was not significantly modified by enzymes addition. Although dough proteins and starch properties were affected by both enzymes addition, bread global quality was not enhanced compared to control. In this sense, control bread displayed good breadmaking properties due to ingredients specific interactions.