INFLUENCE OF ARABINOGALACTAN FROM LARCH WOOD ON BREAD-MAKING PROPERTIES OF WHEAT FLOUR AND BREAD QUALITY
Arabinogalactan (AG) is a water-soluble polysaccharide with a complex of practically important characteristics: low toxicity, high biological activity (prebiotic, immunostimulative, gastro- and hepatoprotective, etc.) The perspective industrial source of AG is a larch wood with AG content about 20 %. The use of AG in food industry opens the perspectives of development of the new improved food products. It is known that some polysaccharides extracted from plants which macromolecules contain fragments of AG improve the end-use quality of wheat bread. In this work, the influence of AG on technological properties of wheat flour and bread quality was studied. Physical properties of dough was determined using Brabender farinograph measuring water absorbing capacity of flour, dough formation time and resistance to mixing, dough thinning. Bread quality was evaluated using the method of Central laboratory of the State Commission of crops testing according 8 parameters: loaf volume, bread appearance, surface, loaf form, crust color, porosity, elasticity, crumb color and taste. It was shown that the addition of 1% of AG to flour does not significantly change quantity and quality of gluten. The addition of 2% and more of AG slightly but significantly decrease gluten content and elasticity. During mixing of dough with addition of more than 2% of AG physical properties of dough considerably changed: water-absorbing capacity decreased while time of dough mixing increased. The addition of 1% of AG to flour demonstrated a significant improvement of all qualitative parameters of bread. In this case all added AG was fully consumed by yeast during bread baking. After introducing of 2-3% of AG its residual quantity in bread consisted 36-50%, while after the addition of 5% of AG it remains unused in bread. This causes worsening of appearance and organoleptic characteristics of baked loafs. For the improvement of quality of bakery products the addition of 1% of AG to flour may be recommended