Erland Bråthen

Effects of enzyme preparations for baking, mixing time and resting time on bread quality and bread staling

Abstract Breads were made using four fungal α-amylase preparations, three different mixing times and three different resting times to study their effect on bread quality and staling. All the four enzyme preparations caused significantly darker crusts. A significant effect of resting time on crust darkness was also obtained. A tendency towards increased bread volume by enzyme addition was observed and the presence of added α-amylases seemed to decrease the effect of resting and mixing time on bread volume. Bread supplemented with enzyme preparations firmed at a lower rate, while only small effects of enzyme addition on retrogradation of starch, as expressed by enthalpy measured by differential scanning calorimetry (DSC), were observed. After 7 days, enthalpy values were significantly lower for the two shorter resting times. No significant correlation between crumb firmness and enthalpy per gram starch was found. Storage of bread increased the amount of non-susceptible starch. The lowest increase was observed for breads baked without added enzymes. The effects of mixing time and resting time on non-susceptible starch were slight.

Effect of Different Preservation Methods for High-Moisture Barley on Feeding Value for Broiler Chickens

Abstract High-moisture barley was preserved anaerobically by ensiling using different additives, aerobically with propionic acid, or by drying. Chemical composition, feeding value and effect on physiological parameters in broiler chickens were studied. The content of true protein, total amino acids, total β-glucans and the viscosity were reduced when barley was stored in the moist stage. Anaerobic storage, which produced lactic acid and ethanol by fermentation, caused the strongest reduction. High-moisture barley reduced feed:grain ratio compared with dry barley, the difference being significant (p < 0.05) for the anaerobically stored barley in one experiment. Feeding high-moisture barley tended to reduce the relative weight of the digestive tract, and owing to less sticky droppings the cleanness of the cages and feathers was significantly improved (p < 0.05).

The effect of storage conditions on chemical content of raw potatoes and texture of cooked potatoes

SummaryTexture of boiled potato tubers (cv. Beate) was studied over several months of storage at either 4 or 8 °C, in relation to dry matter content, non-starch polysaccharides (NSP), methyl groups, glucose, starch and amylose. The dry matter content decreased significantly during storage at 4 °C, but increased at 8 °C due to evaporation. The insoluble NSP contained rhamnose, galactose, arabinose, xylose, mannose, fucose and glucose; the first three sugars decreased significantly after the first 7 weeks of storage. Fracturability and percent compression before break increased during storage at 8 °C, particularly percent compression after 15 weeks. The change in fracturability could partly be explained (R2=43.4%) by the content of the NSP and the increase in percent compression by dry matter (R2=91.8%). Changes in texture during storage at 4 °C, however, were not striking, and could not be explained by changes in the potato components that were analysed.