0000000000541906
AUTHOR
Mihai Ognean
Evaluation of Two Method to Measure Xylanase Activity in Relation with Rheological Effects of Xylanases on White Flour
Many methods are available to measure the xylanase activity of enzymatic preparation. Most of method uses different substrates from those that will be hydrolyzed in various applications in food industry. This fact will lead to a deformed image about how evaluated xylanases will really act in a specific application. The aim of this study is to evaluate the activity of seven xylanase preparation with two method, a colorimetric method with birch insoluble xylan as substrate and a viscometric method with wheat soluble arabinoxylan as substrate.
The Effect of Some Commercial Fibers on Dough Rheology
Bread is largely consumed and could be used as a carrier for different nutrients. Fibers play an important role in human nutrition but the bread are depleted in this nutrient. For fibers, supplementation could be used different sources. The fibers needed to be tested before their use in breadmaking. This work investigates how some commercial fibers (Exafine, Apple AF12, Potato KF 200, Oat HF 200 and Wheat WF400) influence the rheology of dough at 10 and 15 % addition. All fibers increased the water absorption and development time because of competition for water between fibers and flour component. Product Apple AF12 deteriorates the dough rheology by dough stability reduction and increases …
Blends using brabender farinograph and E6 Haubelt flourgraph
The aim of this work is to establish correlations between the values of the Brabender Farinograph and the E6 Haubert Flourgraph. We analyzed two types of flours, white flour with additives (WF add) and brown flour with additives (BF add). The following parameters were varied: water absorption capacity, development time, the stability, the degree of softening and the quality number of wheat and potato flour mixture. A statistical analysis was made from linear regression equations. The obtained values for the E6 Flourgraph are comparable with Farinograph values and units. Hydration capacity values, calculated for a standard consistency of 500 HE, UF, obtained on these two devices are in a clo…
Comparative Analyses for Gluten-Free Biscuits from Mixture Oat and Corn
Abstract Gluten-free products are necessary for the people suffering from celiac disease or having a sensibility for products containing gluten. The aim of this study was to prepare and evaluate gluten free biscuits made from a mixture of flours (50% corn flour and 50% oat flour) with various fats (palm fat, coconut oil) and sweeteners (sugar, stevioside with erythritol). Sample biscuits were made and then analyzed to find out the moisture, water activity, braking point, specific volume and sensory evaluation. All samples had the moisture close to 5-6%. Water activity ranged from 0.49 to 0.71. The breaking point was higher for sample prepared with palm fat and sugar (0.43). This sample was …
Non-Enzymatic Water-Soluble Antioxidants Bioanalysis in Some Teas and Juices by PCL Method
Non-enzymatic water-soluble antioxidants from different teas (black, green, peppermint), coffee, natural extract of rosemary and fruit juices (apple, grape, grapefruit, kiwifruit) were quantized by measuring their chemiluminescence in order to establish their power to protect the living beings from the free radicals. Among the samples high values of antioxidative capacity presents green tea (655 mmol AU) (AU=ascorbic units) and kiwi fruit juice (31 mmol AU). The maximum measuring times are less than 3 minutes. The sensivity of the photo-induced chemiluminescence (PCL) method was very high: nanomolar concentrations of non-enzymatic watwer-soluble antioxidative substances, as ascorbic acid un…
The Effects of Different Formulation of Baking Powder on Short Biscuits Characteristics
Chemical leaveners are used to give cookies, cakes, and other baked goods their characteristic textures. They produce gas when a carbon dioxide source and an acid are mixed together and come into contact with water. The most common sources of gas are sodium or potassium bicarbonate alone or in combination with ammonium bicarbonate. A great variety of acids are used in baking powder formulations. The acid are classified according to their capacity to react at lower or elevated temperature as rapid or slow acting. The aim of these study is to evaluate a very rapid acting acid (tartaric acid) and a slow to very slow acting acid (sodium acid pyrophosphate - SAPP) on the characteristics of short…
Rheological Evaluation of Some Laboratory Mills
The dough rheology is one of the most important aspect in bread making so it is very important to accurate evaluate the wheat potential for breadmaking by rheological test. The wheat must be milled for testing; the mill used influence the relevancy of wheat tests. The objective of this study is to evaluate the rheological properties of flour obtained by grinding ten samples of wheat in three of the most common laboratory mills (Perten 120, Quadromat Jr. and Chopin CD1). The rheological behaviours of the wheat flours obtained in laboratory were compared with those of flours obtained in industrial mill. The rheological measurements were performed using the Alveograph, Farinograph and Mixolab.…
Rheological Evaluation of Some Commercial Xylanases
The arabinoxylans play and the xylanases play an important role breadmaking. For a better selection of xylanases, it is necessary to understand how they work in breadmaking. At the same activity, the xylanases have different effect on dough rheology. The xylanases activity measured through birch xylan hydrolysis it is not correlated with extensographic effects. Weak but better correlations were observed when the xylanase activity was measured as the ability to decrease the viscosity of soluble wheat arabinoxylans solution.