Dilek Sivri Ozay

Potential utilization of Mixolab for quality evaluation of bread wheat genotypes.

ABSTRACT The aim of this study was to determine the possibility of using Mixolab to assess the quality of different wheat genotypes. Mixolab data were compared with various flour quality characteristics and bread volume. The samples were chosen to represent a wide range in terms of grain and rheological properties and baking quality. There are eight paramaters used to evaluate a Mixolab curve. C1 and C2 are related to protein quality, whereas C3, C4 and C5 are related to the starch characteristics. Slopes α, β, γ are the indicators of protein weakening, starching speed, and enzymatic degradation. There were significant correlations between two Mixolab parameters (Stability and C2) and Zeleny sedimentation and Alveograph W values (P < 0.01). Some of the Mixolab parameters (C3, C4, C5) were correlated with Alveograph G and P/L value (P < 0.01). Mixolab values are generally in agreement with Farinograph values. There were significant negative correlations between most of the Mixolab parameters (Stability, C2...

Effects of Suni Bug (Eurygaster spp.) Damage on Milling Properties and Semolina Quality of Durum Wheats (Triticum durum L.)

ABSTRACT Economic losses due to suni-bug (Eurygaster spp. and Aelia spp.) damage are important for the cereal industry in East European and Middle East countries. Samples of five durum wheat cultivars (Diyarbakir, Firat, Ege, Svevo, and Zenith) with zero, medium, and high levels of suni-bug damage were used to determine the effects of suni-bug damage on milling properties and semolina quality. As the damage level increased, semolina yields of all cultivars decreased significantly. The loss of semolina yield was greater than decreases in total yield of semolina plus flour, indicating that semolina yields were affected to a higher extent than were flour yields. The ash contents of the semolina samples increased significantly in all cultivars with increasing suni-bug damage. The falling number values were not correlated with suni-bug damage level and amylase activities of all samples were quite low. The pasting properties did not differ to a great extent depending on the suni-bug damage level. Gluten quality...

Preparation and Functional Properties of Gluten Hydrolysates with Wheat-Bug (Eurygaster spp.) Protease

ABSTRACT Suni-bug (Eurygaster spp.) enzyme was partially purified from bug-damaged wheat and used to prepare gluten hydrolysates at 3% and 5% degree of hydrolysis (DH). Functional properties of gluten and gluten hydrolysates were determined at 0.2% (w/v) protein concentration and pH 2–10. Gluten solubility after enzymatic hydrolysis increased significantly (P < 0.05) up to 89.1, 89.6, and 95.0% at pH 7, 8, and 10, respectively. Emulsion stability (ES) of gluten hydrolysates improved at neutral and alkaline pH (P < 0.05) and emulsifying capacity (EC) increased significantly (P < 0.05) except at pH 10. Foaming capacity (FC) values of gluten hydrolysates were significantly higher (P < 0.05) at pH 6, 7, 8; foam stability (FS) values of gluten hydrolysates were significantly higher (P < 0.05) at pH 6 and 7. Enzymatic modification of gluten by wheat-bug enzyme resulted in hydrolysates with higher antioxidant activity compared to gluten. Significant correlations (P < 0.001) were found between solubility and EC, ...