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  • Application of the SDS-PAGE method for the characterisation of winter wheat flour quality
    112-118
    Views:
    100

    The principle, development and importance of the SDS-PAGE method are presented in this article. The SDS-PAGE method has become one of the basic methods of molecular biological research, because it is widely applicable and its sensitivity is excellent in the separation of wheat storage proteins.
    We have shown the application of this method with a concrete example. It was also tested whether, it was possible to obtain a better baking quality product from a large amount of poor quality less valuable wheat by fractioning the flour according to particle sizes after grinding. We studied the rheological properties of flours with different particle size fractions from the original flour. The baking quality of the original flour was B2. The 125-90 and 90-63 μm fractions have significantly better baking quality (B1) than the original flour. The protein contents of these flour fractions were also significantly higher than the protein content of the original flour. We had a question: what has influenced the baking quality: the protein content or other factors? We searched for an explanation on these results in the protein composition of the flour samples. We studied the distribution of glutenin-fractions by SDS-PAGE method and evaluated them. We found with correlation analysis that the amount of LMW-Glutenin D-group (52-60 kDa) is in a strong, negative correlation to the baking quality (r = – 0.855*). Therefore, the baking quality of flour samples was influenced by this glutenin fraction.

  • Use of extensigraph in the examination of wheat flours
    17-23
    Views:
    114

    The extensograph is widely used in quality control and research laboratories studying wheat flour quality. The most commonly used measurements include Rm, the maximum resistance (maximum height of the curve); R5 the resistance at a constant extension of 5 cm; E, extensibility (total curve length); Rm/E, the ratio of maximum resistance to extension; and A, the area under curve. The extensograph has proved useful in the classification and assessment of flours on the physical dough properties. Another important application is its use in wheat breeding programs. Furthermore, extensograph is an excellent tool to study the effects of a wide range of ingredients on dough properties of wheat flour (like oxidants, enzymes, salt and additives), and it can also be used measure the changes during the frozen storage. In the present study we provide a review of the scientific literature concerning the possible applications of the extensograph.

  • Effects of ingredients and processing conditions on the quality frozen dough bread made from diferent wheat flour
    115-120
    Views:
    67

    A laboratory scale no-time frozen dough procedure that approximates Romanian commercial practice has been
    developed and used to study the effects of ingredients and processing conditions on the bread quality of a straight
    grade wheat flour during prolonged storage (2 days to 26 weeks). All treatments (baking absorption level, mixing
    energy input, mixer type, fermentation and intermediate proof times, removal of oxidant and/or dough
    strengthening conditioners and partial freeze-thaw cycles) had significant effects (P<0.05) upon bread quality (loaf
    volume and/or bread score). In general, these effects were more pronounced with extended frozen storage time.
    High baking absorption, undermixing, bulk fermentation (> 1 h) and removal of oxidant and/or surfactants had
    the most dramatic effects. Addition of a very strong flour at 30% to strengthen the wheat flour had no significant
    effect (P>0.05) upon bread quality under optimum conditions.