Flour changes

As discussed, addition of enzyme active soya flour changes the composition of volatile compounds of white bread. In its practical application as a bread improver component, the soya lipoxygenase isoenzymes are sufficient stable for 5 months to meet the bleaching requirements. 

For products of dissimilar composition, e.g., isolates, concentrates, and flours, changes in the chemical environment undoubtedly elicit different responses from the various constituents of an ingredient, i.e., protein, carbohydrate, etc. Perhaps the properties of the protein can best be examined in the isolate because of its relatively low concentration of nonprotein constituents. Unfortunately, isolates usually have been subjected to the most extensive processing, which also affects the response of the protein. 

Wheat and wheat flour (changed on 4 March 1966 from wheat products) USA 1963... 

Fine grinding and air classification make possible the production of some cake flour from hard wheat and some bread flour or high-protein fractions from soft wheat. AppHcation of the process theoretically frees the miller from dependence on different wheats, either hard or soft, that change each crop year. The problem is how to market the larger volume of low protein or starch fractions at prices adequate to justify the installation and operation of the special equipment (46). 

Dalais et al., 1998 Australian postmenopause n = 44 Women received 45 g of either soy grits containing 52 mg isoflavones, wheat flour or flaxseed daily for 3 months No change in BMD 5.2% increase in BMC in soy group... 

The situation with wholemeal flour is refreshingly simple. Flour treatments are banned and there are no statuary additions. The addition of ascorbic acid to wholemeal flour is forbidden but the use of ascorbic acid in wholemeal bread is allowed. Presumably, it was thought beneficial to allow the change so that the Chorleywood plants could make wholemeal bread. The ascorbic acid presumably goes in as an improver with other ingredients. 

After 1990 the British government changed the law to remove potassium bromate from bread. This move was logical in the circumstances. It was convenient because most of the EU did not permit potassium bromate and its continued use in British flour was a bar to enter EU trade. 

The Chorleywood process produced a considerable change in the way that many plant bakeries work. Even the Chorleywood process has evolved since potassium bromate has been prohibited and the process had to accommodate the use of other flour treatments. 

Dough development is a fundamental process in bread making, without it there is just a paste of flour, water and the other ingredients. If the bread is to expand and form a proper cell structure then this change must take place. While it is quite easy to test for dough development by prodding some dough with a thumb it is more complicated at a chemical level. 

If experiments are to provide a valid source of information care must be taken about weighing and measuring. All ingredients must be from the same batch unless the test is to compare different batches of flour. In any tests there must be a control experiment lest a variation in, e.g. in the freshness of the yeast, masks a smaller change owing to some other factor. Another important point is that all experiments should be recorded. 

The poor performance of finely milled cowpea flours may be due to changes in physical form and structure which occur as a result of milling. Sefa-Dedah and Stanley (10) investigated the relationship of microstructure of cowpeas to water absorption and decortication... 

Yeast bread (42) 2.5-10% pea flour No volume change Acceptable, beany at 10%... 

Instantisation, in which the fluidized bed is responsible for a significant change to the structure and size of the granules, should not be confused with the use of an integrated fluidized bed drier immediately following spray drying. There are many descriptions in the literature of such processes a recent example of a novel application of this technique (Jha et al, 2002) is in the production of a shelf-stable powdered kheer mix, an Indian dessert which consists of a sweetened mixture of cooked partially concentrated milk and rice flour. This is spray dried, the particles are then dried in a fluidized bed and finally dry blended with sugar. 

Figure 2. Exterior morphologies of soy extrudates varying in pH value and feeding rate. LFR (160 g/min) HFR (240 g/min). Note the increasing diameter and surface smoothness when the pH value of soy flour increased. Higher feeding rate could change the characteristics of low-pH-value extrudates. (Mag. I.8X-)...

Effects of Ionic Strengths. Two types of salts (NaCl and CaCl2), at three concentrations (0.2, 1.0 and 2.0%), were added to soy flours prior to extrusion to change the ionic strength. 

Morphological Changes of Soy Flours Extruded at Various Temperatures. Soy flour (Soyafluff 200W) was extruded at temperatures frcm 79 to 149 C, and extrudates were examined visually and microscopically. Extrudates produced at temperatures up to... 

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