Flour quality

C. O. Swanson, Wheat and Flour Quality, Burgess Publishing Co., Minneapolis, Minn., 1938. 

Laboratory production of crackers with the same flavor quality as commercial crackers has been difficult. Micka (11) found that when crackers are produced in a laboratory and no starter sponge is kept, and equipment is kept sterile, fermentation is generally retarded and the resulting dough has a high pH and the crackers have an undesirable flavor. Dynn (17) attempted to develop a procedure for the production of experimental crackers to test flour quality. He found that the crackers made from the same batch of flour varied widely in flavor quality and concluded that commercial crackers could not be produced in a laboratory. However, Pizzinatto and Hoseney (4,14) have recently developed a procedure for the production of satisfactory experimental saltine crackers under laboratory conditions. 

Two major advantages of the HD process are reduction in water consumption to as low as three parts per part of wheat flour, and a 10% increase in A-starch yield. In addition, this process is not as sensitive to flour quality as the other processes, and is also applicable for potato, bean, pea and com starch production. 

In many baking processes a combination of enzymes and other baking active ingredients are used to adapt the flour quality to the needs of the individual baker and especially to those of the industrial bakeries. 

Proteinases help the biscuit manufacturer to become largely independent of the flour quality. For example, the baker can even use flour rich in protein, the flour strength and dough constancy being adapted by proteinases, proteinase / amylase and proteinase / hemicellulase preparations. 

Economics. No consideration of the literature would be complete without the economic study made by the Food Research Institute of Stanford University (66). The studies are mainly concerned with crops, markets, and economics, and comprise a monumental contribution to the literature of wheat. Some technical papers on wheat in the diet, wheat protein, starch and flour quality, bread staling, utilization of wheat germ, and physical tests of flour quality are included. An index to this series (62) consists of abstracts of the annual reviews and special studies, and a chronological list of the individual issues, and lists, by author and subject, of the special studies. 

Table 3.1 Correlations between Flour Quality Parameters and the Two Methods of Measuring Milling Efficiency Ash and Bran by Image Analysis...

Wardlaw, 1. F., Blumethal, C., Larroque, O. and Wrigley, C. W. 2002. Contrasting effects of chronic heat stress and heat shock on kernel weight and flour quality in wheat. Functional Plant Biology 29 25-34. 

Hansen and Lund, 1987). In rye bread, compounds such as alcohols, esters and carbonyls have been identified (Hansen et al., 1989). Choice of fermentation temperature, dough yield, flour quality and starter culture all influence the sensory properties of the final bread. Free amino acids formed during fermentation increase Maillard reaction products, thus intensifying the taste. Sensory analysis has shown that sour dough rye breadcrumbs had the most intense and bread-like flavour compared with chemically acidified doughs (Hansen et al., 1989). 

Because bakers are using the NIR technique for flour quality control, it is appropriate to consider whether NIR can predict the baking quality in terms of measurable properties of the bread or biscuit. The following is a summary of some unpublished results obtained by the Flour Milling and Baking Research Association, Chorleywood, from two experiments designed to explore this possibility. 

The involvement of endogenous lipoxygenase in the baking of wheat flour is not clear. However, by addition of lipoxygenase-active soy flour, a significant improvement of the flour quality is achieved (cf. 15.4.1.4.3). 

Fig. 15.35. Wheat flour quality improvement by the nonspecific lipoxygenase enzyme of soybean (according to Kieffer and Grosch, 1979). Additions 1 control (no addition, bread volume 31 ml), 2 extract of defatted soya meal in which lipoxygenase was thermally inactivated (31 ml), 3 extract of a defatted soya meal with 290 units of lipoxygenase (35 ml), 4 purified type-II enzyme with 285 activity units (37 ml).

The mineral or ash content of flour is also used as an index of flour quality or grade the lower the eish, or the less residue, the whiter or more refined the flour. 

MaUhot, W.C., and Patton, J.C. 1988. Criteria of flour quality. Chapter 2 in Wheat Chemistry and Technology. Vol. II. Y. Pomeranz (ed.). American Association of Cereal Chemists, St. Paul, MN. 

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