Alveograph

FIGURE 15.7 (Continued) The mixograph used for the quick assessment of wheat dough rheological properties with typical curves for hard and soft wheat flours. 

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A bread flour giving a strong and elastic dough Figure 1 Chopin Alveograph results for flour from NABIM group 1 wheat... 

Although the Alveograph measures the same properties as the Bra-bender Extensograph there is no way of converting one set of results into another. Also, unlike the Extensograph, the dough is not kept for a long time. 

Table 1 Typical results obtained with a Chopin Alveograph for flour milled from British wheat varieties (see text for NABIM group classifications )...

NABIM group P value L value Alveograph P/L Alveograph W... 

These important fundamental observations when combined with the operational ease of the instrument make the Chopin Alveograph an attractive candidate for dough research. 

Let us suppose that we wish to modify the balance of dough properties in a variety. In cereal labs, load-deformation instruments such as the extensigraph and alveograph are commonly used to measure two main parameters that characterize dough properties the resistance to extension (or tenacity) and the extensibility. Although measured by the same instruments, these two parameters appear to depend quite differently on protein composition. In a study based on a large number of wheat samples... 

Kernel texture (38-47), Farinograph parameters (48-50), Alveograph parameters (48), Extensigraph parameters (50), Mixograph parameters (50), Zeleny sedimentation (38 0,51), SDS sedimentation (52, 53), bread loaf volume (48,49, 51, 54), water absorption (48,51) FermentabUity, hot water extract, specific gravity (in beer) (55-58), metabolizeable energy (59-62)... 

The UK now exports approximately 20% of the wheat produced. British Cereal Exports have produced two brands to aid export of UK wheat ukp is prerrrirrm wheat for bread making and uks is soft wheat for a variety of rrrarkets. Grain is analysed using the Chopin Alveograph Test when selling into this market as it... 

If grain is to be stored for more than four months, maximum moisture content should be 14%. W and P/L values are from Chopin Alveograph Tests. Hagberg FN, Hagberg falling number. 

The Chopin Alveograph uses air pressure to inflate a bubble of dough until it bursts. The instrument continuously records the air pressure and the time that elapses before the dough breaks (Figure 4). 

The alveograph (Figure 15.8) is the preferred rheological test in Europe and is gaining popularity in the rest of the world. The instrument measures properties while injecting air into a preformed disc of dough. This simulates gas retention during fermentation. 

FIGURE 15.8 The alveograph used to assess rheological properties of wheat dough, with corresponding curves for durum, hard, and soft wheats (photograph courtesy of Guadalupe A. Lopez Ahumada, DIPA, Universidad de Sonora, Mexico). 

FIGURE 15.8 The alveograph used to assess rheological properties of... 

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