Loaf volume

R.C. Junge and R.C. Hoseney, A mechanism by which shortening and certain surfactants improve loaf volume in bread, Cereal Chem., 1981, 58, 408-412. 

The reason for the non-response of the Hagberg Falling Number to fungal a-amylase is that it is inactivated at 75°C rather than the 87°C of cereal a-amylase. It turns out that fungal a-amylase preparations improve loaf volumes considerably. Most of this effect is produced by a lipoxygenase enzyme that is also present. 

Ascorbic acid gives less increase in loaf volume than the same weight of potassium bromate and is more expensive. However, potassium bromate is now banned throughout the EU. Ascorbic acid is now permitted almost everywhere, with some countries such as Australia, Greece, Portugal and Germany not even bothering to limit the maximum level. Ascorbic acid appears to be entirely safe. 

It has since been discovered that the very considerable increase in loaf volume that fungal a-amylase preparations can produce is not caused by the amylase but by a lipoxygenase that is also present. 

Using the bulk fermentation method produce a control sample to the standard recipe and a test sample without adding sugar. Compare the two batches to see if adding sugar speeds up the process, checking the effects on yield, loaf shape, loaf volume and product taste. 

Field Pea Flours in Bread Products. Legume flours, particularly soy, have long been incorporated into wheat-based products, both for their functional effects and for protein fortification. In general, increasing the levels of legume flours results in decreased loaf volume, lower crumb grain quality, and adverse flavor characteristics in the baked bread (Table III). 

Results have varied with respect to the amount of field pea flour that can be incorporated into a yeast bread before an unacceptable product is produced. Tripathi and Dat (40) made breads containing 3, 10 and 13% field pea flour and found breads made with more than 5% pea flour were not acceptable. Loaf volume decreased as the percent substitution increased. At the 5% level, color, flavor and taste of the breads were rated as excellent, but at the 10 and 15% levels, there was a bitter taste. 

Generally, vegetable food protein ingredients are more absorbant than other dough components, with the result that mixing time and loaf volume is decreased. In addition, pan bread crumb becomes coarser and occasionally darker in color. Negative effects on loaf volume appear to be inversely related to phytic acid content. 

The maximum amounts of vegetable food protein flours that can be substituted in bread without affecting loaf volume and texture are 5-10% (depending upon the source), and 18-20% can be substituted in cookies without affecting spread and surface characteristics (26). The quantity of vegetable protein flour that can be accommodated in bread can be increased substantially by pre-toasting and by the use of approximately 1.5% sodium stearoyl 2-lactylate (28) and other emulsifiers. 

Softening action in doughs, reduce mixing time, increase extensibility, improve texture and grain loaf volume, liberate 6-amylase Increase drying rate of proteins, improve product handling characteristics, production of miso and tofu... 

Baking. Flour contains enzymes, the most important of which are amylases and proteases. However, the quantities of these enzymes are not always ideal for baking purposes, and supplementary enzymes are often added. Many potential applications of enzymes are being investigated to improve the properties of bread. Traditional applications of enzymes are for improvement of the dough, loaf volume, crumb structure, and shelf-life. The enzyme products used are free-flowing microgranulates that are easy to handle and freely mixed with flour. 

The loaf volumes of breads baked from wheat starch coming from different classes of wheat, be it hard red winter, hard red spring, soft red winter or soft white, were similar.436 By contrast, club wheat starch produced a larger loaf volume and durum wheat starch a smaller loaf volume. Other investigators found a range in the loaf volumes of breads baked from wheat starches isolated from different classes of wheat.437 Fractionation and reconstitution studies revealed that rye and barley starches can substitute for wheat starch in producing bread of satisfactory volume. Starches from... 

Table XI. Effects of Surfactants on the Loaf Volume of Bread...

Shelf life of fresh and dried whole eggs Overtenderization if not inactivated rapidly Influence on loaf volume, texture if too active Aging, ripening, and general flavor characteristics Conversion of lipids to glycerol and fatty acids Production of milk with slightly cured flavor for use in milk chocolate... 

---