Bread storage

Most of the sugar used by commercial bread bakers is in symp form high fmctose com symp is primarily used. Following shipment in tank cars, it is piped into bakery storage tanks from where it is metered into mixers upon demand. 

Most staple foods such as meat, white bread, potatoes and other vegetables, and most fmits are not artificially colored siace their natural appearance is perfecdy acceptable. Foods are usually colored because they have no natural color of their own, because their natural color was destroyed or drastically altered as a result of processiag or storage, or because their color varies greatly with the season of the year or their geographic origin. Thus, colorants are added to foods to make them appear the way the customer wants and expects them to appear. 

Vegetable oils are added to breads to shorten the strands of gluten and give the bread a more cakelike texture. Adding fats or oils also keeps bread from getting stale, which allows for storage of longer than one day. 

This recrystallisation releases water. This is probably why, although deep freezing prevents starch retrogradation, refrigeration at temperatures above zero causes bread to stale faster than storage at ambient temperature. 

Table IV. Influence of 16-23 weeks of storage of soya containing bread improver PASTE and POWDER on differences (d) in relative decreases (%) of GC peak areas of selected volatile compounds of white bread (22)...

The characteristic aroma of wheat bread crust has been attributed to 2-acetyl-1-pyrroline, and its formation depends on the presence of bakers yeast [31]. In model systems it was demonstrated that the acetylpyrroline is formed from the reaction of proline with pyruvaldehyde or dihydroxyacetone. Other compounds with bread-like aromas formed in the reaction of proline with pyruvaldehyde include l-acetonyl-2-pyrroline and 2-acetyltetrahydropyridine (Scheme 12.5). These compounds are unstable, which explains why the characteristic aroma of freshly baked bread disappears quickly during storage. 

Schieberle, P. and Grosch, W. 1992. Changes in the concentration of potent crust odorants during storage of white bread. Flavour Fragrance J. 7 213-218. 

On the basis of high FD-factors (Table 3) the sensory significance of 3-methylbutanal and 2-acetyI-l-pyrroIine with malty, roasty odors previously identified as the key odorants in fresh wheat bread crust [21] was established. During storage for 4 days the FD-factors of both odorants decreased significantly, while especially butanoic acid (rancid) and (E)-2-nonenaI remained unchanged. The fatty, green note of the latter odorant especially contributes to the stale note detectable in the overall crust flavor of the stored wheat bread. 

Changes in the FD-factors of key crust odorants during storage of wheat bread [55]... 

The concentrations of furfurylsulfides and -disulfides wich possess toasted, bread- and meat-like aromas do not change during storage of roasted coffee. Sulfur containing furans are formed by heating furanaldehydes with cysteine and methionine, respectively (24). 

Thermo-mechanical analysis (TMA)26 and DMTA292 have been used to study the viscoelastic properties of bread, a composite two-phase system. The moisture dependence of Tg was similar to that of pure amorphous starch and gluten.242,282 293-295 At the moisture content of bread, water exerts its full plasticization effect on the composite polymer matrix, reducing the effective Tg to about -10° to - 12°C,26,292 well below normal shelf life storage temperatures of this product. 

Jerusalem artichoke tubers arriving from the field or storage are first washed to remove any soil and extraneous matter, and then mechanically cleaned (Barta, 1993). At this point, the tubers can be ground to produce Jerusalem artichoke flour for bread and other products (Leyst-Kushenmeister,... 

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