There are several methods that can be used to control the aging of bread and extend the shelf life. The purpose of these methods is only to extend the shelf life of bread and prevent it from aging too fast.
Heating and freezing can prevent the aging of bread products, extend the sales time, to heat the bread products and keep in a higher temperature such as 40-60 ℃ or slightly lower, which can keep the bread soft for a long time, especially in winter when the temperature is low. However, due to the high temperature, it is easy to cause mildew and rot, and lose part of water and fragrance. Freezing is a method, but it is different from cold storage. It is necessary to reduce the temperature below - 20 ℃ in order to prevent over aging, and the speed of cooling and thawing should not be too slow. This method consumes a lot of energy and is not cost-effective under the current experience conditions.
Good packaging can prevent the loss of moisture and keep the product beautiful. Although packaging can not inhibit the aging caused by chemical changes, it can maintain longer softness and fragrance than bread without packaging. Generally, the temperature of bread products is 37 ℃ ~ 40 ℃ when they are packed, and the cooling temperature should not be too fast to prevent the bread from cracking. It is not advisable to use the electric fan to achieve heat dissipation, because this will accelerate the evaporation of water.
3. Selection of flour
To make bread from high gluten flour, it has a lot of water absorption, high protein content, low starch content and large volume, so the bread harden slowly and keeps good performance. In order to make bread with high gluten flour, it is necessary to ensure sufficient water to help the expansion of gluten, and to use a mixer with high speed to make the gluten fully expanded.
4.The function of bread improver and α - amylase
The amylase in bread improver can hydrolyze part of starch to dextrin in the initial stage of dough fermentation and baking, so it can change the structure of starch, reduce the degradation of starch and increase the aging time of bread.
5.Function of emulsifier
Glycerl monostearate is an emulsifier, which was widely used in bread 40 years ago to reduce the hardening rate and increase the storage time. The function of the emulsifier is mainly manifested in that it penetrates into the starch granules and combines with the amylose to form a spiral structure, so as to prevent the water from moving out of the starch and keep the water. At the same time, because of the low surface tension and osmotic pressure of the emulsifier, the grease used in the dough is expanded to the maximum area by the emulsifier, so as to increase the lubrication of the gluten and starch in the dough and make the gluten This emulsifier can also make starch difficult to mix into gluten, so it can increase the elasticity and extension of gluten, increase the volume of bread, so using emulsifier is the most effective and simple way to improve the quality of bread, increase the storage time, and the general use amount is 0.5%.