As the water reaches its boiling point during vacuum conditioning in the baked goods, the starch subsequently gelatinises. Together with the shortened baking time, improved freshkeeping can be achieved. The lower germ load of the baked goods in the vacuum conditioning cell can be seen as a major advantage. With conventional cooling in the room, a long cooling time in the ambient air is unavoidable, especially for baked goods with a high scaling weight, tray cakes and filled baked goods, which increases the likelihood of contamination with mould spores.
Vacuum conditioning can be used to improve certain baked goods properties. This mainly concerns the dimensional stability and the volume of the baked goods. Possible effects are shown in the following table.
Pre-baked morning goods
Pre-baked morning goods, which should receive little or no colour in the first baking phase, are particularly suitable for cooling in vacuum conditioning. Through it, the baked goods receive a higher volume and the formation of creases is prevented. However, the final pressures for pre-baked rolls should not be set too low, as otherwise the crust may split more after the second baking phase. If the pre-baked rolls are frozen after vacuum conditioning, it is important to ensure that the rolls do not remain unpacked in the blast freezer for too long. Once a core temperature of -5° C has been reached, the rolls should be wrapped in foil and transferred to the storage freezer.
Confectionery yeast dough plaits baked in a tin
Subsequent vacuum conditioning allows yeast-raised confectionery baked goods such as plaits to be baked very light in colour without the formation of creases or key-holing. The plaits develop a stable shape and a higher volume as well as a moist crumb.
Raisin stuten baked in a tin
A similar effect to that of confectionery yeast dough plaits can be observed with raisin stuten baked in a tin. In addition to the improved dimensional stability and the increase in volume, the crumb is lighter in colour and has finer pores.
Danish pastry baked goods with filling
A significantly higher volume can be achieved in Danish pastry baked goods through vacuum conditioning. In the case of filled baked goods, such as quark turnovers, the crumb under the filling is airy and there is no compaction. The disadvantage, however, is a perceptible loss of flavour in the filling. If lemon or vanilla flavouring is used in the quark filling, the flavour is less pronounced after vacuum conditioning than with conventional baking and cooling.
Croissants
If croissants are cooled via vacuum conditioning, higher baked goods volumes can be achieved and the contours of the layers are more pronounced. In addition, the crumb becomes more fine-textured and lighter in colour due to subsequent physical aeration.
Crust-cracked rolls
The crispness of crust-cracked rolls can be improved by vacuum conditioning. Furthermore, as the pressure decreases, the graining of the rolls becomes more pronounced. Pressures of 50 mbar lead to distinct graining, but also to a hard and brittle crust and drying out of the baked goods. Therefore, as a rule, a maximum pressure of up to 100 mbar is used. The volume of the rolls may increase slightly.
