Part-Baked Products - Minimally Processed Foods - page 154

During the prebaking or par-baking step, the products should be baked until crumb
formation allows its storage for longer time. In the second step, partial-baked
breads are rapidly cooled, wrapped, and stored until its fi nal baking at the point of
sale or consumption. The fi nal baking process reverses certain product properties and
generates its characteristics similar to the freshly baked product (Grau et al. 1999 ;
Vulicevic et al. 2004 ; Barcenas and Rosell 2006c ). Part-baking has a market potential
because it provides fresh baked product with a simple baking stage at home or at the
point of sale (Karao ğ lu et al. 2008 ).

8.5.1 Initial Baking (Part-Baking)

Part-baking involves suffi cient baking of dough to inactivate the yeast and enzymes,
and to set the structure with a minimum crust coloration and moisture loss.
Generally, lower baking temperature is required to avoid excess crust colouring.
However, lower baking time effi ciently extends the period of yeast activity at the
beginning of the fi rst baking. For this reason, a compensatory reduction in proof
time is required. Steam may be applied during both of the baking stages. In the fi rst
baking stage, baking temperature is kept lower to produce scratch. The application
of limited steam may be used to control the oven spring, or break (Cauvain and
Young 2000 , 2006 ). The amount of steam signifi cantly affects colour, glossiness,
and mechanical properties of the crust. The increase of applied steam caused a
reduction in colour, failure force, and failure fi rmness, whereas increased glossi-
ness (Altamirano-Fortoul et al. 2012 ). The objective of part baking is to bake the
crumb without colouring the crust. Baking conditions such as steaming, tempera-
ture, and time are the most important factors affecting coloration of the crust.
Optimum balance must be used to achieve the desired colour and crumb structure
(EU Freshbake 2009 ).
In the baking sage, the yeast continues to produce carbon dioxide until the bak-
ing process becomes hot (i.e. 55 °C) and kills yeast. More molecules of gas are
released into the cells. The extensibility of the cell membranes determines the vol-
ume when internal pressure of the cell is increased. As a result of these events,
dough expands to increase volume by one-third, which is called oven rise. This is
mainly due to the expansion of the gas enclosed in the porous dough structure. The
resistance of the dough to an extension and crust formation is a limiting factor for
the overall and possible local expansion of the dough/bread (Zhang et al. 2007 ).
The pore size in the crust may be differed from the crumb. The crust has a denser
structure than the crumb. The structure of crust and crumb are very important fac-
tors in deterring the quality. The crust is susceptible to the thermomechanical strain
and stresses caused by the freezing process. This depends on the hydration of the
crust at the end of partial baking (Hamdami et al. 2007 ). The degree of baking can
be a control by the length (or dimension) of the product at the end of baking fol-
lowed by chilling at room temperature (EU Freshbake 2009 ).