Pre-fermentation

Measured quantities of the pre-ferment are mixed with flour. The dough is then subjected to the combination of intense mixing and the action of the oxidising agent. It is then extruded and cut into loaf sized portions, proved and baked. Bread made by the Do-Maker process has a very even crumb texture, which is characteristic of the process. 

The AMFLOW process is similar to the Do-Maker process but the mixing chamber is horizontal rather than vertical. The pre-ferment stage is more complicated as it is multi-stage. 

Peinado, R.A., Moreno, J., Bueno, J.E., Moreno, J.A., Mauricio J.C. (2004a). Comparative study of aromatic compounds in two young white wines subjected to pre-fermentative cryomacera-tion. Food Chem., 84, 585-590. 

Six carbon atom (C6) compounds are the major group of volatile compounds formed during the pre-fermentative stage of winemaking. This group includes volatiles such as hexanal, hexanol, c/5 -3-hexenol, tra/i5 -2-hexenol, and cis- and trans- isomers of 2- and 3-hexenal, which, depending on concentration, can have a detrimental effect on wine quality due to their grassy, herbaceous odors (Crouzet 1986). 

Fig. 4.2 Mechanism of formation of six carbon atom volatile compounds from long chain fatty acids during the pre-fermentative stages of vinification...

Yeast-derived saturated short-medium chain and branched-chain aldehydes are formed from sugar metabolism, fatty acid metabolism and branched-chain amino acid metabolism (Fig 8D.7). In addition, hexanal, as well as hexenal isomers, are formed during the pre-fermentative stages of winemaking by the sequential action of grape lipoxygenase and hydroperoxide cleavage enzyme on linoleic and linolenic acid, respectively (Crouzet 1986). 

Consequently, pre-fermentation maceration at low temperature increases the level of anthocyanins and flavanols from pulp and skins while post-fermentation maceration increases that of proanthocyanidins, as a result of enhanced extraction from seeds (Cheynier et al. 2006). 

Darias-Martm, J., Carrillo, M., Diaz, E., Boulton R. B. (2001). Enhancement of red wine colour by pre-fermentation addition of copigments. Food Chem., 73, 217-220. 

Comeau, Y., Lamarre, D., Roberge, F., Perrier, M., Desjardins, G., Hade, C., and Mayer, R. (1996). Biological nutrient removal from a phosphorus-rich pre-fermented industrial wastewater. Water Sci. Technol. 34,169-177. 

During vinification If the must is not protected during pre-fermentation skin contact, enzymatic breakdown and oxidation reactions may cause discoloration. 

The use of certain pectolytic enzyme preparations to facilitate the extraction or clarification of white must may lead to an increase in the vinyl-phenol content of white wines and a deterioration of their aromatic qualities (Chatonnet et al 1992a Dugelay etal., 1993 Barbe, 1995). Indeed, certain industrial pectinases, made from Aspergillus niger cultures, have a cinnamyl esterase (CE) activity. This enzyme catalyzes the hydrolysis of tartrate esters of hydroxycinnamic acids in must during the pre-fermentation phase (Figure 8.7). Feruhc and j9-coumaric acids are then converted into vinyl-phenols during alcohohc fermentation due to the cinnamate decarboxylase activity of Saccharomyces cerevisiae. 

Addition to the food processing of a pre-fermented food containing bacteriocinogenic... 

To a limited extent, modified starter doughs have survived under different names, e.g. ferment, brew and sponges. These pre-ferments are used for traditional French bread types both in Europe and in the USA. 

There is no pre-ferment or bulk dough fermentation after mixing... 

It has also been suggested that some oxidation should be allowed to occur at crushing and pre-fermentation. The potential for browning of... 

---