The Regional Institute - The development of a rapid dough bread baking method using a doughlab (2024)

NSW Department of Primary Indsutries, Wagga Wagga Agricultural Institute, Wagga Wagga, NSW 2650, Australia

There are three major Western style bread production systems: long fermentation, sponge and dough, and a rapid process used extensively in Australia. Test baking methods are used for a number of purposes: they can be used to test variations in baking procedures, to test the influence of various ingredients on baking or, as is the case in wheat breeding programs, to establish the relative quality of wheat varieties and crossbreds (Doerry, 1995). In order to reflect baking practice within Australia when selecting new wheat varieties, an appropriate rapid test bake method was required. Bread manufacturers in Australia use a rapid dough development process for bread baking, while many Asian manufacturers still require wheat varieties that withstand a long fermentation process. The long fermentation test bake method conditions the dough during fermentation and helps develop flavours (Doerry, 1995). However, long fermentation unreasonably discriminates against varieties that have more mellow gluten and perform well in Australian commercial practice. This work concentrated on developing a rapid process suitable for selecting new varieties suitable for the domestic industry in Australia and to test the suitability of the DoughLab for this purpose.

Traditionally, in the test bake laboratory of a wheat breeding program, a National Pin mixer is used for baking. While this is appropriate for long fermentation methods, the pin mixer action does not mix dough sufficiently or transfer energy rapidly enough to simulate the rapid dough process. At Wagga Wagga Agricultural Institute, a rapid dough method utilizing the Newport Scientific Doughlab has been developed for assessment of lines at the advanced stage of the breeding program. The target wheat protein range is 11 to 12%, reflecting Australian commercial practice.

A series of lines ranging in dough strength were baked using both long fermentation and rapid dough methods, all lines were hard. Long fermentation method is based on a modified AACC 40-10 method.

Samples baked were grown in:

1) Early sown trial at Wallendbeen, NSW in 2003.The lines were CHARA (2 samples), CUNNINGHAM, STRZELECKI, WYLAH (2 samples), GILES, WHISTLER and 15 crossbreds of varying dough strength.

2) Main sown trials composites from four trials from 2003 harvest. The lines were CHARA, LANG (2 samples), DIAMONDBIRD, HARTOG and two crossbreds.

Wheat protein ranged from 10.6 to 13.1% in the early sown trials, although this range seems high it reflects the difference seen in trials and is related to the yield of different varieties. In the main sown trial, protein ranged from 12.9 to 14.6%.

Equipment

A pin mixer and variable mix time was used in the long fermentation method and the Newport DoughLab was used for the rapid bake. Moulder, fermentation cabinet settings and bake time and temperature were identical for both methods.

Rapid Bake method

Ingredients including 220g flour, 1% improver, 3.5% compressed yeast, 0.2% ascorbic acid, 2% salt, 1% sugar, and water addition as determined from Farinograph water absorbance. Doughs are mixed for a set time of 5 minutes at 100rpm in the Doughlab fitted with a 300g bowl. At completion of mixing, doughs are scaled in half and placed in sealed containers in fermentation cabinet at 28 – 30^OC for 15 minutes. Doughs are then lightly knocked and run through bread rolls at 4mm gap setting and 17rpm before returning to fermentation cabinet for a further 20 minutes. Loaves are moulded, tinned and proofed at 32 - 34^OC and 80 - 85% RH for 55 minutes before baking at 216^OC for 20 minutes. Loaves are assessed the next day for volume (rapeseed displacement), external appearance, external colour, crumb colour, crumb texture, crumb structure and bread L*, a*, b*. A total loaf score is given that includes a score for the loaf volume, one for crust colour, external appearance, crumb colour, crumb texture and structure (Figure 1).

Generally, with few exceptions, the rapid bake test was superior for the weaker dough strength lines, while the long fermentation straight dough method was better for lines with higher dough strength. The rapid process appears to be kinder to weaker flours

Figure 1: Loaves baking using the Rapid process.

Comparison of the two bake methods show the ranking of varieties for each method followed dough strength. The weak and moderate dough strength varieties baked better using the rapid process and the stronger lines baked better using the straight dough long fermentation method (see Figure 2, Figure 3 and Table 1).

Figure 2: Comparison of varieties baked using both bake tests.

Table 1: The ranking of varieties showing dough strength of rapid and straight dough pan bread.

Figure 3: Results from main season composite sites.

Mixing a dough has three main objectives 1: blending of the flour and ingredients, 2: hydration of the ingredients and 3: development of a gluten structure. In the rapid dough process where a lot of the dough development is completed in the mixer, the DoughLab proved to be a very successful mixer. It allowed complete control over dough temperature and the level of mixing required. The pin mixer for the rapid process does not impart enough energy into the dough, nor does it control the temperature of the dough successfully. At the end of mixing the dough, gluten should be fully developed and should only require a short standing time or floor time. The DoughLab worked well for this whole process.

American Associaion of Cereal Chemists (2002). Approved method Methods 10^th Edition Method (40:10b). AACC St Paul, MN, USA.

Doerry W.T. (1995). An Introduction to Bread Baking in North America; in Breadmaking Technology. American Institute of Baking. AACC St Paul, MN, USA