Technical Talk – March 2010

To mark the 70th anniversary of Bakers Journal, we will look at baking innovations that have changed the industry in the past several decades

To mark the 70th anniversary of Bakers Journal, we will look at baking innovations that have changed the industry in the past several decades

H umans have practised simple bread baking for thousands of years. Then came the industrialization of the baking industry after World War II, in the early 1950s. Since that time, and during the subsequent decades, a number of new technologies came into play that revolutionized the industry. These innovations dealt with the introduction of new processes and novel functional ingredients.

New technologies included continuous mixing and accelerated mechanical and chemical dough development, as well as the use of liquid ferments. Continuous mixing of dough provided advantages in labour costs, efficiency in the use of ingredients as well as reduced equipment needs. Continuous process required a liquid preferment containing the yeast and food necessary to initiate fermentation. Some preferments may include flour to initiate flavour development as well.

Following that, the preferment and the remainder of the dough ingredients (including large amounts of oxidizing agents) are blended in an incorporator and then moved through a small development chamber and kneaded at high speed while under pressure and almost completely devoid of oxygen.

Next, the dough is automatically scaled and deposited into baking pans. As a result of the pressure and the incorporation of the air based on high-speed mixing, the characteristics of the bread crumb are quite different than those from the batch bread-making process.

Another process breakthrough came in the early 1960s with the introduction of the Chorleywood method. This process was developed by the British Flour Milling and Baking Research Association (FMBRA) at Chorleywood. The FMBRA since then has been incorporated into Campden BRI, a major food technology centre in the United Kingdom.

The Chorleywood process is based on high-speed mixing for a much shorter period of time. This approach results in several advantages: substantial reduction of total process time (less than two hours from mixing to the end of baking), specific reduction of fermentation time, increased product yield, precise control of dough development and the ability to use relatively low-protein wheat flours. This process has been adopted in many countries around the world. However, after extensive research, Campden BRI is ready to introduce a new radical approach to bread making that takes into account energy consumption and product quality as well as variability of the raw ingredients.

As the need for mass production and distribution increased and the availability of skilled bakers diminished, other processes were developed to satisfy the need for longer storage and shelf life of baked goods. Two major innovations relate to the production of frozen dough and par-baked baked goods. Frozen dough’s advantages include the ability to be stored for long periods and transported across long distances, thawed and formed into products, then proofed and baked at a facility with minimal equipment requirements.

But freezing dough and storing it for a long period of time has its challenges, especially relating to the yeast-raised products. Formation of ice crystals can damage the yeast cells; therefore, the method of freezing is important.

Traditional bread yeast strains have low tolerance to freezing or cryoresistance. Cryoresistance of yeast is related to the presence of higher amounts of trehalose, which is a cryoprotective compound present naturally in yeast. Thus, selection of yeast with higher trehalose content is important.

Although more resistant to freeze damage, cryoresistant yeast strains might have a lower gassing power due to lower enzyme activity. The challenges of frozen dough can be overcome by carefully selecting yeast strains as well as maximizing cryoresistance by minimizing yeast fermentation prior to freezing. Selecting other specialized ingredients can also provide some solution to these challenges.

Another technology introduced in the past 70 years is the process of par-baking. Partially baked products were originally introduced by General Mills in 1949 by the “Brown N Serve” process. These products were pre-baked to exact size and shape and were fully formed with the exception of the crust browning. Since then the process has been used extensively to satisfy the demand for freshly baked goods in the massive urban consumer market.

The par-baking process requires modifications to a product’s formulation, fermentation, baking and freezing process. Formulation adjustments include reduction of yeast and yeast food to lower oven spring, as well as reduction of dough absorption. Fast proofing at slightly warmer temperatures and baking at lower temperatures to ensure stability of the baked good without the crust browning development is also required. The introduction of steam in the baking process is also essential in order to prevent drying of the product, which will result in lower crust quality.

Many new ingredient innovations have taken place in the past seven decades. These include dough improvers, emulsifiers, modified starches, gums and many others.

One area where ingredient innovation has provided a tremendous contribution to the baking industry is the use of enzymes. Although enzymes have been used in the baking industry for many years, they were simply crude formulations such malt barley flour or simple proteases such as papain from the papaya tree.

The plethora of specialized enzymes available today that can be used to improve baking formulations is amazing. We now have enzymes that are very precise in acting on starches, proteins and fats, making them a tremendous help to bakers.

These enzymes can often replace synthetic chemical improvers and allow us to have a much cleaner label on our products. Enzymes such as glucose oxidase helped with the removal of potassium bromate when its use was banned in Canada. Other enzymes of note here include lipases, which can act on natural lipids in the flour to reduce the use of emulsifiers; and transglutaminases, which link proteins together to provide strength and structure to the bread formulations. Such enzymes can allow the use of poor-quality wheat flour for the production of good quality baked goods.

Transglutaminases are also being researched for use in the development of gluten-free baked goods because of their ability to connect proteins together to form matrices that can mimic the gluten function. Other enzymes of interest include specific amylases that can prevent staling of baked goods and enhance shelf life.

Ingredient innovation is sometimes forced by changes in food regulations. Some of the major chronic health issues we are facing today are pointing toward the use of trans-fats and sodium in our diet. As regulations on labelling or use of these unhealthy ingredients are being established, the development of innovative ingredients to provide replacements is accelerated.

Funding for this report was provided in part by Agriculture and
Agri-Food Canada through the Agricultural Adaptation Council’s
CanAdvance Program.

Dr. John Michaelides is Guelph Food Technology Institute’s director of
research and technology. For more information, or fee-for-service help
with product or process development needs, please contact GFTC at
519-821-1246 or  gftc@gftc.ca.