"This is the way we bake our bread"

Have you ever walked into a bakery to smell fresh bread just as it comes out of the oven? Or better yet, have you ever baked your own bread? That is bread as fresh as it can get, and that is when bread is at its’ very best in many respects. Many people enjoy eating homemade bread and proceed to bake their own to obtain the desired freshness, however, many more people just grab a loaf off of the shelf at the nearest grocery store. A statistic from “Marketplace” explains that one bread company in America, Wonder Bread, has already pulled in 220 million dollars in revenue for the 2010 year (Kaplin). That is just one company, and at the ordinary, everyday grocery store, bread takes up possibly a whole aisle with different kinds of bread varying from wheat to white and from bagels to hoagies. Each of these different styles is produced by many different companies from Nature’s Own to Pepperidge Farm and this results in having to make a huge choice every time a person strolls down the bread aisle. But with so much bread being produced and so much to choose from, how long do those loaves sit on the shelves at the grocery store? And even if they are bought on the first day, how long do the loaves stay not eaten in a cupboard or pantry or just sitting on a counter somewhere? This brings us back to the question of fresh bread. What happens as bread just sits on the shelves of a grocery store or cupboard? Why is bread never as fresh as when it first comes out of the oven? Why does bread sometimes smell, taste, feel, and even look different after it just sits for a few days? The answer to many of these questions has to deal with many aspects of an experiment performed by Omer Mukhtar, Salim ur Rehman, Ghulam Mueenuddin, and Mian Anjum Murtaza. These researchers conducted a study on the effectiveness of combinations of preservatives over time in reducing “microbial and bacterial growth” on bread and other cereal products to prolong the “fresh” characteristics of the loaf that many people enjoy.

There is a little background information that one must know before this entire experiment will make any sense at all. First, the two major factors that contribute to the quality of bakery products are “health safety and optimum sensory properties.” “Optimum sensory properties” is just a very sophisticated way of saying how the bread should look, feel, taste, and smell. The researchers also looked at “quality characteristics” which includes volume, crumb color, and other similar properties. A second major point that these researchers emphasize is that “commercial white breads” that just sit out at a bakery or something “spoil within 48 hours of production” due to “microbial” growth. “Microbial growth” consists of all the disgusting, yet natural things that happen to bread over time, such as the growth of mold, fungus and bacterial growth on the bread. Lastly, the “microbial species can be controlled by improving sanitary conditions” and by the “incorporation of different acids and their salts in bread formulations” to provide protection against “rapidly growing mold and bacterial spoilage.” These salts and acids, for example benzoic acid, sorbic acid, propionic acid, lactic acid, and acetic acid, are the preservatives found in most breads that keep them from growing mold right away. Now with a little basic understanding of mold growth on bread and how it is prevented, the actual experiment of preserving the “optimum sensory properties” with different combinations of acids can be understood with a little more ease (Tarar).

In this experiment, these researchers baked their own bread for testing in accordance to the “AACC” method. However, in each loaf they put a separate combination or dosage of the following acids: Calcium Propionate, Lactic Acid, and Acetic Acid. Calcium Propionate was the only acid put in each loaf of bread and the control of the experiment was a loaf of bread with .2% of Calcium Propionate without any additional chemicals. The other recipes and acidic combinations are shown in the below table(Tarar):

After the bread was baked, it was placed to sit for hours and observed for changes in taste, aroma, crust character, and texture. The bread was also observed for crumb color, grain formation, crust character, volume, color of crust and symmetry based on the different ingredients and acidic combinations. These observations were based on the mean score of a panel of five “bread judges” who gave each loaf a different score for each category. Now that some of the more logistical preparation stuff is out of the way, the actual results and why the moldy bread experiment matters to the average consumer can be explained (Tarar).

First, the researchers examined the time relationship between time and the “optimum sensory properties” of bread. By analysing the researchers’ data and graphs it can be concluded that the longer the bread stayed in storage the more “unacceptable” the taste, texture, and aroma become as all of their mean “sensory” scores made by the judges fell with time. However, the crust characteristics, or how the crust looks and feels, of the different bread recipes stayed relatively constant as time moved onward(Tarar).

Next, perhaps a more telling relationship is the relationship of the different recipes to the “quality characteristics.” However, the changes with recipe in regards to color of crumb, grain, crust character, volume, color of crust, and symmetry were arbitrary and random. This means finding the most effective combination of acids and salts must be based on more than just this particular data for the sensory characteristics. However by analysing each characteristic, one is able to see which acids work best for preserving each sensory property. For color of crumb, each recipe was close to the same, however, T3 (.2% Calcium Propionate and .4% Acetic Acid) had the lowest color score, but just barely. For crust character and symmetry, each recipe seemed to be essentially the same. T5 had the largest score for color of crust, while the other recipes scored fairly evenly in this regard. One thing that is perhaps interesting is that fact that as the chemical composition increased, the volume of the bread decreased. T3, which had one of the highest concentrations of acid, had the lowest volume. Grain formation also decreased with the amount of additional acid, as T3 also had the lowest score (Tarar).

Again those numbers are somewhat dry and boring but they are essential in drawing conclusions and analyzing the truly gross and most interesting and appropriate part of the research, the mold and bacterial counts on the bread. As perhaps expected, the more crazy chemicals you put into the bread the less bacteria and mold grow. This is evident in the fact that T3 and T6, the two recipes with the highest acid concentrations, had less mold and bacteria than all of the other recipes after 96 hours. This table is shown below (Tarar):

So why does all this moldy gross stuff matter to you, the reader and possibly bread consumer? Well I do not know if you have ever wanted a sandwich, piece of toast, or whatever, and you whipped out the bread and it has had green or black spots all over it. Well if you have not, it’s a pretty gross experience. Actually it is a really gross experience and that is why this is somewhat important. This experiment’s research proves that a certain combination of preservative acids, the most effective being .2 % of Calcium Propionate and either .4% of Acetic Acid or Lactic Acid, can significantly reduce mold growth and bacterial growth to keep bread bacteria free and unspoiled longer. However, as the other facts show, chemicals change the physical properties of the bread as well. One interesting example may be is that as more chemicals are added to the bread, the volume of the bread decreases. Because of reasons such as this, bread companies and bakeries must pay careful attention to get the right chemical balance to achieve the desired physical and sensory characteristics and slow down the spoilage of the loaf. This study goes to show that mixing and combining the different acidulants and salts keeps bread that one can buy in a grocery store or bakery from going bad so quickly and provides information as to what keeps bread from looking like it came out of a garbage can (Tarar).

Works Cited

Kaplan, Melissa. “Wheat Bread beats white in sales, and its no big wonder.” American Public Media. http://www.publicradio.org/columns/marketplace/business-news-briefs/2010/08/wheat_bread_beats_white_in_sal.html

Tarar, Omer M., Ghulam Mueen-Ud-din, and Mian A. Murtaza. "Studies on Shelf Life of Bread Using Acidulants and Their Salts." Turkish Journal of Biology 34.2 (2010): 133-38.
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