Lipases assist with extending shelf life by modifying the lipid fractions in the dough or batter to help stabilize the gas cells and improve crumb structure.
“The lipases naturally produce mono- and diglycerides, which provide emulsification to the process,” said Luc Casavant, director, baking applications, Lallemand Baking North America. “Xylanases may also be used. They break down the pentosans, releasing water. This improves gluten performance, providing a more structured crumb cell, resulting in finer cell walls and softer crumb texture.”
Cake shelf life can be tricky with enzymes, Guilfoyle said.
“Some enzyme blenders use lipases in their softening blends, and those lipases can create free fatty acids, which oxidize and can create rancidity issues over time,” he said. “It is recommended finding an enzyme softening blend that contains amylases with possibly including xylanases.”
Enzymes are powerful work horses. If they have no after-bake technical or functional effect, enzymes are considered processing aids and may be exempt from ingredient declaration. Heat-stable enzymes that are not completely inactivated during baking typically are declared. Regardless, when they are alive and active, they need to be able to do their job.
“Baking enzymes need water and time to catalyze reactions,” Weber said. “They are killed off during the baking process, so they need sufficient time to act before baking. Therefore, these ingredients perform better in breads, buns, rolls, tortillas and bagels. They do not work as well in low-moisture or quick doughs, such as cookies and pastries.”
Bakers also need to be aware of different enzymes working together synergistically or antagonistically. Too much activity or too little activity defeats the purpose of addition. Because enzymes may be present in other ingredients without the baker knowing, a thorough inventory of ingredients is recommended.
Then there’s the issue of nonpathogenic microbial growth. Yeast and mold spores are omnipresent in the environment. Even the cleanest bakery has them. Binding free water and reducing pH are options for retarding their growth.
“Microbial inhibition and antimicrobials are necessary for any baked good that requires more than three days of shelf life,” Guilfoyle said.
Vegetable glycerin is a beneficial way to reduce the water activity of a product, which will limit the formation of molds and enable a shelf-stable product, said Mike Beavan, director of technical services, bakery, Glanbia Nutritionals.
“There are also natural preservatives, such as cultured starches and acidulants like vinegar,” he added. “The main goal of these preservatives is to lower the pH of the product, providing an additional hurdle for mold formation to occur.”
However, bakers reducing the pH of products to avoid mold and bacterial growth can affect the flavor of products by making them more sour tasting as the acid content increases, Weber said.
Natamycin is another natural mold inhibitor. It functions more like a chemical preservative.
“Natamycin can be applied to the outside of the bakery product,” Guilfoyle said. “Once a vegetative mold or yeast deposits from the environment onto the treated surface, the natamycin irreversibly binds to the sterols in the cell membrane, changes the permeability and the cell contents leak out, killing the yeast or mold.”
That’s how common chemical mold inhibitors work. Ingredients such as calcium propionate, sodium propionate and potassium sorbate inhibit microbial growth by altering the cell’s membrane. They are a cost-effective way to prevent mold growth but often have a negative perception among consumers.
Antioxidants can provide the last line of full food protection during shelf life. This is especially true for high-fat bakery formulations.
“High-fat formulas benefit from antioxidants, as many may contain milk and egg in the formula, which contain natural metal ions that can cause a faster oxidation rate,” Guilfoyle said. “As shelf life is pushed out longer, the softening technologies will need to change to improve softness and moisture control, and the antimicrobial will have to be increased or will change to improve food protection. Antioxidants will be added to protect freshness of the product.”
Process and package matter, too
Shelf life extending ingredients are only as good as the process and package allow them to be. This applies all the way up to the time of consumption.
“We stress the importance of proper manufacturing practices, sanitation and packaging,” Cropper said. “Ingredients and processes work together, so you should never address one without the others.”
The effectiveness of enzymes is related to temperature, time and substrate availability, as well as inhibitors in the system, said Yanling Yin, director, bakery applications, Corbion.
“Enzymes need an optimum condition to work effectively,” she said. “Processing conditions can often be modified to meet the needs.”
Extended shelf life baked goods must factor in the protection from the package. This includes clear components, where light may penetrate the product and cause oxidation. It also includes material permeability.
“When incorporating shelf life extenders in bread, bakers should also consider the role of packaging,” Zielonka said. “Effective packaging methods can significantly complement ingredient-based solutions. Techniques like nitrogen-filled or vacuum packaging can help reduce oxidation, thus preserving freshness. For specific bread types like artisan breads, micro-perforated packaging maintains crust quality while extending shelf life. Understanding and selecting the right packaging method is crucial in maximizing the effectiveness of shelf life extenders and ensuring the product maintains its desired qualities until it reaches the consumer.”
A simple moisture barrier, such as using a polyethylene bag, can help prevent staling when compared to using simple clamshell packages, Beavan said.
“Additionally, modified atmosphere packaging could be utilized to further extend shelf life,” he added.
When it comes to low-moisture or high-sugar products, such as crackers or cookies, packaging plays a significant role in preventing lipid oxidation. When fats go rancid, products won’t taste good.
“As the industry moves away from the traditional grains used in baking, the suppliers of these functional ingredients continue to adapt their existing product portfolio to the trends taking place within the market,” Mayers said. “Bakers need to work with their suppliers to address these consumer trends.”
Bakeries had shorter shelf life specifications years ago, as there were more bakeries supplying consumers, Guilfoyle said.
“Bakeries are consolidating operations for improved efficiency and driving baked goods much farther than they did before,” he added. “Many bakeries had direct-store delivery and delivered many times a week, so the supply of baked goods was always shorter in shelf life and remained fresh over a consumer’s consumption rate.”
In recent years, that model has changed. With fewer bakery suppliers, warehouse distribution and consumers want a longer shelf life for their bakery goods as they are not consumed in a short period of time.
“I believe that bakery goods’ shelf life requirements will push the boundaries to nearly double what they are today,” Guilfoyle said. “The technology exists for many of the bakery goods already, and consumers are more cognizant of waste. Consumers want a longer shelf life to be able to consume the product over a longer time without having to throw it in the trash.”
Bakery items today are expected to last longer than in years past. For that reason, bakers need to explore the many ingredients and other methods available to extend the life of baked goods, reducing food waste.
This article is an excerpt from the March 2024 issue of Baking & Snack. To read the entire feature on Extended Shelf Life,click here.
