Overcoming The Frozen Bakery Challenge
Wednesday, September 13th, 2017
The concept of frozen dough and par-baking has shifted the economics of freshly baked bread, but can they match the perception of freshness and common characteristics that consumers readily look for when buying pastry products? By Xue Si-Ying, bakery group innovation manager and application specialist, DuPont nutrition & health
Freshness is the top consideration for consumers buying bread, with 78 percent citing it above type and price. Therefore, retailers need to make freshness a central part of their value proposition, deploying strategies that signal their products’ freshness the moment the customer walks in the door.
Robyn Lee, New Jersey, US
Fresh breads can be obtained by buying the bread fresh from the bakery every day, or by buying frozen dough or par-baked breads from the supermarket and baking them at home to enjoy the aroma and taste of freshly baked bread.
The concept of frozen dough and par-baking has shifted the economics of freshly baked bread. It is now possible for bread manufacturers to prepare, and then distribute bread to anywhere they wish.
In large countries, freshness of the breads used to be a challenge as significant time was wasted in delivering breads from the manufacturing site to various distribution points. However, with a frozen dough or frozen par-baked product, a bakery can supply distant outlets with breads ready for baking on demand.
Supermarkets and food services such as cafes also benefit from this concept, because frozen dough and par-baking allows them to reduce the need for skilled bakers in their stores. Since only simple finishing bake is needed, simple instructions and proofing or baking times are easy for untrained store personnel.
Instead of a complex bakery with specialised equipment, only a simple proofer or oven is needed. Bread can also be baked only when necessary, such as when it sells out through the day. This reduces wastage and carbon footprint.
With such benefits, there is a growing interest by the industrial bakeries to produce frozen dough or par-baked bakery products. However, this is no easy feat as several challenges have to be overcome to achieve good quality baked products.
Achieving Crispiness In Full Volume
Bake-off baguettes are not just about freshness and crispiness. Volume is another key parameter to consider. It is important to ensure that baguettes maintain good volume, both after the initial par-baking process and after the second and final baking without compromising on texture.
No matter how you try to avoid it, shrinkage is part and parcel of par-baked bread production. Over the years, the industry has generally accepted a volume reduction of around 15 percent after the final baking—accompanied by a more compact crumb. In an experimental trial conducted, four par-baked baguettes were prepared with:
- Bakery enzymes (including lipase) + ascorbic acid
- Bakery enzymes plus 1% lecithin
- Bakery enzymes plus 0.3% DATEM
- Bakery enzymes plus 0.15% DATEM + 1% lecithin + 0.3% cellulose gum
Specific volumes and extent of shrinkage of these baguettes were studied. Results showed that the enzymes with ascorbic acid solution produced baguettes with the lowest volume—around 14 percent less than the solutions with DATEM and lecithin. It also showed the biggest shrinkage—or volume loss—after the second baking.
The combination of enzyme plus 1% lecithin or 0.3% DATEM resulted in approximately the same volume loss. This supports the general knowledge that an enzyme-emulsifier combination will generally give better result than enzymes alone. Some degree of shrinkage is still inevitable.
The best result was obtained with the baguette sample containing enzyme with both lecithin and DATEM and a small additional dose of cellulose gum on top.
Besides having the biggest specific volume, which is within expectation, it also delivered the lowest baking loss. This is attributed to the ability of cellulose gum to absorb and retain more water in the dough system. As a result, cellulose gum is able to provide both stability and flexibility to the gluten and starch network. This is proven by the fact that shrinkage after the second baking was minimal.
The Frozen Pastry Challenge
Jason Wong, Sydney, Australia
Similar to par-baked products, the frozen dough concept offers cafes and supermarkets convenience as well as freshly baked products without the need to hire skilled bakers.
However, the challenge has been and still is, to produce bakery product with a quality that is comparable to bread baked by traditional processes. The freezing process in a yeast-containing dough system causes the gassing power and gas retention of the dough to decrease.
In the final baked product, this is recognised as reduced oven spring and specific volume compared to products made from dough that has not been frozen. For this reason, the area of frozen dough has been the subject of many investigations aimed at optimising procedures and improving the quality of the finished baked product.
Standard bread improvers in the market are normally added to improve gluten development and improve the volume and softness of the bakery products.
However, most bakers would realise that if they were looking at developing a good quality frozen product with substantial frozen shelf-life and good freeze thaw stability, the standard bread improvers would not be efficient enough to meet their needs.
Frozen dough stabiliser solutions available in the market normally contain more functional ingredients that can give extra stability to the gluten network of the dough during frozen storage, thereby improving the final quality of bakery products. Besides that, industrial bakeries should also review processes and recipes to ensure optimal results are obtained.
Most frozen dough bakery stabilisers available in the market today are suitable for both yeast-raised, frozen dough products that are thawed and proofed after freezing and products that are proofed before freezing and baked straight from the freezer. Products that are baked straight from the freezer are deemed as very challenging.
Despite this challenge, products that are baked straight from the freezer can give significant cost savings as production can be faster and the reduced size of frozen pastries can offer increased efficiency in transportation and storage.
A frozen non-proofed croissant is only around half the size of the frozen pre-proofed croissant. In other words, a standard box can contain around 70 non-proofed units, compared to just 48 of the pre-proofed—a considerable saving on freezer space.
And of course, the other benefit is that non-trained personnel would still be able to bake appealing products without the complication of defrosting or proofing beforehand. But, is this possible?
A study was conducted to determine whether a freezer to oven yeast-raised pastry, which had not been proofed prior to freezing, could match the pre-proofed pastry in volume and quality overall.
Results showed that the non-proofed croissant, using optimised dosage of frozen dough bakery stabiliser and processes, was only slightly smaller than the pre-proofed one. Both baked croissants were comparable in terms of texture and crispiness. Therefore, the conclusion was that it is possible to achieve non-proofed, freezer to oven croissants with good baking characteristics.
A Pastry Crust Above The Rest
A soggy pastry crust can take all the pleasure out of eating a savoury tart. With many bake-off quiches, pies and flans on display in the chilled and frozen counters of today’s supermarkets, it makes sense to look into strategies for keeping the pastry crisp.
Two strategies can be adopted: migration-resistant fillings that keep pastry dry, and pastry formulations for delayed moisture absorption from the filling.
Looking at the pastry formulations, one of the best options is to reduce the fat and add some poly-dextrose in the shortcrust pastry. Poly-dextrose is a recognised dietary fibre with prebiotic and has a satiety-inducing effect. It is also widely used as a bulking agent, and is highly suitable for food and beverage products that are lower in fat, sugar and calories.
The addition of poly-dextrose not only gives the reduced fat shortcrust pastry the same eating quality as a standard full-fat recipe; it also improves the pastry texture and crispness.
There are a couple of theories that can explain this observation. The poly-dextrose interacts with the protein, starch or fat in the pastry, or being soluble, it interrupts the development of flour gluten simply by absorbing water. There’s a possibility that both theories apply.
Upon baking, the fibre turns into syrup, which then solidifies into a glassy state on cooling. This is the characteristic that gives improved pastry crispness. When a filling is added, the poly-dextrose very slowly transforms from its glassy state back into the syrup. In this way, moisture absorption is delayed, and the pastry keeps its crisp, short bite for longer.
Tarts in the chilled counter in particular, benefit from this delayed migration, securing a freshly made eating experience after the final baking. In frozen tarts, the poly-dextrose ensures that any moisture present in the pastry is frozen in small molecules, which are less damaging to the pastry system during defrosting.
The speed of water migration will always vary according to the type and quality of the fats and flour used. Therefore, the optimum poly-dextrose level must still be determined for each pastry recipe.
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