Introduction to the Sprouting Process


Sean Finnie, Senior Manager, R&D
Sneak Peek 1 – Sprouted Grains as a Food Ingredient

This is the first blog in a series dedicated to providing a preview to a book chapter written by Vanessa Brovelli, Darrel Nelson and Sean Finnie from Bay State Milling’s Research and Development Team. The chapter will appear in the book Sprouted Grains: Nutritional Value, Production and Applications. Editors; Hao Feng, Boris Nemzer and Jon Devries. Published by AACC International.  This initial blog focuses on providing an introduction to sprouted grains with a discussion of what happens in the seed during the sprouting process.  The next two blogs will cover the processing of sprouted grains and the functionality and applications of them.

The use of sprouted grains as food ingredients has increased over the last decade based on the general belief they impart significant nutritional, flavor and texture benefits over their unsprouted counterparts.  Traditionally, bread has been the main food product that utilized sprouted grains, but now sprouted grains are used in many baked food products, such as tortillas, granola, cookies, crackers, and muffins, as well as other applications like snacks, bars, breakfast cereals, side dishes and salads.  Unbeknownst to most, sprouted grains actually go back much further in time.  Sprouted grains were used in the Voyages of Captain Cook in 1770, as a means to combat scurvy in sailors while at sea through their increased levels of ascorbic acid. However, even these historical accounts provided insights into the challenges of delivering consistent benefits of sprouted grains since the benefits were not always observed.

To help explain this inconsistency of the finished food, we have to consider two factors 1.) the sprouting process and 2.) seed genetics, as each will contribute to the characteristics of the finished product.  Beyond the nutritional benefits, it is also logical to assume that flavor and texture benefits of sprouting grains will also vary due for the same reasons, and all are important to pleasing your consumer.

So what happens in the seed during sprouting?

Sprouted grains are produced through a controlled germination process with the goal of producing a consistent product batch after batch. Since germination is a complex process, to produce a consistent product, it’s important to understand what’s happening in the grain and the process to know what you need to control.

First, an intact germ on the grain is required for germination, so germination is not possible on pearled barley, white rice, or on any grain whose germ may have been damaged due to abrasion cleaning.  For germination of a seed to initiate, the kernel must achieve a specific minimum moisture content and a specific minimum temperature.  During the steeping phase of sprouting, water flows into the wheat kernel through the micropyle where it enters the germ and scutellum to initiate germination, and continues to move throughout the kernel, accumulating between the pericarp and seed coat.

This is where the fun begins.

Once the moisture content reaches the minimum requirement, the seed initiates the synthesis and/or release of plant hormones. The secretion of these plant hormones throughout the seed causes the release of enzymes such as amylase, proteases and lipases.  The degradation of starch, protein and lipids by these enzymes provides an energy source for the developing embryo (or for the consumer who eats it), and can have a significant impact on the ingredient’s performance and quality that formulators are interested in.

The increase in amylase will result in a decrease in the starch pasting peak viscosity, impacting the starch properties of the ingredient.  The increase in proteases may result in the potential breakdown of gluten forming proteins reducing the overall stability of the dough and the increase in lipase enzymes can result in the degradation of lipids and the potential for auto-oxidation to occur producing off-flavors in the finished product.  The trick is to strike the right balance of all of this activity to produce the perfect blend of nutrition, flavor and performance!

What happens in the processing facility?

… To be continued in the next blog.

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