Meet the Expert
Who: Jo Baker-Perrett
What: Food scientist
Where: Campden BRI
If you’re like most people, then picking up a product to find unfamiliar, chemically synthesised ingredients on the back is a big turn-off – it may even dissuade you from purchasing it. You’d probably prefer to see ingredients that are easily recognised, understood and pronounced.
For this reason, manufacturers are seeking to replace artificial ingredients with those from more natural sources that will appeal to consumers. But introducing a ‘clean label’ is no easy task. Many key functions in the foods we eat are performed by chemically synthesised ingredients – and for a good reason, so finding natural alternatives that work as well is a real challenge.
Campden BRI have been evaluating the performance of plant-based food ingredients against existing additives. Our recent study investigated the potential of using sorghum, millet and chickpea flour as thickeners in the filling of apple pies when compared to refined starch (the pies’ usual thickening agent).
Why is starch an effective thickener? Because, when heated, this carbohydrate gelatinises, causing the starch granules to absorb water and expand – significantly increasing viscosity.
Sorghum, millet and chickpea all contain a significant amount of starch, so we attempted to thicken the filling of an apple pie by incorporating these ingredients as flours. The added benefit is that these flours also contain micronutrients which may further promote good health.
The plot thickens
Of the three flours tested, sorghum absorbed the most water and formed the most viscous gel when tested on a rapid visco analyser. It showed the greatest potential as an alternative thickener in processed foods, followed closely by millet.
Other analysis showed that both demonstrated rheological properties similar to refined starch when added in at elevated levels. In layman’s terms, this means manufacturers could reformulate their apple pie’s filling with one of these alternative flours to achieve a similar gelling effect as seen with refined starch – assuming about three times more of one of these flours is added.
Better yet, they could substitute ‘modified starch’ with ‘millet flour’ on this product’s ingredients list, increasing its appeal to consumers looking for ‘cleaner’ label products.
Chickpea flour, on the other hand, didn’t perform as well when tested. However, what we did observe was its ability to form a strong gel structure that didn’t easily breakdown. Why? Well, unlike the other two materials tested, chickpea contains a high amount of protein (about 20%), so we believe this protein interacted with the starch granules creating a starch-protein gel network. More testing would be required to confirm this hypothesis.
Manufacturers could potentially find a use for this strong gelling behaviour in other specific applications. However, it’s worth noting that after testing the apple filling containing chickpea flour underwent ‘syneresis’: a process in which the gel network contracts, ultimately squeezing out some of the water.
The results we found for these flours may apply to a number of other pseudo-cereals and ancient grains, widening the industry’s choice of potential alternative ingredients to use.
Next, our research will focus on the functionality of novel ingredients in doughs and batters.