The scientists from Campden BRI revised a traditional tortilla to repurpose food waste while at the same time creating a product with higher fiber content. They replaced 20% of the ordinary flour with butternut squash skin powder, increasing the tortilla’s fiber by 97% (from 3.3g to 6.5g per 100g).
Campden BRI told WorldBakers that maintaining all the product characteristics was one of the major challenges of this project. “However, through the use of our powdered ingredient we created an attractive new product with an appealing yellow color and a slight taste of butternut squash,” Lucas Westphal, senior bakery scientist, Campden BRI, said.
Campden BRI wanted to develop a product to support fiber consumption in the UK. A report produced by the Scientific Advisory Committee on Nutrition in 2015 suggested the average adult should consume 30g of dietary fiber a day. According to the research institute, manufacturers use two common methods to enhance the fiber in their products, by pure fibers, e.g. inulin, or whole ingredients naturally high in fiber, e.g. seeds or nuts.
“We aimed to utilize a side stream of vegetable processing and use it to improve the nutritional quality of an existing bakery product. People in the UK and Europe consume roughly just half of the recommended amount of fiber per day (30g). The major contributors to the fiber intake are cereals and cereal products, followed by vegetables and potatoes. Although cereal products are already one of the major contributors, there is vast scope to increase the fiber intake from such products through reformulation,” Westphal told us.
Alternatively, manufacturers can tap into food waste streams to incorporate highly fibrous foods into their products – with the added benefit of repurposing food and reducing waste. The member-funded project “Calorie reduction and fiber enhancement” is focused on this.
The team of researchers created this powder by grinding up peels supplied by Campden BRI member, Barfoots of Botley Ltd, to support the project. The peels would otherwise go to waste when manufacturers process butternut squash, for example, with soup.
Wheat flour has many favorable qualities; for example, it forms gluten relatively quickly. Unsurprisingly, replacing the tortilla’s wheat flour with the butternut squash skin powder affected the tortilla’s functionality. As the powder increased gluten formation time, longer mixing times would need to be factored in when taking on a similar approach. In a previous experiment, the researchers had used butternut squash skin powder to make a loaf of naan bread, but they also found that, as more powder was incorporated, the naan lost volume and became hard. However, as the ratio of water is higher when using the powder instead of wheat flour, there is potential for higher yields at lower cost.
On the other hand, the specialists observed a slight increase in sugars, but the carbohydrate content remained constant.
The development was started with identifying raw materials that are currently not utilized to their full potential. Butternut squash was one of the products that the researchers considered to be of interest because the peels are usually not used for human consumption despite providing valuable dietary fiber and micronutrients. “Hence, we thought of a way in which we could bring these nutrients back into our diet. Peels were dried and ground to extend the shelf-life and make it easier to use in different applications. We choose a tortilla as our test product, because there is a great consumer acceptability for the use of colors and vegetables,” Westphal added.
To mitigate the negative effects of the incorporation of the vegetable powder, Campden BRI trialed different drying and milling techniques to fine-tune the particle size and water absorption of the powder as well as adjusting our recipes accordingly. “We are working closely together with our members so that those who wish to make products like this available on the market can exploit the developments,” the senior bakery scientist underlined.
Campden BRI is currently trialing different types of commercial fibers at varying concentrations in a pizza base, tomato sauce and meatballs, while assessing any characteristics that may affect product quality or consumer acceptability.