Brewer's spent grains as a functional ingredient in plant-based biscuits for a more sustainable chain

Brewing involves the creation of many by-products, among which brewer’s spent grain (BSG) is the one which is wasted the most, albeit having a great nutritional potential. Indeed, it is especially rich in fiber and proteins, as well as in polyphenols. From a perspective of circular economy, therefore, it appears evident how this raw material, characterized by a low price, could be employed to add value to several foodstuff. This study deals with exploring the potential use of brewer’s spent grain as a functional ingredient for plant-based digestive type biscuits. In detail, the amount of whole wheat flour present in the original recipe has been substituted by various percentages of brewer’s spent grains (25%, 50%, 75%, and 100%). Several physicochemical parameters, as well as sensorial acceptability, have been evaluated in order to define the production specifics of each batch and to determine which one was the most appealing for the final consumer. The substitution of BSG resulted to be inversely related to spread ratio and L* color coordinate. On the other hand, weight loss, humidity levels and force tend to increase when more by-product is added to the batch. Furthermore, results showed that the replacement of the whole wheat flour with BSG is linked to a higher polyphenolic content along with a higher antioxidant activity. Moreover, a value proposition map and business model canvas have been filled in for a potential business based on these plant-based biscuits, taking into consideration the concept of circular economy.