From Orange Juice By-Product in the Food Industry to a Functional Ingredient: Application in the Circular Economy.

In the orange juice industry, more than 50% of raw material becomes by-products that are rich in active compounds and have high nutritional content. Improved use of these by-products could represent a key strategy for a circular economy. The objective of this study was to produce a flour from orange juice by-product, characterize it, and then apply this flour to produce cookies. Orange by-product flour (OBPF) was characterized in terms of its chemical composition, dietary fiber, phenolic compounds, antioxidant potential, and hygroscopic properties. Subsequently, the effect of substituting wheat flour by OBPF in cookies was evaluated. OBPF presented a very high content of dietary fiber (73.61% dry matter (DM)), minerals (ash = 2.72% DM), and total phenolic compounds (534 ± 30 mg gallic acid equivalent (GAE)/100 g of DM). In general, the properties of cookies were not significantly influenced by using OBPF as a substitution for wheat flour. Sensorial analyses showed that cookies produced with 10% OBPF presented the higher scores. Therefore, OBPF showed interesting characteristics, suggesting its possible use in the development of fiber enriched foods such as cookies; and its production represents a key strategy for the orange juice processing industries towards the application of a circular economy in the food system.