Fennel ( Foeniculum vulgare Mill.) by-products are rich in bioactive compounds with antioxidant and antimicrobial properties, yet their use in food products is limited. This study explored the partial incorporation (20%) of fennel residues into traditional Spanish Hojuelas manchegas using dehydrated flour (DW), freeze-dried flour (LW) to replace refined wheat flour and liquid extract from fennel residues (EW) to replace white wine. Physicochemical, nutritional, total polyphenols, (TPC) and antioxidant activity (AA) were assessed. A sensory evaluation was carried out with 150 untrained participants, assesing expected and actual liking, willingness to pay (WTP), and food neophobia. Reformulated wafers showed increased hardness after seven days, indicating structural consolidation. DW and LW samples significantly increased crude fiber (up to 303% vs. control), and DW also showed higher sugar content. Flours from fennel demonstrated high total phenolic content, identifying the residue as a potent source of bioactive compounds. The inclusion in a bakery matrix in small percentages and the frying process reduced the TPC and antioxidant activity (AA), but the fortified samples with fennel flours maintained a significant higher AA than the control, even after seven days of storage. Interestingly, the fennel extract, despite its low TPC, exhibited high AA, suggesting the presence of potent non-phenolic antioxidants. Sensory analysis showed that all fortified products were well-accepted. A significant interaction was observed between the Moment x Product, particularly for taste and overall liking, which improved after tasting for the functional formulations (DW, LW, and EW). Furthermore, the Willingness to Pay (WTP) for LW and EW increased after tasting, emphasizing that consumers assign a higher monetary value to perceived functional benefits once the product is experienced. The study provides a framework to assess how different forms of fennel by-products affect technological, nutritional, functional, and sensory properties, highlighting their potential as value-added ingredients in sustainable bakery products. • Fennel by-products increase antioxidant activity in confectionary. • Freeze-dried fennel flour improves the nutritional profile. • Reformulated wafers show higher hardness after seven days. • Consumers show a high willingness to pay for fennel wafers • Fennel residues are a sustainable alternative for the bakery industry.
Martínez et al. (Sun,) studied this question.