Nutritional and Bioactive Valorization of Vegetables and Red Algae for Functional Food Innovation

Abstract In this study, a food-structured product resembling vegan seasoning cubes was developed utilizing vegetables, red algae (Gracilaria caudata and Hypnea pseudomusciformis) and their residues as bioactive, nutritional, and aromatic ingredients. The current demand for sustainable, healthy, plant-based diets highlights a market need for accessible and nutrient-rich culinary products that replace synthetic additives. The product was formulated by blending two solutions: an aqueous solution of Gracilaria (2%) and Hypnea (1%) extracts and a liquid concentrate of garlic, onion, chives, habanero pepper, parsley, and tomato (95%), obtained via 50% ethanolic extraction, combined with solid algal and vegetable residues (5%). The mixture was molded and cooled (4 °C/24 h). Fresh and freeze-dried samples were analyzed for color, antioxidant activity, rheology, chromatography, volatile compounds via GC-NOSE, and the bioaccessibility of Folin-Ciocalteu-reactive compounds and carbohydrates. The samples exhibited a neutral pH, greenish-yellow color, phenolic content ranging from 2.98 to 5.20 mg GAE/g, and an aroma profile characterized by acetaldehyde. Dissolution time in water was 0.97 min for the fresh product and 15.61 min for the freeze-dried version, due to molecular rearrangement. Bioaccessibility results demonstrated how the food matrix and processing affect nutrient release in the gastrointestinal tract. The highest Folin-Ciocalteu-reactive compound bioaccessibility for the fresh food-structured product occurred during the intestinal phase (79.5%), while the carbohydrates in the freeze-dried sample showed better bioaccessibility in the gastric phase (98.8%). This food-structured product serves a vegan ingredient with functional, practical, and sustainable characteristics, capable of enhancing the aroma, flavor, and bioactive compound content of foods.