The Evaluation of Amino Acid Profiles in Gluten-Free Mini Sponge Cakes Fortified with Broccoli By-Product

Many gluten-free products are deficient in amino acids, especially in essential amino acids (EAA). Therefore, the incorporation of additives rich in free amino acids (FAA) into gluten-free products can be a promising strategy to alleviate certain symptoms of celiac disease associated with EAA deficiencies. This study aimed to evaluate the effect of the incorporation of broccoli leaf powder (BLP) into gluten-free mini sponge cakes (GFS) on the profile of FFA. BLP replaced an equivalent amount (2.5%, 5%, 7.5%; w/w) of corn and potato starches in GFS formulation, resulting in B1-B3 formulations. The first step was the selection of the most efficient method for extraction of FAA. Extraction based on 50% methanol (method 1) was compared to extraction by 25% of acetonitrile in 0.1 M hydrochloric acid (method 2). In total, 26 and 14 FAA were found in BLP after extraction using methods 1 and 2, respectively. Moreover, considering the total content of FAA, method 1 was more efficient, reaching a 14-fold higher concentration of FFA in BLP compared to method 2. The incorporation of BLP resulted in a significant increase in FAA, irrespective of the applied extraction method. The total concentrations of NEAA and EAA increased significantly in B3 compared to control GFS. In summary, this study showed that 50% methanol was more efficient for the extraction of FFA from plant and bakery matrices. Moreover, BLP was found as a good source of FFA, including EAA, and the obtained experimental GFS could be considered a promising product for individuals on a gluten-free diet.