SpiruPower® INCORPORATION INTO VEGAN COCOA CAKE: EFFECTS ON FUNCTIONAL PROPERTIES

SpiruPower^® is the residual biomass obtained from Spirulina processing and is an ingredient registered by our research group that has been incorporated into different food formulations for nutritional and bioactive enrichment as a non-animal protein source. Incorporating Spirulina, and consequently SpiruPower^® (SPW), into food products may be a promising strategy for improving their nutritional value. Therefore, this study aimed to develop two wheat flour-based vegan cocoa cake formulations, with and without SpiruPower^® incorporation, and to evaluate its effects on proximate composition, antioxidant activity (DPPH and FRAP, expressed as µM TE/g), total phenolic content (mg GAE/100 g of sample), and protein digestibility using an in vitro digestion assay. Analyses were performed in triplicate, and differences between samples were assessed using Student’s t-test at a 95% confidence level (p < 0.05) using Jamovi software. The formulations exhibited significantly different nutritional profiles. The SpiruPower^®-containing formulation showed higher values for ash, lipids, and proteins, corresponding to 2.73 ± 0.02, 8.34 ± 0.14, and 5.87 ± 0.23 g/100 g, respectively. As expected, carbohydrate content decreased proportionally, with the control formulation showing the highest value (50.72 ± 0.67 g/100 g), compared with 47.21 ± 0.87 g/100 g for the SPW formulation. Both cake formulations exhibited antioxidant activity regardless of SpiruPower^® incorporation; however, its addition significantly increased DPPH radical scavenging activity and total phenolic content, reaching 3.45 ± 0.07 µM TE/g and 0.67 ± 0.03 mg GAE/100 g, respectively. In contrast, FRAP antioxidant activity showed no significant difference. After in vitro digestion, both formulations showed significant increases in antioxidant activity, ranging from 1.21- to 4.27-fold in the DPPH and FRAP assays, along with increased total phenolic content. Protein digestibility did not differ significantly between formulations, reaching 99.09 ± 0.12% for the control and 99.13 ± 0.06% for the SPW formulation. These values are nutritionally relevant and notably high for formulations containing a non-animal protein source. Overall, the results indicate that SpiruPower^® has potential as a partial wheat flour substitute from a nutritional perspective, increasing protein and phenolic contents and antioxidant activity without compromising protein digestibility. These findings reinforce SpiruPower^®'s potential as a food ingredient and non-animal protein source.

Acknowledgments: This study was financed, in part, by the São Paulo Research Foundation (FAPESP), Brazil, process n° 2024/19218-0 and 2023/00857-0. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001, and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) grant number 405238/2025-8, and A.R.C.B (PQ 305518/2024-0) acknowledges the research productivity fellowship from CNPq.