Development and Characterization of a Sunflower-Seed Press-Cake-Based Fermented Food Prototype

Growing environmental and food security concerns have increased interest in circular
strategies to valorize agri-food by-products. Sunflower-seed press cake (SSPC), a proteinrich
residue from oil extraction, is largely underutilized despite its high nutritional and
functional value. This study aimed to develop a fermented plant-based food prototype
(PBFP) from SSPC using Lactococcus lactis B12 and Penicillium camemberti, evaluating microbiological
safety, chemical characteristics, and sensory acceptability. A blend containing 40%
SSPC and 60% water was autoclaved, inoculated, and ripened for 4 weeks under controlled
temperatures. Microbial counts, pH evolution, free amino acids, biogenic amines, volatile
organic compounds (VOCs), cyclopiazonic acid (CPA) content, and sensory attributes were
evaluated using cultural techniques, HPLC, HS-SPME/GC-MS, LC–ESI–MS/MS (QTRAP
4000), and sensory evaluation. L. lactis efficiently acidified the matrix (pH ≈ 4.5–4.9), ensuring
microbial food safety, with high LAB counts (~109 CFU/g) and absence of pathogens
(Listeria monocytogenes and Salmonella spp.) and hygienic markers < 2 log CFU/g (B. cereus,
E. coli, and Enterobacteriaceae). Free amino acids decreased during fermentation, and no histamine
or tyramine was detected. VOC analysis revealed diacetyl, acetoin, 2,3-butanediol,
and 1-octen-3-ol, contributing to mild dairy-like notes. CPA was detected at 0.48 ng/g, well
below levels reported in cheeses. Sensory evaluation showed no significant differences in
overall intensity between inoculated and control blends, although qualitative descriptors
indicated subtle changes in aroma and texture. These results demonstrate the feasibility
of safely producing a fermented plant-based prototype from SSPC. Future studies should
explore longer ripening times, additional microbial consortia, and strategies to enhance
texture and aroma complexity.