Extraction of peixinho proteins (Stachys byzantina) and evaluation of its techno-functional properties

Abstract

Peixinho (Stachys byzantina) is a leaf native to Brazil, known for its hairy structure and flavor similar to fish, due to the presence of oil in its composition. This leaf has attracted attention due to its high percentage of protein, when compared to other common vegetable sources, such as spinach and beans. However, it is noteworthy that little is known about the structural characteristics and techno-functional properties of this protein. The structural properties are directly correlated to the protein obtaining process: technology, solvents, and forms of recovery used during the extraction. Thus, the present work aims to optimize a process of extracting proteins from Stachys byzantina leaves and to correlate structural changes with their techno-functional properties, for application in the food industry. The project will consist of three steps: a) optimize the extraction and recovery of Stachys byzantina proteins; b) structural evaluation of the obtained proteins and c) study their techno-functional properties. First, an experimental design for protein extraction will be carried out, evaluating pH and extraction temperature. Furthermore, two forms of protein recovery, isoelectric and saline precipitation, will be tested. Then, the best results obtained will be selected for the study of protein structural analysis (particle size, SDS-PAGE, free sulfhydryl groups, fluorescence, and secondary structure analysis) and techno-functional properties (solubility, water and oil holding capacity, and emulsifying capacity). As a final result, it is expected to obtain vegetable proteins with interesting techno-functional properties for application in the food industry.(AU)