Efficacy of fermentation parameters on protein quality and microstructural properties of processed finger millet flour

The present study aims to explore the outcome of processing methods such as fermentation; treatments using lemon juice (T 1 ), sodium chloride (T 2 ), lemon juice followed by sodium chloride (T 3 ) and fermentation followed by treatment-T 3 on the quality characteristics of processed finger millet flour to develop a specialized low protein food supplement for a protein-related inborn error of metabolic disorders. The clean dirt-free finger millet grains were made into slurry subjected to treatment T 1 (FMFT 1 ), T 2 (FMFT 2 ), T 3 (FMFT 3 ), fermentation for 8-36 h with 4 h intervals using yoghurt as starter culture (FFMF) and fermentation (8-36 h) followed by treatment T 3 (FFMFT 3 ). The acidity of the finger millet slurry significantly increased with the increase in fermentation time when compared to control. The IVPD was found to be 89% in FFMF (20 h) sample which was significantly higher than the IVPD of control sample flour (27%). However, the crude protein content (%), the protein fractions and the IVPD of FFMFT 3 (8-36 h) samples were found to be lesser than the FFMF (8-36 h) samples. The findings were further ensured by the results of scanning electron microscopic images and FT-IR spectra which showed the morphological and chemical modifications caused by the processing methods. The setback and breakdown viscosity of control (945 cP and 664 cP respectively) approximately reduced to two-third in FFMF (20 h) samples and one-third for FFMFT 3 samples (303 cP and 286 cP respectively). From the study, it is evident that the processing method of fermentation followed by treatment-T 3 could be utilized in the development of low protein food supplements.