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

Abstract

The present study aims to explore the outcome of processing methods such as fermentation; treatments using lemon juice (T1), sodium chloride (T2), lemon juice followed by sodium chloride (T3) and fermentation followed by treatment-T3 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 T1 (FMFT1), T2 (FMFT2), T3 (FMFT3), fermentation for 8-36h with 4h intervals using yoghurt as starter culture (FFMF) and fermentation (8-36h) followed by treatment T3 (FFMFT3). 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 (20h) 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 FFMFT3 (8-36h) samples were found to be lesser than the FFMF (8-36h) 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 (945cP and 664cP respectively) approximately reduced to two-third in FFMF (20h) samples and one-third for FFMFT3 samples (303cP and 286cP respectively). From the study, it is evident that the processing method of fermentation followed by treatment-T3 could be utilized in the development of low protein food supplements.