Enhancing cooking and eating quality of semi-dried brown rice noodles through Lactobacillus fermentation and moderate lysine addition.

Abstract

Various concentrations of lysine were added to <i>Lactobacillus fermentum</i>-fermented brown rice flour to examine their effects on the sensory evaluation, color, pH, cooking quality, and texture of the resulting noodles. The potential mechanisms were explored through analyses of water distribution, thermodynamic properties, crystallinity, and microstructural observations using low-field nuclear magnetic resonance (LF-NMR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Low concentrations of lysine (1 % and 3 %) effectively mitigated sourness while maintaining a color similar to natural brown rice noodles, with minimal structural damage and good cooking quality. The 3 % lysine group received the highest sensory scores (73.3 ± 5.4), likely due to moderate lysine-mediated starch network formation and improved water retention. While, a high lysine concentration (5 %) resulted in an undesirable reddish-brown color, poor texture and cooking quality. This is likely due to the formation of rigid lysine-mediated starch structures, which made the noodles brittle.