COLORIMETRIC EVALUATION OF QUINOA FLOUR FERMENTED BY Monascus purpureus ENRICHED WITH MONOSODIUM GLUTAMATE AND SODIUM CHLORIDE

Natural pigments in foodstuffs are important when it comes to their choice. A good biotechnological alternative is to produce red pigmented flour by fermentation on solid substrate for use as an input in the food industry. In the present study, the colour and carbon:nitrogen ratio of M. purpureus pigmented quinoa flours supplemented with monosodium glutamate (MSG) and sodium chloride were evaluated during 14 days of fermentation. The MSG concentration was 1.0%, and the salt levels were 0.05, 0.1, 0.2 and 0.4%. Flour colour was analysed with a colourimeter (CM-5, Konica Minolta, Japan) for L*, a* and b* values. A completely randomised statistical design with n=4 was used to compare the data and the results obtained were evaluated by analysis of variance (ANOVA) with an α = 0.05 using the R software. The best values corresponded to the eighth day, with L*, a*, b* and C:N of 49.55±1.684, 19.85±1.174, 19.90±0.775 and 11.306±0.258 respectively. This research demonstrated that the pigmented flour produced by solid-state fermentation of quinoa by M. purpureus supplemented with monosodium glutamate and sodium chloride showed variations of red colour along with C:N ratio during the fermentation time, resulting in a product with good visual sensory attribute that can be used to develop new naturally pigmented products with possible functional characteristics.