Quality and Sensory Characteristics of Fermented Milk Adding Black Carrot Extracts Fermented with Aspergillus oryzae

Abstract

In this study, we compared the organoleptic and other qualities of fermented milk containing 10 or 15% purple carrot extract that had either been previously fermented with Aspergillus oryzae or not fermented. Fermentation characteristics, pH, chromaticity, viscosity, viable cell counts, and sensory evaluations were measured. The pH and acid values did not differ between purple carrot extract fermented with Aspergillus oryzae and non-fermented extract. Viable cell counts were significantly higher in 15% purple carrot extract fermented with Aspergillus oryzae compared to the control after fermentation. Regarding characteristic changes, purple carrot extract fermented with Aspergillus oryzae group showed a lower red value but higher yellow value compared with non-fermented purple carrot extract due to heat-sterilization. Both fermented and non-fermented extract groups showed significantly increased viscosity compared to control. In the sensory evaluation, 15% purple carrot extract fermented with Aspergillus oryzae showed the highest score. In conclusion, addition of 15% purple carrot extract fermented with Aspergillus oryzae resulted in a superior fermented milk product.