EFFECT OF BACTERIAL CULTURE, FERMENTATION TIME AND INOCULUM SIZE ON QUALITY OF EMASI PRODUCED IN THE KINGDOM OF ESWATINI.

Abstract

Emasi is a dairy product produced by fermenting milk at room temperature. Traditionally fermented milk may have low hygienic quality hence it is important to produce emasi that resembles the traditionally produced product with improved hygienic qualities. The aim of the study was to determine the effect of bacterial culture, fermentation time and inoculum size on sensory attributes and physiochemical properties of emasi. Commercial mesophilic lactic acid culture,isolated Leuconostoc mesenteroides ssp. mesenteroides/ dextranicum and Lactococcus lactis ssp. lactis, mixed culture from emasi sorghum meal and mixed culture from traditional emasi were used for fermentation for 12, 18 and 24 hours; at 2.5%, 5% and 10% (v/v) inoculum size. The samples were examined for physiochemical properties and sensory attributes. The effect of type of culture on physiochemical properties was significantly different (P < 0.05) between the sources. Titratable acid ranged from 0.96% to 1.22%, whilst viscosity ranged from 3551cP to 2222cP. The isolated bacterial strains had the lowest syneresis percentage whilst mixed culture from emasi sorghum meal had the highest. It ranged from 48.6% to 56.5%. The pH ranged from 4.26 to 3.87. The overall acceptability by the panellists showed that they preferred the commercial mesophilic lactic acid bacteria and isolated bacterial strains compared to the mixed culture of traditional emasi and emasi from sorghum meal produced emasi. Fermentation time and inoculum size did not have any significant effect on the physiochemical properties and sensory attributes of emasi. More studies need to be done on isolating bacterial strains that will produce characteristics that resemble the traditional product emasi.