Abstract: This paper studied how fermentation time and temperature and initial pH affected the conversion ratio of reducing sugar in honey yoghurt. Single factor and orthogonal test design methods were applied to determine the optimum fermentation parameters i.e. fermentation time 4 h, fermentation temperature 42 ℃ and initial pH 6.8 with the essential constituents 8% honey, 10% defatted milky powder and 2% mixed inoculation in the proportion of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus 1:1. In respectively, the ratio of reducing sugar conversion is 36.18%.

Key words: honey, acidophilus milk, conversion ratio of reducing sugar, fermentation technology