Abstract:

Main materials, namely kudzu roots from the west of Hunan province and skimmed milk powder, were processed into a yoghurt beverage with the additions of adjuncts including high fructose corn syrup, xanthan and sodium carboxymethyl cellulose. Some crucial process conditions for yoghurt making were studied. The results showed that the optimum compound color fixatives contributing to the maintenance of the milk-white color of kudzu root juice was composed of 0.1% citric acid and 0.1% VC. The optimum process for yoghurt making consisted of the following steps: preparation of reconstructed milk by thoroughly dispersing skimmed milk powder in water (1:8, m/V), blending of reconstructed milk and kudzu root juice (2:5, V/V), addition of 10% high fructose corn syrup, 0.05% xanthan and 0.1% sodium carboxymethyl cellulose to the blend, 95 ℃ heating for 10 min for sterilization and fermentation with Lactobacillus bulgaria/Streptococcus thermophilus mixture (1:1) at 43 ℃ for 5 h, and the product processed through these steps exhibited a nice sweet-and-sour balance and a full-bodied flavor and were rich in nutrients.

Key words: kudzu roots, yoghurt, Lactobacillus, processing process