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Chinese yam is rich of nutrients.After fermentation with lactic acid bacteria, fat ball got smaller, lower fatty acid and essential fatty acid content increased;Chinese yam will be more conducive to digestion and absorption by the human body.At the same time, Chinese yam contains unsaturated fatty acids, which can reduce the cholesterol, to prevent deposition in the vascular wall, so it has positive effect on the prevention of hypertension, cardiovascular disease and cancer.Yam yogurt has strong antimicrobial activity, which can inhibit the growth of harmful bacteria, make the beneficial bacterium predominate, and these beneficial bacteria can produce organic acid, antibiotics and other material, and synthesize B vitamins,which can promote the intestinal health.In addition, yam that contains no lactose can relieve the situation of oriental lactose intolerance effectively.In this paper, we used the fresh milk and yam juice as main raw materials, to study yam yogurt and color protection methods with single factor and orthogonal tests.The results showed that: yam juice being blanched at 95 ℃ for 15 min, using 0.3% citric acid and 0.4% ascorbic acid for joint color protecting, and adding sugar, inoculated with Lactobacillus burglarious and Streptococcus thermopiles as inoculant after sterilization, fermentation parameters were set with L9 (34) orthogonal test.The optimum combination of ingredients was: 7% yam juice and 6% sucrose addition.Inoculation with 4% inoculant, the mixed cultures were fermented at 42 ℃ for 6 h, yam yogurt was developed, which was a new kind of lactic acid bacteria fermented yogurt with yam rich flavor, and integrated with the health functions of yam and yogurt.