Study On Functional Yoghurt Of Dendrobium Huoshanensis Juice

Dendrobium huoshanensis is a rarely Chinese plant with high medicinal value.Based on research,it has antioxidant,anti-fatigue,anti-tumor,immunomodulation,fall hematic fat effects,and fresh juice can effectively retain the nutritional components of Dendrobium huoshanensis.Functional yoghurt is a dairy product with physiological health function,which not only has the inherent nutritional value of general yoghurt,but also has some special functional substances or physiological active ingredients.In this paper,the effects of Dendrobium huoshanensis juice on the physiological characteristics of compound lactobacillus were studied.The yoghurt of Dendrobium huoshanensis juice was prepared and optimized.Its antioxidant and lipid-lowering abilities in vitro were explored.The changes of various indexes during storage period were also investigated,which provided theoretical basis for the development of functional yoghurt of Dendrobium huoshanensis juice.The main results of this paper are as follows:1.The effects of Dendrobium huoshanense Juice on physiological characteristics of lactobacillus.The effects of different dosages of Dendrobium huoshanensis juice on the biomass of combined lactobacillus were studied,and the optimum dosage of lactobacillus was determined.The effects of Dendrobium huoshanense juice on growth curve,utilization of reducing sugar,pH,protein and lactic acid synthesis of lactobacillus and activities of beta-galactosidase and lactate dehydrogenase were studied at the optimum dosage.The results showed that the optimum dosage of Dendrobium huoshanense juice was 6 mL/L.Under these conditions,Dendrobium huoshanense juice could significantly increase the biomass of lactobacillus,promote the utilization of reducing sugar and protein synthesis by lactobacillus,and enhance the capacity of lactic acid production.Compared with the control group,the addition of Dendrobium huoshanensis juice increased the activity of beta-galactosidase by 1.9 U/mL and lactate dehydrogenase by 38.6 U/mL.2.Process optimization of Dendrobium huoshanense juice yoghurt.Relying on the sensory evaluation score as the main reference index,titration acidity,water holding capacity and diacetyl content as the secondary indicators,the single factor experiment was carried out by selecting four factors of Dendrobium huoshanensis juice added concentration,sucrose added amount,inoculation amount of starter and fermentation time.According to the experimental results,L9(33)positive factors of Dendrobium huoshanensis juice added amount,inoculation amount of starter and fermentation time were analyzed and designed.The optimum fermentation conditions of fermented milk of Dendrobium huoshanense were obtained by cross-optimization experiment.The concentration of added juice was 7 mL/L,the amount of added sucrose was 5 g/L,the amount of inoculant was 2 g/L,and the fermentation time was 6 h.Experience has proved that the optimum fermentation conditions are reliable.The titration acidity of fermented milk prepared under this condition is 88 °T,the water holding capacity is 43.69%,and the diacetyl content is 18.22 ug/mL.3.Study on antioxidant and hypolipidemic properties of Dendrobium huoshanensis yogurt in vitro.The cholesterol-lowering ability,triglyceride-lowering ability and antioxidant activity of Dendrobium huoshanensis yoghurt in vitro were determined.Compared with ordinary fermented milk,the cholesterol-lowering ability of Dendrobium huoshanensis yoghurt in vitro was increased by 17.28%,and the triglyceride-lowering ability in vitro was increased by 12.74%.According to the results of antioxidant experiment,the DPPH free radical scavenging capacity,hydroxyl radical scavenging capacity,ABTS free radical scavenging capacity and Fe2+ chelating capacity of Dendrobium huoshanense juice yoghurt in vitro are significantly better than those of ordinary fermented milk.It is preliminarily proved that the yoghurt prepared by adding Dendrobium huoshanense juice has the function potential of reducing blood lipid and antioxidant.4.The quality changes of functional yoghurt from Dendrobium huoshanensis juice during storage.The changes of quality and functional characteristics of Dendrobium huoshanensis juice yoghurt during storage were studied.The titration acidity,diacetyl content,water holding capacity,viable bacteria number,cholesterol-lowering ability,triglyceride-lowering ability and antioxidant(hydroxyl radical)properties of the yoghurt within 0-12 days of storage were determined.It was found that the quality of Dendrobium huoshanensis juice yoghurt maintained a good level in the early storage period.Even if the quality declined in the later storage period,the quality of Dendrobium huoshanensis juice yoghurt was much higher than that of ordinary yoghurt.In terms of functional indexes,Dendrobium huoshanensis juice yoghurt had good stability in reducing blood lipid and antioxidant functions in a certain storage period.