The Study On Probiotic Milk Tablets

In recent years there have appeared some reports on probiotic milktablet, it has both the nutritional value of milk and special physiologicalfunctions of the probiotic, not only nutrition but also health, probioticmilk tablet overcomes the shortcomings of liquid probiotic dairystorage difficult, short shelf life and efficacy difficult to exert.According to the currently literature, the probiotic milk tablets are takemilk powder as main raw material, made by adding probiotic powderand other accessories, such methods highly dependent probiotic powderand bacteria, as probiotic powder obtain from freeze-drying or spraydrying operation, it is complex, expensive equipment, operatingtechnical requirements, high cost, so the application is limited. Inaddition, the bacterial activity reduce, due to the powder’s secondaryprocessing.This experiment take Lactobacillus acidophilus as the main strain,and mainly through probiotics high cell density fermentation andcentrifuged makes probiotics concentration to obtain high bacteriaprobiotics levitation liquid, and then get directly with high bacteriastrong probiotics levitation liquid as the glue soft granulation system,mixing with milk powder, then sieving and granulation, add variousaccessories in the tablets. This method is a simple process technology,low demand of equipment, low cost, correspond the factory equipmentindustrialization. This research probiotic milk tablets can directlyedible also can manufacture yoghourt. The results are as follows:Firstly, high density culture solution of probiotics was achieved byhigh density cultivation. Chose the material enrichment effect of lacticacid bacteria to prepare high-density medium for Lactobacillusacidophilus: selecting the different concentration ratio of5%,7%,9%whey medium, different concentration ratio of2%,3%,4%corn steepliquor medium and the concentration ratio of0.5%,1%,1.5%yeast extract medium culture to proced single factor experiment, the resultsshowed that Lactobacillus acidophilus can grow well in the three media.In different proportions, the growth state of Lactobacillus acidophilusin the7%whey powder,3%corn syrup and1%yeast extraction is thebest, reach108cfu/mL at highest. Determined high-density medium ofLactobacillus acidophilus by orthogonal test, and ultimately determinethe high-density medium ratio:7g whey powder,3mL corn syrup,1gyeast extraction,100mL pure water. When Lactobacillus acidophiluswas fostered in the medium at41℃for18h, the number of bacteriacould reached2.74×109cfu/mL at the highest.Secondly, access to high bacteria concentration of bacterialsuspension by centrifugation re-suspension process, this study selected4500r/min,6000r/min,7000r/min different centrifugation speeds,4℃,15℃,25℃centrifuge temperature and10min,20min,30mincentrifugation harvested time execute the orthogonal experimentanalysis.The culture solution of probiotics, cultivated in the enrichedmedium, was centrifuged at the speed of6000r/min for10min at4℃.Remove the supernatant to obtain bacterial, in the study, put skim milkoscillation for one minute at different proportions:1:3,1:5,1:7,1:10,1:12,1:14compared with uncentrifuged the initial culture of bacteria,bacteria weight suspended by microscopic examination to ensure thatthe bacterial suspension fully uniform, and ultimately determine theoptimal suspension ratio of1:10. Probiotics bacteria dense suspensionafter resuspension, the bacterial suspension obtained at41℃underanaerobic incubation for1⁵hours, measured the number of viable cells,acidity and bacterial incubation heat resistance. The experimentsshowed that the total number of viable cells showing a downward trend,the number of viable cells reached a peak at2,3,4hours, at5hoursthere is a clear downward trend, the highest number of viable cells canbe achieved as10¹²cfu/mL. After heat-resisting, the number of viablecells showed increasing trend in the first, the longer the incubation time,the higher the stability of the bacteria. Description of the preparation ofhigh concentrations of bacteria in the use of high-speed refrigerated centrifuge, centrifugal finished hatching is a necessary step. The acidityof high concentration of bacteria suspension tend a rapid increase after2hours, affecting the final taste of the milk tablets. In generally, selectthe incubation time of2hours, the number of viable cells is largest,stronger stability and vigor also increased significantly. When theprobiotic suspension of bacteria to restore maximum vitality state,resulting in high bacteria concentrated, high vigor. Bacterial counts inthe detection, maximum concentration is up to1012cfu/mL by85℃heattreatment for10min can up to10⁸cfu/mL.Thirdly, the preparation of probiotic milk tablets was studied. Highdensity suspension of probiotics was directly used as adhesives toprepare the soft materials, and it was pressed with milk powder. It wasconfirmed that4g milk powder was added to1mL suspension ofbacteria, erythritol was added as sweetener, magnesium stearate aslubricant, CMC-Na as adhesive, and inulin as protective agent. Finally,the optimal technology of preparing probiotic milk tablets was asfollows:25mL suspension of bacteria，100g skimmed milk powder，2%magnesium stearate，3%CMC-Na，1.4¹.6%erythritol，3%inulin. Thesuspension of bacteria was mixed with skimmed milk powder, screenedby20mesh and granulated..At last, the number of viable cells in themilk tablets could reach more than2.5×10¹¹cfu/g.Finally, the quality of probiotic milk tablets was checked. Atpresent, probiotics milk tablets have not explicit national standard, andeach standard of enterprises was different from each other. According tothe method of Pharmacopoeia, the appearance, hardness, friability andthe number of viable cells of the probiotic milk tablets were examined.The results showed that appearance, hardness and friability were allmeet the provisions. Physical and chemical indexes were tested referredto GB5009, and the results were qualified. Results about the livebacterial count of the tablets were as follows： As to the probiotic milktablets made by high density cultivating method, the initial number ofthe probiotic was about7.6×10⁹cfu/g. After preserving for10months,the number of the probiotic turned to5.6×10⁶cfu/g. As to the probiotic milk tablets made by the means of centrifugation and suspension, theinitial number of the probiotic was about2.7×10¹¹cfu/g. Afterpreserving for10months, the number of the probiotic turned to4.1×10⁷cfu/g.