lactic agent selection

1 choice of chelating agent. During the fermentation process, the pH value decreased to less isoelectric point of casein, the calcium ion in free state, the bridging effect. Can cause precipitation of casein, affecting the stability of the beverage, so need to choose an appropriate chelating agent chelating total Ca2 + Ca2 + chelator used with phosphate and lactic acid powder, the screening process was carried out Take skimmed milk 25mL, then adding a chelating agent solution appropriately diluted after mixing be adjusted with citric acid, flocculation occurs when the system tilting stop adding acid, NaOH solution titrated with 0.1 standard value of its acidity, acidity higher values ??indicating Ca2 + chelator chelating ability is stronger, the results show that, NaH2PO4 strongest chelating ability, so choose NaH2PO4 as a chelating agent. (2) the choice of stabilizer. Since lactic acid bacteria beverage stabilizer on taste and stability of very large, so the present process commonly used stabilizer (PGA, acid CMC, reducing glue, sodium alginate, etc.) were screened for the stabilizer agent and three times zinc lactate, Select various stabilizers were 0.4% mass fraction, dissolved with warm water added to milk, the comparison by the line selection, the results show that, PGA stabilizing effect on the fermented milk is best, but due to high cost, and therefore need to be considered other stabilizers composite applicable, restore the CMC glue and acid stabilizing effect little difference, in addition to the stabilizing effect of sodium alginate is poor, so you can consider choosing PGA and acid CMC and restore gum as a composite stabilizer.