Study On Chemical And Microbiological Compositions And Identification Of Lactic Acid Bacteria From Natural Fermented Goat Milk In Qinghai

Chemical and microbiological compositions of 11 samples of natural fermented goat milk in Qinghai province were determined. The average contents of fat, protein, total solids and ash were 3.69±1.51, 5.75±0.87, 11.35±1.59 and 0.95±0.05g/100mL respectively, lactose was 1.92±0.35 g/100g. On average, pH was 3.9, titratableacidity was 194.9±19.6°T, temperature was 13.8℃. The average contents of VC, VB1, VB2, VB6, lactic acid, acetic acid, citric acid and ethanol were 1.359±0.79g/100g, 0.935±0.729μg/g, 8.474±2.856μg/g, 0.638±0.455μg/g, 1.379±0.294g/ 100g, 0.010±0.017 g/100g, 0.217±0.053 g/100g and 2.102±1.786g/L. The average contents of Ca, P, K, Mg, Na, Fe, Zn and S were 2063.81±260.87mg/kg,1629.40±160.37mg/kg,1776.31±251.21mg/kg,194.19±24.48mg/kg,371.37±55.33mg/kg,2.46±1.11 mg/kg,4.47±0.85 mg/kg,601.25±67.18 mg/kg,the contents of Mn and Cu were blow the detection limit. The counts of lactic acid bacteria were 2.49×108～2.98×109cfu/mL, the counts of yeast were 2.60×106～1.63×108cfu/mL.33 strains isolated from these samples belonged to Lactic acid bacteria . Among of 33 strains 7 were Lb. delbrueckii subsp. delbrueckii, 4 were Lb. dellbrueckii subsp. bulgaricus, 3 were Lb. acidophilus, 1 was Lb. coryniformis subsp. coryniformis, 10 were S. thermophilus, 5 were Ped. acidilactici and 1 for each of the Enterococcus faecalis,Enterococcus avium and Leu. mesenteroides subsp. mesenteroides respectively. The major lactic acid bacteria were S. thermophilus and Lb. delbrueckii subsp. delbrueckii.