title: Effect of bacteria proportion on the fermentation of goat yoghurt with probiotic culture.
abstract: BACKGROUND
  Goat milk production in Shaanxi province is dominant in China, but the product is mainly infant formula and adult milk powder; product homogeneity is serious and has no goat yoghurt with probiotic culture.
  
  
  METHODS
  The effect of bacteria proportion (1:3:1, 1:2:1, 1:1:1, 2:1:1, 3:1:1) on pH, acidity, and viable counts and sensory evaluation of goat milk fermented by probiotics including L. acidophilus, B. bifidum  or L. casei besides, S. thermophilus and L. bulgaricus for developing AB-goat yoghurt and BC-goat yoghurt was investigated.
  
  
  RESULTS
  The optimum bacteria proportion of L. acidophilus : B. bifidum : S. thermophilus and L. bulgaricus for AB-goat yoghurt and B. bifidum : L. casei : S. thermophilus and L. bulgaricus for BC-goat yoghurt were both 2:1:1. The pH, acidity, the viable counts of L. acidophilus and B. bifidum, the total viable counts were respectively 4.60, 7.73 (g/L), 3.50×107 cfu/mL, 3.40×107 cfu/mL and 2.30×109 cfu/mL in AB-goat yoghurt. The pH, acidity, the viable counts of B. bifidum and L. casei, the total viable counts were respectively  4.61, 8.16 (g/L), 7.60×107 cfu/mL, 5.60×107 cfu/mL and 2.04×109 cfu/mL in BC-goat yoghurt.
  
  
  CONCLUSIONS
  The bacteria proportion had a significant effect on fermentation of AB- and BC-goat yoghurt, the results are beneficial for developing AB-goat yoghurt and BC-goat yoghurt.
authors.affiliation: School of Food and Biological Engineering, Shaanxi University of Science and Technology Xi&#;an, China.
authors.forename: Guowei
authors.initials: G
authors.lastname: Shu
authors.affiliation: School of Food and Biological Engineering, Shaanxi University of Science and Technology Xi&#;an, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Wang
authors.affiliation: Xinxiang Institute for Food and Drug Control, Henan Province Xinxiang, China.
authors.forename: Zikun
authors.initials: Z
authors.lastname: Chen
authors.affiliation: School of Food and Biological Engineering, Shaanxi University of Science and Technology Xi&#;an, China.
authors.forename: He
authors.initials: H
authors.lastname: Chen
authors.affiliation: School of Food and Biological Engineering, Shaanxi University of Science and Technology Xi&#;an, China.
authors.forename: Changfeng
authors.initials: C
authors.lastname: Wang
authors.affiliation: Shangqiu Entry-Exit Inspection and Quarantine Bureau, Henan Province Shangqiu, China.
authors.forename: Yaning
authors.initials: Y
authors.lastname: Ma
mesh_terms: D000818:Animals; D058491:Bacterial Load; D000069985:Bifidobacterium bifidum / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D055598:Chemical Phenomena; D002681:China; D003116:Color; D003612:Dairying; D005285:Fermentation; D063427:Food Quality; D006041:Goats; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007779:Lactobacillus acidophilus / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D007780:Lacticaseibacillus casei / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D048668:Lactobacillus delbrueckii / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D055595:Mechanical Phenomena; D050296:Microbial Viability; D009812:Odorants; D012677:Sensation; D048249:Streptococcus thermophilus / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D013649:Taste; D015014:Yogurt / Q000032:analysis / Q000382:microbiology*
keywords: B. bifidum; L. acidophilus; L. casei; bacteria proportion; goat milk; yoghurt