Why isyoghurt putin the fridgefor storage?To minimiseany furtherfermentationCan we makeyoghurt at lowand hightemperatures?Yes, but thecultures willtake longerto growWhat are thetypical pHvalues ofmilk andyoghurt?Milk is6.8, andyoghurt is4.5How do weevaluatetheyoghurt?pH value,smell,appearance,taste, textureDescribe thereproductionof theyoghurtbacteriaBinaryfission and atypicalgrowth curveWhathappensto the pHand why?The pHdecreasesas lactose isconverted tolactic acidGiveexamples ofMRS GRENfor yoghurtproductionWhy is milkusuallyheatedbefore cultureis added?To kill anyunwantedbacteriaWhatmicroorganismsare used?LactobaccilusbulgaricusandStreptococcusthermophilusWhat abioticand abioticfactors affectyoghurtproduction?How doesheating themilk affectthe milkproteins?The milk proteinsget damaged bythe heat(denaturation)and can form afirmer coagulumWhathappens tostarter culturegrowth as thepH drops?BacterialgrowthdecreasesWhathappenedwith differentamounts ofculture?More cultureresulted in afirmer yoghurtas morebacteria werepresentHow can weproduce afirmer andmore tartyoghurt?Use morestarterculture orferment forlongerWhat type offermentationis used?Anaerobicfermentation,i.e., in theabsence ofoxygenWrite thetypicalprocess forproducingyoghurtHeat milk to killbacteria, cool milkto ~40C, addstarter culture,incubate for 4-8hours, pack andstore at 5CWhat isyoghurt?AfermentedmilkproductWhathappenedwith differentmilks?Soy milkmade a weakyoghurt whileoat milk didnot workWrite thereactionfor energyproductionLactose(sugar) -->Lactic acid+ energyWhat wasteproduct isexcreted by thebacteria duringfermentation?LacticacidWhy isyoghurt putin the fridgefor storage?To minimiseany furtherfermentationCan we makeyoghurt at lowand hightemperatures?Yes, but thecultures willtake longerto growWhat are thetypical pHvalues ofmilk andyoghurt?Milk is6.8, andyoghurt is4.5How do weevaluatetheyoghurt?pH value,smell,appearance,taste, textureDescribe thereproductionof theyoghurtbacteriaBinaryfission and atypicalgrowth curveWhathappensto the pHand why?The pHdecreasesas lactose isconverted tolactic acidGiveexamples ofMRS GRENfor yoghurtproductionWhy is milkusuallyheatedbefore cultureis added?To kill anyunwantedbacteriaWhatmicroorganismsare used?LactobaccilusbulgaricusandStreptococcusthermophilusWhat abioticand abioticfactors affectyoghurtproduction?How doesheating themilk affectthe milkproteins?The milk proteinsget damaged bythe heat(denaturation)and can form afirmer coagulumWhathappens tostarter culturegrowth as thepH drops?BacterialgrowthdecreasesWhathappenedwith differentamounts ofculture?More cultureresulted in afirmer yoghurtas morebacteria werepresentHow can weproduce afirmer andmore tartyoghurt?Use morestarterculture orferment forlongerWhat type offermentationis used?Anaerobicfermentation,i.e., in theabsence ofoxygenWrite thetypicalprocess forproducingyoghurtHeat milk to killbacteria, cool milkto ~40C, addstarter culture,incubate for 4-8hours, pack andstore at 5CWhat isyoghurt?AfermentedmilkproductWhathappenedwith differentmilks?Soy milkmade a weakyoghurt whileoat milk didnot workWrite thereactionfor energyproductionLactose(sugar) -->Lactic acid+ energyWhat wasteproduct isexcreted by thebacteria duringfermentation?Lacticacid

Yoghurt Bingo - Call List

(Print) Use this randomly generated list as your call list when playing the game. There is no need to say the BINGO column name. Place some kind of mark (like an X, a checkmark, a dot, tally mark, etc) on each cell as you announce it, to keep track. You can also cut out each item, place them in a bag and pull words from the bag.


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  1. To minimise any further fermentation
    Why is yoghurt put in the fridge for storage?
  2. Yes, but the cultures will take longer to grow
    Can we make yoghurt at low and high temperatures?
  3. Milk is 6.8, and yoghurt is 4.5
    What are the typical pH values of milk and yoghurt?
  4. pH value, smell, appearance, taste, texture
    How do we evaluate the yoghurt?
  5. Binary fission and a typical growth curve
    Describe the reproduction of the yoghurt bacteria
  6. The pH decreases as lactose is converted to lactic acid
    What happens to the pH and why?
  7. Give examples of MRS GREN for yoghurt production
  8. To kill any unwanted bacteria
    Why is milk usually heated before culture is added?
  9. Lactobaccilus bulgaricus and Streptococcus thermophilus
    What microorganisms are used?
  10. What abiotic and abiotic factors affect yoghurt production?
  11. The milk proteins get damaged by the heat (denaturation) and can form a firmer coagulum
    How does heating the milk affect the milk proteins?
  12. Bacterial growth decreases
    What happens to starter culture growth as the pH drops?
  13. More culture resulted in a firmer yoghurt as more bacteria were present
    What happened with different amounts of culture?
  14. Use more starter culture or ferment for longer
    How can we produce a firmer and more tart yoghurt?
  15. Anaerobic fermentation, i.e., in the absence of oxygen
    What type of fermentation is used?
  16. Heat milk to kill bacteria, cool milk to ~40C, add starter culture, incubate for 4-8 hours, pack and store at 5C
    Write the typical process for producing yoghurt
  17. A fermented milk product
    What is yoghurt?
  18. Soy milk made a weak yoghurt while oat milk did not work
    What happened with different milks?
  19. Lactose (sugar) --> Lactic acid + energy
    Write the reaction for energy production
  20. Lactic acid
    What waste product is excreted by the bacteria during fermentation?