Cultured Dairy Product

1. Microbiology andTechnology of Fermented Foods
Graduate Program in Biotechnology
School of Life Sciences andTechnology

2. Type Cultures used Examples
I Mesophilic lactococci and
leuconostoc strains
Buttermilk, Cultured cream, Sour
milk, Scandinavian buttermilks,
Taetmjolk, Kjaddermilk, Viili,
Smetanka, Aerin
II Lactobacillus strains Bulgarian buttermilk,Yakult
III Thermophilic streptococci and
lactobacilli
Yoghurt, Prostokvasha, Ryazhenka,
Varenets, Skyr, Ayran, Gioddu, Tan,
Tulum,Torba, Kurut, Gruzovina,
Leben, Dahi, Lassi Snezhanka
IV Mixed populations of different
lactic acid bacteria and yeasts;
sometimes micrococci and acetic
bacteria
Kefir, Koumys, Brano, Hooslanka,
Zhentitsa, Maconi

3. Viili is a yogurt-like mesophilic fermented milk
originated in Finland. Lactic acid bacteria (LAB) used
in its production produce exopolysaccharides which
gives viili a ropey, gelatinous consistency and a
pleasantly mild taste resulting from lactic acid
Viili also has a surface-growing yeast-like fungus
Geotrichum candidum present in milk, which forms a
velvet-like surface.
Most traditional viili cultures also contain yeast
strains such as Kluveromyces marxianus and Pichia
fermentans.
The LAB identified in viili including Lactococcus lactis
subsp. cremoris (produce a phosphate-containing
heteropolysaccharide, named viilian), Lactococcus
lactis subsp. lactis biovar. diacetylactis, Leuconostoc
mesenteroides subsp. cremoris.

4. Yakult, is a probiotic dairy product made by fermenting a mixture of
skimmed milk with a special strain of the bacterium Lactobacillus casei
Shirota
• Sugar (sucrose, dextrose)
• Skimmed milk powder
• Natural flavours
• Live Lactobacillus casei Shirota strain, 6.5 billion
per 65 mL bottle (concentration of 108 CFU/mL)
• Water
StandardYakult
contains:

5. Lassi is a traditional yogurt-based drink from Bangladesh, India and Pakistan.
Lassi is a blend of yogurt, water, spices and sometimes, fruit.Traditional lassi is
a savoury drink, sometimes flavoured with ground and roasted cumin. Sweet
lassi, however, contains sugar or fruits, instead of spices.
Indian-style yogurt has over a billion per gram of L. acidophilus, Bifidobacterium,
Propionibacterium freudenreichii, and L.casei.

6. Kumis is a fermented dairy product traditionally made from
mare's milk.The drink remains important to the peoples of the
CentralAsian steppes, of Huno-Bulgar,Turkic and Mongol
origin: Kazakhs, Bashkirs, Kalmyks, Kyrgyz, Mongols, and
Yakuts.
Kumis is a dairy product similar to kefir, but is produced from a
liquid starter culture, in contrast to the solid kefir "grains".
Mare's milk contains more sugars than cow's or goat's milk, so
kumis has a higher, though still mild, alcohol content compared
to kefir.
Industrial-scale production generally uses cow's milk, which is
richer in fat and protein, but lower in lactose than the milk from
a horse. Before fermentation, the cow's milk is fortified in one
of several ways. Sucrose may be added to allow a comparable
fermentation.

7. Product Organisms
Yoghurt Streptococcus thermophilus
Lactobacillus delbruecki subsp. bulgaricus
Buttermilk Lactobacillus lactis subsp. lactic
Lactobacillus lactis subsp. cremoris
Leuconostoc lactis
Leuconostoc mesenteroides subsp. dextranicum
Sour Cream Lactobacillus lactis subsp. lactic
Lactobacillus lactis subsp. cremoris
Leuconostoc lactis
Leuconostoc mesenteroides subsp. dextranicum
Kefir Lactobacillus kefiri
Lactobacillus kefiranofaciens
Saccharomyces kefiri

8. Organism Supplier or source
Lactobacillus acidophillus NCFM Danisco, Madison, USA
Lactobacillus acidophilus SBT-2062 Snow Brand Milk Products, Japan
Lactobacillus casei strain Shirota Yakult, Japan
Lactobacillus casei F19 Arla Foods, Denmark
Lactobacillus fermentum RC-14 Urex Biotech, Canada
Lactobacillus johnsonii KA1 (NCC533) Nestle, Switzerland
Lactobacillus plantarum 299v Probi, Sweden
Lactobacillus reuteri SD2112 (ATCC55730) Biogaia, Sweden
Lactobacillus rhamnosus GG (ATCC53103) Valio Ltd., Finland
Lactobacillus salivarius UCC1 118 University College, Ireland
Bifidobacterium longum BB536 Morinaga Milk Industry, Japan
Bifidobacterium breve strainYakult Yakult,Tokyo, Japan

9. Desired properties of yoghurt cultures
• Stable during frozen or lyophilized storage
• Viable and active after thawing or rehydration
• Resistant to bacteriophage
• Able to produce the “right” consistency or body, i.e.,
ropiness
• Produces good yoghurt flavor, without excess acid or
acetaldehyde
• No syneresis
• No acidity produced during storage (over-acidification)

10. The dry matter content
• The higher the dry matter (solids non
milk fat – SNF min 12%) the firmer
the yoghurt will be
• Normal methods used to standardize
the dry matter content are:
• Evaporation
• Addition of skimmed milk powder
• Addition of milk concentrate
• Addition of the ultra filtration
retentate from skimmed milk
• Addition of whey powder
• Addition of sodium caseinate
powder
• Addition of sugar and sweeteners
Stabilisers
• Help to prevent syneresis
• A traditional produced natural yogurt
will require no stabilizers to produce a
firm, fine gel
• Commercially produced yogurt that
has to be pumped, stirred, fruited and
filled will break down into liquid
without stabilizers
• Pasteurized yogurt need to be
stabilized as the nature of heat
treatment will affect the yogurt
consistency
• Common stabilizers are gelatin,
pectin, agar, starch
• Quantities in the order of 0.1% to 5%

11. Good quality milk, free
of antibiotics and other
inhibitory subtances,
can be from skim (non-
fat), reduced fat (using
centrifugation), or
whole milk
Increasing total
milk solids by:
• Adding nonfat dry
milk (12% to 13%)
• Concentration the
milk via evaporation
• Adding other
permitted ingredients
Mixes are heated to 85-88oC
for up to 30 min to:
• Killing pathogens and
spoilage organisms and
inactivating enzymes
• Making the mixture
essentially free of
competing microorganisms
• Denaturating the major
whey proteins (α-
lactalbumin and β-
lactoglobulin)  exposing
amino acid residues and
enhancing their ability to
bind water
MilkTreatment

12. SWISS-STYLE
Stirred or Swiss-style, yoghurt
that is mixed with flavors, fruit, or
other bulky ingredients
Mix is pumped into vats and the
culture is added  incubation
At the end of the fermentation the
mixture is agitated and cooled, and
the flavor ingredients are introduced
CUP-STYLE
Fermented in the Cup-style
yoghurt
Mix is inoculated with culture,
and pumped immediately into
the container
If wanted, the fruit or flavoring material is
first dispensed into the cup and the
yoghurt mix added on top, followed by
incubation and fermentation

13. Milk
Heat treatment
Cool
Inoculate
Incubate
Mix and dispense
Cool
Yoghurt Mix
Dispense
Incubate 40-45oC
Cool
Swiss
Style
Cup-Style
0-4oC
40 – 45oC, 3 - 6 h
2.0-2.5% thermophilic culture
40 – 45oC
85oC for 30 min
Homogenize
Standardize (nonfat, lowfat, whole)
Nonfat milk solids
Stabilizers, other ingredients

14. • Yoghurt is incubated and cooled in the final package and is characterized by a
firm jelly like texture
Set yoghurt
• Yoghurt is incubated in a tank and the final coagulum is broken by stirring prior
to cooling and packing.The texture will be less firm than set yoghurt
Stirred
yoghurt
• Very similar to stirred yoghurt, but the agitation used to break coagulum is
severe.
Drinking
yoghurt
• Usually consists of a thin yoghurt blended with a high solids ice cream base
mix. Freezing is achieved by pumping through a freezer similar to ice cream
Frozen
yoghurt
• Following the breaking of coagulum the yoghurt is concentrated by boiling off
some of the water, usually (under vacum to reduce the temperature required)M
Concentrated
yoghurt
• The flavours are usually added at or just prior to filling into pots.These
additives often have as much as 50% sugar, but many manufacturers offer a
low sugar and low fat version
Flavoured
yoghurt

15. Kefir originated in the Caucasus Mountain in Russia
Kefir fermentation is unique in that the culture
organisms are added to the milk in the form of
insoluble particles called kefir grains
The flavor of plain kefir is primarily due to lactic and
acetic acids diacetyl, and acetaldehyde, produced
by lactic acid bacteria. Kefir grain also contain yeast

16. Yoghurt Kefir
Microorganisms
involved
Contains two types of
bacteria, Lactobacillus
bulgaricus and Streptococcus
thermophillus
Contains several strains
bacteria: Lactobacillus,
Leuconostoc, Acetobacter,
Streptococcus, Pseudomonas.
Also contains different strains
of yeast: Candida,
Kluyveromyces and
Saccharomyces
Starters Both mesophilic and
thermophilic
Mesophilic
How to use starters Re-cultured starters by
mixing starters (back
slopping) into fresh milk
Kefir grains are transferred to
a fresh batch of milk

17. • to regulate the immune system,
• to promote production of bile,
• to provide natural protection against diseases,
• to improve blood circulation,
• to regulate cholesterol and sugar levels,
• to regulate blood pressure,
• to strengthen the kidneys,
• to slow down aging,
• and many more
Health benefits of kefir

18. Bacteria Yeasts and Mold
Lactobacillus brevis Candida kefir
Lactobacillus fermentum Candida maris
Lactobacillus kefiranofaciens Candida incospicua
Lactobacillus kefiri Candida lambica
Lactobacillus parakefir Candida krusei
Lactobacillus plantarum Saccharomyces cerevisiae
Lactococcus lactic subsp.cremoris Kluyveromyces cerevisiae
Lactococcus lactis subsp.lactis Geotrichum cancicum
Leuconostoc mesenteroides subsp.cremoris Zygosaccharomyces sp.
Leuconostoc sp.
Streptococcus thermophilus
Actobacter aceti

19. Step on How to Create Milk Kefir

20. Boil for 10 min
Inoculate with
kefir grains
Incubate at 20oC for up to 24 h
Separate kefir grains by sieving
Cool to 4oC and store
Dispense into container
Raw milk
Cool to 20oC
TRADITIONAL

21. Homogenize
Cool to 20oC
Incubate at 20oC for up to 24 h
Cool and gently agitate at 4oC
Dispense into containers
Raw milk
Heat at 85-95oC
for 5-30 min
MODERN
Inoculate with kefir starter culture