Microbial fermentation of Sauerkraut

1. Sauerkraut
Prepared by- Abhikarsh (4608)
19081564005
B.Sc.(H) Microbiology 3rd Sem.
Submitted to- Dr. Anjana
Kapoor
Deptt. Of Microbiology
Swami Shraddhanand
College, Univ. of Delhi

2. • Sauerkraut is the clean, sound product of characteristic flavor, obtained by
full fermentation, chiefly lactic, of properly prepared and shredded
cabbage in the presence of not less than 2% and not more than 3% salt.
• The word has German origin, meaning “sour cabbage”.
Sauerkraut
• It has a sour taste with a clean
acid flavor.
• Mild flavoured, sweet, solid,
white-headed cabbage is the
best choice for making superior
kraut.

3. History of Sauerkraut
• Although "sauerkraut" is a German word,
the dish did not originate in Germany, as
fermenting cabbage as Suan cai was
already practised back in the days of the
building of the Great Wall of China.
• The practice was likely transmitted from
China to Europe by the Tartars.
Suan cai
• It then took root mostly
in Central and Eastern European cuisines,
but also in other countries including the
Netherlands, where it is known as zuurkool,
and France, where the name
became choucroute.
• The English name is borrowed from
German where it means "sour cabbage"

4. Preparation
of
Sauerkraut

5. • Cabbages are willed for 1-2
days. Spoiled spots and
defective outer leaves are
trimmed.
• Heads are washed with pure
water.
• The core is drilled out and
shredded, then added to the
rest of the cabbage.
• The head is cut into desirable
size(2-5mm thick), usually
slim ones.
Deleaf, core, trim, shred.

6. Addition of salt
• 2.25% to 2.5% of salt by weight
must be added to the shredded
cabbage to obtain kraut of the
best quality.
• The salt should be distributed
evenly.
The salt added serves the following functions-
(i) It extracts moisture from the shredded cabbage by osmosis to form the brine in
which the fermentation will take place.
(ii) It helps to inhibit the natural micro-flora of the cabbage such as Pseudomonads
which would otherwise cause spoilage and helps to select for the lactic acid bacteria.
(iii) It helps to maintain the crisp texture of the cabbage by withdrawing water and
inhibiting endogenous pectolytic enzymes which cause the product to soften.
(iv) Salt contributes to flavor of the product.

7. Fermentation
• Anaerobic conditions develop
quickly in the salted, shredded
cabbage and the surrounding
juice in the fermentation vats,
chiefly as a result of removal of
O2 by respiration of plant cells
and also due to bacteria.
• The juice contains natural flora
from soil and some
contaminants from soil and
water.
• At first different kinds of
bacteria grow but then acid-
forming soon predominate.
• Early microbes to predominate
include Enterobacter cloacae,
Erwinia herbicola, which
produce volatile acids and gas
and contribute to some flavor.
• Soon, Leuconostoc
mesenteroides bacteria
begin to outgrow all
other organisms and
continue producing
lactic acid.
• These Streptococci are
not inhibited but rather
stimulated by 2.5% salt.
• They attack sugars to
form lactic acid, acetic
acid, ethanol, mannitol,
dextran, esters and
carbon dioxide, which
contribute to good flavor
of sauerkraut.
• Similarly, lactic acid
rods and cocci
metabolize the lipids of
cabbage to produce
volatile fatty acids giving
good flavor.

8. • Next, non-gas forming
lactobacilli, especially,
Lactobacillus planarum
continue the production of
acid(chiefly lactic acid) and
raise it to 1.5-2%.
• They also utilize the mannitol
produced by Leuconostoc and
thus remove the bitter taste.
• L. planarum completes the
desired fermentation till the
final acidity reaches 1.7%
which is most desirable.
• At this point, fermentation
can be stopped by canning or
refrigerating the sauerkraut.
• The fermentation can last
from 4-8 weeks with the ratio
of volatile to non-volatile acid
of around 1-4.

10. Pic courtesy- Meatandsausage.com

12. Characteristics of good
sauerkraut
 Light coloured
 Crisp.
 Acidity of about 1.7%.
 Clean, acid flavor.
 Small amounts of diacetyl
gives pleasant aroma and
taste.
 pH of 3.4 to 3.6.
 Lactic acid= 1.25%.
 Acetic acid = 0.3%.

13. Sauerkraut defects and spoilage
Soft
kraut
Pink
kraut
Slimy
/
ropy
kraut
Black
kraut
Faulty
fermentation
and exposure to
air, or excessive
pressing.
Exposure to air,
yeasts and
molds, uneven
salting and high
temperature.
Red, asporogenous
yeasts in the
presence of air and
high salt, iron
salts, pigments in
cabbage
Encapsulated
varieties of
Lactobacillus
plantarum.

14. Health benefits of sauerkraut-
 It is rich in fiber, Sodium, B vitamins,
Vit K1, Iron, and other minerals.
 Beneficial probiotics.
 Combats inflammation.
 Reduces the risk of depression and
Alzheimer’s disease.
 Supports natural antibodies of the
body.
 Aids in weight loss.
 According to a study from King’s
College, London, sauerkraut’s large
amounts tyramine, a
neurotransmitter, makes it one of the
most powerful aphrodisiacs.
 Maintains healthy gut flora.
 Good for gum diseases and heart
diseases.

15. Kimchi
 Kimchi (Korean origin) is
similar to sauerkraut in some
respect since both are
fermented cabbage
 The level of salt used is low,
<3%.
 It has a shorter fermentation
time.
 The best kind of kimchi get
ready within 3 days at 20*C
when the acidity is 0.6% and
the pH is around 4.2.
 Leuconostoc mesenteroides
is the principal organism.
 Kimchi is rather salty
whereas sauerkraut is more
tart.
Pic courtesy- Pinterest.com

16. References-
Adams, M.R. and Moss, M.O.(2000). Food Microbiology, 2nd
edition. New Age International Publishers, India.
Banwart, P.M., Sofors, J.N. and Branen, A.L. (2005).
Antimicrobials in foods. 3rd edition. CRC Press, UK.
Frazier, W.C., Westhoff, D.C. and Vanitha, N.M.(2013). Food
Microbiology. 5th edition, Tata McGraw-Hill Publishing
Company Ltd, India.
Ray, B. and Bhunia, A.Fundamental Food Microbiology,4th
edition. CRC press, U.S.A.

17. Thank You!
For your patience.