Lesson 5: Fermentation and Pickling

Fermentare

To leaven

The word fermentation stems from the Latin _____ , defined as “to leaven.”

Myriads

Household

Commercialized

Industrial

The word fermentation is

• Rooted in _______of cultural norms throughout the world

• Expanded from the _____ to ______ and ______ scale production systems intended for the mass marketplace

Fermentation

The transformation of food by various bacteria, fungi, and the enzymes they produce.

Enzymatically altered

Fermented foods and beverages are _______ by microorganisms in a desirable way (taste and smell).

Palatability

New food varieties.

Beyond preservation, fermentation improves _______ and introduces ______

Antihypertensive activity
Blood glucose-lowering benefits
Antidiarrheal properties
Antithrombotic properties

Health benefits of fermentation

Antithrombotic properties

Based from anecdotal information

Vitamins, minerals, amino acids
Phytochemicals (e.g., phenolics, fatty acids, saccharides)

Fermentation enhances content of

Grapes

Barley

Apples

Rice

Wheat

Milk

Milk

Milk

Milk

Grapes

Soybeans

Soybeans

Cucumber

Cabbage

Olives

Meat

Wine		Yeast
Beer		Yeasts
Cider		Yeasts
Sake		Molds
Bread		Yeasts
Yogurt		LAB
Cheese		LAB
Buttermilk		LAB
Kefir		LAB + Yeast
Vinegar		Yeast → Acetobacter / Gluconobacter
Tempeh		Molds
Soy Sauce		Molds + LAB + Yeasts
Pickled Cucumber		LAB + Yeasts
Sauerkraut		LAB
Pickled Olives		LAB + Yeasts
Fermented Sausages		LAB + Molds

Complete the table

Yeast

Yeasts

Yeasts

Molds

Yeasts

LAB

LAB

LAB

LAB + Yeast

Yeast → Acetobacter / Gluconobacter

Molds

Molds + LAB + Yeasts

LAB + Yeasts

LAB

LAB + Yeasts

LAB + Molds

Food	Principal Ingredient	Key Microorganism(s)
Wine	Grapes
Beer	Barley
Cider	Apples
Sake	Rice
Bread	Wheat
Yogurt	Milk
Cheese	Milk
Buttermilk	Milk
Kefir	Milk
Vinegar	Grapes
Tempeh	Soybeans
Soy Sauce	Soybeans
Pickled Cucumber	Cucumber
Sauerkraut	Cabbage
Pickled Olives	Olives
Fermented Sausages	Meat

Complete the table

Developing countries, rural communities

Natural preservation

Fermentation remains vital in:

• ________and ________ (due to low equipment and cost requirements)

• Markets seeking _________ (no chemical additives)

1. Minimize microbial contamination (asepsis)

2. Inhibit microbial growth

3. Kill microorganisms

4. Remove microorganism

What are the preservation principles:

1–3

Substrates

Fermentation uses principles ____ and relies on high-quality _______, and not only on substandard substrates. 

Bactericidal and bacteriostatic substances
Inhibit spoilage and pathogen growth
Extend shelf life by preventing undesirable sensory changes

Lactic Acid B produce:

• _

• _

• _

Negative effects

Negligible effects

Positive effects

Contaminating microflora can cause:

• _

• _

• _

Negative effects

What effects cause spoilage, pathogens, toxins

Negligible effects

What effects cause no noticeable change

Positive effects

What effects cause improved appeal (desirable fermentation)

Sensory appeal 

Microorganisms can be consumed as food or used for improving other foods; Most of it is _____

Biochemical activity

Sensory appeal is largely due to __________ of microorganisms.

Fermented foods

It is developed simultaneously by many culture to:

1. Preserve abundant seasonal produce.

2. Improve sensory appeal of otherwise unappealing food.

Preserve abundant seasonal produce.
Improve sensory appeal of otherwise unappealing food.

Fermented foods is developed simultaneously by many culture to:

• _

• _

Low

Fermentation has ____ energy demands and is carried without sophisticated technology and designated plants. 

Yes

Yes or No. Studies have shown that consumers regard fermented foods to be healthy and natural—profitability for business. 

Sensory appeal

_____ is largely due to biochemical activity of microorganisms.

Safety

Health benefits

Retail value

Nutritional value

Digestibility

Suitability for processing

Sensory properties

Ease of storage/transport

Shelf life

Table 5.2 – Potential Benefits of Fermented Foods

Increased	Lowered
	Toxicity
	Cooking time
	Production costs
	Equipment needs
	Antinutritional factors

Complete the table

Toxicity

Cooking time

Production costs

Equipment needs

Antinutritional factors

Table 5.2 – Potential Benefits of Fermented Foods

Increased	Lowered
Safety
Health benefits
Retail value
Nutritional value
Digestibility
Suitability for processing
Sensory properties
Ease of storage/transport
Shelf life

Complete the table

Lactic Acid Bacteria (LAB)

Performs an essential role in preservation and production of wholesome foods. 

Sauerkraut, cucumbers, radishes, carrots, olives

Yogurt, kefir, cheeses

Sourdough

Sausages

Lactic Acid Bacteria (LAB)

Applications:

• Vegetables: _____

• Milk: ________

• Breads: _______

• Meats: _____

Lactic acid

Preservative, acidulant, dough conditioner

LAB Traits:

• Produce _____ that is primarily used as:

  • a

  • b

  • c

Anaerobically

LAB Traits:

• Work ______, the conversion of carbohydrate to lactic acid plus CO2, and other organic acid

Microaerophilic

In this LAB traits where it anaerobically, the conversion of carbohydrate to lactic acid plus CO2, and other organic acid. This process is called?

No

If LAB is microaerophilic, this means, large or no drastic changes in food composition?

Mild

In LAB traits, is there drastic or mild changes to food composition?

Lactobacillus acidophilus

L. bulgaricus

L. plantarum

L. brevis

L. thermophilus

L. pentoaceticus

L. caret 

What are the key LAB species?

L. plantarum: homofermenter

What LAB species dominates vegetable fermentations

Leuconostoc mesenteroides

What LAB species key for sauerkraut and pickle fermentation

Homofermenter

Heterofermenter

What are two main groups of LAB species

Lactic acid only (via glycolysis/Embden–Meyerhof)

What is the process of Homofermenters

Heterofermenter

 lactic acid + ethanol + acetate + CO₂ (via 6-phosphogluconate/phosphoketolase)

• Homofermenter

• Heterofermenter

Homofermenter

lactic acid only (via glycolysis/Embden–Meyerhof)

• Homofermenter

• Heterofermenter

lactic acid only (via glycolysis/Embden–Meyerhof)

What is the process of Homofermenter

Acetic Acid Bacteria

2nd group of bacteria with importance in food preservation

Acetic acid

One of the oldest chemical known 

Acetum

Acetic acid is named after the Latin word for vinegar “_______”

Acid-tolerant, Gram-negative,  motile rods, obligate aerobes

5.0

Vinegar production

What are the Characteristics of acetic acid:

• _____tolerant, Gram-____,  _____ rods, ____aerobes

• Grow below pH ____

• Primary use: _________ (most desirable action)

Yeast converts sugar → ethanol

Acetobacter oxidizes ethanol → acetic acid

What are the ywo-stage process of vinegar production

Sour wine

Vinegar = "_____" (acetum)

Yeast

Widely distributed in natural habitats that are nutritionally rich in carbohydrates, such as fruits and plant nectars 

Rarely

Is yeast rarely pathogenic or pathogenic

Saccharomyces cerevisiae

Most common yeast?

Glucose

Yeast does not ferment lactose or starch but?

Mold

They are enzyme rich and aerobic

Specific enzyme production

Flavor development

Antibiotics

Mycotoxin

Molds are used for:

• _________ (e.g., amylases for baking)

• Spoilers and preservers of food and in particular ________

• Some produce ____ or harmful ________

Aspergillus oryzae

What mold for soy fermentations 

Rhizopus oligosporus

What mold for tempeh

Penicillium spp.

What mold for ripening and flavor of cheeses

LAB

Acetic acid bacteria

Yeast

Mold

What are the bacteria used in fermentation?

Alcoholic Beverages

Distilled Spirits

Lactic Acid Products

What are the fermented products?

Alcoholic fermentation

Preservative

Beer, Wine

Mutation, selection, and genetic engineering

Alcoholic Beverages

• Require _______ of sugary materials by yeasts

• Alcohol content acts as _________

• Common: ___ and ____

• Modern yeasts improved through ___ ___ ______

17%

Higher

Distillation

Whiskey, Vodka, Rum, Gin, Liqueurs

Distilled Spirits

• Fermentation yields max _____ alcohol only

  • _______ concentration inhibits the metabolism of yeast

• _________happens if  there is a need higher concentrations

• Examples: ____ _____ _____ ____

Dairy Products

Fermented Vegetables

Fermented Animal Products

Combined Fermentation

What are the lactic acid bacteria products?

Yogurt

Cheese

2 examples of dairy products

Yogurt

A coagulated milk product that is prepared using either whole or skim milk

Streptococcus thermophilus + Lactobacillus delbrueckii subsp. bulgaricus

Yogurt is fermented by?

12–15%

In yogurt, Non fat Milk solids raised to ________ by concentrating the milk, or adding powdered or condensed milk

82–93°C

30–60 min

40–45°C

Yogurt is

• Pasteurized by ______

• For ____

• Then cooled to _______

Cheese

Concentrated milk product from coagulation and whey separation of milk, cream, or partially skimmed milk,  buttermilk, or mixture of these.

Cow, ewe, goat, or buffalo milk

Cheese is from what type of milk?

Pasteurized

Thermized

Cheese is commonly done in a process of these two?

Thermized

To limit the heat-induced changes in milk without compromising microbial safety 

Propionibacterium shermanii with L. bulgaricus and S. thermophilus

LAB or other microbes involved for Swiss cheese

Molds like Penicillium roqueforti

LAB or other microbes involved for Blue cheese

P. camemberti

LAB or other microbes involved for soft cheese

Brine solution

What solution does fermented vegetables used?

Sauerkraut

Olives

Cucumber

3 common fermented vegetables

Leuconostoc mesenteroides

Lactic acid, acetic acid, CO2 

L. brevis 

L. plantarum

4.0 

Anaerobically

What is the process of sauerkraut?

• ________ will produce _____ _____ _____

  • Followed by _____

  • Then,  _______ that will produce more acid and lowering pH to below _____

  • this proces will allow cabbage to be preserved ________ in long period 

1.25–2% lye (NaOH)

21–25°C

4–7

Oleuropein

What is the process of olives?

• Has special treatment: _________ at _______ for______ hrs 

• To remove _____

Acetic acid and buffered

L. plantarum ± Pediococcus cerevisiae

What is the process of olives?

• Sometimes acidified with ________ and buffered

• Inoculated with __________

Gram positive micrococci

Have important role in fermented animal products

Enhancing flavors 

Fermented Animal Products

• Many traditional fermentation methods are still in use, although not mainly for preservation, but _______

Sausage

Fish

Two examples of fermented animal products

Salt and LAB → rapid pH drop

Curing, smoking, drying, aging

Hurdle effect

Fermented Sausages:

• Achieved by using:

  • ___________

• May include: ____________

• Aside from the low water activity of salt, _________ is added to create a combination of other inhibitors

Hurdle effect

Contributes to sausage preservation

Pediococcus cerevisiae, Staphylococcus carnosus, L. plantarum

Microbes used in fermented sausage

Micrococcus varians and Staphylococcus carnosus

It convert nitrates → nitrites (react faster and less is required for compound stabilization)

Fermented Fish

Common in Southeast Asia, esp in diet

1%

What is the carbohydrate content of fish?

Carbohydrates

Fish requires added?

Fermentation 

Higher level of added carbohydrates in fish means faster ________

Sauces and paste

Whole, eviscerated, mashed fish is used for

• Sauces and paste or

• Anchovies

Anchovies

Low value and small fish is for

• Sauces and paste or

• Anchovies

3:1

0.75

Shelf life

18 months

Sunlight

Process of fermented fish:

• Fermentation of fish used a fish to salt ratio of? with water activity below?

• Higher concentration of salt slow the production rate, but extended ______ of final product

• Stored in sealed vessels up to ______ (_________may speed up process)

Leavening agent

Carbonation

The release of CO2 by microorganisms have 2 major role in food fermentation

• ____

• ____

Digestibility and eating ability of grains

Bread fermentation has main goal of

• Shelf life or

• Digestibility and eating ability of grains

Wheat

Gluten proteins

Bread process:

• Uses flour from grains like _____ that contain ______
  

Kneading

Gluten matrix

Elastic

Extensible

Stretch

Retain gas

Bread process:

• _______ forms a _______ making dough:

  • __

  • ___

• This allows the dough to:

  • a

  • b

Air

Carbon dioxide (CO₂)

Gas responsible for leavening:

• ______ (from mixing and kneading)

• ________ (from yeast fermentation)
  

Saccharomyces cerevisiae

Known as baker’s yeast and for bread making

Bread

Sourdough

Vinegar

Products of combined fermentation