Food Fermentation Technology

Question 1

Fermentation

Answer 1

Any process involving the production of organic products by the mass culture of a microorganism

Microorganism, grown on large scale, able to produce valuable commercial products or to carry out important chemical transformation

Question 2

Zymology

Answer 2

The art of studying fermentation

Question 3

Fermentation Technology

Answer 3

Discipline of biotechnology which involves he development of new fermentation processes & the improvement of the current process

Question 4

What is fermentation in biochemistry?

Answer 4

1) A metabolic process of deriving energy fro organic compounds.

2) The common group of microb involved is Bacteria, Yeasts, and Molds

3) Fermentation allows the production of a small amount of ATP in anaerobic conditions

Question 5

Primary fermentation processes

Answer 5

1) Lactic Acid Fermentation
2) Alcohol Fermentation

Question 6

How does lactic acid fermentation happens in human?

Answer 6

1) Happens in many cells including human muscle cell during rapid exercise

2) Muscles are not getting enough O2 to produce all the ATP they need, so lactic acid fermentation was used

3) This process regenerates NAD+ so that glycolysis can continue to make small amounts of ATP

Question 7

Lactic Acid Fermentation in Food

Answer 7

Lactic acid fermentation is a metabolic process by
which glucose and other six-sugars are converted into cellular energy and the metabolite lactate, which is lactic acid in solution

Question 8

Examples of the products that were produced by LAB

Answer 8

1) Fermented Vegetables = Pickles

2) Fermented Dairy Product = Yogurts, Cheese

3) Fermented Cereal = Idli, Dosa

4) Fermented Meat = Salami

Question 9

LAB

Answer 9

1) Major group
- Lactobacillus
- Lactococcuss
- Pediococcus
- Streptococcus

2) LAB are mesophiles (10 - 40 oC)

3) pH rang from 4 - 8

4) They grow readily in most food substrates and lower the pH rapidly to a point where competing organisms are no longer able to grow.

Question 10

What is homolactic fermentation?

Answer 10

• Homolactic fermentation is a type of fermentation where microorganisms, such as certain bacteria, convert sugars into lactic acid.
• In homolactic fermentation, the microorganisms only produce lactic acid as the main end product.
• This process does not produce any gas or other byproducts.

Question 11

What is heterolactic fermentation?

Answer 11

• Heterolactic fermentation is a type of fermentation where microorganisms convert sugars into a combination of lactic acid, ethanol (alcohol), and carbon dioxide gas.
• In heterolactic fermentation, the microorganisms produce lactic acid as well as other byproducts.

Question 12

LAB (Gram-positive bact)

Answer 12

Lactic acid bacteria (LAB) are gram-positive bacteria, including Lactobacillus, Leuconostoc, and Streptococcus, that play a vital role in food production.

In products like buttermilk, yogurt, and cottage cheese, Lactobacillus bacteria produce acid through fermentation, which helps eliminate competing bacteria.

This acid also benefits humans who consume these foods. During the production of yogurt and cheese, the lactic acid fermentation creates a highly acidic environment that causes proteins in milk to solidify, resulting in the formation of curds.

Question 13

Advantages of brining and lactic acid fermentation

Answer 13

• low cost
• have low energy requirements for both processing and preparing foods for consumption
• high yield acceptable
• diversified flavors.
• microbial spoilage
• toxin development

Question 14

The use of salts in fermentation

Answer 14

Depending on the salt concentration, salting directs the subsequent course of the fermentation, limiting the amount of pectinolytic and proteolytic hydrolysis that occurs, thereby controlling softening and preventing putrefaction (decay process).

Question 15

ALCOHOL FERMENTATION

Answer 15

A biological process in which sugars such as glucose, fructose, and sucrose are converted into cellular energy and thereby produce ethanol and carbon dioxide as metabolic waste products.

Alcohol fermentation is done by yeast and some kind of bacteria

Yeast were used to break down complex carbohydrates to simple sugars

Question 16

The process of alcohol fermentation

Answer 16

1) Begins after glucose enters the cells
2) The glucose is broken down into pyruvic acid
3) Pyruvic acid is then converted to CO2+Ethanol+Energy
4) Takes place in anaerobic conditions

Question 17

Etahnol is used as

Answer 17

• Solvent - Resins, Cosmetics, Pharmaceutical
• Chemical intermediate - Petroleum derived chemicals
• Fuel - Used as a biofuel

Question 18

Bacteria for ethanol production

Answer 18

1) Many bact can produce ethanol

2) Many of them produce end products such as;
- Other alcohols
- Organic acids
- Polyols
- Ketone gases

3) Bacteria that metabolize EMP pathway;
- Clostridium sp
- Streptococcus sp

Question 19

Yeast for ethanol production

Answer 19

Primary interest are Saccharomyces sp

Question 20

How does the organism for the ethanol production were selectedd?

Answer 20

1) Low pH
2) High temperature
3) High growth & fermentation rate
4) Osmotolerance

Question 21

What are the raw materials for the ethanol production?

Answer 21

1) Saccharine
2) Starch
3) Cellulose materials

Question 22

Saccharine

Answer 22

1) Glucose, Fructose, Maltose

Question 23

Molasses

Answer 23

1) Contain 52-55% fermentable sugars
2) Molasses with above 15-20% sugar contents will need to be dilute

Question 24

Cane Sorghum

Answer 24

1) 14% fermentable sugar contents
2) Extraction requires heavy duty
3) Acidification is necessary

Question 25

Sugar Beet

Answer 25

1) Mostly preferred
2) 15% sugar, 82% water, small amount of starch
3) Juice is extracted by crushing
4) Enzymes improve the alcohol yield

Question 26

Sugar Corn Waste

Answer 26

1) Sugar is extracted same with sorghum
2) Back slopping in the range of 20-25%
3) Acidification is necessary

Question 27

Grains

Answer 27

1) Must be milled, diluted, cooked, and fermented
2) Conttain large amounts of fermentable materials
3) Alcohol yield is dependent on converted starch

Question 28

Jerusalem Artichokes

Answer 28

1) Abundant source of alcohol (16-18%) fermentable materials

2) Materials should be crushed to pulp and cooke for 2-3 hours

3) Dilution is not necessary

Question 29

Potato

Answer 29

1) Cooked with steam under pressure

2) After cooking, mash is cooled to conversion for 15-20 minutes

3) Once converted, pH should be adjusted mash is fermented

Question 30

Sweet Potato

Answer 30

1) Similar manner to potatoes

2) Dilution is necessary

Question 31

Starchy materials are of 2 categories

Answer 31

• Encased by grain hulls
• Starch is readily available

Question 32

Malting

Answer 32

1) Seeds are moistened & allowed to sprout

2) The seeds are powdered, and the powder is called malt

Question 33

Miling

Answer 33

1) Grains are milled to expose he starch

2) Material is ground as fine as possible

Question 34

Cooking

Answer 34

1) Starch is liquefied by boiling under pressure
2) TO dissolve the water soluble starches
3) Done with steam under pressure at 100oC
4) Use less water during cooking
5) Water may be added to dilute the mash
6) So cooling time may be saved
7) The cooked malt is called mash

Question 35

Conversion of starch

Answer 35

1) Conversion starch to fermentable sugar by certain enzymes in the malt or by acid hydrolysis

Question 36

Enzyme Extracts

Answer 36

1) Commercially available

2) 3 basic types;
- Alpha amylase = Produce dextrose
- Beta amylase = Prooduce maltose
- Gluco amylase = Reduce the remaining starch

Question 37

Acid hydrolysis

Answer 37

1) Requires acid proof equipment and high temperature
2) Dilute mineral acids is added to grain slurry
3) Then immediately neutralized with calcium hydroxide

Question 38

Mash Cooling

Answer 38

1) Done after conversion and pH is checked
2) Cooling coils are used for cooling

Question 39

Product recovery

Answer 39

1) Cell biomass is separated by centrifugation/sendimentation

2) Desired microorganism aggregated, readily separated from broth by sendimentation

Question 40

Separation of cell biomass

Answer 40

1) Flocculation
2) Filtration
3) Flotation
4) Centrifugation

Question 41

Flocculation

Answer 41

1) Flocculation agents is added;
- Hydrocolloids
- Inorganic salts

2) Produce large aggregate which still settle more readily

Question 42

Filtration

Answer 42

1) Bacterials cultures - Absolute filters

2) Filamentous fungi - Depth filters

Question 43

Flotation

Answer 43

1) By introducing gas into liquid

2) Cells gets adsorbed to the gas bubbles and rise to the foam layer at the top of vessels

Question 44

Distillation

Answer 44

1) Separation for a mixture of liquids
2) It relies on differences in boiling points of the components liquids to be separated
3) The mixture to be separated is added to the distilled pot and is heated
4) Low boiling point will vaporize first
5) This vapors passes into distilling head and then into condenser

Question 45

What is ethanol boiling point

Answer 45

78.5

Question 46

Purification

Answer 46

1) HPLC
2) GLC

Question 47

Applications of ethanol

Answer 47

1) Used as antiseptic
2) Used as a biofuel
3) As a disinfectant
4) In many medicines and drugs

Question 48

Byproduct

Answer 48

1) Distiller dried grain with soluble (DDGS)
2) CO2 - Preparation of soft drinks
3) Yeast biomass