Alcoholic Beverages

Question 1

Define Beer

Answer 1

Beer is a term associated with non-distilled alcoholic beverages made from partially germinated cereal grains, referred to as malt.

Question 2

What is included in this group?

Answer 2

These include ales, lagers and stouts, which normally contain 3-8% ethanol.

Question 3

What are the ingredients?

Answer 3

The main ingredients are hops (giving beer the characteristic flavor and aroma), water and yeast.

Question 4

How many stages?

Answer 4

4

Question 5

What is stage 1?

Answer 5

Malting: the partial germination of cereal grain to form malt (6-9 days). This is the primary beer ingredient, it contains mainly starch. Malted barley , or malted wheat, or malted oats.

Question 6

What is stage 2?

Answer 6

Mashing and wort preparation: the production of an aqueous fermentation medium, “wort”. It contains fermentable sugars, amino acids and nutrients. This is sterilized by boiling, and hops are added for flavor.

Question 7

What is stage 3?

Answer 7

Yeast fermentation: selected strain of Sacchromyces cerevisiae, the wort undergoes an alcoholic fermentation, to produce ethanol, CO2, 2-7 days, depending on the beer produced.

Question 8

What is stage 4?

Answer 8

Post fermentation: the fresh beer is subjected to various treatments to make it acceptable for the shelf.

Question 9

What is wine made of?

Answer 9

Wine can be made from any plant extract or fruit juice that contains sufficient levels of fermentable sugars. However most wine is made from grapes, Vitis vinifera, which can be grown all over the world. The amount of wine produced all over the world, 1010 liters/yr.

Question 10

What does grape juice contain?

Answer 10

Grape juice contains high levels of fermentable sugars, glucose and fructose, 160-240 g/liter.

Question 11

What is the natural acidity?

Answer 11

pH 2.8-3.8 prevents spoilage from occurring

Question 12

How much ethanol is in wine vs port?

Answer 12

Most table wines are 14% ethanol. Some regions fortify the wine with ethanol, sherry, port may be as high as 22% ethanol.

Question 13

What kind of variety in wine?

Answer 13

Immense variety of wines, by color, sweetness.

Question 14

What other factors influence wine?

Answer 14

Other factors that influence: specific grape variety, soil, climate, cultivation, grapes condition at harvest, grape must (destemmed, macerated, pressed grapes), fermentation, post fermentation treatments, maturation in the bottle.

Question 15

How is alcoholic fermentation carried out?

Answer 15

The alcoholic fermentation of wine is carried out by indigenous yeast or added yeast. Done in a controlled cool setting, for every 10g/l of sugar fermented the temperature of the vat rises 1.3 C, therefore temperature control a must. White wine fermentation is maintained at 10-20 C, red wine maintained at 24-29 C.

Question 16

What is whiskey made of?

Answer 16

made from malts except the wort is not boiled, no hops are added.

Question 17

What is the primary fermentation of “sour mash” whiskey?

Answer 17

Lactobacillus delbrueckii, the lactic acid produced is 1.5% before being killed. The yeast used for fermentation is S. cerevisiae, distillation follows to increase the ethanol level. The distillate is colorless caramel coloring is added, maturation occurs in oak flasks, usually 40% ethanol at bottling.

Question 18

How is the industrial process completed?

Answer 18

Stainless steel vessels, 250-100,000 gal. in size. These vessels are temperature controlled with jackets and controllers, pH controllers, aeration if necessary, nutrients are added at the beginning (batch), or throughout (continuous).

Question 19

What does the culture medium contain?

Answer 19

carbohydrate, hydrolyzed protein, trace elements, and buffers.

Question 20

How do they monitor the levels?

Answer 20

. Probes are in the tank to monitor temperature, oxygen level, pH, nutrients (if possible).

Question 21

Why is carbon used?

Answer 21

Used in the fermentation process, is required for all biosynthesis leading to reproduction, it also serves as an energy source.

Question 22

What is the biomass yield coefficient?

Answer 22

biomass produced divided by carbon substrate utilized

Question 23

What are the culture methods?

Answer 23

Batch vs. Continuous
Liquid vs. solid
Immobilized microbial cells

Question 24

How much is the industrial enzyme market worth?

Answer 24

$1 billion/yr

Question 25

What is the typical enzyme yield?

Answer 25

Typical enzyme yield/bacillus fermentation is 20 g/liter. Therefore per 1000 l fermentation, 20,000 g of enzyme. Genetically engineered strains have improved the yields.

Question 26

WHat bacteria are chosen for these fermentations?

Answer 26

B. licheniformis, B. amyloliquefaciens

Question 27

What is starch degrading enzymes, amylases used for?

Answer 27

, this enzyme is used to convert starch into high fructose corn syrup, used in the beverage soft drink industry.

Question 28

How does bacterial cellulase differ from fungal?

Answer 28

bacterial cellulases function best at neutral or alkaline pH values. Used in fruit juice and olive oil extractions, also used in stone washed denim products.

Question 29

What is lipases used for?

Answer 29

fastest growing applications include detergent applications. Also for the removal of fat in leather processing. Important in cheese and meat applications.

Question 30

What is protease used for?

Answer 30

most important enzymes produced by Bacillus sp. Have of the enzyme market are these enzymes. Subtilisin, for use in laundry detergents, baking, brewing, cheese making, meat tenderizers, leather processing.

Question 31

How many proteases are produced by B. subtilis?

Answer 31

7, Two of these proteases present in the highest concentrations are neutral and serine protease (subtilisin).

Question 32

How much amino acid is produced each year?

Answer 32

Bacteria produce amino acids, glutamate, 100,000 tons/yr. Corynebacterium glutamicum, yield up to 60g/liter of broth. This species has an incomplete TCA cycle and therefore produces glutamte, lacks α-ketoglutarate dehydrogenase. Lysine is also produced by a mutant of this species.

Question 33

What bacteria make organic acid?

Answer 33

Aspergillus niger, makes citric acid. Lactobacillus delbrueckii, makes lactic acid, used for the food industry.

Question 34

What makes Polysaccharides, dextrans, homopolysaccharides, α linked polymers of glucose?

Answer 34

Leuconostoc dextranicum. Xanthan gum, a heteropolysaccharide made by Xanthomonas campestris

Question 35

What makes vitamins?

Answer 35

vitamin B12 made by Propionibacterium freundenenreichii, P shermanii.

Question 36

What makes penicillin?

Answer 36

produced by Penicillium chrysogenum, grown in glucose, corn steep liquor and phenylacetic acid. The fermentation takes 200 hrs, extracted on a rotary vacuum filter drum, chemical extraction 99.5% pure.

Question 37

What makes cephalospoins?

Answer 37

Cephalosporium

Question 38

What makes Tetracyclines?

Answer 38

made by Streptomyces aureofaciens, in production broth it will inhibit the producing strain, therefore it is precipitated from the medium during growth with calcium ions.

Question 39

What makes streptomycin?

Answer 39

produced by Streptomyces griseus.

Question 40

How many single cell proteins are contained in microbial cells?

Answer 40

Microbial cells, contain as much as 60-70% protein. Therefore it represents a food or animal feed supply. Cost of production can limit its use.