Tag: food production and microorganisms

Questions Related to food production and microorganisms

Study the following statements regarding lactic acid bacteria (LAB) which are used to convert milk into curd.
(i) They produce adds that coagulate and partially digest the milk proteins.
(ii) A small amount of curd added to the fresh milk as an inoculum contains millions of LAB, which at suitable temperature, multiply and convert milk into curd.
(iii) Conversion of milk into curd improves its nutritional quality by increasing vitamin $B _{12}$.
(iv) LAB may result in acidity in the stomach of human beings.
Which of the given statements are correct? 

zoology introduction to microbiology commercial use of microorganism microbes in household and industry microbial products - food, medicines and industrial products food production and microorganisms

  1. (i) and (ii)

  2. (ii) and (iii)

  3. (i), (ii) and (iii)

  4. (i), (ii), (iii) and (iv)

Show answer
Correct Option: C
Explanation:

Microbes such as. Lactobacillus and others commonly called lactic acid bacteria (LAB) grow in milk and convert it into curd. During growth, such bacteria produce adds (mainly lactic add) that coagulate and partially digest the milk proteins. A small amount of curd, known as starter, is added to the milk and kept at a suitable temperature, where lactic acid bacteria multiply in millions and converts milk into curd that also improves its nutritional quality by increasing vitamin BI2. It also checks the growth of disease-causing microbes in the stomach.

So, the correct answer is '(i), (ii) and (iii)'

Statement 1 : Besides curdling of milk, LAB also improve its nutritional quality by increasing vitamin $B _{12}$.
Statement 2 : LAB, when present in human stomach, check disease causing microbes. 

zoology introduction to microbiology commercial use of microorganism microbes in household and industry microbial products - food, medicines and industrial products food production and microorganisms

  1. Both statements 1 and 2 are correct.

  2. Statement 1 is correct but statement 2 is incorrect.

  3. Statement 1 is incorrect but statement 2 is correct.

  4. Both statements 1 and 2 are incorrect.

Show answer
Correct Option: A
Explanation:
LAB improve its nutritional quality by increasing vitamin B$ _12$ besides curdling the milk.
LAB produce myriad beneficial effects for human beings include, alleviation of lactose intolerance, diarrhoea, peptic ulcer, stimulation of immune system, antiallergic effects, antifungal actions and prevention of colon cancer.
So, the correct option is 'Both statements 1 and 2 are correct'

Identify the bacteria that promotes the formation of curd.

zoology introduction to microbiology commercial use of microorganism microbes in household and industry microbial products - food, medicines and industrial products food production and microorganisms

  1. Vibrio cholerae

  2. Lactobacillus

  3. Mycobacterium leprae

  4. Clostridium tetani

Show answer
Correct Option: B
Explanation:

Lactobacillus acts on the lactose of the milk and converts it into lactic acid. The increased acidity causes the milk proteins (casein) to coagulate and form the curd. So, the correct answer is option B.

How is the lactic acid fermentation used in milk industry?

zoology introduction to microbiology commercial use of microorganism microbes in household and industry microbial products - food, medicines and industrial products food production and microorganisms

  1. To convert milk sugar to lactic acid

  2. Lactic acid coagulate the milk protein casein

  3. Lactic acid coagulate the milk fats

  4. All of the these

Show answer
Correct Option: A
Explanation:
  • Lactobacillus bacteria cause the fermentation of milk in which milk sugar lactose is converted into lactic acid. This produces yoghurt and curd.
  • Lactobacillus is acidophiles which best grow at a pH of 1 to 5.4.

Milk is converted into curd by 

zoology introduction to microbiology commercial use of microorganism microbes in household and industry microbial products - food, medicines and industrial products food production and microorganisms

  1. Bacteria

  2. Fungi

  3. Algae

  4. None of these

Show answer
Correct Option: A
Explanation:

Milk is converted into curd by the action of Lacto bacillus. It multiplies and promotes the formation of curd in milk.

Bacteria responsible for fermentation of dairy milk are

zoology introduction to microbiology commercial use of microorganism microbes in household and industry microbial products - food, medicines and industrial products food production and microorganisms

  1. Lactobacillus

  2. Hay Bacillus

  3. Acetobacter

  4. Rhizobium

Show answer
Correct Option: A
Explanation:

The most common bacteria responsible for fermentation of dairy milk are Lactobacillus species. Bacteria like Lactococcus and Leuconostoc are also used in production of fermented milk products. Lactobacillus produce lactic acid from lactose by the process of glucose fermentation. This also increases acidity and sours and thickens the milk.

Thus, the correct answer is 'Lactobacillus.'

........... is used to make wine and bread.

biology introduction to microbiology food production and microorganisms microbial products - food, medicines and industrial products uses of microorganisms commercial use of microorganism microbes in household and industry

  1. Amoeba

  2. Yeast

  3. Tradescantia

  4. Rheo leaf

Show answer
Correct Option: B
Explanation:

Yeast is a single-celled, microscopic fungus which uses sugar as food. Ethanol fermentation is a biological process of converting sugars to alcohol and carbon dioxide. It is performed by yeasts in the absence of oxygen. 

So, the correct answer is option C.

Why yeast is used in baking industry

biology introduction to microbiology food production and microorganisms microbial products - food, medicines and industrial products uses of microorganisms commercial use of microorganism microbes in household and industry

  1. It reproduces rapidly

  2. Yeast produces carbon dioxide during respiration

  3. Both A and B 

  4. None of these

Show answer
Correct Option: C

What is the basis of using yeast is baking industry? 

biology introduction to microbiology food production and microorganisms microbial products - food, medicines and industrial products uses of microorganisms commercial use of microorganism microbes in household and industry

  1. Bubbles of gas fill the dough

  2. Bubbles of gas increase its volume

  3. Both A and B

  4. None of these

Show answer
Correct Option: C
Explanation:

Yeast reproduces rapidly and produces carbon dioxide during respiration. Bubbles of the gas fill the dough and increase its volume.

........... is used in the making of bread and yoghurt.

biology introduction to microbiology food production and microorganisms microbial products - food, medicines and industrial products uses of microorganisms commercial use of microorganism microbes in household and industry

  1. Virus

  2. Bacteria

  3. Yeast

  4. None of the above

Show answer
Correct Option: C
Explanation:

Fermentation is the process which is carried by anaerobic respiration of microorganism which leads to the production of lactic acid or alcohol with the release of carbon dioxide. When the yeast is added to the dough of the bread it converts the sugar to ethanol and carbon dioxide which forms bubbles. Yeast has a lot of economical value to the mankind. It is used in the production of bread, wine, curd etc.

So, the correct answer is option C.