Food Science & Technology Quiz

FOOD TECHNOLOGY (09-10-2021)

Q1. _________  is designed to reduce the viscosity and slipperiness of the pulp.

  1. Mash Enzyme Treatment
  2. De-pectinization
  3. Disintegration
  4. Hot break process

ANSWER: 2. De-pectinization

  • Explanation: De-pectinization reduces the viscosity and slipperiness of the pulp, allowing for the use of decanters and presses with the correct press aids. It’s particularly good for digesting aged and stored fruit that yields little juice. Several depectinizing tanks are used to ensure that a constant flow to the presses or decanters is maintained.


Q2. ________ is a commonly used system for grape juice pressing.

  1. Willmes Press
  2. Bucher-Guyer Press
  3. Bucher horizontal piston press
  4. Screw press

ANSWER: 1. Willmes Press

  • Explanation – The Willmes Press is a widely used grape juice pressing machine. It’s a pneumatic system with a perforated, rotatable horizontal cylinder in the center and an inflating rubber tube (airbag) in the middle. The grape mash is poured into the cylinder through a door on the cylinder wall that has been rotated to the top position. The press is rotated after filling to achieve even filling. The cylinder is then rotated while the bag is collapsed.


Q3. _________ is the main bitter fraction of “Navel‟ oranges.

  1. Limonin
  2. Butyl acetate
  3. Isoamyl isobutanoate
  4. Ethyl acetate

ANSWER – 1. Limonin

  • Explanation: The main bitter component of “Navel oranges” is limonin. At a pH of about 3.0, the non-bitter monolactone of limonic acid is rapidly converted to the bitter dilactone, limonin. Delayed bitterness is due to chemical change i.e. conversion of the non-bitter precursor to bitter compounds by the process of extraction of the juice.


Q4. Which among the following contains a high proportion of fruits?

  1. Conserves
  2. Preserves
  3. Marmalades
  4. All of the above

ANSWER: 1. Conserves

  • Explanation: Conserves are similar to jams, but with the addition of chopped nuts (pecans, walnuts, and other nuts) and raisins for texture and flavor. Conserves are fruit mixtures made up of two or more fruits, usually citrus fruits. Figs, peaches, pears, plums, oranges, or carrots are the main ingredients in specific conserves. Conserves have a higher fruit content than preserves and marmalades.


Q5. Pectic acid does not form a gel, except in the presence of added ________ molecules.

  1. Magnesium
  2. Sodium
  3. Calcium
  4. Acetic acid

ANSWER – 3. Calcium

  • Explanation – The protopectin that hasn’t converted to pectin is partially hydrolyzed or converted to pectin when the fruit is cooked. Some acid must be added to the extraction solution, and heat must be given to increase the amount of pectin removed. Other enzymes break down pectin into pectic acid and alcohol when the fruit is overripe. Except in the presence of calcium molecules, pectic acid does not form a gel.


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