This set of Fruits Processing Multiple Choice Questions & Answers (MCQs) focuses on “Manufacturing Jams”.
1. What is the amount of chlorine is used in washing the fruits?
a) 100ppm
b) 200ppm
c) 300pm
d) 400ppm
View Answer
Explanation: Washing is an important unit operation. For effective washing of fruits, 200 ppm of chlorine can be used in water. The pH and temperature should be maintained, to prevent fruits from getting damaged or bruised. Dump and spray washers can be used in industries.
2. What is purpose of pulping?
a) To remove seed
b) To remove core
c) To remove seed and core apart
d) To remove dust
View Answer
Explanation: Pulping is done to remove seed and core part. Various pulping machines are available in market for fruits such as mangoes, peaches, tomatoes, bananas, straw berries and celeries. The gap between the sieve and rotor can be adjusted to suit different type of size and qualities of materials to be pulped.
3. What are the total soluble solids of fruit jam?
a) 68%
b) 78%
c) 58%
d) 48%
View Answer
Explanation: Jam is a product made by boiling fruit pulp with sufficient quantity of sugar to a reasonably thick consistency. It should be firm enough to hold the fruit tissues in position. The Fruit Product Order specifications of total soluble solids of jam are 68.5% per 100 gm of the prepared product.
4. Which of the following is added during boiling of jam to avoid foam scum?
a) Sugar
b) Salt
c) Butter
d) Water
View Answer
Explanation: Boiling is the most important step in jam making. A foamy scum may form on the surface of the jam. This is normal and can be removed by adding a little butter to break the surface tension or by skimming it off with a spoon while the mixture is cooling.
5. How much percentage of fruit pulp should be in jam?
a) 25%
b) 30%
c) 15%
d) 45%
View Answer
Explanation: The Fruit Product Order specification of jam is 45% of fruit pulp per 100 gm of the prepared product. Jam should be prepared from sound, ripe, fresh, dehydrated, and frozen. It is boiled with nutritive sweeteners namely sugar, dextrose, invert sugar or liquid glucose to a suitable consistency.
6. How much percentage of citric acid should be in jam?
a) 0.5-0.6%
b) 1-2%
c) 0.01-0.05%
d) 4-5%
View Answer
Explanation: The Fruit Product Order specification of jam is 0.5-0.6% of acid (citric acid) per 100 gm of the prepared product. The amount of pectin in the gel is quite small (< 1.0% of the weight of jam). The sugar content is very high (60-70%).
7. Are these statements about the jam true?
Statement 1: The finished jam should have 30-50% invert sugar / glucose to avoid crystallization.
Statement 2: For pectin jam, pH of 3.3 gives a good set.
a) True, False
b) True, True
c) False, True
d) False, False
View Answer
Explanation: The finished jam should have 30-50% invert sugar / glucose to avoid crystallization of cane sugar during storage. With excess sugar, the jam becomes gummy and sticky. Acidity can be enhanced by use of citric, tartaric or malic acid. The pH influences inversion of sugar and setting of the jam. For pectin jam, pH of 3.3 gives a good set.
8. Adding more pectin results in harder jam.
a) True
b) False
View Answer
Explanation: Required amount of sugar and pectin is added to the fruit pulp or juice. Water can be added, if needed. The sugar binds to the water molecules and frees up the pectin chains to form their network. Adding more pectin results in harder jam and using more sugar can make it sticky.
9. Why does citric acid added to jam?
a) Lowers the pH of the jam mixture
b) Increases the pH of the jam mixture
c) Maintains the pH of the jam mixture
d) Maintains the flavor of the jam mixture
View Answer
Explanation: The pH plays a key role in making jam. The citric acid lowers the pH of the jam mixture. It also neutralizes those negative charges on the strands of pectin, so they can now assemble into a network that will set the jam.
10. What is the ratio of sugar to fruit when making jam?
a) 1:1
b) 1:2
c) 2:1
d) 2:3
View Answer
Explanation: The amount of sugar to make jam depends on the amount of pectin in the fruit. But generally, the fruit-to-sugar ratio for traditional jams is 1:1. Over-ripe or damaged fruit is not ideal for the production of the jam. It will not set well and is likely to deteriorate rapidly.
11. At what temperature does Jam set?
a) 104-105.5°C
b) 114-115.5°C
c) 154-155.5°C
d) 1034-145.5°C
View Answer
Explanation: The temperatures required for setting point of jams is 104-105.5°C. The main reason for jam not setting is that it wasn’t boiled for long enough once the sugar has dissolved. Setting point is when the boiling mixture reaches 105°C.
12. How long does it take for jam to set after processing?
a) 24-48 hours
b) 30-60 minutes
c) 20-24 hours
d) 48- 72 hours
View Answer
Explanation: Jams are made from crushed or ground fruit and usually have a thick consistency due to high pectin content. The jam takes 24-48 hours to set up. Once the jam is set, complete removal of oxygen from the headspace is done for longer protection from undesirable color and flavor changes.
Sanfoundry Global Education & Learning Series – Fruits Processing.
To practice all areas of Fruits Processing, here is complete set of 1000+ Multiple Choice Questions and Answers.
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