Q1. According to the _________ , pectins are classified as high methoxyl or low methoxyl pectins.

1. Degree of ripening
2. Degree of esterification
3. Degree of senescence
4. None of the above

ANSWER: B. Degree of esterification

• Explanation – Pectins are classed as high methoxyl or low methoxyl depending on the degree of esterification. The qualities of the two groups differ, and they gel in distinct ways. Pectins with a low methoxyl content. Pectins with low methoxyl content have largely free carboxyl groups. Only about 20%–40% of the carboxyl groups are esterified. As a result, the majority of them can form cross-links with divalent ions like calcium.

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Q2. Low-methoxyl pectin can be obtained by demethylating pectin with enzymes, acid, or alkali until it is ______ esterified.

1. 5-10%
2. 10-20%
3. 20–40%
4. 40-60%

ANSWER: C. 20–40%

• Explanation – Apple cores and skins (apple pomace) and the white inner skin (albedo) of citrus fruits are used to make purified pectin. It comes in two forms: liquid and granular. The shelf life of granular items is longer than that of liquids. Demethylating pectin using enzymes, acid, or alkali until it is 20–40 percent esterified yields low-methoxyl pectin. These pectins can be used commercially to make low-calorie jams, jellies, and desserts since they gel with divalent ions and don’t require sugar. They’ve also been introduced to the retail market, allowing people to make low-calorie foods at home.

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Q3. _______ are a group of complex hydrophilic carbohydrates containing thousands of monosaccharide units.

1. Pectin
2. Seaweed
3. Gums
4. All of the above

ANSWER – C. Gums

• Explanation: Gums are a complex hydrophilic carbohydrate with thousands of monosaccharide molecules. The most frequent monosaccharide present in gums is galactose; glucose is usually missing. Because of their affinity for water and their size, gums are commonly referred to as hydrocolloids; when mixed with water, they form stable aqueous colloidal dispersions or sols. Because the molecules are highly branched, most gums are incapable of forming gels.

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Q4. The seed gums include _______.

1. Guar gum
2. Locust bean gum
3. Xanthan gum
4. Both A and B

ANSWER: D. Both A and B

• Explanation: Guar and locust bean gums are among the seed gums. These gums are mannose and galactose-based branching polymers. Guar gum has a 2:1 mannose/galactose ratio, whereas locust bean gum has a 4:1 ratio. Guar gum dissolves in cold water, whereas locust bean gum requires hot water to dissolve. When applied alone, neither gum creates a gel. They can, however, be used in conjunction with other gums to make gels.

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Q5. ________ gum is produced using fermentation by microorganisms.

1. Curdlan
2. Carrageenan
3. Guar gum
4. Cellulose

ANSWER: A. Curdlan

• Explanation – Xanthan gum, gellan gum, dextran, and curdlan are all gums made from microbial fermentation. Xanthan is the most prevalent of them. Xanthan produces viscous sols that are stable throughout a wide pH and temperature range. Except when combined with locust bean gum, it does not create a gel. It’s utilized as a thickener, stabilizer, and suspending ingredient in a variety of products. Xanthan gum is found in most salad dressings.

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