GATE — Engineering Sciences (XE), Section G Food Technology · India · IITs and IISc on rotation (2026: IIT Guwahati)
Original practice questions written to the published syllabus · not past papersWhat each class of additive and ingredient does, how it is chosen and dosed, and how its safety is assessed and regulated: preservatives, antioxidants, emulsifiers, hydrocolloids, colours, sweeteners, flavour enhancers and processing aids.
In the exams: GATE XE-G Section 3 (addition of preservatives and food additives); ICAR AIEEA-PG Code 18 Unit I (food additives); ICAR AICE 35.a Unit 1
GATE — Engineering Sciences (XE), Section G Food Technology
Section 3 names addition of preservatives and food additives. Expect MCQs on functional classes, preservative mechanisms and pH dependence, antioxidants, emulsifier HLB, gelling agents and sweeteners, and NATs on undissociated acid fraction, blend HLB and sweetener equivalence.
GATE — Life Sciences (XL), Section U Food Technology
Same Section 3 content, often through chemistry: pKa and dissociation, radical scavenging, polysaccharide structure and gelation.
How our questions for GATE spread across the units of Food Additives & Ingredient Technology. Difficulty: 14 easy, 4 medium, 4 hard.
| Preservatives: benzoates, sorbates, sulphites, nitrites and natural antimicrobials | 4 | |
| Definitions, classification and the INS/E-number system | 2 | |
| Safety evaluation: JECFA, ADI and good manufacturing practice | 2 | |
| Antioxidants: synthetic and natural | 2 | |
| Emulsifiers and stabilisers | 2 | |
| Hydrocolloids: starches, gums, pectins, carrageenan, alginates and gelatin | 2 | |
| Food colours: synthetic and natural | 2 | |
| Sweeteners: nutritive and non-nutritive | 2 | |
| Flavour enhancers and acidulants | 2 | |
| Leavening agents, enzymes and processing aids | 1 | |
| Fat replacers and sugar replacers | 1 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
The INS system for food additives is maintained by:
C. Codex Alimentarius
The EU uses the same numbers with an E prefix.
Further reading: Codex CAC/GL 36-1989 and CXS 192-1995
The acceptable daily intake of an additive is usually derived by dividing the NOAEL by:
C. 100
10 for species differences × 10 for individual variation.
Further reading: JECFA evaluations; WHO EHC 240
Weak-acid preservatives act mainly in their:
A. Undissociated form
The neutral molecule crosses cell membranes.
Further reading: Davidson, Taylor and David, Antimicrobials in Food
At pH equal to the pKa of a weak-acid preservative, the undissociated fraction is:
A. 50%
Undissociated fraction = 1/(1 + 10^0) = 0.5.
Further reading: Davidson, Taylor and David, Antimicrobials in Food
Nitrite is added to cured meats mainly to:
D. Control C. botulinum and fix colour
It forms nitrosomyoglobin.
Further reading: Davidson, Taylor and David, Antimicrobials in Food
Which is a natural antioxidant widely used in clean-label products?
A. Rosemary extract
Carnosic acid and carnosol are active.
Further reading: Branen et al., Food Additives; Saltmarsh, Essential Guide to Food Additives
Tartrazine belongs to which chemical class of synthetic colours?
C. Azo dyes
Erythrosine is xanthene; brilliant blue triarylmethane.
Further reading: Branen et al., Food Additives; Saltmarsh, Essential Guide to Food Additives
The reference sweetener with relative sweetness 1 is:
D. Sucrose
Glucose is about 0.7.
Further reading: O'Brien Nabors, Alternative Sweeteners
Sucralose is about 600 times as sweet as sucrose. How much sucralose matches the sweetness of 100 g of sucrose?
A. 0.17 g
Sucrose mass / relative sweetness = 100/600 = 0.17 g.
Further reading: O'Brien Nabors, Alternative Sweeteners
Which leavening agent is suitable only for thin, low-moisture products such as biscuits?
B. Ammonium bicarbonate
Ammonia escapes only from thin, dry products.
Further reading: Branen et al., Food Additives; Saltmarsh, Essential Guide to Food Additives
Ten here, 22 in the app. The Laisha app has every practice question we have written to GATE in this subject, marked as you go, with timed papers, a jump-to-unanswered list and a certificate when you pass at 70 per cent.
Free for ten days, then one subscription of US$10 a month. We would rather say so here than have you find it later.
An AI operating system for agriculture: free guides, manuals and tools written for every country.