ICAR AIEEA-PG / PGS — Code 18 Food Science Technology · India · ICAR through the National Testing Agency
Original practice questions written to the published syllabus · not past papersProcessing spices and herbs, extracting essential oils and oleoresins, and the technology of natural and synthetic flavours and food colours, including encapsulation and flavour stability.
In the exams: GATE XE-G Section 3 (spice; extraction of essential oils and oleoresins from spices); ICAR AIEEA-PG Code 18 Unit III (flavouring and pigment technology); ICAR AICE 35.a Unit 7
ICAR AIEEA-PG / PGS — Code 18 Food Science Technology
Unit III names spices and flavouring and pigment technology. MCQs test active principles (piperine, capsaicin, curcumin, eugenol, cinnamaldehyde, crocin), curing of turmeric and pepper, classes of flavourings, encapsulation wall materials, natural colours and their stability, and common adulterants with their simple tests.
How our questions for ICAR AIEEA-PG / PGS spread across the units of Spices, Herbs, Essential Oils & Flavour Technology. Difficulty: 28 easy, 47 medium, 14 hard.
| Quality standards and adulteration of spices | 11 | |
| Spice processing: cleaning, drying, grinding and sterilisation | 9 | |
| Essential oils: steam distillation and other extraction methods | 9 | |
| Major spices: composition and active principles | 8 | |
| Oleoresins: solvent and supercritical CO2 extraction | 8 | |
| Natural, nature-identical and artificial flavours | 8 | |
| Natural colours and pigment technology | 8 | |
| Cryogenic grinding | 7 | |
| Flavour encapsulation and delivery | 7 | |
| Process flavours and reaction flavours | 7 | |
| Medicinal and aromatic plants in foods | 7 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
The pungent principle of black pepper is
B. Piperine
Piperine and related amides give black pepper its pungency. Capsaicin is the pungent principle of chilli, gingerol of fresh ginger, and eugenol is the main aroma compound of clove.
Further reading: Pruthi, Spices and Condiments
The coolant most used in cryogenic grinding of spices is
B. Liquid nitrogen
Liquid nitrogen at about −196 °C cools and embrittles the spice and leaves an inert gas atmosphere. Ammonia is toxic, and brine or ice slurry would wet the product.
Further reading: Peter (ed.), Handbook of Herbs and Spices
Which hazard is specific to working near a cryogenic grinding line in a closed room?
C. Asphyxiation as nitrogen displaces oxygen
Evaporating liquid nitrogen expands into a large volume of gas that lowers the oxygen content of an enclosed space, so ventilation and oxygen monitors are needed. Nitrogen is inert and does not explode or release ammonia or chlorine.
Further reading: Peter (ed.), Handbook of Herbs and Spices
In a cryogenic grinding line, the screw conveyor before the mill in which liquid nitrogen is sprayed onto the spice is the
C. Precooler
The precooler, usually an insulated screw conveyor with nitrogen spray, brings the spice to grinding temperature before the mill. The cyclone separates powder from gas, the sieve classifies the product, and an airlock meters material.
Further reading: Peter (ed.), Handbook of Herbs and Spices
In steam distillation at atmospheric pressure, an oil component of molar mass 136 g/mol has a vapour pressure of 4.0 kPa and water 97.3 kPa at the boiling temperature. The mass of oil distilled per kg of water condensed is closest to
A. 0.31 kg
m_oil/m_water = (P_oil × M_oil)/(P_water × M_water) = (4.0 × 136)/(97.3 × 18) = 544/1751 = 0.31 kg per kg water. 0.041 kg ignores the molar masses (4.0/97.3); 0.0054 kg inverts the molar mass ratio; 7.6 kg multiplies by 136/18 without the pressure ratio.
Further reading: Baser and Buchbauer (eds), Handbook of Essential Oils
Folded (deterpenated) citrus oils are made because removing terpene hydrocarbons
C. Better stability and solubility
Terpene hydrocarbons such as limonene contribute little odour, oxidise easily and dissolve poorly in water and dilute alcohol; removing them concentrates the oxygenated flavour compounds and improves stability and solubility. Folding lowers, not raises, limonene.
Further reading: Baser and Buchbauer (eds), Handbook of Essential Oils
A spice gives 12% oleoresin. Taking yield as the only basis, 0.5 kg of this oleoresin carries the extractable flavour of about how much ground spice?
D. 4.2 kg
Spice = 0.5 ÷ 0.12 = 4.17 kg. 0.06 kg multiplies 0.5 by 0.12; 6.0 kg multiplies 0.5 by 12; 2.4 kg divides 12 by 5. In practice replacement ratios are confirmed by sensory and chemical comparison.
Further reading: Mukhopadhyay, Natural Extracts Using Supercritical Carbon Dioxide
Retronasal aroma is perceived when
C. Volatiles reach the nose from the mouth
Retronasal olfaction occurs when volatiles released during chewing travel from the back of the mouth to the olfactory epithelium. Sniffing is orthonasal; taste buds and pain receptors give taste and chemesthesis.
Further reading: Reineccius, Flavor Chemistry and Technology
A meaty reaction flavour is made by heating ribose with which amino acid?
A. Cysteine
Cysteine supplies sulphur that forms thiazoles, thiophenes and thiols with meaty character. Proline gives bready notes, leucine gives malty 3-methylbutanal, and glycine gives general roasted notes without meatiness.
Further reading: Reineccius, Flavor Chemistry and Technology
Menthol is obtained mainly from
B. Mentha arvensis
Japanese or corn mint, Mentha arvensis, is the main source of natural menthol. Cymbopogon species are lemongrass (citral), Ocimum tenuiflorum is tulsi, and Withania somnifera is ashwagandha.
Further reading: Peter (ed.), Handbook of Herbs and Spices
Ten here, 89 in the app. The Laisha app has every practice question we have written to ICAR AIEEA-PG / PGS 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.