ICAR AICE-JRF/SRF (PhD) — Food Processing Technology, Food Safety & Quality, Processing and Food Engineering · India · ICAR through the National Testing Agency
Original practice questions written to the published syllabus · not past papersThe dairy course taught inside food technology degrees: milk as a raw material, fluid-milk processing, the main dairy products, and dairy ingredients (powders, whey and milk proteins) used across the food industry. For depth in dairy chemistry, microbiology and plant engineering see the Dairy Technology track; for Indian traditional dairy products and FSSAI dairy standards see Veterinary's milk-products-technology.
In the exams: GATE XE-G and XL-U Section 3 (milk and milk products processing: pasteurisation, sterilisation, cream, butter, ghee, ice cream, cheese, milk powder); ICAR AIEEA-PG Code 18 Unit III; ICAR AICE 35.a Unit 3
ICAR AICE-JRF/SRF (PhD) — Food Processing Technology, Food Safety & Quality, Processing and Food Engineering
35.a Unit 3 names dairy processing. Expect deeper questions on heat stability and age gelation, membrane fractionation of milk and whey, powder functionality and WPNI, infant formula hazards, cheese yield, and CIP validation.
How our questions for ICAR AICE-JRF/SRF spread across the units of Dairy Science & Technology for Food Technologists. Difficulty: 1 easy, 21 medium, 20 hard.
| Homogenisation | 6 | |
| Cheese: coagulation, cheddar and mozzarella principles | 5 | |
| Milk powders and infant formula basics | 5 | |
| Whey and milk-protein ingredients | 5 | |
| Dairy plant cleaning and sanitation | 4 | |
| Composition and physicochemical properties of milk | 3 | |
| Pasteurisation, UHT and sterilised milks | 3 | |
| Clarification, separation and standardisation | 2 | |
| Cream, butter and ghee | 2 | |
| Fermented milks | 2 | |
| Ice cream and frozen desserts | 2 | |
| Condensed and evaporated milk | 2 | |
| Milk reception, quality testing and platform tests | 1 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
Homogenised milk in clear bottles under shop lighting develops off-flavour faster than unhomogenised milk mainly because
B. It oxidises more in light
Homogenised milk is more susceptible to light-induced (sunlight) and oxidised flavours. Lactose, pasteurisation temperature and fat content are not changed by homogenisation.
Further reading: Tetra Pak, Dairy Processing Handbook
Homogenisation pressures for milk in the first stage are commonly in the range of
C. 10–25 MPa
First-stage pressures of roughly 10–25 MPa (100–250 bar) are common. 100–250 MPa is the range of high-pressure processing, and kPa values are far too low.
Further reading: Tetra Pak, Dairy Processing Handbook
Chymosin coagulates milk by cleaving
C. κ-casein
Chymosin specifically cleaves κ-casein at Phe105–Met106, removing the stabilising caseinomacropeptide so the micelles aggregate with calcium. It does not act on the other proteins or on lactose.
Further reading: Walstra, Wouters and Geurts, Dairy Science and Technology
The buttery aroma of cultured buttermilk comes from
A. Diacetyl
Citrate-fermenting lactococci and Leuconostoc produce diacetyl, the buttery aroma. Acetaldehyde is the key yoghurt flavour; ethanol and propionic acid belong to other fermentations.
Further reading: Walstra, Wouters and Geurts, Dairy Science and Technology
Ice cream kept in a shop freezer whose temperature cycles develops a coarse, icy texture because
B. Ice recrystallisation
Heat shock melts the smallest ice crystals and refreezes the water onto larger ones, coarsening the texture. Lactose crystallisation gives sandiness, overrun falls rather than rises, and fat does not leave.
Further reading: Walstra, Wouters and Geurts, Dairy Science and Technology
The organism of greatest concern in powdered infant formula, because it survives in dry powder and causes severe illness in newborns, is
D. Cronobacter sakazakii
Cronobacter sakazakii, with Salmonella, is the critical hazard in powdered infant formula. Listeria is a concern in moist ready-to-eat foods, C. perfringens in cooked meats, and S. thermophilus is a harmless yoghurt culture.
Further reading: Tetra Pak, Dairy Processing Handbook
ATP bioluminescence swabs are used after CIP to
B. Check for organic residue
The test detects ATP from residues and microorganisms, giving a rapid check of cleanliness. It does not measure detergent strength, identify species or test hardness.
Further reading: Tetra Pak, Dairy Processing Handbook
100 kg of cream at 45% fat is to be standardised to 40% fat with skim milk at 0.05% fat. The skim milk needed is about
D. 12.5 kg
Skim = 100 × (45 − 40) ÷ (40 − 0.05) = 12.5 kg. 112.5 kg is the final standardised cream; 11.1 kg divides 5 by 45; 5.0 kg subtracts the percentages directly.
Further reading: Tetra Pak, Dairy Processing Handbook
Whey powder that becomes sticky and cakes in humid storage does so mainly because
C. Amorphous lactose absorbs water and crystallises
Spray drying leaves lactose as an amorphous glass; water uptake lowers its glass transition so it becomes sticky and then crystallises, cementing particles. Pre-crystallising lactose before drying makes non-caking whey powder. Proteins, fat and minerals are not the main cause.
Further reading: Tetra Pak, Dairy Processing Handbook
CIP records show the caustic stage of a pasteuriser clean reached only a fraction of the specified concentration. The correct action is to
B. Treat it as failed and reclean
A cleaning step outside its validated limits is a deviation: the equipment is recleaned and verified before production, and any product made after a failed clean is held and assessed. Relying on the rinse, adjusting the acid or releasing product would leave the cause uncorrected.
Further reading: Tetra Pak, Dairy Processing Handbook
Ten here, 42 in the app. The Laisha app has every practice question we have written to ICAR AICE-JRF/SRF 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.