Name of the University : Jadavpur University
Department : Food Tech & Bio-Chemical Engineering
Degree : B.Tech
Subject Name : Food Process Engineering
Year/Sem : III/II
Website : jaduniv.edu.in
Document Type : Model Question Paper
Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/dspace.jdvu.ac.in/6177-Food%20Process%20Engineering.pdf
Jadavpur Food Process Engineering Question Paper
Bachelor Of Technology (Ftbe) Examination, 2013 :
(3rd Year, 2nd Semester)
Time : Three hours.
Full Marks : 100
Use a separate Answer-Script for each part.
Related : Jadavpur University Chemistry Of Foods B.Tech Question Paper : www.pdfquestion.in/6175.html
Model Questions
PART – I
(50 marks)
Answer q.no. 1 and any two from the rest. :
1. Fill in the blanks : 1×10=20
(a) ………… is the critical temperature zone in freezing of foods.
(b) Insulated vans have ………… thickness of PUF.
(c) Thawing curves are ………… than freezing curves.
(d) ‘n’ is known as ………… in GL method of calculation of freezing time.
(e) d= ………… in Tao solutions.
(f) ß1= ………… in an Ede chart.
(g) ………… method is used to predict freezing time for frozen fishes.
(h) Microwave thawing has limited applicability due to …………
(i) Bulk freezing is achieved in ………… freezer.
(j) Food freezing is commonly by ………… contant freezing.
2. (a) Describe the freezers you would use to freeze
(any three) 3×2=6
(i) Cherries
(ii) Cod
(iii) Prawns
(iv) Diced carrots
(b) Where does thawing find application in industries? Why is complete thawing not preferred for a food product undergoing processing? 2+2=4
(c) Sweet cherries, approximately 1.5cm in diameter, are frozen in an IQF system with air at –30°C and a surface heat transfer co-efficient of 50W/m2K. If the initial temperature of the product is 5°C, how much time will be required to reduce its centre temperature to –15°C? Estimate the freezing time using the Celand-Earle approach. Take all relevant data from standard charts and tables.
For spherical geometry :
P = 0 . 1 0 84 + 0 . 0 9 24 NPK+ NSte ( 0 . 2 31 NPK –
0.3114/NBi + 0.6739)
R=0.0784+NSte(0.0386NPK – 0.1694)
3. (a) With diagrams, comparatively evaluate the two latest designs of fluidized bed freezing equipments used industrially.
(b) A continuous plate-freezing system is being designed to freeze 0.5Kg cod fillet packages at a rate of 500 Kg/h. The package dimensions are 0.04m by 0.1m by 0.14m and it enters the freezer at 5°C. The plates for each station are 1m wide and will accommodate 8 packages of the indicated dimensions.
The plates are maintained at a temperature of –30°C and the surface heat transfer co-efficient is 28W/m2K. The package material has thickness of 8×10–4m and a thermal conductivity of 0.05W/mK. Compute the number of freezing stations (or compartments) required for freezing the product to –25°C by Plank and Mott procedures. Use standard tables and charts. Comment on discrepancies of results, if any. 16
4. (a) Diagrammatically describe the operation of a continuous LN freezer. What parameters influence its productivity? 6+2
(b) What is refrigeration load? How are the following calculated for a cold storage?
(i) Freezing load
(ii) Respiration load of fruits and vegetables stored in the cold storage. 2+4
(c) Using Gurnie-Lurie chart, determine the time required for the centre of a package of meat of
5cmx 10cmx30cm dimensions to reach 4.4°C.
Consider the following data : ta=1.7°C, to=26.7°C,
h=1.95 cal/h/cm2C, Cp=0.85, K=5.21cal/hcm2C, ?=1.04g/cc.
PART – II
(50 marks)
Answer q.no. 1 and any two from the rest. 5. Answer any two questions : 5×2=10
(a) Write the principle of entrusion of food material with neat sktech.
(b) Write the advantages of limitations of different types of air flow pattern in a funnel drier.
(c) Write a short note on fluidized and drier.
6. (a) What are the advantages and disadvantages of entrusion processing over other concentional processing methods.
(b) Make a comparison between single sesew and favin sesew entrusion system.
(c) Mention the process variables associated with entrusion processing.
(d) Entrudate materials are light and brittle (for expanded products)–Why?
(e) If the feed material for an entrusion contains high amount of soyabean flour then what type of values are expected for BD, ER & WHC. Justify your answer.
(f) Nutritional quality and digestibility of extrudate products are high–Explain. 3+3+3+3+5+3=20
7. (a) Write the mathematical expressions (model equation) which define die characteristic; metering zone characteristic and feed zone charactistic for an extruder.
(b) How would you calculate LEI, SEI & VEI of extrudates?
(c) How do rate of heat transfer relates mass transfer during surface heating of atray of food material?
(d) State how does air flow rate relate surface heat transfer coefficient in both parallel and perpendicular flow.
(e) Mention the bed height range usually maintained in belt drying.
(f) Why ‘Bin drier’ is used as ‘finishing dirier’?
(g) Write some applications of drum drying. 6+4+3+2+1+2+2=20
8. (a) What do you mean by ‘foam mat drying’?
(b) Write the advantages of funnel drier.
(c) With a schematic diagram show the operating principle of a cabinet drier.
(d) Write the objectives of employing
(i) distributor
(ii) Plenum chambear
(iii) free board in fluidized bed drier
(e) Mention different types of atomizer used in spray drier and write the mechanism of action of ultrasonic atomizer.
(f) How the process of spray drying is designed to cause little damage to food material during drying? 4+2+5+4+3+2=20