THIS IS FOR EDUCATION

1. PRESENTATION ON PHYSICAL PROPERTEIS OF Food MATERIALS PFE-502 SUBMITTED BY :- Er. OM_SURYAWANSHI 9302528033 M. Tech. (Previous) Department of APFE

2. Physical Properties
Mechanical Properties
Thermal Properties
Electrical Properties
Optical Properties
Chemical Properties
Rheological Properties &
Hygroscopic Properties
Important Properties of Food Materials :-

3. Physical Properties:-
Shape & Size
Density & Specific gravity
Volume
Porosity
Surface Area etc.
It is important in the design of any particular machine or analysis of the behaviour of the product during process.

4. Importance of Physical Properties:- These properties are necessary for the design of :-
Cleaning unit
Grading unit
Separating unit
Handling unit
Shorting unit
Storing and
drying system.

5. Shape & Size :- Shape is the rigid form of body while, Size is the measurement of dimensions. Used in :-
Shape & Size of Screen openings.
Selection of Disk
Adjustment of Cylinder Clearance.
Angle of inclination.
Vibration amplitude & Frequency of Screen.

6. Parameters for determining the shape & size :-
Roundness:- measure of the sharpness of the solid materials.
Roundness, = Ap/Ac Ap= largest projected area of object Ac=area of smallest circumscribing circle
Roundness,=Σr/NR r= radius of curvature R= radius of maximum inscribed circle N=total no. of corners
 Roundness,=r/R r= radius of curvature of sharpest corner R=mean radius of the object

7. Sphericity:-
It is the cubic root of volume of solid and the volume of circumscribed sphere.
It may be defined as the ratio of surface area of sphere having same volume as that of particle to the surface area of the particle
Ratio of the solid to the volume of circumscribed volume. Sphericity, = Di/Dc Di=dia. of largest inscribed circle Dc=dia. of smallest circumscribed circle

8. Almost all spherical objects have sphericity approaching 1
The value of sphericity ranges from 0 to 1.
An orange has sphericity of the order of 0.95 and
Paddy has 0.130to 0.1520
Sphericity continues……
Sphericity = [Volume of solid/Volume of circumscribed sphere]1/3

9. Methods for measuring Size
Vernier calliper :- least count 0.01 cm
Micrometer Method :- least count 0.01mm
Projection Method :- Ac = (A1+A2+A3)
Travelling Microscope
Sieve Analysis Method :- D = 0.10332(2)FM

10. Instruments for Measuring Shape & Size:- Vernier Callipers

11. Screw Gauge

12. Density & Specific gravity :- Density = Mass/ Volume (Kg/M3) Used in :-
Design of Silos and Bins
Mechanical composition of silage
Separation of crops
Sorting and Grading
Maturity evalution
Texture and softness

13. True Density
Bulk Density
Apparent Density
This properties are used in designing of silos and storage bins, separation of desirable materials from impurities, cleaning and grading etc. Density & Specific gravity…..

14. Specific gravity = weight in air x specific gravity of water weight of displaced water Specific gravity Methods :-
Suspension Method
Density column Method
Platform Method
Specific gravity balance Method
Relative density bottle Method

15. Suspension Method
Density of mixture = V1 S1 V2S2V1V2 Density of grain = Density of mixture Where V1 = volume of one liquid S1 = specific gravity of one liquid V2 S2 = Respectively of other liquid
Density column Method
Carbon tetrachloride
Cyclohexane

16. Platform Method
Weight of fruit in air = W1 gm Weight of fruit in water = W2 gm Specific gravity of fruit = W1 / (W1 – W2)
Specific gravity balance Method
If the solid is heavier than water
If the solid is lighter than water

17. If the solid is heavier than water
Volume = Weight in air – weight in water / weight density of water Specific gravity = [weight in air / weight in air – weight in water]x (Sg)L Where, (Sg)L = Specific gravity of water
If the solid is lighter than water
Specific gravity = (Wa) object / (Wa - Ww) both – (Wa -Ww) sinker x (SG)L Where Wa = weight in air, Ww = weight in water

18. Relative density bottle Method
Weight of bottle in air = W1
Weight of bottle + Water in air = W2
Weight of bottle + toluene in air = W3
Specific gravity of toluene = W3 – W1 / W2 – W1
Weight of the bottle + 10 of the grain + toluene to cover the sample = W4
Specific gravity of grain = (S.G. of toluene) x Weight of the grain / weight of toluene displaced by the grain.

19. Porosity:- It is relationship between volume of the inter-grain space to the total column of grain mass. Porosity =- BgWhere, B= bulk density of material, g = True density of material

20. Porosity determination Method:-
Air compression pycnometer method
Porosity Measuring Method

21. Surface Area:-
Leaf Surface Area:-
Graphical Method
Air Flo Planimeter :- Two perforated plates Having 100 holes per square cm. Fruits Surface Area:-
Apple, S=6.72+0.129W
Pears, S=7.49+0.99W
Eggs, S=4.82W0.66
Plum, S=2.18+0.149W Where, S= surface area in sq. inch, W= fruit weight in gm.

22. References:-
Singhal OP & Samuel DVK. 2003. Engineering properties o Biological Materials. Saroj Prakashan
Sahay KM & Singh KK. 1994. Unit operation of Agricultural Processing. Vikas Publ. House.