Lecture 4

1
Lecture 4 Physical AttributesAnnouncements
2
Lecture 4 Physical AttributesChpt 2, Pages 11-20

• For grain, seeds, fruits, vegetables
• Size described by 3 dimensions
• Major diameter longest dimension of the max
  projected area (fat part)
• Intermediate diameter min. diameter on the max
  projected area, assumed to be equal to the
  longest diameter of the min projected area
  (thickness)
• Minor diameter shortest dimension of the
  minimum projected area (skinny part)
• May be referred to differently in industry
• Usually called length, width, and depth

3
Lecture 4 Physical AttributesChpt 2, Pages 11-20

• Shape used to describe unprocessed foods
• Example carrots cones
• Style used to describe processed foods
• Example carrot coins, french cut beans, apple
  wedges, banana chips
• Shape use geometric solidssphere, truncated
  cone (see appendix C)

4
Lecture 4 Physical AttributesChpt 2, Pages 11-20

• Sphericity
• Ratio of volume of triaxial ellipsoid to a
  circumscribed sphere (show correction in book
  for 2a, 2b, 2c, page 13 and pg 14 example)
• Blueberry example

5
Lecture 4 Physical AttributesChpt 2, Pages 11-20

• Sphericity, Sc
• Palm fruit examplewill it roll or slide???
• research paper
• Aspect ratio, Ra (b/a)100
• Ra gt50...tends to slide
• Sc gt50...tends to roll
• Both gt 50, will tend to roll with some sliding

6
Lecture 4 Physical AttributesChpt 2, Pages 11-20

• Volume
• Volume determined by liquid or gas displacement
• Pycnometers or graduated burettes
• Weight of fluid displaced by solids divided by
  the density of the fluid volume of the solid
  particles
• Buoyant force of water on object, page 16, 2.3
• Platform balance
• Optical method

7
Lecture 4 Physical AttributesChpt 2, Pages 11-20

• Volume
• Volume determined by gas displacement
• Page 17 Fig.2.2
• Gas penetrates grains and seeds
• Coat with wax

8
Lecture 4 Physical AttributesChpt 2, Pages 11-20

• Volume
• Estimation through calculation
• Use Appendix C for equations of similar
  geometries
• Error determination,
• (Your calculation test value)/(test
  value)100
• Example calculated volume using equation48.7
  mm3
• Gas pyncnometer measure 50.1 mm3

9
Lecture 4 Physical AttributesChpt 2, Pages 11-20

• Surface Area
• Peel
• Coating and peeling
• Bread loaf estimation example
• Estimate Surface Area
• Similarity to geometric solids
• Appendix C (not A!!!)
• Example 2.3 page 19

10
HW4 Part 2 AssignmentDue 1/31

• Problem 1
• A) Calculate the sphericity of a blueberry, a Red
  Haven peach, and a Norchip potato.
• B) Which one is more spherical?
• Problem 2
• Calculate the volume of a Bart 46 Wheat kernel
• Reference class handout
• What is the percentage error when compared to the
  volume determined by testing?
• Problem 3
• Using a piece of fruit or vegetable of your
  choice, and example 2.3 in Chpt 2, determine the
  volume and surface area.

11
HW4 Part 2 AssignmentDue 1/31

• Problem 4
• 2.6 in book
• Problem 5
• 2.10 in book