Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 Quick Review Describe size, shape, style Sphericity Determining volume, equipment Surface area Electronic method for estimation 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 Density: Definition: weight per unit volume Liquid density determined by pycnometer, hydrometer Common liquid food product in Table B.1 in Appendix B May change significantly with temperature Specific Gravity: Definition: ratio of density of liquid to density of water Change due to temperature is small 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

BAE2023 Physical Properties of Biological Materials Lecture 5 Hydrometer Brix: sucrose Lactometers: milk density Oleometers: veg. oil 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 Foams: products with large amounts of air incorporated during processing Whipped cream, sherbet, ice cream Describe using “overrun”: % increase in volume attributed to air Icemilk: 30-40% Sherbet: 50-80% Cream: 100-120% 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 Particulate Materials Solid Density: weight per unit volume excluding interior pores Particle Density: weight per unit volume of individual kernel Bulk Density: weight per total volume occupied by large quantity of kernels Density of water is different than other components…we can distinguish solid density and water density 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

For water and solids: BOOK CORRECTION ex. 2.4 Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 For water and solids: BOOK CORRECTION ex. 2.4 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 “particle density is highly dependent on moisture content” EX: suppose the soybean moisture content were 0.16 and the kernel density were 1.232 g/cm3 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 Density of fruits and vegetables: Determined by water displacement method. Example 2.5 Table 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

BAE2023 Physical Properties of Biological Materials Lecture 5 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 Bulk density Determined by pouring a sample into a container with known dimensions. Variables: method of filling and striking surface Conversion: 1 bushel = 1.244 ft^3 or 0.035239 m^3 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 Test Weight Factors affecting test weight…moisture content, broken kernels, fines, variety/hybrid, growing conditions Bulk density Table 2.3 (you will need this table later on!!!) Porosity: space between particles, not within particles Calculated from bulk density and particle density Example 2.6 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 Regression and Statistical Distribution Equation 2.6 What is this business about logs? Mean and standard deviation (measure of variability) r^2 Normal distribution Influences how we design equipment to handle particles 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

Sieve analysis Sized by the 64th Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 Sieve analysis Sized by the 64th 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 Radius of Curvature Sharpness of curvature will determine how readily an object will roll Determined by radius of curvature Figure 2.6 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 Applications Separate foreign material Proper singulation during planting Separate germs, pericarps, hulls from endosperm or cotyledon Size grades and shape Density separation (milk separator) Watermelon sorting by shape and weight Sorting by shape…orientation is a problem Optical sorting 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5

Lecture 5 – Physical Attributes Chapter 2, pgs. 21-48 Homework #4 Due 1/29 Problem 1: #2.2 in book Problem 2: #2.8 in book Problem 3: #2.10 in book 2/24/2019 BAE2023 Physical Properties of Biological Materials Lecture 5