Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 1701/13/19 BAE2023 Physical Properties of Biological Materials Lecture 41•HW #3 due Jan. 30th in classLecture 4 – Physical AttributesAnnouncements01/13/19 BAE2023 Physical Properties of Biological Materials Lecture 42•Quick Review–Describe size, shape, style–Sphericity–Determining volume, equipment–Surface area–Electronic method for estimationLecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 43–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 smallLecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 44•Hydrometer–Brix: sucrose–Lactometers: milk density–Oleometers: veg.oil01/13/19 BAE2023 Physical Properties of Biological Materials Lecture 45–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%100%foam liquidliquidV VOR xV-=Lecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 46–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 densityLecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 47•For water and solids: •BOOK CORRECTION ex. 2.4 11solidsniiimrr==�ker11.0nelwater solidsM Mrr r=-+Lecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 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/cm3Lecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 49–Density of fruits and vegetables:•Determined by water displacement method.•Example 2.5 •TableLecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 41001/13/19 BAE2023 Physical Properties of Biological Materials Lecture 411–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^3Lecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 412–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 2.6Lecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 413–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 particlesLecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 414–Sieve analysis–Sized by the 64thLecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 415–Radius of Curvature•Sharpness of curvature will determine how readily an object will roll•Determined by radius of curvature•Figure 2.6Lecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 416–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 sortingLecture 4 – Physical AttributesChapter 2, pgs. 21-4801/13/19 BAE2023 Physical Properties of Biological Materials Lecture 417–Homework #4 Due 2/6–Problem 1: #2.2 in book–Problem 2: #2.8 in book–Problem 3: #2.10 in bookLecture 4 – Physical AttributesChapter 2, pgs.
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