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Experimental Food Science Virtual Laboratory Manual Table of Contents Food Composition Tables: Proximate Analysis PowerPoint Presentation
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Experimental Food Science Virtual Laboratory Manual Table of Contents Food Composition Tables: Proximate Analysis

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  1. Experimental Food Science Virtual Laboratory Manual Table of Contents Food Composition Tables: Proximate Analysis Food & Drug Law: Standards of Identity, Quality and Fill of Container Weights and Measures Food Preparation: Heat Penetration Sensory Evaluation Water Sugars Starches Fats and Oils Fruits and Vegetables Meats Eggs and Dairy Products Flour Mixtures: 1. Quick Breads 2. Yeast Breads Experimentalfood ScienceLabManual ExperimentalFood ScienceVirtual Lab Instructor’s Manual

  2. Experimental Food Science Virtual Laboratory Manual Instructor’s Manual (Excerpt) Water: Moisture Content of Foods Slide 18 13. How much moisture was lost. (show work) 10.0 -1.3 = 8.7g moisture which evaporated in the moisture oven. 14. % Moisture = 10.0 -1.3 = 8.7/10.0 = 87% contained in the apple 15. Compare your moisture value with the value obtained from a food composition handbook such as Pennington’s Bowes and Church or USDA’s Ag. Handbook No. 8 or online at: http://www.nal.usda.gov/fnic/foodcomp/search/index.html This value was obtained and integrated into the moisture analysis using the old USDA Handbook #8. A more recent reference (on-line) is: http://www.nal.usda.gov/fnic/foodcomp/search/index.html. Of course all nutrients vary depending on plant (apple) variety, time of harvest, time held during storage, sampling, sample weighing, drying oven temperature, time in oven, etc.

  3. Experimental Food Science Virtual Laboratory Manual Instructor’s Manual (Excerpt) Osmosis and Syrup Formation Slice the strawberry. Sprinkle sugar on the slices. Let stand for 30 minutes. 29. What is the liquid that formed on the strawberry slices? Syrup. 30. Explain how it formed. Sprinkled sugar dissolves in surface sap creating an osmotic pressure gradient with higher osmotic pressure outside the slices which withdraws water from the strawberry cells creating the syrup on the surface of the strawberry slices. 31. What is the process called? Osmosis (Type 2)

  4. Experimental Food Science Virtual Laboratory Manual • Instructor’s Manual (Excerpt) • Weights & Measures Laboratory • Fill the liquid measure to the ½ cup line. Note the surface of the milk in the cup. • 9. Is it level? • a. Yes • b. No • 10. Why or why not? • a. Milk fat sticks to sides of glass container • b. Capillary action of liquid for glass container • c. Attraction of milk solubles (proteins, lactose, water- soluble vitamins) for glass container • Since water molecules of milk are polar, they have an affinity for the silicate of the glass and form hydrogen bonds and thus adhere to the sides of the glass measure forming a concave surface (meniscus).

  5. Experimental Food Science Virtual Laboratory Manual • Instructor’s Manual (Excerpt) • Standards of Identity, Quality and Fill of Container • Place some of the packing medium on the refractometer prism and read scale in % sugar at line between light and dark areas. Record: 18% • A refractometer is a device that measures very accurately the concentration of dissolved sugar (irrespective of the particular sugar) in solutions by determining the degree of refraction of light through the sugar solution with the refractive index of the solution calibrated in percent sugar.For fruit cocktail packed in heavy syrup, percent sugar ranges from 18-22% according to 21CFR, § 145.

  6. Experimental Food Science Virtual Laboratory Manual • Instructor’s Manual (Excerpt) • Heat Penetration Laboratory • Use of Broiling Element • Turn on broiler element • Open door • Insert pan containing two cups of water • Insert temperature probe into water (record ambient temperature) • Partially close oven door & monitor & record water temperature and time until 180*F endpoint is reached. • 4. How was heat transferred from element to water in container? Radiation. • 5. Why was the door left ajar during the broiling period? • To prevent the high-limit oven switch from automatically turning the element off.

  7. Experimental Food Science Virtual Laboratory Manual • Instructor’s Manual (Excerpt) • Heat Penetration Laboratory • Use of Broiling Element • Turn on broiler element • Open door • Insert pan containing two cups of water • Insert temperature probe into water (record ambient temperature) • Partially close oven door & monitor & record water temperature and time until 180*F endpoint is reached. • 6. Why did this water sample heat faster than the previous one? • Water closer to heat source. • 7. How is broiling temperature controlled? • Distance from heat source to material (water) being heated.

  8. Experimental Food Science Virtual Laboratory Manual • Instructor’s Manual (Excerpt) • Factors Affecting Enzymatic Browning: Acid • Dip apple slice 1 in water and note browning • Dip apple slice 2 in dilute acid at pH 5 and note • browning • Dip apple slice 3 in dilute acid at pH 2 and note • browning • 32. Which medium inhibited enzymatic browning best? • pH 2 • 33. Why? • Changes the surface of the enzyme such that binding to the substrate does not occur as readily, and minimal or no browning results.

  9. Experimental Food Science Virtual Laboratory Manual • Instructor’s Manual (Excerpt) • Proximate Analysis Laboratory • Kjeldahl Method • Titrate with 0.1 M HCL to clear endpoint. • Read burette and record: 12.5 mL • Based on titration data, compute % crude protein for the red bean sample using the formula: • 4. % Nitrogen = MHCL x VHCL x 14 x 100 • Sample wt x 1000 • = 0.1 x 12.5 x 14 x 100 = 1.25 • 1.4 x 1000 • 5. % Protein = % N x 6.25 (protein factor for mixed diet) • = 1.25 x 6.25 = 7.8%

  10. Experimental Food Science Virtual Laboratory Manual • Instructor’s Manual (Excerpt) • Meats Laboratory • Remove a 1” core sample of raw roast • Place in triangular opening of shear tester. • Activate shear tester and record maximum shear • result in pounds. • Record maximum deflection pointer value of raw • sample & reset 10.7 lb • Shear tester device is based on the Warner-Bratzler Shear Tester that measures the amount of force, in pounds, applied in order to shear, in this case, a one-inch core of meat. The device is spring-loaded and elongates a spring within the instrument face housing that is calibrated to record the load applied, much like a dietetic scale, until the core is sheared which releases the load and the (black) pointer attached to the spring returns to zero (no load) leaving the maximum load (red) pointer to indicate the amount of force required to shear the core sample, 10.7 lb..