Quality and Analysis of Food

1. Quality and Analysis of Food Objective and Sensory Testing

2. Objective Food Testing Tools and Procedures

3. Optical Sorting Machines • Sorts • Foreign objects • Quality control • Uniformity • https://www.youtube.com/watch?v=V54iBP2CU6c

4. Consistometer • https://www.youtube.com/watch?v=4c6t_2JFVbs • Used to measure the viscosity of a product

5. Line Spread Test • A simple, somewhat less accurate, way to measure viscosity of a product

6. Refractometer • Used to measure Brix or sweetness level of a product • https://www.youtube.com/watch?v=lij4oawWONg

7. Can Seam Evaluation • Determines can seam integrity • https://www.youtube.com/watch?v=deqeOvAWp_c

8. Moisture Analyzer • Measures total water content • https://www.youtube.com/watch?v=XgJQuiv9ixc

9. Water Activity

10. Water Activity Meter • Measures the available water or water vapor • https://www.youtube.com/watch?v=g4xa3e3T5s8

11. Compression and Shear • Used to measure texture • https://www.youtube.com/watch?v=D-R6xatWzbM

12. Sensory Testing

13. Sensory Testing • The food people choose depends largely on quality • The only way to determine what a population thinks is to ask them! • Sensory and objective tests are best when they correlate or complement each other • Flavor is the hardest attribute to predict

14. Food Appearance – size

15. Food Appearance – shape

16. Food Appearance – color

17. Food Appearance – structure

18. Food Appearance – turbidity

19. Food Appearance – dullness/gloss

20. Food Appearance – whole/damage

21. Texture • Tactile character (mouthfeel) • The shape, form, and feel of a food, as assessed by the mouth, tongue, teeth, and jaws. • For example • Graininess • Brittleness • Chewiness

22. Texture – describe the following

23. Texture – describe the following

24. Texture – describe the following

25. Texture – describe the following

26. Texture – describe the following

27. Texture – describe the following

28. Texture – describe the following

29. Texture – describe the following

30. Texture – describe the following

31. Texture – describe the following

32. Texture • Tactile sensations • Carbonated beverages • Astringency – Puckery, dry feeling in the mouth • Unripe persimmons • Rheology • The science of deformation and flow of matter • Reaction of food when a force is applied • Shortometer, Warner-Bratzler Shear, etc.

33. Flavor • The combination of tastes, aromas and other sensations caused by the presence of a foreign substance in the mouth • Flavor is to food what hue is to color and what timbre is to music

34. Taste • The sensations we detect when a substance comes in contact with the taste buds on the tongue • Sweet • We consume an average of 127 pounds per year per American • Sour • Salt • Bitter • Umami

35. Taste • First line of defense • How do we taste? • Insects with feet • Fish with skin • 2,000 to 5,000 avg. taste combinations • Children hard-wired for sweet-bitter • Pregnant women don’t like bitter • Taste buds wrapped in pain detection fibers • Sensitive to temperature, menthol and capsaicin • Self-renewing

36. Smell • One molecule can evoke positive or negative emotions • 4,000 to 10,000 basic scents • About the same as mice • Rabbits = 20,000 • Bloodhound = 100 million • Bear = ? • 80% of taste

37. Taste sensitivity • Time • Salt - quick detection • Bitter – longer, about a second • Detection threshold • Concentration required for detection of a substance or stimulus in a medium

38. Factors that effect flavor perception • Temperature • Frozen foods diminished sweetness • Warm foods – taste perception increased, odor increased • Hot foods • Effect of “burned tongue” leads to decreased taste till taste bud regenerates

39. Factors that affect Tastes/Flavors • Consistency • Presence of contrasting tastes • Presence of fats • Color

40. Enhancing your sense of taste • Eat slowly, allow food to vaporize • Eat a little bit of this, and a little bit of that (variety) • Avoid smoking, abundant alcohol, scalding • Expose food to all taste buds

41. Compromises to the Perception of Taste • Age • Health • Smoking

42. Tests for Sensory Evaluation

43. Sensory Evaluation • Definition • A scientific method used to evoke, measure, analyze, and interpret those responses to products as perceived through the senses of sight, smell, touch, taste, and hearing. • Types of Panels • Consumer Panel • Usually not trained but willing to participate • Trained Panel • Received through training on how to evaluated foods

44. Types of Sensory Tests • Discrimination or Difference • Is there a perceivable difference between products • Triangle and Duo-trio Tests • Affective, Acceptance, or Preference • Used to determine whether a specific consumer group likes or prefers a particular product • Ranking or Likeability Tests • Descriptive Testing

45. Difference Testing Sample 647 Sample 481 Sample 549 Sample B Triangle Test All three samples given together or given one at a time Need to choose which sample is different 33.3% chance of being right

46. Descriptive Testing • Profiling • A detailed word description (usually of flavor or texture) with an intensity rating developed by a highly trained panel • Individuals submit their own scores and the panel leader records comments and discussion while determining a consensus rating. 713

47. Preference and Acceptability – consumer testing usually Hedonic scaling for each attribute of interest

48. Example of Descriptive Panel • When would you do this type of panel? • What information does this testing give a researcher? What does it not provide?

49. Key Principles for Sensory Tests • Random Numbers • Order and other bias • Sample Differences – color, temperature, etc. • Asking the right questions • Evaluation of data