1. Food Sensory Analysis Fernando Pérez Muñoz May-June 2013

2. Agenda Day 1 – Introduction to sensory – Color and appearance – Experiencing Jelly Beans – Sensory testing basics Day 2 – Triangle testing – Student experiments Day 3 – The five tastes – What is flavor? – Rediscovering Flavor Day 4 – Rating tests – Food texture – Student experiments

3. DAY 1 Introduction to sensory Color and appearance Experiencing Jelly Beans Sensory testing basics

4. Introduction to Sensory

5. What does this tell you? Feel? Taste? Aroma? Look? Sound?

6. What does this tell you? Man or Woman? Age? Social Status? Type of Car? Cost?

7. Introduction to Sensory What is Sensory Evaluation? – IFT Food Sensory Division “Sensory evaluation is the scientific discipline used to evoke, measure, analyze, and interpret reactions to the characteristics of food and materials as they are perceived by the senses of sight, smell, taste, touch, and hearing.”

8. Introduction to Sensory If Sensory evaluation utilizes the five senses… – What are the testing instruments? – Will measurements be qualitative or quantitative? – What could be some of the problems? – Is it possible to fix those problems? – Can those instruments be calibrated?

9. COLOR AND APPEARANCE Introduction to Sensory

10. Color and Appearance What is needed to perceive the world through your eyes? Light Source Object Sight

11. What Characteristics can be Perceived Through Your Eyes? Stimulus – Color – Transparency – Shape – Size – Surface texture – Porosity – Surface wetness Interpretation – Flavor – Hardness – Wetness – Sponginess – Cohesiveness

12. What is Light? Electromagnetic waves (380 to 760 nm)

13. What is Light? RGB: Primary colors

14. What is Light? RGB: Primary colors What are Black and white?

15. What is Light? Transmission, reflection and absorption Light Reflection Absorption Re-emission transmission

16. Object Properties Physical state: solid, liquid, gas Size Surface roughness (gloss) Color (pigments)

17. Object Properties Pigments – Primary pigments: CYM

18. Eyesight Eyes receive the stimulus Information sent to the brain Brain interprets data – Based on past experience and associations Reaction occurs

19. Factors Affecting Eyesight Iris – Light control Lens - Focus Retina – Cones (gray levels) – Rods (color) Less sensitive Capability lost at low light levels Past Experience

20. Factors Affecting Eyesight Carry-Over

21. Factors Affecting Eyesight Color Implications Universities!! What’s this?  Which looks more appealing?

22. Factors Affecting Eyesight Color Implications – What color comes to mind? Hielo Smiley Dog Bear Banana Cool

23. Factors Affecting Eyesight Expectations What’s the shape inside the square? What color is the object in the square?

24. Factors Affecting Eyesight Cultural Expectations

25. Factors Affecting Eyesight Metamerism

26. EXPERIENCING JELLY BEANS Introduction to Sensory Color and appearance

27. Demo #1 – What Color are Them? You will be presented with Jelly Bean samples. When instructed, uncover and observe the samples one at a time Use the score sheet to write the observed color of the samples No comments, please!!!

28. Demo #1 – What Color are Them? What happened ? ? ! ! !

29. SENSORY TESTING BASICS Introduction to Sensory Color and appearance Experiencing Jelly Beans

30. Basic Concepts Data types Qualitative – Blue, red, yellow… – Round, square, oval… – Apple, melon, peach… – Yes, no – Same, different Quantitative – Integers: 1, 2, 3, 4… – Decimals: 3.5, 8.2… – Fractions: ½, ¼,… – Ordinal: 1 st, 2 nd, 3 rd … – Multiples: double, triple…

31. Basic Concepts Test types Difference tests – Compare 2 treatments to determine if they are different Attribute tests – Compare 2 or more treatments to determine difference in the intensity of a specific attribute Descriptive test – Describe the attributes of importance in a product and their respective intensities Consumer test – Determine preference or acceptance of a product by consumers

32. Basic Concepts Testing protocol – Identify treatments – Prepare experimenter sheet and panelist score card – Train panelists – Conduct experiment and gather data – Analyze data – Report results

33. Basic Concepts Test Controls – Environment Location, light color and intensity, time of day, etc… – Sample Size, shape, matrix, presentation order, etc… – Panelists Smoking, health status, chewing gum, etc…

34. Basic Concepts Data analysis – Statistics makes it a science-based field Instrumental analysis – Useful to establish relationships between panel data and instrumental data Thresholds and limits

35. Basic Concepts Panel vs. Instruments

36. Questions? Day 1 ends here…

37. DAY 2 Triangle testing Student experiments

38. Review from Yesterday Sensory is a science that uses people’s senses to measure food properties If proper care (controls) are taken, data can be analyzed statistically to make decisions Instruments can also be used to measure properties – …but sensitivity can differ

39. Review from Yesterday Test types Difference tests – Compare 2 treatments to determine if they are different Attribute tests – Compare 2 or more treatments to determine difference in the intensity of a specific attribute Descriptive test – Describe the attributes of importance in a product and their respective intensities Consumer test – Determine preference or acceptance of a product by consumers

40. TRIANGLE TESTING

41. Difference Tests Objective – Determine overall difference between two treatments No indication of the magnitude or direction of the difference Simplest tests Test types – Triangle – Two-of-Five – Duo-Trio – Same or Different – “A” – “Not A” – Different from control

42. Triangle Testing Application – Effect of change in process, ingredient, supplier, etc. – Compare competitor products – Select panelists

43. Triangle Testing Test procedure – Prepare enough samples of both treatments Controls over samples

44. Look Closely… Are they obviously different?

45. Triangle Testing Test procedure – Prepare enough samples of both treatments Controls over samples – Present samples to panelists Random presentation – AAB, ABA, BAA, BBA, BAB, ABB Coded samples – Three digit random number

46. Triangle Testing Test procedure – Experimenter cheat sheet

47. Triangle Testing Score Card

48. Triangle Testing

49. Let’s Practice…

50. Data Analysis Data analysis based on the binomial distribution – Two possible outcomes: right or wrong Count the number of correct answers Perform statistical analysis – With equations (can be set in a worksheet) – Using tables (easier)

51. Data Analysis Critical number of responses in a triangle test. Meilgaard, M.C., B.T. Carr and G.V. Civille. 2006. Sensory Evaluation Techniques. Fourth Edition. CRC Press

52. STUDENT EXPERIMENTS Triangle Testing

53. Exercise 1: Triangle Testing Select your project 1.Cheddar vs. Colby 2.Pepsi ® vs. Coke® 3.Pepín® vs. Holsum® 4.Hormel® vs. Armour® 5.Suiza Premium® vs. Tropicana® Prepare and execute triangle test Analyze data

54. Exercise 1: Triangle Testing Project presentations and discussion Test objective Test type Number of panelists Controls Number of correct responses Conclusions

55. Final Comments

56. Questions? Day 2 ends here…

57. DAY 3 The five tastes What is flavor? Thresholds and prejudices

58. Review of Concepts Sensory is a science that uses people’s senses to measure food properties If proper care (controls) are taken, data can be analyzed statistically to make decisions Instruments can also be used to measure properties – …but sensitivity can differ

59. Review of Concepts Test types Difference tests – Triangle test Attribute tests Descriptive test Consumer test Triangle test Compare two treatments Three samples – Two equal, one odd Count correct responses Use table to analyze data

60. THE FIVE TASTES

61. The Five Tastes Umami

62. The Five Tastes Taste buds are the tongue receptors – They regenerate constantly Taste sensitivity is lost with age – Kids are specially sensitive to sweets – As we age, sensitivity decreases Specially for sweet and salty Thus, we can enjoy bitter and sour foods – Or increase seasoning/sugar content

63. The Five Tastes Taste detection depends on concentration of chemical stimulant – Bitter – Sour – Umami – Salty – Sweet …but there are interactions between the tastes that affect the perceived intensity of each other.

64. The Five Tastes There is also a time-intensity relationship characteristic of chemical stimulants – Food modifiers (e.g., gelatin, maltodextrin, MSG) can be used to alter it

65. The Five Tastes Stereochemistry – There must be a match between the chemical and taste receptor – Receptors saturate Perception lost due to saturation Saturation avoided by cleaning frequently – Water – Soda crackers (unsalted)

66. The Five Tastes Perception affected by – Temperature – Viscosity – Consumption rate – Contact duration – Area of contact – Chemical state of saliva – Presence of other stimulant chemicals

67. WHAT IS FLAVOR? The five tastes

68. What is Flavor? Flavor is the integrated perception resulting from stimulating – Taste buds – Olfactory receptor – Trigeminal nerve in the palate, throat and cheeks ++

69. Smell - Nose Receptors Aromas are the result from the interaction of volatile chemicals with nose receptors – Not all volatiles can be perceived by humans, but in order to smell it, it has to be volatile Aromas are affected by – Structural modifications – Heat – volatilization

70. Smell - Nose Receptors Nose receptors – Saturate – Adapt (get use to the aroma) – “Are emotional” – Are highly sensitive (better than any instrument) – Discriminate about 10,000 different volatiles But can identify around 200

71. Trigeminal Nerve http://dictionary.reference.com/browse/trigeminal Also called trigeminal nerve. Either one of the five pairs of cranial nerves, consisting of motor fibers that innervate the muscles of mastication, and of sensory fibers that conduct impulses from the head and face to the brain.

72. Trigeminal Nerve Responsible for sensations from irritant chemicals – Carbonation – Burning – Cooling – Warm/Hot – Pungency – Astringency

73. Trigeminal Nerve Trigeminal sensations are difficult to separate from the taste/aroma perceptions – These are expected in certain products Implications to sensory panels and consumer acceptance of products – Perception of taste/aroma can be affected by trigeminal factors – Can affect time-intensity perception curves of taste/aroma compounds

74. REDISCOVERING FLAVOR The five tastes What is flavor?

75. Rediscovering Flavor

76. Score Card Scale #1 Not sweet Extremely sweet Scale #2 Not sweet Extremely sweet Scale #3 Not sweet Extremely sweet Scale #4 Not Acid Extremely Acid

77. Exercise 2: Relating Perception to Instrumental Data VS.

78. Exercise 2: Relating Perception to Instrumental Data Pick your product – Orange juice – Apple juice – Tomato Ketchup – Grape jelly – Vanilla yogurt Conduct test Analyze data and prepare graphs

79. Graphs

80. Exercise 2: Relating Perception to Instrumental Data Product tested Brand rating Graphs – Sweetness – Acidity

81. Summary Flavor = Taste + Aroma + Trigeminal Sensations – Combination of three senses Taste  Sweet, Salty, Sour, Bitter, Umami Aroma  Volatile compounds Trigeminal factors affect acceptance

82. Questions? Day 3 ends here…

83. DAY 4 Rating tests Food texture Student experiments

84. Review of Concepts Sensory is a science that uses people’s senses to measure food properties If proper care (controls) are taken, data can be analyzed statistically to make decisions Instruments can also be used to measure properties – …but sensitivity can differ

85. Review of Concepts Test types Difference tests – Triangle test Attribute tests Descriptive test Consumer test Triangle test Compare two treatments Three samples – Two equal, one odd Count correct responses Use table to analyze data

86. Review of Concepts Flavor – Interaction between taste, aroma and trigeminal nerve sensations – It can be useful to establish relationships between sensory and instrumental data

87. RATING TESTS

88. Attribute Difference Test Determine degree of difference between two or more treatments on a specific attribute – Training might be required to ensure panelists understand the attribute to be evaluated – Training is required if more than one attribute will be evaluated

89. Attribute Difference Test Test types: – Directional difference – Paired ranking – Simple ranking – Rating

90. Rating Tests Determine the intensity of an attribute on several treatments at the same time – Three or more treatments No less than 10 panelists – Trained to identify attribute Data collected on scales – Line – Category

91. Scales Line Scale Category Scale Scale #1 Not sweet Extremely sweet

92. Data Analysis Prepare data table Analyze using ANOVA – In Excel, use “ANOVA two factors without replication” PanelistABCDE 123153 201022 302020 434255 ……………… ……………… 1724331 1823343 1901002 2064343

93. Data Analysis ANOVA Source of VariationSSdfMSFP-valueF crit Rows128.51196.7644.9980.0001.725 Columns57.56414.39010.6340.0002.492 Error102.84761.353 Total288.9199 <- Panelists <- Treatments F > F crit, reject “No difference” P-value < α, reject “No difference” “No difference” on the Rows (panelist) is not desired. This can be corrected by training or replication of the experiment.

94. Data Analysis If ANOVA yields a “reject no difference” verdict – At least one treatment is significantly different

95. FOOD TEXTURE Rating tests

96. Food Texture Food texture refers to the way we perceive food through the senses of touch Provide info such as hardness, cohesiveness, sponginess, gumminess, adhesiveness, firmness, etc.

97. Food Texture Texture Profile Analysis

98. Food Texture

99. AttributeDescription FirmnessSlope to maximum force of first cycle Hardness 1Maximum force of first cycle CohesivenessRatio of Area 2 to Area 1 AdhesivenessMinimum force (negative) of first cycle SponginessRatio of Hardness 2 to Hardness 1

100. STUDENT EXPERIMENTS Rating tests Food texture

101. DEMO 5: Texture Profile Analysis

102. Exercise 3: Rating Test on Texture Select your project 1.Firmness of chocolate ganache 2.Softness of scrambled eggs 3.Cohesiveness of cookies 4.Adhesiveness of rice crisps treats 5.Sponginess of cup cakes Prepare and execute rating test Analyze data

103. Exercise 3: Rating Test on Texture Test Objective Treatments Panel results Instrumental data Conclusion

104. Final Words Sensory is a science that uses people’s senses to measure food properties Measuring food properties can be misleading if proper controls are ignored Not just eat your food, enjoy it! – There is much more to it than just nourishment – Let the inner kid out to play (with food) !!!

105. Questions? Workshop ends here…