Sensory evaluation of essential oil final ppt by shivanand m.r

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Sensory evaluation of essential oils..................

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Sensory evaluation of essential oil final ppt by shivanand m.r

  1. 1. WEL-COME
  2. 2. Presentation on, Principles of sensory evaluation of Essential oils Shivanand, M.R. UHS11PGM143 Dept. of PMA 2KITTUR RANI CHANNAMMA COLLEGE OF HORTICULTURE, ARABHAVI 591 218
  3. 3. • Quality of any product - acceptance by the consumer - marketability• However, it was realized that without sensory evaluation, the acceptability of a product cannot be determined• In the past, human sensory perception has been the only means of evaluation of quality as illustrated by the classical examples of cooks, who knew, how to mask the off nodes long before microbial assessment of quality came into existence 3
  4. 4.  The product quality was being traditionally determined by physical, chemical and microbiological criteria with the assumption that the products meeting the prescribed specifications in the above parameters would automatically meet the desired sensory quality However, soon it was realized that without sensory evaluation, the acceptability of a product cannot be determined The sensory evaluation is of great significance as a quality control tool in the oil processing plant Sensory analysis maintains the product quality and pattern matching with the consumer concepts and provides a mean to optimize the product successfully
  5. 5. “Sensory analysis is a scientific discipline used tomeasure, interpret and analyse reactions to thosecharacteristics of foods and materials as they are perceivedby the senses of sight, smell, taste, touch and hearing”. 5
  6. 6. Objectives To understand the difference between trained and untrained testers To know which senses are used in sensory evaluation To understand how sensory tests are used To know the different tests commonly used in the oil industry To influence product listings with retailers by presenting independent research demonstrating that the company has a greater understanding of their products profile and consumers To understand how the product performs against competitors 6
  7. 7. Sensory EvaluationThe role of sensory evaluation is to…. provide valid and reliable information to R&D, production, and marketing for management to make sound business decisions about the perceived sensory properties of products.
  8. 8. ComponentsMajor components of sensory evaluation are:-The human sense organs (the judges)Methods of sensory evaluationThe laboratoryData analysis and interpretation 8
  9. 9. Human SensesSight Smell Taste Hearing Touch 9
  10. 10. Sensory AttributesWe tend to perceive the attributes of a any item in the following order…..AppearanceOdor / aroma / fragranceConsistency and textureFlavor (aromatics, chemical feeling, taste)
  11. 11. Sensory EvaluationThere are at least three steps in the process of sensory perception:
  12. 12. Essential oils are perceived by senses individually and processed by brain into total impression of quality
  13. 13. Impression of Flavor Flavor Mouth Trigeminal Taste Odor feel perceptionThe overall impression of flavor is a combination of taste, odor,mouthfeel, and trigeminal perception
  14. 14. Types of PanelistsConsumer (untrained)Semi-trained (experienced)Trained (highly experienced)Responses recorded on ballots (scorecards) 16
  15. 15. Expectations form Panelists To produce reliable and valid data, the sensory panel must be treated as a scientific instrument It is therefore, necessary that panelists are free from any psychological features and physical conditions which might affect human judgments Panelists must have an ability to perform the task and to repeat their judgments
  16. 16. Sensory abilityIt is necessary that each panelist must be free fromthe following defects:  Taste perception disorders  Odour perception disorders  Color blindness  Denture defects Allergies Use of those medications that effect the ability to taste
  17. 17. Psychological Factors Affecting Sensory PanelExpectation Error- This occurs when panelists are given too much information about the samples. Therefore the panelists should not be informed about the types of ingredients used in the sensory testing.Suggestion Error- This occurs when panelists are aware of reactions of others during the sensory evaluation. This should be addressed by providing panelists with individual sensory booths (designed as per the details shown earlier).
  18. 18. Halo Effect- Sometimes panelists evaluate more than one quality characteristic at a time. They should therefore be trained and instructed to evaluate each quality parameter separately.Central Tendency Error- Panellists may choose the mid range to avoid extremes. All panelists should therefore be advised to choose the correct scale for each quality characteristic rather than just selecting the mid range of the scale to avoid extremes.Order Effect- This may affect the panelists if the sensory samples are provided in a defined order. All samples to be presented in a random order with a three digit number assigned to each sample to avoid the order effect.
  19. 19. Ballots / Scorecards• Developed for specific experiment, date, name of judge• Listed in order of evaluation• Descriptive characteristics need careful descriptions & way to score numerically• Acceptability 21
  20. 20. STEPS IN SENSORY EVALUATION Define overall project objective Define test objective Screening the samples Designing the test (method and judges) Conducting the test Analyzing the data Reporting the results
  21. 21. CONTROLS IN SENSORY EVALUATION Temperature Lighting Atmosphere -smell Individual booths Sample selection (identical code dates) Coding samples (3 digits codes) Sample preparation Sample presentation Subject selection
  22. 22. Guidelines help to improve sensory evaluations:Please read instructions carefullyTake as much time you need to arrive at your decisionNote a flavor sensations when judging - initial, overall, andaftertasteEvaluate samples from left to right, as they face you on the trayRinsing your mouth with water between each tasting helps removethe flavors and “standardizes” your mouth for the next testWhen testing between products with strong aftertaste, give yourself1-2 minutes between tasting to avoid flavor carryover
  23. 23. Making sounds like groaning, laughing, or talking during theevaluation may influence others. Please use the form forrecording all your sensationsIf you avoid eating, drinking, chewing gum and smoking 1/2hour before tasting, it will sharpen your ability to taste andsmellCheck your results as they leave to see how you didIt‟s a great temptation to share your “taste experience” withothers. Please wait until everyone has tasted, so you can‟t biastheir judgement
  24. 24. Different tests in sensory evaluation1) Discrimination test2) Affective test3) Preference test a) Paired comparison test b) Ranking test c) Hedonic scale test 27
  25. 25. 1) Discrimination test Difference between two or more products The product A is identical to product B Find two similar products among three samples The type of panel required for this type of testing would normally be a trained panel 28
  26. 26. 2) Affective test Also known as consumer testing, this type of testing is concerned with obtaining subjective data, or how well products are likely to be accepted Usually large (50 or more) panels of untrained personnel are recruited for this type of testing, although smaller focus groups can be utilised to gain insights into products The range of testing can vary from simple comparative testing (e.g. Which do you prefer, A or B?) to structured questioning regarding the magnitude of acceptance of individual characteristics (e.g. Please rate the "fruity aroma": dislike/neither/like) 29
  27. 27. 3) Preference test It involves the biochemical and psychological theories relating to human sensations.a) Paired comparison test – Two samples – 1) Standard (control) 2) Experimentalb)Ranking test – • Several samples differ on the basis of single characteristics • Rank will be given for similar productsc) Hedonic scale test – • Measure consumer acceptability of the products • Products are scored on a 5 or 9 point scale 30
  28. 28.  Descriptive analysis - As a major branch of the sensory science, descriptive analysis is widely used for collecting peoples sensory opinions on an object being food, cosmetics, apparel items, etc Normally, for descriptive analysis, a minimum of 5 experts is required, while with respect to naive panelists, this number should be much bigger The sensory experiment should be carried out according to standardized techniques and procedures designed before the evaluation After experiments, statistical analysis is often applied to the interpretation of the sensory results obtained
  29. 29. Sensory EvaluationSystem Grading Grading System Five grading categoriesCategory Excellent Very Good Satisfactory Unsatisfactory GoodQuality Outstanding Superior/ Typical Weak/Not at Faulty /Level /Exceptional Very full potential Defective Correct www.ngfl-cymru.org.uk 32
  30. 30. Grading Form Characteristics Grading Categories Comment & Attributes Excellent Very Good Satisfactory Unsatisfactory GoodAppearance & Colour CorrectnessAroma Intensity Quality Correctness IntensityTaste Finish QualityHarmony www.ngfl-cymru.org.uk 33
  31. 31. Sensory evaluation of nutmeg seeds essential oilCharacteristics Observation Odor Turpentine-like or spicy Odor intensity Strong pungent and spicy Taste Color Colorless to pale yellow Clarity clear Insoluble in water, soluble in ethanol, Solubility petroleum ether, diethyl ether, chloroform
  32. 32. Qualitative and Quantitative Analysis Qualitative testing helps to determine exactly what individual constituents are present in an essential oil, and quantitative testing provides information on how much of each component is present This is very important because it is well known by experts that for any given essential oil, here are several origins and the quality between them varies tremendously
  33. 33. Physical parameters If an essential oil sample passes all of the sensory tests, the next stage is to test the physical parameters of the essential oil by means of measuring the Specific Gravity, Optical Rotation and Refractive Index The combination of these physical tests is usually sufficient to determine if it is worth proceeding to the final stage of testing an essential oil If an oil successfully passes the first two stages it is then tested using Gas Chromatography/Mass Spectrometry (GC/MS)
  34. 34. Gas chromatography When using Gas Chromatography to test an essential oil, a tiny sample of the oil is injected (pictured right) into the apparatus which contains a very thin coiled silica tube called a capillary column This capillary column may measure up to 100 meters in length and is coated on the inside with a material that has an affinity to different chemicals at different temperatures The column is housed within a temperature regulated oven and is programmed to steadily increase in temperature over a period of time in a very precise manner
  35. 35.  When the sample of oil is injected into the column it immediately vaporises, and an inert carrier gas (usually hydrogen or helium) moves the vapour along the column to a detector called a Flame Ionisation Detector which is situated at the end of the column The flame ioniser detector responds quantitatively to the vaporised constituents of the oil and converts this information, via an integrator/computer, into proportional peaks printed onto computer listing paper. The height of every peak„ on the graph corresponds proportionally to the level of that component within the oil
  36. 36.  Every individual component of the essential oil can be identified by the time at which the peak elutes on the trace. The data produced can then be compared to an established profile or fingerprint for that particular essential oil to finally determine the purity of the oil Adulterants can usually be identified by this means of testing, although it does require the expertise of an organic analytical chemist
  37. 37. Industrial applications of sensory evaluation Distinguish between the products Test the popularity of products Describe specific product attributes Maintain consistent uniform product quality Profile the characteristics of a modified product against those of an original product Developing new products Measure shelf life of the product 40
  38. 38. Sensory evaluation pitfalls Selecting wrong objective for sensory analysis Choosing wrong participants for the sensory test Asking wrong questions of the participants Judgments biased against the products tested Lacking scientific control Conducting test in an inadequate situations 41
  39. 39. Thank You

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