Sensory Evaluation and Food Product Development PDF

Sensory Evaluation and Food Product Development FNS 2001 1  What is sensory evaluation? Why should we care? 2  Outline What is sensory evaluation? – Definition – Senses involved – Purpose –...

Sensory Evaluation and Food Product Development FNS 2001 1  What is sensory evaluation? Why should we care? 2  Outline What is sensory evaluation? – Definition – Senses involved – Purpose – Factors and sciences in food sensory Sensory evaluation tests – Responses contributing to sensory perception – Principles – Sensory specialist’s role – Test room conditions – Classes of sensory tests Food product development 3  Objectives After completing this lecture, you will be able to Discuss the meaning and value of sensory evaluation Classify sensory methods as discrimination, descriptive, and affective testing Explain the stages of product development 4 Sensory Evaluation - definition The scientific discipline used to evoke, measure, analyze, and interpret human reactions to those characteristics of foods and beverages as they are perceived by the senses of sight, smell, taste, touch and hearing. » Sensory Evaluation Division of the Institute of Food Technologists (Anon., 1975) Sensory and Consumer Sciences Division (current) 5 What are the senses involved? Sight Smell Taste Touch Hearing 6  Purpose of Sensory Evaluation 1) It ensures a cost-efficient delivery of new products with high consumer acceptability 2) It reduces uncertainty and risks in decision making 3) Human observers are good measuring instruments People can sometimes detect odorants at levels lower than what can be detected by an instrument Instruments can not measure liking (although they can be used to determine what characteristics of a food correlate with liking) 7  Sensory process Multi-step process Stimulus (food) Intensity threshold Sensory Sensation (nerve signal) organ Brain Perception Response 8 Factors and sciences in food sensory 9 10  Central principles of sensory evaluation Using Using proper test proper panel conditions type Sensory evaluation principles Matching sensory test to study objective 11  Sensory tests--Principles Trained panel- not for obtaining acceptable judgement Consumer panel-not for accurate descriptive information Individuals involving in the R & D of products: should not serve on panels Samples- three digit codes Sample order- randomized Panelist interaction during evaluation - forbidden 12  Sensory specialist’s roles 1. Determine project objective 2. Determine test objective 3. Test design (test technique, score sheet, https://tse1.mm.bing.net/th?&id=OIP.M11473376b1ae1777380532fb5a5e283fH0&w=143&h=279&c=0&pid=1.9&rs=0&p=0&r=0 selection and training panelists, criteria for sample preparation, data analysis) 4. Conduct test 5. Analyze data 6. Interpret data and report results https://tse1.mm.bing.net/th?&id=OIP.M068797029ad0bf77624b02b7cce189eeo0&w=300&h=154&c=0&pid=1.9&rs=0&p=0&r=0 13  Test Room and Booth Conditions Minimize distractions Individual sensory booth seating, with partitions between panelists Neutral color such as gray Comfortable temperature Two-way hatches or sliding doors between scientist and panelist Separation between panelists and sample preparation area Adequate ventilation No talking Inclusion of computer terminals 14 Test Room and Booth Conditions 15 http://www.sp.edu.sg/schools/cls/cls_pics/T234-2.jpg 16 http://www.dieselprint.com/__work/Syrup/Loreal/Files/Research%202%20(Low)/ Sensory%20and%20Consumer%20Evaluation%201.jpg Test Room and Booth Conditions (cont’) http://www.dieselprint.com/__work/Syrup/Loreal/Files/Research%202%20(Low)/Sensory%20and%20Consumer%20Evaluation%202.jpg Sensory lab: https://www.youtube.com/watch?v=QupZlmliekM&t=13s 17 Floor plan 18  Sensory Tests- Classes Sensory Evaluation Question Asked Technique Are selected products detectably Discriminative different from each other or from a standard? What are the perceptible sensory Descriptive characteristics of a product and their intensities? Affective Does the consumer like the product – (Acceptance/ Will he/she buy it? Preference) Goal is to match the right test with the right question 19  Sensory Evaluation Tests According to IFT 1981 Sensory tests Analytical Affective Discriminative Descriptive 1. Paired – preference test Difference Sensitivity Attribute Descriptive 2. Ranking test Rating Analysis 3. Rating test 1. Paired 1. Threshold 2. Duo-trio 2. Dilution 1. Category 1. Flavor profile 3. Triangle scaling analysis 4. Ranking 2. Ratio 2. Texture profile 5. Rating scaling analysis difference 3. Qualitative descriptive analysis 20  Discriminative Tests (Analytical tests) Attempt to answer whether any difference exists between two types of products Data are analyzed statistically to come to conclusion (p < 0.05) Triangle test, duo-trio, paired test, ranking etc. 21  Examples: Question: Are two products different from one another? A A B Triangle Test: Choose the 342 608 194 sample that is most different Duo-trio Test: Choose the Reference (B) A B sample that matches the 437 821 976 reference Paired Comparison Test: B A Which sample is sweeter? 315 759 22  Example: Paired test (cont’) Test sample: Chicken broth Name: Terrence Test Subject no: 10 Date: Oct 12 You will receive several pairs of samples Circle in each pair the number of the sweeter sample. Don’t swallow the sample. Rinse your mouth between samples Sample no. Correct 123 367 446 678 234 345 890 143 23  Descriptive tests (Analytical tests) Seek to describe specific product attributes related to flavor, texture, mouthfeel, etc. by quantifying their perceived intensities Require highly trained panelists Wordings used are precise Scorecards developed by researcher or panelists Tests: – Quantitative descriptive analysis – Flavor profile (odor, taste, flavor…) – Texture profile (mechanical…) 24 http://oregonprogress.oregonstate.edu/sites/oregonprogress.oregonstate.edu/files/issue/spring-1999/tasters.jpg  Descriptive tests Sample Ballot What does trained mean? 305 - It means that the panelists are trained to evaluate products similar to how any instrument would give a reading In essence, the panelists are calibrated so that they have an understanding of each attribute and the range of intensity For example, a trained panel would be able to rate the same level of turbidity, color, viscosity, etc. for a given grape juice 25  Descriptive tests Mean attribute ratings are calculated, statistics is used to determine if the means are significantly different The data can be plotted onto graphs – such as the spider plot – to easily compare samples In this example two products A & B were compared: – Which is brighter, fresher, softer? – Which has more thickness? 26  Affective test To quantify the degree of liking or disliking of products Tests: preference or acceptance Large numbers of panelists (50 – 100 or more) https://tse1.mm.bing.net/th?&id=OIP.Mdc7d186ac389a22090de717f2302bd79o0&w=300&h=223&c=0&pid=1.9&rs=0&p=0&r=0 27  Consumer Tests: Acceptance  Used to measure how much people like a product  There are several types of scales that can be used Sample Ballot Taste each product in the order listed. Circle how much you like the product. Quartermaster Corp. 9-point hedonic (liking) scale The Smiley Scale (Most common) (Used with kids) 9 LIKE EXTREMELY 8 LIKE VERY MUCH 7 LIKE MODERATELY 6 LIKE SLIGHTLY 5 NEITHTER LIKE NOR DISLIKE 4 DISLIKE SLIGHTLY 3 DISLIKE MODERATELY 2 DISLIKE VERY MUCH 1 DISLIKE EXTREMELY 28 Other hedonic scales 29 Questionnaire for Acceptance Test □ Like extremely □ Like very much □ Like moderately □ Like slightly □ Neither like nor dislike □ Dislike slightly □ Dislike moderately □ Dislike very much □ Dislike extremely https://tse1.mm.bing.net/th?&id=OIP.M4617da04133e24c713ff8651a97353ceH0&w=299&h=177&c=0&pid=1.9&rs=0&p=0&r=0 Using the above scale, rate the following: – How do you rate the color of the beverage? – How do you rate the color impact of the beverage? – How do you rate the citrus flavor of the beverage? – How do you rate the sweetness of the beverage? – Overall, how do you rate the beverage 9-point hedonic rating scale 30  Consumer Tests: Preference  Used to determine which product is preferred, although people have the option to choose “no preference” Sample Ballot Taste each product in the order that they are listed. Circle the number of the product that you prefer, all things considered. 470 193 no preference Questionnaire for Preference Test Affective test (cont’) 32 Sensory triangle testing https://www.youtube.com/watch? v=nFXfg3ONgl0 Descriptive sensory testing https://www.youtube.com/watch? v=RvBbo8-U0t0 33 34  Food Product Development Process that new food product ideas are generated, and products are created and marketed Expands the variety of products New products are costly and risky  Many products fail in market Need organized and effective process  use scientific method + follow defined sequence of steps 35 http://www.nasa.gov/images/content/751066main_space_food_226.jpg  Scientific Method in Product Development Define a problem: what new food product are we trying to create? Set hypothesis: proposal for the formulation and processing Test hypothesis: designed experiments Accept/reject hypothesis: analysis and interpretation 36  Product Development Stages True starting point for product works: corporate mission Product strategy: a plan established to accomplish a company’s mission & objectives Feasibility: formulation, equipment, package costs, etc. Project development objective emerges & involves various stages and activities 37  Product Development Stages Idea stage Development stage Commercial stage Product Analytical Sensory Idea testing evaluation 1. What is the anticipated demand, and who is the competition? 2. Does the product meet a specific consumer need? Product Benchtop Commercial Market 3. Which ingredients, processing, and packaging are required to design prototype product testing formulate and manufacture the product, and are they available 1. Is the formulation reproducible, or are changes at reasonable cost? needed? 4. What are the desired 2. How will quality and cost be affected by altering 1. How much cost is involved in large characteristics of the new ingredients and processing conditions? commercial batch production runs? product? 3. What are the storage requirements of the 2. Are there any concerns regarding the bulk 5. How much time and money will product and its shelf life? storage of raw materials in the commercial it take to bring the product to 4. Will spoilage due to yeasts molds, or bacteria be plant? the commercial stage? a problem? 3. Does the product have to be returned to the 6. What are the profit objective 5. Does the product require any special packaging? pilot plant for retesting for any reason? and profit potential of the new 6. Does sensory analysis indicate the product is 4. Where will the product be test marketed? product - how much money meeting its concept goal? 5. How will consumer attention be directed will it make for the company? 7. What is required to scale up for commercial toward the new product? production of this product? 38  Take home messages Sensory evaluation is a quantitative science involving the measurement and analysis of consumer reactions to foods as they are perceived by the senses Stimuli interact with the senses, which transmit sensations as electrical signals to the brain for interpretation, perception, and response Carrying out sensory evaluation involves affective, discrimination, and description test methods In product development, new products are conceptualized, formulated, processed, tested, marketed, and evaluated 39  Reference Murano, P.S. 2003. Sensory evaluation and food product development. In Understanding Food Science and Technology. Ch. 15. Thomson Learning, Inc. pp419-442. 40