Food Evaluation Lecture Notes PDF

Food Evaluation CH A PTER 2 L E CT U R E R : H I B A C H AT I L A FA L L 2 0 2 4 Lesson Outline Review Lesson 1 Sensory evaluation ◦ Analytical (effective) Tests ◦ Detects obvious differences ◦ More objective than affective tests ◦ Usually conducted by a trained panel ◦ Discriminative test Are...

Food Evaluation CH A PTER 2 L E CT U R E R : H I B A C H AT I L A FA L L 2 0 2 4 Lesson Outline Review Lesson 1 Sensory evaluation ◦ Analytical (effective) Tests ◦ Detects obvious differences ◦ More objective than affective tests ◦ Usually conducted by a trained panel ◦ Discriminative test Are the products different? ◦ Most common difference tests are the triangle and duo-trio tests ◦ Descriptive test How are the products different (in terms of flavor and texture?) ◦ Rely on a trained panel to document a product’s sensory characteristics ◦ Affective (Acceptance or Preference) Tests ◦orDetects preferences ◦ Participants asked to rank products or state whether they like a product not ◦ Usually given to untrained consumers ◦ Hedonic Tests How much do you like the product? Like extremely→ Dislike extremely ◦ Personal Preference Which product do you prefer?( select the preferred sample) Objective evaluation ◦ Physical Tests Physical tests measure certain observable aspects of food such: o Size and shape o Weight o Volume o Density o Moisture o Texture o Viscosity ◦ Chemical test Review 1. The definition of flavor best describes a) Taste b) Taste and sight c) Taste and odor d) Taste, odor and mouthfeel Review 2. Which religion(s) encourages vegetarian diet? a) Buddhism b) Hinduism c) Seventh-Day Adventis d) a and b e) All of the above Review 3. What is the approximate recommended daily kcalorie intake for women and men? a) 1600 for women and 2400 for men b) 1400 for women and 2400 for men c) 1600 for women and 2000 for men d) 1200 for women and 1600 for men Review 4. How many kcalories in deficit does it take to loose a pound (0.5kg) of body weight? a) 500 1kg in two weeks if in a 3500kcal deficit b) 1,000 c) 2,500 d) 3,500 Food Evaluation The food industry uses many testing methods to measure the sensory factors used to select food and to evaluate food quality. These tests are conducted for ◦ Research and development ◦ Product improvement ◦ Sales and marketing ◦ Quality assurance ◦ Nutrient content analysis (for labeling requirements) ◦ Detection of contamination or adulteration  Food Evaluation Food is evaluated using both Sensory (subjective) tests Evaluation of food quality based on sensory characteristics and personal preferences as perceived by the five senses Objective tests Evaluation of food quality that rely on numbers generated by laboratory instruments that are used to quantify the physical and chemical differences among foods. Food evaluation Sensory Objective test (subjective) test  Sensory Evaluation Sensory evaluation is the scientific discipline of measuring the responses of people to food products as perceived by their senses of sight, taste, touch, smell and hearing. Relies on opinion of selected individuals Two main types ‫ﻓﻌﺎل‬ Analytical (effective) tests -detect difference Affective tests (acceptance or preference test) ‫ﻋﺎﻃﻔﻲ‬ Food evaluation Sensory Objective (subjective) test test Analytical (effective) Affective test Sensory Evaluation is it sweeter or salter etc Sensory Evaluation Figure 2-1 Summary of subjective tests for food evaluation. Sensory Evaluation Analytical (effective) tests ◦ Detects obvious differences ◦ More objective than affective tests ‫اﺧﺘﺒﺎرات أﻛﺜﺮ ﻣﻮﺿﻮﻋﻴﺔ ﻣﻦ اﻻﺧﺘﺒﺎرات اﻟﻌﺎﻃﻔﻴﺔ‬ ◦ Usually conducted by a trained panel Discriminative tests ◦ Are the products different? ◦ Most common difference tests are the triangle and duo-trio tests Descriptive tests ◦ How are the products different (in terms of flavor and texture?) ◦ Rely on a trained panel to document a product’s sensory characteristics Sensory Evaluation Sensory Evaluation Affective tests (acceptance or preference) tests ◦ Detects preferences ◦ Participants asked to rank products or state whether they like a product or not ◦ Usually given to untrained consumers Hedonic tests ◦ How much do you like the product? Like extremely→ Dislike extremely Preference tests ◦ Which product do you prefer?( select the preferred sample) Sensory Evaluation Figure 2-1 Summary of subjective tests for food evaluation. Sensory Evaluation Elements of sensory evaluation ◦ Taste panels ◦ Usually at least five people ◦ Mixture of gender, and age ◦ Panelists are representative of the consumers who will be using the product ◦ Criteria: ◦ Free of colds, no gum, no other food for at least 30 to 60 minutes before testing, nonsmokers, not color-blind, no strong likes or dislikes for the food to be tested ◦ Sample preparation ◦ Same size samples; same part of food, same temp.. etc. Sensory Triangle testing (discrimination test) Video https://www.campdenbri.co.uk/videos/sensory-triangle-testing.php  2. Objective Evaluation Laboratory instrument used instead of humans Most objective food evaluation is based on two major types of tests ◦ Physical and chemical evaluation These tests: ◦ Analyze for presence of potentially harmful bacteria, yeast, and mold (food safety) ◦ Create standards for maintaining quality control ◦ Identify chemicals in food Food Evaluation Sensory Objective Test (subjective) Test Affective Physical Chemical Analytical (effective) Test 2. Objective Evaluation Physical tests measure certain observable aspects of food such: o Size and shape o Weight o Volume o Density o Moisture o Texture o Viscosity 2. Objective Evaluation do not memo 2. Objective Evaluation do not memo 2. Objective Evaluation do not memo  do not memo 2. Objective Evaluation  A Melamine Test is used to detect the presence of melamine, a toxic chemical, in food products. Melamine is sometimes illegally added to food to falsely boost the protein content in food testing After the 2008 Chinese milk scandal, where melamine was found in baby 2. Objective Evaluation formula and milk products, tests were developed to detect melamine in dairy products. In these tests, milk samples are treated with reagents that react with melamine, forming a colored complex that can be measured to determine melamine concentration. After instances of pet food contamination, melamine tests were used to Chemical tests check pet food for this compound. A positive result would indicate adulteration, leading to product recalls and legal actions. ◦ Manny different tests available ◦ In-house vs. food testing laboratories ◦ Testing influenced by real-world situations (i.e., melamine testing) ◦ Electronic noses device that mimics the human sense of smell to detect and identify odors, ◦ Detect certain chemicals responsible for aroma gases, and volatile compounds. It uses an array of chemical sensors combined with pattern recognition systems to analyze the chemical composition of a sample. E-noses are used to assess the freshness of food, detect spoilage, or ensure the consistency of flavors. Food Evaluation Sensory Objective Test (subjective) Test Affective Physical Chemical Analytical (effective) Test 2. Objective Evaluation 2. Objective Evaluation TABLE 2-3 Examples of Chemical Tests Conducted by a Food Testing Company Sensory vs. Objective Evaluation Both are important for food evaluation! Sensory evaluation ◦ More expensive and time-consuming ◦ Vital for product research and development Objective evaluation ◦ Advantages: ◦ Not subject to human opinion ◦ Reliable and repeatable ◦ Faster, cheaper, more efficient than sensory testing ◦ Good for routine quality control Chapter Summary Sensory evaluation ◦ Analytical tests ◦ Affective tests Objective evaluation ◦ Physical tests ◦ Chemical tests