In the competitive world of product development, sensory evaluation has become an essential tool for companies. It not only helps identify and improve the sensory characteristics of products, but also ensures they meet consumer expectations and preferences. Various methods are used to evaluate the sensory attributes of a product, each with specific objectives that help companies differentiate their products in the market.
In this article, we will explore the main sensory evaluation methods, highlighting their importance, applications and the statistical analysis that ensures reliable results. These methods include discriminative testing, quantitative descriptive analysis (QDA) and affective or hedonic testing, focusing on preference testing.
1. Discriminative Tests
Discriminative tests are essential to identify whether there are perceptible differences between products. These tests are often used when changes are made in formulation, production processes or when evaluating product consistency over time.
Main characteristics of discriminatory tests:
- Two products are generally compared to determine whether there are perceptible differences.
- They do not indicate the magnitude of the difference, but whether the products are perceived as different or the same.
- They are especially useful for quality control and product development, but not recommended when differences between products are obvious.
One of the most common discriminative tests is the triangular test, in which three samples are presented to the evaluators: two are the same and one is different. Evaluators must identify which sample is different. This test is easy to implement, has a low probability of random response (1/3) and is effective in detecting sensory differences.
The analysis of the results in discriminative tests, such as the triangular test, is performed using non-parametric statistical tests, such as the binomial or chi-square distribution, depending on the number of correct evaluations.
2. Quantitative Descriptive Analysis (QDA)
Quantitative Descriptive Analysis (QDA), developed by Stone et al. in 1974, is a powerful sensory method that provides a detailed and quantitative description of the sensory attributes of a product. It is particularly useful when an in-depth analysis of how consumers perceive different aspects of a product is needed.
Main characteristics of Quantitative Descriptive Analysis:
- Trained panel: A group of 10 to 16 trained judges evaluates the products, describing and scoring the sensory attributes perceived, such as flavor, aroma, texture, among others.
- Unidimensional scale: Judges rate each attribute on an unstructured 15 cm linear scale, which measures the intensity of each attribute.
- Repetition: Products are evaluated in duplicate or triplicate to ensure consistency of results.
QDA is valuable because it not only determines if there are differences between products, but also the magnitude of those differences. This is crucial in the development of new products, as it helps identify areas for improvement or differentiation from the competition. In addition, in quality control, it helps establish clear sensory specifications. The statistical analysis of the results is performed through analysis of variance (ANOVA), which allows determining the reproducibility of the evaluators’ judgments and the differences between the products studied.
Affective or Hedonic Tests
Affective tests, also known as hedonic tests, measure consumer acceptance and preference for a product. Unlike the previous tests, these tests are conducted with untrained consumers, who represent the product’s target market.
Main characteristics of the Affective or Hedonic Tests:
- Focus on overall product acceptance and perceived liking or disliking.
- Essential in the early stages of product development, as they provide direct feedback from consumers.
- Conducted blindly to avoid brand or packaging bias.
One of the most common applications of affective testing is in the evaluation of new formulations, where it is crucial to ensure that the final product meets consumer sensory expectations prior to market launch.
4. Preference Tests
Among affective tests, the preference test is one of the most widely used. This test compares two or more products to determine which one is preferred by consumers.
Main characteristics of the Preference Tests:
- Consumers compare two or more products and choose which one they like best.
- Paired comparison test: In this test, consumers evaluate a pair of products (A vs. B) and select the one they prefer. It is simple to organize and is often used when comparing two products.
- It is possible to include a “no preference” option, although it is not recommended in studies with small samples, as it may decrease statistical power.
Statistical analysis in preference tests is generally based on the binomial test, which makes it possible to determine whether the observed differences are significant. Tables based on the binomial distribution can also be used to establish the minimum number of responses needed to obtain statistically valid results with a standard probability of p=0.05.
5. Differences between Sensory Tests and Market Research Tests
Although sensory tests and market research tests may seem similar, there are key differences:
- Sensory tests: Focus on the intrinsic perception of the product (taste, aroma, texture) without considering factors such as price or brand. They are mainly performed in the early stages of product development.
- Market research tests: Include extrinsic aspects of the product, such as packaging, price and branding, and are conducted when the product is closer to its launch.
In addition, market research tests usually require larger samples of consumers (more than 100), while sensory tests can be conducted with smaller groups (between 50 and 75 participants).
Sensory evaluation is a crucial process for product development and optimization. From discriminative testing to descriptive analysis and preference testing, these methods provide valuable information on how consumers perceive and prefer a product. Performing these tests rigorously and complementing them with solid statistical analysis ensures that decisions made during product development are based on reliable and representative data.
At Sherpa Consulting, we understand that the key to your product’s success in the market lies not only in its technical quality, but in how it is perceived by your consumers. Our team of sensory evaluation and market research experts is prepared to guide your company through every step of the process, from initial research to the implementation of sensory strategies that will drive your growth.
If you seek to differentiate yourself in a competitive market and ensure that your products not only meet, but exceed your customers’ expectations, we invite you to contact us. Together, we can transform your ideas into products that captivate consumers and dominate the market. Contact us today and find out how we can take your business to the next level!