1. Food & Nutritional Sciences Course 1 How the Cookie Crumbles
Sensory Evaluation
Food & Nutritional Sciences Course 1
How the Cookie Crumbles

2. Developing a Sensory Evaluation Instrument
List all important characteristics
Narrow list to 5 items
Develop a scale for each characteristic from one extreme to another
Example: Chewiness goes from too chewy to too crunchy
Draw a 10cm line and place the extremes at either end of the line.
Repeat for all characteristics
More than 5 items will deter participants

3. Hypothesis
Before we can collect any data, we have to have a hypothesis to test for each item.
Null hypothesis always states “no difference”
Alternate hypothesis states “difference”
Example for chewiness:
Null: There is no difference in chewiness between the original recipe and the healthy recipe.
Alternate: There is a difference in chewiness between the original recipe and the healthy recipe.
We are not stating a direction of difference because we want to know only if it is different. Some people prefer crunchier, some prefer chewier and we would have to create a much more complicated instrument and analysis for that. Since we are not looking at direction of difference, we will use a two-tailed t-test in analysis later.

4. Hypothesis
Note: we didn’t state a direction of difference (chewier or crunchier)
Write a hypothesis for each item.
We’ll explain testing after we have data.

5. Data Entry
Measure the distance from the left side of the line to the participant’s mark on each item and write in the margin (in centimeters).
The number of centimeters – with decimal values – is the data.
Enter into the cell for the participant and item #.
Automatically calculates significance for you.
If p < 0.05, there is a difference between the cookies.
This is practice using the spreadsheet. We’ll do data analysis in-depth with the students’ recipes.

6. Data Entry Enter all data in the spreadsheet: Item 1 Item 2 Item 3
p1O
4.5
p1H
2.3
Difference
Will
Enter
Formula
Later
p2O
6.8
p2H
5.0

7. Data Collection Decide on a labeling plan (and stick to it!)
participant number
Something to indicate healthy or original WITHOUT revealing to participant
Present participant with on cookie on a plate & have taste
Provide form & allow them to continue tasting while completing form

8. Data Collection
Repeat with the other cookie
You need 40 participants!

9. Data Analysis The spreadsheet has formulas ready to go
You can type in the blue cells only.

10. Data Analysis
If the p-value is less than 0.05, reject the null hypothesis
There is a significant difference between the cookies
If two-tailed t-score is greater than 0.05, keep the null hypothesis.
There is not a significant difference between the cookies
Repeat for all items and record your findings.

11. Drawing Conclusions
Conclusions are the decisions you make based on your results.
On which items did you have a significant difference between cookies?
What do you think that means about people’s cookie choices?
Do you think your healthy option cookies will sell?