Food Science - Sensory Evaluation, Exam 2

What are some subjective tests?

• Difference tests • The Triangle Test

What are the factors that influence odor?

Ability of chemicals to reach olfactory lobe • A cold blocks odor and therefore reduces flavor • Volatility increases with temperature, so warm food has more flavor • Chewing Previous exposure • The olfactory system fatigues easily

What are the affective testing options for food evaluation?

Acceptance Preference Discussion - attitude, wants, needs Behavioral

What are the analytical testing options for food evaluation?

Discrimination Descriptive Threshold Volume

What is the difference subjective test?

Panelists are asked to look at differences in samples Not concerned if samples are better or worse Sometimes you want a difference Sometimes you do not

What are some factors that influence taste?

The individual • Each of us varies in our sensitivity to tastes • The are some people who are taste blind Age Smoking Temperature of food Other chemicals present

What is the triangle subjective test?

Three samples are presented • Two are the same • One is different • Panelists are asked to choose the different one • Results are scored on the basis of the number of correct answers

Why do we care about sensory evaluation?

- If you are a company making a food product you want it to be successful - From a nutritional view

How many smells can most people differentiate from?

1,000 - 2,000

What do artificial flavors combine?

A limited number of the important components

What is sensory evaluation?

A scientific discipline used to evoke, measure, analyze, and interpret reactions to those characteristics of foods and materials as they are perceived by the senses of sight, smell, touch, taste, and hearing

What is color the result of?

Absorption by the food of specific wavelengths of visible light • What we see is light that is either transmitted through the food or reflected off the surface

What test is it when panelists are asked what they like and dislike - no correct answers -?

Affective testing. Examples: Hedonic Scales • Odd-number of choices allows for neutral answers • Even number of choices forces a decision • Results are analyzed by calculating the mean and standard deviation of each sample • Then the mean values can be compared statistically.

What are some questions that can be asked for an analytical test?

Analytical test - Descriptive • What does this product taste like? • What are its perceived sensory characteristics/attributes? • How does a change in process/formulation/packaging/storage conditions affect the sensory quality? • How do these products differ from one another in sensory quality? • For which sensory attributes are the differences most marked?

Examples of analytical testing options:

Analytical test - Discrimination • Is this product the same as that? • Is this one different? • How great is the difference? • Would people notice the difference? • Would people detect this taint? • How many would discriminate/detect this difference?

What's the difference between analytical testing and affective testing?

Analytical testing is based on objective view; whereas, affective testing is based on subjective views.

What is the name for odor blindness? Can some drugs induce this effect? What else can lead to this?

Ansomia, yes. Old age.

What is the chemical basis of something that taste umami?

Comes from monosodium gulamate (MSG) and other compounds - brothy, savory taste

What is the chemical basis of something that taste salty?

Comes from salt ions [Na+] in sodium chloride (NaCl) or other salts found naturally in some foods.

What is the chemical basis of something that taste bitter?

Imparted by compounds such as caffeine (tea, coffee), theobromine (chocolate), and phenolic compounds (grapefruit and vegetables).

Four important factors in product development from the research and development standpoint:

Ingredients Processes Packaging Shelf-stability

Are odors easy to categorize as taste?

No

Can any chemical stimulate taste? What is needed?

No, the chemicals need a proper fit into a receptor to cause the sensation

Are taste and flavor synonymous terms? Define flavor.

No. • Flavor is the combined sense of taste, aroma, and trigeminal sensations.

How many odors are detected?

Over 16 million

For sight, color can denote:

Ripeness, the degree of heating, strength and flavor

What effects the chemical stimulation of the taste?

Saliva (breaking down carbohydrates) and chewing (crushing and breaking apart the compound)

What are some qualities that are developed based on sight evaluation?

Serving size Shape, color, consistency Presence of defects

What is the chemical basis of something that taste sour?

The concentration of hydrogen ions (H+), which are found in the natural acids of fruits, vinegar, and certain vegetables

What are the factors affecting color perception?

The food itself The observer The light of illumination

What does the sense of touch - inside the mouth or by the fingers convey about the food?

The food's tactile, or physical properties: Texture Consistency Temperature

What is the aroma of food?

The odor of a food product

What is the fragrance of food?

The odor of a perfume or cosmetic

Where does the sensation from aroma of a food occur in?

The olfactory lobe within the nasal passages

What is the chemical basis of something that taste sweet?

The sweetness of sugar comes from the chemical configuration of its molecule.

What is the triangle test used to determine? How does it do this? What is the $ chance of guessing the right answer?

Triangle test • To determine difference • All three samples are presented simultaneously • Must identify the odd sample • Chance of guessing the right answer is 33.3%

Do chemicals need to be volatile (a gas) in order to be recognized?

Yes

Is smell almost as important as the appearance when evaluating a food item for quality and desirability?

Yes

Does each of us vary in our sensitivities to taste? Examples..

Yes Taste blind people (ansomia) People who smoke Temperature of food Other chemical present

Do humans have an odor threshold? What is it based on?

Yes, it's based on odor adaptation.

Are volatiles sniffed through the nose?

Yes, volatiles perceived by the olfactory system from a substance in the mouth

In quanitative descriptive analysis, can panelists score several factors at in sitting?

Yes.

Is a aroma a chemical sensation?

Yes.

Is the aroma of something more sensitive compared to the tastebuds flavor of something?

Yes. When you have a stuffy nose the taste of everything is severely degraded.

Can the sounds associated with foods play a role in evaluating their quality? Examples:

Yes. Tapping of a watermelon to determines its ripeness/sweetness Crunchiness of a cracker Sizzling of steak on the grill Popping of popcorn Fizzing of soda pop Bubbling sound of a boiling soup

Does descriptive evaluation require trained panelists? What do the panelists do during training?

Yes. • During training, panelists sit together and agree on what scores should be Examples: the hardness scale • Cream cheese - 1 • Hotdog-7 • Life Savers - 14 • These can be combined into a flavor/texture profile

How many judges are in a quantitative descriptive analysis? What are the steps?

• 10-12 judges(panelists) • Panelists generates A set of terms - Describe differences among the products Description - to describe the sensory differences among the samples Reference standards • Individual product evaluation in isolated booths • Replicate up to 6 times-check consistency

What is the main procedure for analytical testing?

• Allow to obtain complete sensory descriptions of products • Help identify underlying ingredient and process variables • Determine which sensory attributes are important to acceptance • Produce objective descriptions of products in terms of the perceived sensory attributes.

What in particular is stimulated within the nose by aroma?

• Chemicals stimulate nerve endings there (cilia)

Why collect sensory data?

• Human sensory data provide best models • How consumers will react to products • Sensory data need to predict ingredient formulations • How products have changed during development

How is food analysis used?

• New product development • Product improvement • Product tracking • Develop "Gold Standard" • Ingredient changes • Cost reduction • Quality control/assurance • Gauging consumer acceptance • Claims tests

What factors affect taste and flavor?

• Person • Temperature of the product • Fat in product • Color of the food • Time of day • Hunger • Consumption patterns • Medication Sickness

What is the purpose behind focus group testing? What are the researches interested in?

• Qualitative testing with the purpose to develop insights and direction. • Researchers are interested in Attitudes Opinions as they relate to products, services, and concepts.

What is stimulated in order to taste? What is the stimulation caused by?

• Sensation in taste buds - mostly on the tongue, some on the palate • Stimulation is caused by chemicals in solution The chemicals need a proper fit into a receptor to cause the sensation Affected by saliva and chewing

What are trigeminal sensations? Examples:

• Sensations from chemical irritation (with food these usually occur in the nose and mouth) • Examples: Astringency Burn (e.g. from peppers - not temperature) Metallic Cooling (e.g. from mint - not temperature)

What are some questions that would be asked for affective testing?

• Which product do you prefer? • Is this product better than that one? • How much do you like this product? • Is it acceptable? • Is it as good as another product? • What do you like (or dislike) most about this product? • Which other features/attributes do you like (or dislike)?