Chapter 3 Notes Sensory Evaluation Sensory Evaluation The

Chapter 3 Notes Sensory Evaluation

• Sensory Evaluation: The Human Factor Chapter 3 • What makes one texture like potato chips pleasant and another, like chewing on raw fish eyes unpleasant?

• Opinions about food are subjective. Your environment influences your food likes and dislikes. Food scientists can use computerized equipment to measure such characteristics as volume and mass of food but evaluating taste, aroma, and texture is more difficult.

• Sensory evaluation: is the human analysis of the taste, smell, sound, feel, and appearance of food. Influences on Food Likes and Dislikes • I. Physical Influences: physiologists have discovered that people inherit slightly different body chemistries. Some people are born “taste blind”. They are unable to distinguish between tastes.

Number of taste buds, gender, health, and age play roles in your ability to detect flavors. People are classified as • Supertasters – have as many as 1, 100 taste buds per square centimeter. • medium tasters • non tasters – have as few as 40 taste buds per square centimeter.

II. Psychological Influences: research shows that many adults who detest a particular food became ill after eating that food as a young child. When food becomes linked with unpleasant memories, the food will become distasteful to one degree or another. • Taste bias: when negative experiences cause a person to dislike a food. It can also be caused by

• • Positive experiences of taste preferences. Table terms and brand names Advertising, peers, and settings influence bias https: //www. youtube. com/watch? v=k 4 z. J 5 o. O LZUs Truth about food - Kids

III. Cultural Influences: culture is the beliefs and behaviors followed by a group of people. • The French lifestyle often includes daily shopping for fresh ingredients. • Traditionally, Jewish religion do not eat pork • Hindu followers do not eat beef. • In US, food most often eaten on Halloween is candy.

IV. Environmental Influences: climate, geography, and fuel availability have much to do with food costs and obtain ability. • Alaskans eat less fruit due to their colder climate • Jamaicans eat much fresh fruit due to warm climate • People who live near the coast eat more seafood. • In Asia where fuel was scare, raw fish and stir fry became common. • In US where fuel is plentiful, slowly cooked stews and roast became popular.

Sensory Characteristics of Food Products: There are three main sensory characteristics of food products, appearance, flavor, and texture.

Appearance: refers to the shape, size, condition and color of a product. • Appearance is usually evaluated on exterior and interior of a product. • Color is one aspect of appearance that can be measured. A colorimeter measures: Hue, value and chroma – Hue: basic color – Value is lightness and darkness of the color – Chroma is how intense the color is

Flavor: the combined effect of taste and aroma. Taste starts in the mouth with the taste buds on the tongue. Four basic tastes are salty, bitter, sour, and sweet. Each food will stimulate a combination of taste regions on the tongue.

• Research indicates a food’s taste is related to the shape of molecules in the food. These molecules bind to the taste bud • Sour foods are evaluated in terms of astringency which is the ability of a substance to draw up the muscles in the mouth.

• Your ability to taste foods is related to the temperatures of the foods. Ex. Europeans serve cheese at room temperature rather than chilled.

Smells impact flavor. Aroma: the odor of a food. The nose is capable of identifying thousands of odors. A substance’s odor results from volatile particles coming in contact with the olfactory nerves deep in the nose.

Volatile substances: contain particles that evaporate or become gaseous quickly. These gas-like particles stimulate the olfactory bulb. Olfactory bulb is a bundle of nerve fibers located at the base of the brain behind the bridge of the nose. Odors can reach the olfactory bulb through the nostrils and through the back of the mouth. The nasal and oral passages are connected at the top of the throat.

Texture: is how a food product feels to the fingers, tongue, teeth, and palate (roof of the mouth). • Chewiness: refers to how well one part of a food slides past another without breaking. • Graininess: refers to the size of the particles in a food product. Cream is very smooth whereas grits have a grainy texture.

• Brittleness: refers to how easily a food shatters or breaks apart. Pie crust and crackers are very brittle. • Firmness: describes a food’s resistance to pressure. Tough foods require considerable biting force to chew them. Beef jerky is a good example.

• Consistency: describes the thinness or thickness of a product. Broth vs. beef gravy. Measuring texture objectively: Food texture can be evaluated objectively by measuring its resistance to force. • Compression machine: instrument that measures food texture. It shows how much pressure it takes to compress one food compared to another. It will tell a manufacturer how much packing is needed to allow a product to be shipped without being crushed.

• Penetrating probe: used to determine the quality of beef. Inspectors insert the probe into the meat carcass. The pressure needed to penetrate a given distance has been compared to how tender the meat will be after cooking. This is how beef can be labeled as prime or choice.

Taste Test Panels: A group of people who evaluate the flavor, texture, appearance and aroma of food products. They can be trained professionals or untrained consumers. • Trained sensory panelists are more likely to be used during a product’s development. They are also used for federal and state grading.

• Untrained consumers are used to evaluate products after the products have been developed. Consumer taste panels are used to determine what the average consumer will prefer. Setting up Taste Test Panels: • Must try to remove any factors that could sway testers. • Researchers must create forms for testers to use in rating samples and recording responses. • Each tester may be isolated in a booth so he/she can’t see facial expressions of others.

• Products may be tested by one person at a time. • Panelists may also receive strict instructions to make no comments or sounds that could sway other Other environmental factors: • Lighting • Aromas in the setting • Aromas can linger, take a sip of warm water between each sample you taste. • Temperature of food samples should be controlled.

Controlling Psychological Biases: psychological biases can affect the way test panelists respond to various food samples. Test samples are usually identified by codes. • People prefer samples with low numbers to samples with higher numbers

• People tend to prefer samples labeled with letters near the beginning of the alphabet. • Researchers have found that bias goes away when three-digit code numbers are used. • The number of samples a taster can judge is limited. Four or five seems to be the most at one time. • Tasters tend to prefer the first samples presented to later ones.

Creating an Evaluation Form: • Ranking on a scale of 1 -5, 1 -7 • Using verbal labels like: definitely like, mildly like, neither like nor dislike etc. • Numbers might be combined with descriptive observations.