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Sensory Evaluation of Food:. Influences on Food Choices and Sensory Characteristics. By: S. Klimek. Influences on Food Likes and Dislikes. Opinions about food are subjective - they are affected by personal views and backgrounds.
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Sensory Evaluation of Food: Influences on Food Choices and Sensory Characteristics By: S. Klimek
Influences on Food Likes and Dislikes • Opinions about food are subjective - they are affected by personal views and backgrounds. • Your environment influences your food likes and dislikes. Personal experiences affect whether you like spaghetti sauce chunky or smooth, with mushrooms or meat, and spicy or mild.
How do you measure like or dislike? • A wide variety of foods are available and people have different opinions over what is good. • Food scientists can use computerized equipment to measure characteristics such as volume and mass. • However, evaluating taste, aroma, and texture are more difficult. • There is not tool to accurately measure whether people will like or dislike a food. • As researchers develop food products they try to look at the human factors that affect food choices. • They then make a prediction about product’s potential for success or failure. • The subjectivity of their evaluation is called sensory evaluation.
Sensory Evaluation • Sensory evaluation is the human analysis of taste, smell, sound, feel and appearance of food.
Physical Influences • People inherit slightly different body chemistries. • These differences in chemistries affect a person’s perception of taste. • Some people are born “taste blind” and are unable to distinguish between tastes. • Number of taste buds, gender, health and age play roles in your ability to detect flavors. • Super tasters can have as many as 1,100 taste buds per square centimeter on their tongues, while non-tasters have been found to have as few as 40 taste buds per square centimeter.
Psychological Influences • Research shows that many adults who detest a particular food became ill after eating that food as a young child. • Although the food might not have caused the illness, the person subconsciously links the two events. • When negative experiences cause a person to dislike a food, the person has developed a taste bias. • Taste bias can be caused by positive experiences or taste preferences.
Psychological Influences Cont. • Other factors that can cause bias in food products are label terms and brand names. • Many students will state a brand preference and then select a competitor’s brand in a blind taste test. • Advertising, peers, and environmental setting influences these types of biases. • Food manufacturers have found such biases very difficult to overcome in the marketplace.
Cultural Influences • The cultural patterns of people’s lives strongly influence what and how people eat. • These beliefs and behaviors are passed on from one generation to another. • “Grits” is a regional food that is more likely to be served in the south than in the midwest. The French lifestyle often includes shopping for fresh ingredients.
Environmental Influences • People are more likely to eat what is available and economical. • Environmental factors such as climate, geography, and fuel availability have much to do with food costs and obtainability. • People who live on coastal regions tend to eat more seafood. • In Asia where fuel was scarce for centuries, raw fish and stir-fry dishes grew popular.
Environmental Influences Cont • Food preferences are affected by your immediate surroundings as well as by the larger environment. This has been revealed in studies with young children. • Most children learn to like the foods they are exposed to. • Adults who enjoy oysters are more likely to have eaten oysters as children than adults who do not enjoy oysters.
Sensory Characteristics of Food • To evaluate a food product your first need to identify the desirable characteristics of that product. • What is desirable changes from one product to the next. • You want crackers to be crunchy but cake to be moist. • There are many sensory characteristics of food products: appearance, flavor and texture.
Appearance • Appearance refers to the shape, size, condition, and color of a product. • Is usually evaluated on both the exterior and interior of a product. • You may check to see if the inside of a muffin is full or large tunnels or small, even holes. (You may also cut it in half and draw around it to show shape.) • Both the shape of muffin and size of air cells indicate quality.
Appearance Cont • Color is one aspect of appearance that can be measured exactly. • A colorimeter is a device that measures the color of foods in terns of hue, value, and chroma. • Color can influence a person’s perception of other sensory characteristics. For instance, you might think a dark brown chocolate bar has a richer flavor than a light brown bar. • When researchers do not want color to influence a taste panel, they use colored lights.
Flavor • Flavor is the combined effect of taste and aroma. • Taste starts in the mouth with the taste buds on the tongue. • Each region of the tongue is designed to respond to one type of taste. • The four basic tastes are salty, bitter, sour and sweet. • Each food will stimulate a combination of taste regions on the tongue.
Flavor Cont • Research indicates a food’s taste is related to the shape of molecules in the food. These molecules bind to the taste bud. • For example, a molecular shape that triggers sweetness has been identified. • Suppose a molecule of food matches up to a sweetness taste bud. This will cause nerve endings to begin sending messages to the brain. • The brain knows that when nerve impulses come from that part of the tongue, the food is sweet.
Flavor Cont • Your ability to taste foods is related to the temperatures of the foods. • Flavors of some foods become more intense as the foods become warmer. • However, some foods are heated to high temperatures may lose some of their flavors. • Europeans serve cheese and milk at room temperature rather than chilled.
The Fifth Taste • Umani: The term is Japanese meaning delicious or savory. Some people have described this taste as brothy or meaty. • Flavor enhancers such as monosodium glutamate (MSG) appear to increase this flavor in foods. • Researchers found that umani works with other flavors to amplify taste sensations.
Smell Impacts Flavor • The second component of flavor is aroma. • The aroma is the odor of the food. • The nose is capable of identifying thousands of odors. • Example: Without seeing or tasting a cake you can identify it as chocolate because of its aroma • Through training most people can improve their ability to recognize odors and thus improve you ability to distinguish flavors.
Smell Impacts Flavors Cont • Liking or disliking odors is related to experiences. • Odors people like are often connected to home, holidays and situations that make them feel secure. • Odors people do not like are often remind them of unpleasant events.
Smell Impacts Flavor Cont • 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. • The olfactory bulb is located at the base of the brain behind the bridge of the nose. • The brain learns to associate thousands of types of nerve stimulation with specific foods or experiences.
Smell Impacts Flavor Cont • Odors can use two pathways to reach the olfactory bulb. The first is through the nostrils. • Small gaseous particles of the pie are released into the air during baking, these gaseous particles trigger the sense of smell, which contributes to your perception of flavor. • The second pathway is through the back of the mouth. The nasal and oral passages are connected at the top of the throat. Gas-like substances are pumped up into the nasal cavity during the chewing process. • The brain registers the flavor of food as a combination of aromas and sour, sweet, bitter and/or salty tastes. The mind remembers the combination of aromas and tastes and then identifies the food based on experience.
Texture • Texture is how a food product feels to the fingers, tongue, teeth and palate (roof of the mouth). • Texture of food is described in terms of: • Chewiness – refers to how well one part of a food slides past another without breaking. (Taffy) • Graininess – refers to the size of the particles in a food product. (Cream is very smooth, Grits have a grainy or gritty feel.) • Brittleness – refers to how easily a food shatters or breaks apart. (pie crusts, crackers)
Texture Cont • Firmness – describes a food’s resistance to pressure. Tough food requires considerable biting force to chew them (beef jerky). • Consistency – describes the thinness or thickness of a product. It can be measured in terms of pour-ability. • Texture preferences are also subjective.
Measuring Texture Objectively • Food texture can be evaluated objectively by measuring resistance to force. • There are an assortment of instruments that can measure how much force is needed to compress, tear or juice a food. • These types of measurements are used to evaluate uniformity. • However, they will not determine whether a customer will like one variation of a food over another.
Taste Test Panel • Taste test panels are groups of people who evaluate the flavor, texture, appearance and aroma of food products. • Panels are comprised of either professionals or untrained consumers. • Consumer taste test panels determine what the average consumer will prefer. These panels may test new products and compare them to similar products on the market.
Setting up a Taste Test Panel • Requires thought and preparation. • Researchers must try to remove any factors that could sway testers. Examples of factors are the influence of others, environment, etc. • Participants are in rooms with controlled lighting, aromas, and are isolated in booths away from others. Temperature of food is also controlled. • Participants also sip warm water between tastes. • Researchers create forms for testers to use in rating samples and recording response.
Creating an Evaluation Form • Test panel members need some kind of numerical scoring system to rank food samples and are usually asked to rank 1 - 5. A numerical scale that goes above 9 gives too many choices. • At times, researchers ask testers to use verbal labels to rank foods. Examples are “definitely liked,” “mildly liked,” “did not like,” etc. • Numerical scores are often combined with descriptive observations so that the researcher knows why a panelist gave a product a high or low ranking. • The reason for evaluations are because if you do not know what is wrong with a product, you will not know what to do to improve the quality.
