NUTR 211 Exam # 1 Study Guide September 1-29, 2014Sensory Evaluation of Food-Define the terms palatability and aesthetics as they relate to foodpalatability: pleasing to the taste aesthetics: a pleasing appearance- “eye appeal”-Describe various characteristics of food than can be impacted by color (i.e. in what ways can color affect sensory perceptions of food?)Color can determine a food’s freshness or ripeness, whether it’s cooked or burnt, if it has defects, and its overall nutrition value. Color gives expectation of flavor:red: sweet, berryyellow, green: sour, bittervisual descriptors of food : dull, transparent, glossy, turbid, carbonated-Describe how volatile compounds in foods affect their aroma; describe the relationship between temperature and aroma/odoraromas/odors: results from volatile compounds that stimulate the olfactory center of the nervous systemaroma/odor impacts food selection through: flavor, stimulation of appetite, and detection of wholesomeness Volatile compounds: gaseous substances of low molecular weight that are released when food is put into the mouth and chewed. Temperature of food affects how intensely we perceive odors; a warm or hot food releases lots of volatile compounds even before eating, and a cold or freezing food releases very few. -Define anorexia and anosmia; describe circumstances in which food aromas/odors can eitherenhance or diminish food appealAromas/odors can enhance or decrease food intake—anorexia (loss of appetite) can be negatively affected by odors (eat food cold, avoid greasy or fried foods, avoid foods containing sulfur); anosmia (inability to smell), use of flavor enhancers may increase intake associated with age-related perceptual loss-Differentiate between papillae and taste buds as structures responsible for taste; define taste; describe the role of water/liquid in tasteTaste: recognition of volatile and nonvolatile compounds by taste buds on papillae of the tongue, palate, and pharynx.Taste buds are found on the papillae. Taste requires food to be dissolved in a liquid medium. -Identify the five gustatory taste sensations and which compounds are generally responsiblefor stimulating recognition of each; explain how genetic differences in the taste for “bitter” impacts vegetable intake in children (supplemental reading); what are possible implications of this research for interventions to increase vegetable intake for health promotionsweet: compounds that generate sweet recognition- sugars, glycols, alcohols, aldehydes (OH groups)sour: compounds that generate sour recognition- acids in food, H+ ionssalty: compounds that generate salty recognition- Na+ ionsbitter: compounds that generate bitter recognition- caffeine, theobromine, phenolic compounds, alkaloidssavory (umami): compounds that generate umami recognition- amino acidsResearch in taste:Does ability to taste 6-n-propylthiouracil (PROP) impact vegetable consumption in children?65 preschool children identified as tasters or non-tasters by ability to taste a .56 mmol/L solution of PROP-free choice snack test: bitter (black olives, raw broccoli, cucumbers) and non-bitter vegetables (carrots, red bell pepper)—non-tasters ate twice as much bitter vegetable as tasters-Describe how the concentration of a substance impacts taste (i.e. define threshold level of taste)Concentration: the least amount of a substance that must be present to stimulate response=threshold levelTaste fatigue: the point at which you can’t taste any more intensely-Explain the relationship between temperature and taste; define the temperature at which most primary tastes are the most intense; describe exceptions to this relationshipTemperature: room temperature is where taste is most intense (68-86 degrees); salty taste will be most intense cold; sweetness intensity increases with higher temperature.-Name factors that affect the mouthfeel of a food (tactile descriptors, temperature); name chemical substances responsible for “hot” and “cool” sensations in foodsTactile descriptors: consistency, geometric propertiesTemperature: actual temperature vs. perceived temperature (sucking on a mint, hot chili peppers)Responsible compounds for this sensation: eugenol (cloves, nutmeg, cinnamon); piperine (black pepper); capsaicin (hot chili peppers); ginerol (ginger); menthol (peppermint or mint oils)Chemesthesis: sensation of heat or cooling from food-Name the sensory perceptions that interact to create flavor, as well as describe their relativeimportance in a food’s flavorThe combined sensory perception odors, taste, and mouthfeel-Aroma plays the largest role in flavor of food (75%)-Flavor of food vs aftertasteOther factors that impact flavor perception: consistency of the food, fat content of the food, health status-Describe how the consistency of a food and its fat content impact the perception of flavorOther factors that impact flavor perception: consistency of the food, fat content of the food, health statusFat content: can provide smoothness or richnessConsistency: smooth, rough, grainy, hard, soft, chewyEnhancing Flavors in Food-Define palatePalate: the complex of smell, taste, and touch receptors that contribute to a person’s ability to recognize and appreciate flavors-Describe the concept of flavor balancewestern cultures: salt, sweet, soureastern cuisines: hot, sour, salty sweet-Describe how sub‐threshold concentrations of each of the primary tastes influence other primary tastesSub-threshold levels of primary taste compounds: level that is not detectable, but influencesother ‘taste’ perceptions.At sub-threshold levels:salt enhances sweetsalt softens acidacid enhances saltinessacid enhances sweetnesssweet softens salt, bitter, sour-Differentiate between primary and supporting flavors in foods (from Gisslen’s Professional Cooking on “Building Flavors” in course reserves)-Describe the four general concepts of flavor building (from Gisslen’s Professional Cooking on“Building Flavors” in course reserves)-Differentiate between seasoning and flavoring; describe the key principles of seasoning andflavoring (from Gisslen’s Professional Cooking on “Building Flavors” in course reserves)-Summarize guidelines for using herbs and spices (from Gisslen’s Professional Cooking on “Building Flavors” in course reserves)Subjective and Objective Measurement of Food Characteristics-Differentiate between subjective and objective methods of sensory evaluation of