Food Categories and Composition Chapter 2 Food Composition Tables Composition the substances or components found in a food or beverage Food scientists have developed tables that depict the composition of a wide variety of foods Includes Fat protein carbohydrate water vitamins minerals The USDA maintains a database of these tables Food Categories Commodities useful consumer goods of agricultural origin generally referring to raw products USDA lists 14 commodities some are processed foods Red meats poultry fish and shellfish eggs dairy products beverage milks fats and oils fruits vegetables shelled peanuts and tree nuts flour and cereal products caloric sweeteners coffee cocoa Processed Commodities value added commodities derived from agricultural commodities that offer convenience longer shelf life and sometimes added nutrients Food Categories MyPlate Nutritionists and food scientists generally consider foods in a similar manner for major categories but differ slightly in regard to minor constituents Nutritionists are primarily focused on the nutrient content of the commodity How much of various commodities should be consumed to MyPlate includes some processed foods but does not include obtain proper nutrition consideration for additives Food scientists must factor in additives in order to assess their functional contribution to food products Serving Sizes In addition to composition we must also take into account the serving size MyPlate recommends quantity of food which is specified on product labels Food Composition tables use measurements Serving Sizes Serving size is dependent on the particular food item and generally reflects the amount normally consumed Nutrition Labeling and Education Act Serving sizes are specified according to the FDA established Reference Amounts Customarily Consumed Per Eating Occasion Serving Sizes Food composition tables normally give composition for common quantities such as cups or oz and also per 100g Beverages A beverage is a drinkable liquid consumed for a variety of reasons Thirst quenching Stimulant effect Alcoholic content Health value Enjoyment Beverages Nutrient Density Concentration of nutrients relative to calories This concept applies to beverages A nutrient dense item supplies variety of protein complex carbohydrates vitamins minerals without excess fat and calories Water is the primary component of beverages but it varies among types Coffee almost 100 water Orange Juice 90 water Alcoholic Beverages Contains less even less water The Degrees Brix of Beverages Many beverages are sweetened naturally or artifically so regulating the sweetness can be an important quality control measure Degrees Brix the weight percent of pure sucrose in a solution grams of sucrose 100 grams of beverage Measured using either a refractometer or hydrometer calibrated for degrees Brix The Importance of the Brix Acid Ratio In fruit and vegetable juices Ratio of sugar to acid is an important consideration for flavor Cereals Grains and Baked Products Cereals tend to be major agronomic crops throughout the world Rice corn and wheat barley sorghum rye millet and oats Carbohydrate is the major component 75 of cereals Primarily in the form of starch along with some simple sugars and some fiber Cereals Grains and Baked Products The three major parts of a cereal grain seed Endosperm high in starch Bran high in fiber Germ high in lipid because this is the source of energy to the sprouting seed Protein tends to be of lower nutritional quality due to lower levels of the essential amino acid lysine as indicated by low Biological Value Amount of nitrogen utilized by the body for growth Leavening of Baked Products Leavening is the production of gas in a dough that increases volume and creates the typical texture of the bread crumb upon cooking Biological leavening agent Yeast Chemical leavening agent Baking powder baking soda Leavening of Baked Products Fruits and Vegetables Fruit the ripened ovary that contains seeds surrounded by pulpy flesh Vegetable an herbaceous plant containing an edible portion leaf stalk root etc Generally have high moisture low protein and very low fat contents Health Benefits MyPlaterecommends the following amounts men women 19 50 per day 2 cups of fruits 2 3 cups of vegetables Fruits and vegetables contain many vitamins and fiber which may provide protection against cancer and heart disease Newer evidence suggests that other factors broadly referred to as phytochemicals may be of greater importance as well Ex Resveratrol Maturity and Ripeness Maturity the condition of the fruit when picked Ripeness the optimum condition of the plant in terms of food qualities such as flavor and color Fruits and vegetables are often harvested prior to being ripe in order to facilitate transportation and storage Ex Tomatoes Quantitative Qualitative Quality Considerations Quality of fruits and vegetables depends on a variety of qualitative factors such as color size flavor firmness etc Quantitative measures of quality include pH Titratable acidity Moisture content Degrees Brix Microbiological determinations Solids content Component content Ex pectin citric acid Dried Fruits Dehydration removes moisture in order to prevent microbial spoilage or enzymatic degradation Fruit must be highly ripe in order to maximize the sugar content Additional sugar and other flavorings can be incorporated by a process called infusion Utilizes heat and pressure to force the sugar in and the water out Results in a chewy or soft texture Legumes Legumes are edible seeds and pods of certain flowering plants Tend to be high in protein that is of greater nutritional value than most other plant proteins Offer a lower fat alternative to red meats Low in sodium have high fiber vitamin mineral content Deficient in amino acid methionine Common Soy Products Soy is used as both a source of oil and as a source of protein Flour 50 protein concentrate 70 isolate 90 These products are used in a variety of food processing applications such as extending meat products including hotdogs or hamburger Soy protein contains an important class of phytochemical called isoflavones which may prevent heart disease and certain types of cancer Tree Nuts Now considered a healthy option similar to red meats High quality protein fiber vitamins minerals unsaturated fatty acids Popular tree nuts include almonds hazelnuts filberts pecans pistachios macadamia and walnuts Interesting features of different tree nuts include