Marjorie P. Penfield

Food- and nutrition-related attitudes of elderly persons living alone

Abstract The objective of this study was to identify food- and nutrition-related attitudes of elderly persons living alone. We interviewed 66 individuals who were retired and 60 years of age or older. The instrument used to assess the attitudes consisted of 97 belief statements relating food and nutrition to food use, cost, convenience, health, social status, aesthetic-sensory perceptions, and quality. We analyzed the responses to all belief statements by factor analysis and calculated attitude scores for each respondent. Four salient attitude factors emerged and were labeled “social-adventuresome,” “frugal-utilitarian,” “qualitative-pleasurable,” and “nutritious-healthful.” Although these attitudes were predominant among the respondents, there was variation to what degree each respondent agreed or disagreed with each attitude factor, as measured by the respondents attitude score. None of the attitude factors correlated with age. The identified attitude factors have been observed among other population groups, a finding that suggests that segmenting a population by chronological age instead of by needs is not the best approach to the development of a food and nutrition education program.

Food intakes of working and nonworking adolescents

Abstract We compared the evening meal patterns and quality of the diets of 74 adolescents who worked on the day of our survey with those of 74 adolescents who did not work on that day. The adolescents were paired for gender, race, and school attended. All adolescents who were surveyed completed 24-hour food records and questionnaires that provided information on their usual eating patterns. We found that the working adolescents were more likely to eat the evening meal away from home, more likely to include a sandwich-type food, and somewhat less likely to include a vegetable, other than potatoes, at the evening meal than were the nonworking teens. Eleven percent of the working and 3% of the nonworking respondents skipped the evening meal. Although adequate, mean intake of vitamin C for the 24-hour period was lower for the working teens than for those not working on the survey day. Working adolescents also had lower intakes of calcium and riboflavin per 1,000 kcal than did the nonworking adolescents.

EVALUATING FOOD BY OBJECTIVE METHODS

Methods used by food scientists to evaluate food quality include objective and sensory methods. This chapter describes the objective methods that do not depend on the observations of an individual; these methods can be repeated using an instrument or a standard procedure. Instrumental or objective methods include a wide variety of tests. The advantages of these tests are many. They may offer a permanent record of results and invite confidence because they are reproducible and less subject to error than the sensory methods of evaluation. However, if results of objective and sensory methods do not correlate, then they may not be measuring the same component of quality and hence the chemical or physical method may not be useful for the study. The appearance of foods can be recorded by means of photography or, in some cases, photocopying. A preliminary acceptance or rejection of a food is based on the visual appearance, including the color. In addition, the measurement of the size of food material particles or structural components may be of interest in research and quality control. The objective measurement of texture is complex because it must reflect the action of the mouth in removing food from an eating utensil; the action of the tongue and jaws in moving the food; and the action of the teeth in cutting, tearing, shearing, grinding, and squeezing food.

Relationships between Mothers' Employment and Nutritional Quality of Adolescents' Diets.

Nutrient intakes and meal patterns of 123 adolescents with employed mothers were compared with those of 88 adolescents with nonemployed mothers. The 24-hour food records indicated few differences between the two groups of ad olescents in total nutrient intakes or in intakes at breakfast, the evening meal, or snacks. Nutrient intakes per 1000 kilocalories indicated that adolescents with employed mothers had diets that were lower (p < 0.05) in nutrient density for iron, and they consumed snacks lower (p < 0.05) in nutrient density for iron and thiamin than did adolescents with nonemployed mothers. There were no signif icant differences between groups in the percentages of adolescents who skipped breakfast on the survey day, in the number of snacks they consumed, or in the number of evening meals eaten away from home.

FATS AND THEIR LIPID CONSTITUENTS

Fats are mixtures of lipids. Lipids are chemical compounds present naturally in many foods. Lipid mixtures in the form of shortenings, frying fats, and salad oils are used in food preparation and are referred to as fats. The major functions of a fat in food preparation include (1) to tenderize, (2) to contribute to batter or dough aeration, (3) to serve as a heating medium, (4) to serve as a phase in an emulsion, (5) to contribute to flavor, and (6) to enhance smoothness, body, or other textural properties. The chemical structure of lipids determines both the physical properties and the chemical reactions that may occur. The relationship between the chemical properties of lipids and the physical properties of lipids and fats underlies the processing methods used for fats. The relationship between chemical and physical properties of lipids also underlies the functional properties of the fats used in food preparation. This chapter discusses the chemical structure of lipids. The chemical structure of lipids is basic to the study of all other aspects of lipids and the fats that contain them.

CHAPTER 16 – STARCH

Publisher Summary Starch is obtained from cereal seeds and certain roots and tubers. Corn is the major commercial source of starch worldwide, but other sources such as wheat, rice, potatoes, and cassava are important in some countries. This chapter discusses the chemical nature of starch, involving the molecular structures, properties, and changes they can undergo; it further discusses the physical nature of starch, involving granular structures, properties, and changes they can undergo. The chapter discusses the changes that occur in starch during food production, the commercial process of starch modification, and the use of modified starches. Huge array of treatments can be applied to raw starches to change the performance in use. Through these treatments (1) improved resistance to heat, acid, and shear stresses can be achieved, (2) temperatures at which thickening of raw starch occurs can be altered, (3) the specific properties of finished products can be controlled, and (4) the shelf stability of foods destined for cold storage and freezer storage can be enhanced. Starches can be treated for many kinds of modification of their functionality in starch-containing foods.

EVALUATING FOOD BY SENSORY METHODS

Sensory evaluation is an essential component of a food research project or product development. The Sensory Division of the Institute of Food Technologists (IFT, 1981b) defines sensory evaluation as “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, taste, touch, and hearing.” Sensory evaluation tests may be used in product development, research, quality control, and shelf-life studies. In each of these applications, sensory evaluation data may be used as the basis for decision-making. Several factors must be controlled in conducting a sensory evaluation test to minimize experimental error in the data. Sensory tests may be divided into three groups based on the type of information that they provide. The three types are discrimination, descriptive, and affective. The selection of the appropriate test should be based on clearly defined objectives for the project.

CHAPTER 21 – SHORTENED CAKES

Publisher Summary This chapter discusses the respective roles of ingredients in cakes. The rules for cake formulation are based on balance between tenderizing ingredients—sugar and fat—and structural ingredients—flour and egg. Earlier, the weight of sugar in cakes could not exceed the weight of flour. With improvements in cake flour and cake shortenings, it became possible to use larger amounts of sugar and liquid. Balance between liquids and the batter constituents that have an affinity for water is the basis for the rule that the weight of the liquids, including fluid milk, water, and eggs, should equal or slightly exceed the weight of the sugar; otherwise, the high sugar concentration interferes with hydration of proteins and gelatinization of starch. Fat melts and batter viscosity decreases in the early stages of baking. Leavening gases are formed and they diffuse into the gas cell nuclei; new gas cells are not formed. Cake quality is assessed by the measurement of volume, compressibility, and breaking strength and by sensory evaluation.

FRUITS AND VEGETABLES

Many parts of different plants are used as fruits or vegetables. They may be roots; tubers; bulbs; stems and shoots; leaves; flowers and fruits; or pods and seeds. The characteristic texture of a fruit or vegetable depends on the presence and the relative proportions and arrangement of the various types of cells. An important textural characteristic of plant foods is juiciness, which pertains to the quality of having extractable liquid in cells and tissues. Much of the appeal of fresh fruits and vegetables is in their varied colors. The attractive color of the raw fruit or vegetable is, however, subject to change under various conditions associated with use, often resulting in unattractiveness. The characteristic flavor of a fruit or vegetable is attributable to a mixture of many compounds, some of which are present in small amounts. The nutritive value of vegetables also varies with cooking method. This chapter discusses the cooking of dried legumes and the production and use of tofu.

State of the Art: Food Research.

Study of the physical and chemical properties of food and its response to treat ment, and the food-related behavior of individuals is discussed in terms of three domains of the research process: methodological, substantive, and conceptual. Advances in the field are discussed in relationship to these domains and linkages among them. The discussion is illustrated with examples from the literature with emphasis on work by individuals in home economics units, or units with similar missions.