Measurement of carbohydrate components and their impact on energy value of foods

摘要

In order to expand data on the Brazilian Food Composition Database Web site (TBCA-USP), the present work aimed to complement information about carbohydrate content in foods as well as to evaluate the influence of different carbohydrates on energy value. The sugars (glucose, fructose and sucrose) and the indigestible fractions (IF) (total, soluble and insoluble) were quantified in 11 starchy foods usually consumed by the Brazilian population. The total IF content found was bigger than the total dietary fiber (DF) for all foods. Consequently, when the IF was subtracted on the estimate of "available" carbohydrate by difference, it resulted in lower values. Similar results were found in relation to the energy values. The method applied to the IF analysis is relatively simple and considerably reproducible, representing an alternative for the analysis of indigestible components. However, this method does not discriminate each component individually. The total sugar content was lower than 0.5% (fresh wt.) for all foods. The "available" carbohydrate content and energy amount were similar in all 11 foods either when carbohydrates were analyzed individually or by difference subtracting DF in the difference. However, when the carbohydrates are analyzed individually, they provide information about several carbohydrates that are differently utilized in the gastrointestinal tract. Efforts must be driven towards a better differentiation among the different carbohydrate fractions, aiming to insure the quality of carbohydrate and energy information on food composition databases.